WO2025024512A1 - Adaptive traction footwear - Google Patents

Abstract

Footwear having arrays of traction elements, such as cleats or studs that are used for athletic play in field sports, are disposed upon a flexural chassis. Incursions into the perimeter of the chassis allow regions of the chassis to articulate independent of the sole plate. Chassis in the disclosed footwear system are provided with resilient flexural structure so that their traction elements can be orbitally displaced, and then return to a home position when the footwear is disengaged from the ground. The positional freedom of the studs in their plane of articulation permits the sole plate and footwear upper to move over a significant spatial and operative range, while the relief traction elements remain seated in the ground. Embodiments of the disclosed traction system allow for modular interchangeability of diverse chassis.

Description

ADAPTIVE 'FRACTION FOOTWEAR

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent Application No. 63/628,483, titled STRESS RELIEVING FIELD SHOE, filed on July 25, 2023, U.S. Provisional Patent Application No. 63/630,042, titled ADAPTIVE TRACTION ATHLETIC SHOE, filed on December 22, 2023, and U.S. Provisional Patent Application No. 63/731,461, titled ADAPTIVE TRACTION FOOTWEAR, filed on May 3, 2024, each of which is hereby incorporated herein by reference in its entirety.

BACKGROUND OF DISCLOSURE

Aspects and embodiments of the present disclosure relate to athletic shoes that use arrangements of traction elements such as cleats, studs, spikes, or treads, or pads to provide grip on natural or artificial surfaces.

Field shoes represent a subclass of athletic footwear targeted for use on a substantially level field of natural or artificial turf. A further subclass of field shoes includes footwear in which sets of studs designed to engage directly with impressible or penetrable ground are also devised to be removable or interchangeable.

Field sports commonly involve spontaneous and responsive stopping or turning in response to sudden changes in game activity. Both amateur and professional athletes routinely suffer from joint injuries when an article of footwear, momentarily planted in the playing surface, exerts forces upon a lower limb that exceed the safe natural thresholds of bone, muscle, or connective tissue.

The disclosed articles, devices, methods, and systems particularly relate to the type of athletic shoes in which traction elements extending from the sole are permitted a degree of displacement relative to the sole plate and the occupied shoe. This category historically includes so-called turntable shoes, which include a pivoting or rotating sole component. The category more broadly includes any footwear in which traction components located at the sole translate, compress, bend, shift, tilt, or break away relative to the sole through the express intention of the design. The disclosed articles, devices, methods, and systems also relate to the engineering discipline that originates devices known as flexural or compliant mechanisms. This discipline derives structures that may functionally replace multicomponent mechanical assemblies with monolithic components that reliably and repeatedly deform under the application of a working force.

Athletic footwear typically includes a fitted upper shell composed of leather, fabric, or polymer meshes, as well as supportive components such as a last, arch support, heel counter, insole, and a set of durable sole components made of cast or molded rubber, polymer, or elastomer. The sole plates of athletic shoes commonly include locally thick or thin sole areas to provide strength, flexibility, or grip suited to the targeted use.

Athletic shoes for use on playing fields, running tracks, or natural landscapes typically include an array of discrete prominences that extend from the sole plate in order to better engage with herbaceous, mineral, or synthetic contact surfaces. Because these contact surfaces vary in resilience and penetrability, footwear of this type is often tailored to a particular activity, surface, field position, field condition, or style of play.

Irrespective of the particular use, cleats are often deeply engaged with real or simulated earthen surfaces during physical activity. The largely unyielding engagement of athletic footwear with the turf is known to be a common source of lower-limb injury. It is widely accepted that damage to connective tissue occurs because the foot cannot be released from the ground before a damaging threshold force is encountered. These injuries routinely result in transient, enduring, or irreparable joint damage, and acute or chronic pain. While men and women are both disabled by ACL tears, the rate of such injuries have been estimated to be five times as high for women.

The degree of permissible displacement between the engaged foot and the field provided by current footwear is usually limited to the combined compliance and elasticity of the bonded footwear materials. Accordingly, the relative in-plane displacement of the engaged traction elements, in any axis, is usually negligible. The most common ameliorative measures are the preferential use of relatively short cleats, or of cleats arranged in an orbital layout at the forefoot.

Acceleration and agility remain so critical to competitive play that this combination of motives commonly results in the acceptance of a high risk of torsional injury. In particular, the deep cleats that maximize speed and agility on athletic fields are known to cause a disproportionate number of injuries to connective tissues. SUMMARY

Accordingly, it has been observed that, ideally, an athlete should be able to turn a shoe while it is engaged with the ground, without experiencing any meaningful slippage in the ground along the axis of ambulation.

A longstanding challenge in the development of protective footwear for field play is that meaningful orbital displacement of cleats in the field plane can only be made if the cleats are mounted upon a device that is mechanically separate from the sole plate. As used herein, the term “field plane” refers to a plane that is parallel to the field of play.

This implicit functional circumstance prevails because of the need for the cleats to orbit in order to provide a mechanical buffer between the lower body joints and the ground. Within this scenario, there also arises the practical need for intermittent mechanical separation of the traction component from the sole plate in order to inspect, repair and maintain the buffering mechanism.

The disclosed articles, devices, methods, and systems provide a set of practical instructions that are realized in a common modular footwear platform. Realizations of the disclosed footwear platform provide both orbital motion within the set of cleats, and separability of the motile components from the static sole plate.

One aspect of the disclosure describes articles of footwear that includes an articulating traction mechanism on the underside of the shoe that permits meaningful orbital motion in the field plane by the use of resilient, articulating flexural chassis. The articulating traction mechanism includes a sole plate or a platen coupled to the shoe upper and a chassis.

The chassis includes at least one retentive positioning element, and at least one zone that is left free to articulate in the field plane independent of, and relative to, the sole of the shoe. The chassis is operationally linked to the sole plate, meaning that it is mounted upon the sole plate or analogous platen, but nevertheless permitted to articulate relative to its mounting.

This specification accordingly describes a diversity of solutions which confine and captively couple the chassis upon the sole plate without securing it in a conventional fixed relation to the sole plate. This mechanically permissive relationship permits a range of relative and restive orbital motion that research suggests would relieve anatomical stresses that contribute to frequent joint injury. In realized embodiments, sympathetic and responsive movements are also enabled aside from, or in addition to, such orbital motions.

Functionally discrete zones are devised to be mechanically distinct from the sole plate to which they are held in proximity, and to remain structurally independent of the sole plate throughout sessions of athletic activity. The free articulation of the chassis through a succession of deformative states permits force-responsive displacement of the traction elements relative to the sole plate, as well as an unimpeded return to a home position.

The chassis is retentively mountable upon the article of footwear' through the influence of one or more retentive positioning elements. While the retentive positioning elements connect the sole plate and chassis in a dependable relationship, they do not irreversibly bond the chassis to the sole plate. Indeed, in many useful applications of the disclosed material, there is no location where the chassis is compressed against or otherwise fixed to the sole plate.

The chassis is instead held in intimate engagement with the sole plate by retentive features that overly and obstruct one or more locations of the chassis, so that any significant lifting of the chassis in a direction perpendicular to the sole plate, aside from any tolerance necessary to permit the intended sliding, rotation, or other articulation, is impeded.

The position of the chassis relative to the sole plate is also regulated by relief features that control the motion of the chassis in the field plane. These in-plane control features typically include circular', arcuate and annular relief mating features that provide defined centers of rotation. In-plane control features also include posts or stops that provide specific points of resistance to in-plane articulation. The free articulation of the chassis by such means permits inplane forces encountered in the field to be adaptively distributed throughout the chassis’ flexural features.

Within the disclosed articles, devices, methods, and systems, this accommodation of externally applied in-plane force can be provided by both rotational motion within the chassis, and by its local flexural articulations. These articulations can be interdependent. For example, in the disclosed implementations, the spring force imposed by the flexure of a chassis’ resilient member upon a pivoting relief structure can impart local rotary motion between the chassis and sole plate, while that rotary motion in turn can alter the shape and position of the same connected resilient member. It is a pervasive understanding of the disclosed footwear system that the implementations of its principles yield sympathetic motions within its relevant parts and assemblies. The term “sympathetic” in this parlance refers to the property of a physical object in which an effect arises in response to an action imposed elsewhere in the object. A sympathetic flexural system can be knowingly derived within the disclosed principles so that it acts as a complex mechanical regulator. The comprehensive behavior of such interdependent force regulation can be computationally modeled, both to predict the experience of the athlete, and to engineer and manufacture a durable and functional pail.

In applications of the disclosed footwear, and in view of the preceding understandings, chassis zones are made operationally independent from each other, or from one another, by incursions into the perimeter of the chassis of sufficient extent to allow a meaningful displacement of one region of the chassis from another. The zoned arrangement is realized in the footwear in such a way that when the chassis is mounted on the sole plate of the article of footwear, a single zone or a plurality of zones within the chassis is independently displaceable in the field plane upon the imposition of an external force to the chassis’ traction surfaces.

A first zone may be held static relative to the sole plate, while a second zone permits movement. Both a first zone and a second zone may each be permitted movement independent of one another. Both a first zone and a second zone may each be permitted movement independent of one another, and independent of the sole plate to which they are captively coupled. The chassis may include a plurality of zones beyond the first and second nominal zones.

By way of example, a chassis, formed in accordance with the disclosed structures and methods, is made of polymeric material by a process such as injection molding, and is divided in its form by incursions into the perimeter of the chassis such that the chassis is divided into a plurality of zones capable of elastic displacement, owing to narrowed region generated by the incursion, upon the imposition of an external force expressed in the field plane.

This configuration allows the discretely identified zones a degree of relative articulation that results in an equal degree of axial independence between the foot and any articulable field- engaged traction elements. The axial independence may be rotational, linear, or geometrically idiosyncratic, depending on the particular design and the momentarily applied forces. The disclosed footwear particularly enables orbital motion. In this specification, orbital motion of a chassis is meant to include not only strict arcuate rotation, but any movement that permits the captive foot to turn independently of the flcxurally compliant chassis.

Embodiments of the disclosed structures and processes describe a system in which zones are embodied by beams, struts, limbs, lobes, or panels bearing surface-engaging traction elements, such as studs, cleats, blades, spikes, pads, patterns, or matrices. Among the diversity of disclosures of the footwear system, an array of such surface-engaging traction elements is incorporated within a common flexural chassis.

The surface-engaging traction elements are disposed so that the zones on which they are formed are displaceable in the field plane during active play, while the chassis bearing the displaceable traction elements remains captive on the article of footwear. Depending on the geometrical layout of the chassis, the articulation of a set of flexural chassis extremities can be collective, interdependent, or independent.

Within the disclosed instructive materials, flexural zones encompass the term flexural lands and flexural limbs. A flexural land is an articulating flat feature of relatively large area that is provided motion by a structurally linked flexural member. A limb is one of a plurality of members that possesses in its length a workable degree of flexibility.

Limbs within the disclosed footwear system encompass two forms. Limbs which are characterized by closed panels are termed lobes. Their flexural property is imparted by incursions between the closed panels. In the disclosed footwear system, limbs which include one or more openings within the limb are termed struts. Struts allow the chassis to be interpenetrated with openings to yield an open fretwork of articulating beams and bars. The disclosed footwear system may encompass one or both foundational forms, and their intermediate and extrapolated embodiments.

In certain designs, owing to the closed panel format, the greater flexural property of lobes is imparted by necks or beams intermediate between the discrete lobes rather than by the lobes themselves. In this disclosure, a flexurally operative beam located at or along the intersection of other constituent limbs is termed a spine. A spine commonly has a flexural property complementary to its integral limbs.

Articulation is also, in a subset of cases, bounded by regulated contact between a limb and its neighboring limb. Examples of such mutual interference apply to chassis using both closed lobes and open struts. Motion is also regulated by knowing local interference between a chassis and the sole plate onto which it is mounted.

Through the mechanisms provided in this disclosure, the traction elements are permitted local movement in the field plane by 1 cm or more, while being closely retained against the sole plate of the shoe. Shoes in adult sizes realized within the disclosed footwear system commonly attain progressively resistive orbital motion over ± 15° or more, relative to the foot held in a fixed footwear upper.

In view of the guidance for realizing the disclosed footwear’ disclosed herein, arrangements of articulating zones and their associated surface-engaging traction elements can be laid out to allow specified ranges of directed movement in designated axes. Relevant traction chassis patterns formed in accordance with the disclosed material are provided with a bias toward orbital movement.

As noted, it is desirable to preserve on-axis traction even while providing orbital rotation. In disclosed embodiments, when no turning force is present, the load on the traction elements is substantially equalized at the lateral and medial margins. Accordingly, the effect of stud displacement upon traction exerted along a straight path is relatively small. This result preserves linear traction, while significantly relieving incidental rotational stresses upon the lower limbs during turning or cutting. This result corresponds to the functional properties identified by sports medicine professionals as optimal for injury reduction in competitive play.

The chassis is, by various mechanisms, mechanically coupled with a sole plate. In theory, the chassis may be formed to be entrapped within the sole plate, in the sense that is enabled by additive manufacturing. A chassis may be fused or spot- welded with the sole plate, so long as the chassis’ limbs are left free to articulate. However, for a diversity of motives, it is generally more useful to form, manufacture, and preserve the articulating chassis as a discrete and routinely separable part.

The disclosure particularly describes articulating chassis which can be injection-molded using relatively simple equipment and operations, allowing a wide range of materials to be implemented. The elastic properties of their material composition can be chosen so that a range of chassis modules can be safely installed, removed, or interchanged with rapidity and spontaneity. Useful embodiments of these assembly methods involve a sequence including momentary deformation of the chassis out of the field plane, in combination with a second non-deforming motion, such as a rotary or sliding action.

These operations permit a chassis to be easily replaced with an identical part. It also allows the exact function of the traction system to be altered at the option of the athlete by the use of differing chassis. The alterability of the footwear article allows the maker, vendor, or wearer to mount traction chassis to suit any incidental physical condition, or environmental situation.

Notably, the disclosed articles, devices, methods, and systems enable previously unobtainable traction states in relation to penetrable playing surfaces. Namely, because fixed studs cannot shift out of their original positional relationship, they arc inclined to stand upon the inhomogeneous fibrous and particulate materials that commonly compose playing grounds, rather than disrupt them in an optimally engaged manner.

The novel decorrelation of position among the traction elements allows the elements to wander to some degree within the field plane during engagement with a penetrable playing surface, allowing the articulating studs to follow paths of least resistance into inhomogeneous ground materials.

For a given applied load, this idiosyncratic effect increases the collective penetration into the turf, relative to a traction array having a static version of the same stud pattern. In addition to torsion-reduction and stud interchangeability, the articulating chassis made according to the disclosed footwear system can yield more grip for a given set of motile studs than would be experienced in an equivalent set of fixed studs.

Among its other provisions, the disclosed footwear system may also be understood as providing relief from the laborious practice of removing and replacing individual studs. Embodiments may also be taken as diminishing the costly and cumbersome need for multiple pairs of different shoes for different surfaces, sports, or field conditions.

While a subset of designs in the disclosure allows for the spontaneous manual installation and removal without resort to any tool, the same or similar designs can nevertheless integrate the use of a pre-existing or dedicated tool. Making a chassis removable only by the use of a tool can provide both confidence and peace of mind to the athlete. The disclosed articles, assemblies, devices, methods, and systems are applicable to diverse types of footwear, but arc particularly serviceable in the area of shoes or boots designed for field sports. Field sports include activities such as soccer football, North American football, rugby, lacrosse, field hockey, baseball, and cricket. The sole plates of such athletic footwear normally include surface-engaging elements, which commonly have a significant degree of relief above the base level of the sole plate.

High-relief surface-engaging elements are commercially and colloquially referred to as studs, cleats, blades, or spikes. Low-relief surface-engaging elements include ribs, ridges, pins, posts, pads, cups, and patterns. Relief patterns of varied geometries are diversely applied as both functional and cosmetic devices in athletic shoe design.

While injuries are most commonly caused by cleats entrapped in turf, the disclosed footwear is equally applicable to sports played on closely groomed grass such as tennis and golf. It also applies to athletics played in wholly or partly enclosed venues, such as tracks, gyms, or courts, and their range of prepared playing surfaces. It applies to any activity where joint injury is a risk, including walking, climbing, hiking, or trail running. In its broadest sense, it applies to any ambulatory activity on natural or synthetic surfaces on either level or inclined ground.

In field sports, conic or pyramidal traction elements are nominally categorized as studs or cleats, while conspicuously elongate traction elements are commonly differentiated by their identification as blades. Intermediate or hybrid geometries such as chevron shapes can be assigned any of these terms. For clarity, references to studs in the following descriptions should be understood to encompass any traction element that extends, in relative relief, out of the sole plate. Field shoes for use on natural turf typically include six to twelve studs.

Field shoes for soft, wet, or disturbed ground are often outfitted with exceptionally long or broad studs. Studs for play on soft ground can be removable so their exact length can be selected by that athlete. As a general rule, shoes for artificial turf typically have lower relief, and an increased number.

In the following description, and in keeping with established use, the durable, wearresistant outer covering of the shoe underside and affixed to the show upper is termed a sole plate. Embodiments of the disclosed footwear include integral modifications of the sole plate that promote mounting of one or more chassis to the sole plate. Other embodiments include a removable platen that similarly provides a foundation for the mounting of a chassis. In this specification, a platen can also be a mounting surface formativcly integrated into the sole plate.

In discussion of the disclosed footwear, an articulating set of interconnected zones carrying surface-engaging traction elements is termed a chassis. The term chassis should be construed by practice and convention to incorporate both the singular and plural meaning of the word, throughout the following descriptions. Accordingly, one shoe can carry a single chassis, or a plurality of chassis. The term chassis is expressly extended to include variants within a modular system in which the articulation in the field plane has been subverted, so long as the part is flexurally mountable upon the article of footwear within the teachings of the disclosure.

Nevertheless, the disclosed material prominently includes footwear in which surfaceengaging traction elements are incorporated monolithically within a common chassis, and arc devised to be meaningfully displaceable in the field plane upon the application of an abrupt or progressive load. The disclosed arrangements allow a degree of relative rotation, orbital motion, or axial displacement to be imparted to the captive shod foot, while, relative to the ground, the surface-engaging traction elements remain at a meaningfully less transposed position.

The disclosed material particularly describes articulating chassis comprising displaceable zones or limbs. A chassis may be understood as having a primitive geometrical template, for example, that of the shape of a forefoot, a heel, or of the full foot. In one principle of the disclosure, incursions are made into or through the abstract perimeter of the primitive geometrical template to divide the part into functional zones, and create a working plan for an articulating chassis.

In realized components, the set of incursions locally relaxes the coherent mechanical structure of the part so that the elastic properties of the material can be expressed in the field plane when the chassis is installed on a shoe. The incursions also increase the flexibility and conformability of the applied chassis in axes out of the field plane, particularly in the active bending and twisting of the forefoot.

These incursions divide the chassis into discrete zones which are partially bounded by the incursions, and intermediated at narrowed locations by the proportioning of deformable necks or beams. The deformable locations in the chassis identified by the incursions may be envisioned as a sort of articulating spine, or set of cooperating flexural hinges. Zones in the broader view of the disclosure may take the form of lands, panels, plates, lobes, arms, beams, or other nominal features having an open or closed form, so long as they have the capacity for local and variable relative motion. In general, flexural mechanisms formed according to the teachings of this disclosure preferentially bend within the field plane, and afterward rebound to an original unloaded state, so that the athlete experiences a predictable initial condition upon each foot strike.

Depending on the application and design, the chosen level of component elasticity can range from that of an elastomer to that of a highly rigid polymer, so long as the conjoined chassis and sole plate interact such that the chassis’ limbs are free move autonomously in response to the wearer’s activity, and then substantially return to a home position. Studded limbs having individuated, articulating features are often embodied within the disclosure as chassis including two or more beams and an integral crossbar or platform that carries one or more surfaceengaging elements, such as a studs, cleats, or blades.

The principles of the disclosure encompass the further and useful understanding that beam stresses and strains are minimized when, in an array of beams, the medial or centroidal lengths of the cooperating beams within a given beam array are kept substantially equal. In any other condition, a degree of triangulation is present in the strut that requires greater compression or extension to occur locally or comprehensively along its member beams.

This principle is often intermodulated with the formation of beam arrays into curved, serpentine, or convolute shapes, so that elongation is permitted by the geometry as well as by the elastic value of the polymeric material. Certain implementations modulate the curvatures of neighboring beams in an array so that they are idiosyncratically adapted to their position and operation in the applied configuration.

Within certain embodiments, beams in this strut arrangement are located between a displaceable traction element and a pivotable linkage to the sole of the shoe. Beams in a strut arrangement can also be located between limbs, lobes, or other stmts. Beams within a given compound-beam strut can differ dramatically in their static curvature, but may nevertheless exhibit various kinds of mathematical symmetries or geometrical constraints.

A given article of disclosed footwear typically employs at least one retentive connector to join the sole plate and chassis. Connection can be diversely realized. Mechanical rotary coupling of the chassis to the sole plate may be attained by conventional threaded hardware such as screws and bolts, in conjunction cooperating devices such as threaded inserts. The disclosure of the footwear system also provides pivotable connective features that arc effective using polymeric material alone.

The disclosed footwear proposes and realizes integral and cooperating features in the chassis and sole plates that promote guiding, retention, and mounting of the functionally joined parts. In effect, the captivity of the chassis is devised so that interfering structures mechanically constrain the sole plate and chassis, but permit articulation in the desired axes. In realized cases this result is obtained without securing the chassis to the sole plate at any real point.

Regulating sole plate features include stops, posts, flanges, or platens that identify undercut channels so that the structures hold, limit, guide, regulate, or obstruct part of or the whole of a mounted chassis. As will be illustrated in the following descriptions and drawings, the sole plate or chassis can diversely include cooperative raised or recessed devices such as holes, posts, grooves, slots, tabs, corrugations, or cavities that serve the interoperation of the chassis and the sole plate.

In practical realizations of the disclosed instructions, undercut posts or platens are molded integrally with the sole plate. An undercut post or platen of the general form has a base and a cap. The cap extends locally beyond the base such that a retentive undercut is created beneath the overhang of the lateral cap extension. Sole plates are devised so that the sole plate undercuts can be molded simply and monolithically by the use of ports beneath the undercuts, Variants without such ports can also be realized or through the use of a sliding-core, side-action, or collapsing mold.

Such undercuts need only be of sufficient local proportion that commensurate connective elements on the chassis can be entrained about them in a reliably retentive fashion. In the case of posts, a chassis may be devised to have compatible clips so the chassis snaps about or around the posts. The overhanging cap prevents the clip from sliding off the post.

In the case of a platen, an undercut perimeter channel is integrated along the outside edge of a raised template formed of rigid material. The perimeter channel then accommodates guide tabs on compound struts within a commensurate and compatible chassis. In a subset of realizations of the disclosed footwear, inward-oriented tabs located toward the perimeter of the chassis are dimensioned and oriented to engage in a sliding manner with the undercut channel, allowing the integral relief traction elements a degree of displaceablity, while at the same time substantially constraining them, whether in a moving or stationary state, to the field plane.

An outward-oriented flange on a platen channel can be continuous or nearly continuous about the perimeter of a platen, or portions of that perimeter. It can also be apportioned into abutted or staggered sections to accommodate the extent and range of movement in individual limbs.

The platen can be notched or corrugated to increase flexibility of the sole plate, while still permitting tabs to move continuously. A degree of rigidity is required in the sole plate to ensure retention of chassis tabs in the sole plate channels, but otherwise the material choice is unrestricted.

In certain practical embodiments of the disclosure, corrugating features on the sole plate are made to intrude through a platen cap and base so that the incursions act as expansion joints. Upon convex deformation of the sole plate, as occurs during foot flexure at a running gait, the expansion joints widen, local elongation stresses in the polymeric sole plate are relieved, and the sole plate responds with greatly increased compliance to the foot’s momentary posture. Corrugation allows pliability with a relatively rigid material composition.

In the practice and parlance of the present disclosure, chassis extensions such as limbs, beams and struts encompass both open-loop and closed-loop exemplars. A strut typifies a closed- loop exemplar, in that it incorporates two or more beams that are enclosed by an armature and a crossbar. An open loop is a hook or coil that extends from an armature, but does not close or reconnect.

Both open and closed limbs may be enlisted within the disclosed footwear articles to impart end express energy storage and release in the form of resilient springs. Conscientious extensions or recesses within the chassis geometry can serve other functions beyond agile traction, such as mounting, detention, stopping, or the regulation of individual or collective motion.

By way of example, versions of the disclosed articles of footwear include flexurally hinged keepers that extend from the heads of the compound studs, along the axis of the bar interconnecting the compound beam array. These keepers have diverse effects, and serve in part to cover or occupy otherwise exposed portions of the undercut channel. The pliable keepers are further enlisted in the disclosed footwear to perform one or more functions, such as to serve as accommodative guides for chassis articulation, to center the chassis during installation and removal, to exclude and clear debris from the channel, to deter collapse of the channel, and to cushion and limit articulation of the struts so that elastic thresholds of the constituent polymer material are not destructively exceeded.

A subset of the disclosed footwear solutions includes local rotations about real or virtual centers. Real centers correspond to round pins and cavities, while virtual centers are more often identified by arcuate pins and cavities. In this case, the centers are mathematical points that have no dimension, so material at every real coordinate within the assembly will exhibit a quantifiable degree of relative motion.

Accordingly, references to rotation in consideration of the disclosed articles, devices, methods, and systems should not be conceptually bound to the existence of any real mechanical pivot, or even the presence of any exact center of rotation. Instead, rotations should be taken to encompass any complex of radially experienced displacements, and may be understood to be conceptually akin to those experienced in rotational articulations of anatomical joints. Such movements are broadly described in this specification as orbital.

This broad understanding, and the associated solutions derived from it, allow deformative stresses to be accommodated, distributed, and equalized throughout the chassis. The local bending of beams, struts or interconnecting spines can be provided by the assignment of an optimized length, width, depth, and cross-sectional profile to the contributing member structures.

Layouts conforming to the disclosed footwear articles allow studs to be placed at locations analogous to those employed in current field shoes. Sole plate designs in the disclosed footwear commonly integrate a discrete forefoot mounting and a discrete heel mounting, each with its own chassis and mounting arrangement. When two separate chassis are mounted on a shoe, the forefoot chassis is typically the more complex, commonly including four to ten studs. The heel chassis typically includes two to five studs.

In traditional practice, stud layouts are bilaterally symmetrical in consideration of the right and left shoe as a pair, but often depart from bilateral symmetry within the individual shoe layout. In some examples shown, the chassis and sole plate are bilaterally asymmetrical. In other examples shown, the chassis are bilaterally symmetrical, but the sole plates are not. It may be appreciated that chassis designs can be derived to exhibit various states of symmetry to accommodate the natural mirror-image geometry of a pair of feet.

Of particular relevance to the disclosed innovations is the behavior of beams interconnected within a compound-beam strut. A pantograph is a known type of closed, four-bar linkage having opposing pairs of rigid equal-length bars. In this abstract case, four comers act as pins or hinges such that the linkage translates into a range of parallelograms. If one bar is fixed at its ends, without fixing the comer pins, all points on the opposite bar are inclined to sweep through a common and predictable arc.

The broad understanding of the footwear system loosely applies the principle of a rectangle of pivoting, displaceable beams. However, in this application of the disclosed footwear, the joints between adjacent sides in the compound stmts are not mechanical pivots, but instead are monolithically formed or fused intersections. Beams confined in any such compound stmt configuration, if simple and straight in their neutral state, become serpentine as the stud is displaced in one direction or the other within the field plane.

It is also appreciated that the response of a beam to bending moments anticipated in the disclosed structures often argues for the depth of a beam to be greater than its width. In the application of this understanding in the disclosed footwear system, the beam’s resistance to a deforming load inherently keeps the compound strut close to the sole plate, while the spatial separation between the beams within a compound-beam strut makes the strut resistant to torsional deformation.

The serpentine translation of the beams in the field plane, within a given compound stmt, results in a relief traction feature, such as a stud or blade, following a substantially arcuate path, owing to the foreshortening of the beam length as the beams deform under the influence of an applied force. As in a pantograph, the radius of the relevant swept arc is directly related to the working length of its constituent beams.

A degree of intentional curvature imparted to the beams in their original and relaxed state reduces incidental stress by allowing significantly increased localized compression and extension to occur in the individual beams during active articulation of the strut.

Beams having such deliberately imparted local curvature also resist buckling or breakage from sudden on-axis loading. The imposed curvature essentially initiates bending in anticipation of any actual load. The informed introduction of designed curvature into the beams also allows studs within a chassis to respond to forces from off-axis impacts, such as side collisions. The imposed curvature furthermore permits the entire chassis to more readily deform, without putting the beams abruptly into compression or tension.

Accordingly, and in addition to pseudo pantographic designs, realizations of the disclosed footwear articles include networks of curved beams and intricate convolutions. Given sufficient convolution of the beams, the restrictive bounds of triangulation are significantly eased, so that a beam array can obtain a range of motion that extends beyond pseudo pantographic translation.

For example, a convolute beam on one side of an array of serpentine beams can compress, while a beam on the opposite side extends. Energy from both the compression and extension are recovered when the load is removed. This understanding allows a convolute beam array to be disposed, for example, about two rotating or counter-rotating centers. It also allows for a convolute beam or beam array to be disposed between two rotating or counter-rotating centers.

In particular convoluted applications, it has been found that the relative equalization of the rate of curvature in an open chassis structure can more evenly distribute stress, and even allow curved features to usefully bear against one another as the applied force reaches predetermined local thresholds. These understandings broaden the range of effective designs that can be originated within the breadth of the present disclosure.

It has also been observed that loops that are brought to bear against one another can locally reverse stress after contact, as the polarity of the stress in contacting loops or beams is often inherently in opposition to the stressing condition that is imposed once the loops mechanically connect. Loops can be devised so that they contact cotangently, or obliquely. Cotangent loops will exhibit mutual compression, while obliquely contacting loops will exhibit a degree of slippage.

In view of the foregoing principles, practical optimizations of chassis designs often yield open fretworks of strut beams and ancillary supporting beams or armatures. For example, a given chassis has beam depths varying between 2 mm and 5 mm, and beam widths between 1 mm and 3 mm. The cross-sectional proportioning of the flexural beams for a given polymer affects the beam behavior. A general proportion in the interest of comprehensive desired effect is a beam depth 1.2-2.0 times the width of the beams. A common optimization of beams in accordance with this disclosure yields beams having cross-sectional aspect ratios in the vicinity of 1.5. This sectional proportion promotes the natural constraint to the field plane without imposing undue additional thickness to the sole. For a typical field-sport athlete, an exemplary average beam section in a polymer having flexural modulus of 2800 Mpa, other factors being set at a pragmatic mean, might be typified in the range of 2.4 mm wide x 3.6 mm deep. These values are disclosed only in the interest of disclosure, as such dimensions are strongly influenced by factors such as the length, position, curvature, and number of beams.

In lobed chassis, the necks of an armature are commonly narrowed to between 4 mm to 8 mm to realize the desired flexural result, and may be spatially repeated to obtain a cumulative secondary bending moment. In such lobed embodiments within the disclosed footwear system, in which the limbs are closed figures, a suitable panel base thickness is about 2-3 mm in elastomers and 1.5-2.5 mm in harder plastics. Lobed embodiments can carry a full range of surfaceengaging elements. Such elements on any chassis can be hollowed on their internal side to reduce weight and accelerate molding cycles.

Field sports are diverse, and design considerations vary accordingly. One field sport might be concerned with abrupt turning by players of moderate build, while another might have to accommodate intentional collision between players of extraordinary weight and stature. It may generally be appreciated that participants in field sports routinely vary in weight from 20 Kg to 160 Kg, and design factors within realized embodiments will vary accordingly.

Chassis parts in unfilled polymer formulations can usefully have flexural moduli between 1500 and 4000 MPa. Recommended materials exhibit elongation at break of at least 30%, and preferably 40% or more. Homopolymeric polyoxymethylene (POM-H) and copolymeric polyoxymethylene (POM-C) are both suitable for use in molding the chassis components. Both polymers are available in a range of flexural moduli, melt viscosities, alloys, and colors.

Because, in disclosed embodiments, the operational linking of the chassis to the sole plate is mechanical, and does not involve adhesives or thermal bonding, low surface-energy polymers resistant to surface bonding, such as POM, can be used in molding the articulating chassis. POM polymers are hydrophobic, and naturally shed water and saturated soils. The hydrophobicity of POM formulations is further enhanced by alloying with fluoropolymers.

Polyamide- 12 and Polyamide- 11 formulations are also available having properties with the accepted range. Sole plates or chassis can be made of or include current thermoplastic materials such polyurethane (TPU) or PEBA. As noted, more rigid formulations can be made flexible by introducing corrugated in the design. Diverse materials are available for the making of athletic shoes, many of them engineered for a specific use, functional condition, or application.

The disclosed footwear articles integrate multiple functions that result from the compliant properties of the a mechanically discrete chassis. Specific solutions are described that use the flexural properties of the chassis to allow for fast and simple mounting and demounting of a chassis upon a sole plate. These solutions generally involve combined actions of sliding, turning, lifting, or flexing of the chassis into undercut channels formed integrally with the sole plate, or within a separable platen.

Comprehensive realizations of the disclosed articles, devices, methods, and systems are therefore modular, and include and enable a broad range of functional components within the interoperable system. Details and operational benefits of the modular system may be further appreciated through assessment of the disclosures in view of the following descriptive figures:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a sketch of the counter-rotational forces encountered during on-field play that commonly lead to knee injury;

FIG. 2 shows a schematic drawing of a twin-beam flexural strut formed according to the disclosed footwear system, having two beams and carrying a single stud, showing its default, relaxed state;

FIG. 3 shows a schematic drawing of a twin-beam flexural strut formed according to the disclosed footwear system, having two beams and carrying a single stud, showing a condition in which the stud is displaced by an applied force in one direction;

FIG. 4 shows a schematic drawing of a twin-beam flexural strut formed according to the disclosed footwear system, having two beams and carrying a single stud, showing a condition in which the stud is displaced by an applied force in a direction opposite to the displacement shown in FIG. 3;

FIG. 5 shows an external plan view of a flexural chassis designed for mounting on a rigid sole plate, including a distributed array of seven articulating studs extending from independent twin-beam flexural struts, with one additional coring stud in a central location;

FIG. 6 shows a front oblique perspective view of the flexural chassis of FIG. 5; FIG. 7 shows a rear oblique perspective view of the flexural chassis of FIG. 6;

FIG. 8 shows a rear oblique perspective view of a sole plate commensurate and compatible with the flexural chassis shown in FIGS. 5 through 7;

FIG. 9 shows the assembly of the flexural chassis and the sole plate;

FIG. 10 shows the characteristic deformation of the flexural chassis under rotational stress, as when the athlete’s foot is planted and turned;

FIG. 11 shows the characteristic deformation of the flexural chassis under axial stress, as when the athlete’s travel is linear and the foot is abruptly planted to decelerate;

FIG. 12 shows a modification of the disclosed footwear system in which the heel includes an independent flexural chassis rather than fixed studs;

FIG. 13 shows a modification of the disclosed footwear system showing a four-beam flexural struts arrayed in a chassis, in which retention clips are devised to permit a degree of inplane rotation to each strut array, and in which each studded strut is provided with four beams and a retention tab at its outermost extremity;

FIG. 14 shows a studded sole plate including conic studs, and in which a subset of the conic studs is devised to capture the retention clips shown in FIG. 13;

FIG. 15 shows a perspective view the assembly of the four-beam flexural chassis to the studded sole plate, illustrating how the studs are closely retained against the sole plate by the cooperative effect of a tab and a guide channel;

FIG. 16 shows a second perspective view of the assembly of the four-beam flexural chassis to the studded sole plate shown in FIG. 15;

FIG. 17 shows a studded strut having symmetrical beam attenuations;

FIG. 18 shows a studded strut having asymmetrical beam attenuations;

FIG. 19 shows a studded strut having symmetrical beam attenuations in which buckling is locally promoted in the beam length;

FIG. 20 shows a studded strut having symmetrical, concave parabolic beam attenuations;

FIG. 21 shows a schematic sectional view of a guide channel integrally formed on the inside of the sole plate;

FIG. 22 shows a schematic sectional view of a guide channel integrally formed in the side edge of the sole plate; FIG. 23 is an oblique external view of a sole plate provided with a forefoot platen and a heel platen;

FIG. 24 is an oblique external view of a sole plate provided with a heel platen and a corrugated forefoot platen;

FIG. 25 is an oblique view showing the internal side of the sole plate illustrated in FIG. 24;

FIG. 26 is a forward-looking perspective view of a bladed forefoot chassis formed according to the disclosed footwear system;

FIG. 27 is a rearward-looking perspective view of a bladed chassis of FIG. 26;

FIG. 28 is a top oblique view of a heel chassis carrying three blades;

FIG. 29 is an underside view of the heel chassis of FIG. 28;

FIG. 30 is a forward-looking perspective view of the heel chassis and forefoot chassis of the preceding figures mounted on the corrugated sole plate of FIGS. 24 and 25;

FIG. 31 is a rearward-looking perspective view of the assembly shown in FIG. 30;

FIG. 32 is a forward-looking perspective view of a corrugated tool-readied sole plate having relief stops and accommodations for installation and removal with a dedicated tool;

FIG. 33 is an internal perspective view of the corrugated tool-readied sole plate of FIG. 32;

FIG. 34 is an external perspective view of a tool-readied bladed forefoot chassis;

FIG. 35 is an internal perspective view of a tool-readied bladed forefoot chassis;

FIG. 36 is an external perspective view of a tool-readied bladed heel chassis;

FIG. 37 is an internal perspective view of a tool-readied bladed heel chassis;

FIG. 38 is a perspective view of an assembly of the tool-readied sole plate and tool- readied chassis of the preceding figures;

FIG. 39 is a perspective view showing one side of a tool expressly devised for use with the tool-readied components and assemblies in the preceding figures;

FIG. 40 is a perspective view showing the other side of a tool shown in FIG. 39;

FIG. 41 is a perspective view of the tool in place for deflecting and lifting a rear bladed strut in the process of removal of the forefoot chassis;

FIG. 42 is a perspective view of the tool in place for lifting and deflecting the foremost bladed strut in the process of removal of the heel chassis; FIG. 43 is an external perspective view of a ribbed, resilient forefoot pad compatible with sole plates formed within the disclosed footwear system;

FIG. 44 is an internal perspective view of the ribbed, resilient forefoot pad of FIG. 43, showing an array of integrally molded resilient spurs formed on its internal face;

FIG. 45 is an external perspective view of a ribbed, resilient heel pad compatible with sole plates formed within the disclosed footwear system;

FIG. 46 is an internal perspective view of the ribbed, resilient heel pad of FIG. 45, showing an array of integrally molded resilient spurs on its internal face;

FIG. 47 is a perspective view of the ribbed, resilient pads of the preceding figures mounted on a sole plate;

FIG. 48 is a perspective view of an overmolded chassis having resilient pads molded onto its compound struts;

FIG. 49 is a perspective view of modification of a forefoot chassis having additional surface-engaging blades integrated into the chassis to improve traction in soft grounds;

FIG. 50 is a plan view of modification of the forefoot chassis of FIG. 49;

FIG. 51 is a perspective view of a lobed flexural chassis having a pattern of low-relief surface-engaging elements formed on its limbs;

FIG. 52 is an internal perspective view of the lobed flexural chassis shown in FIG. 51;

FIG. 53 is an exterior perspective view of a lobed flexural chassis having a pattern of conic studs of moderate relief;

FIG. 54 is an interior perspective view of a lobed flexural chassis having a pattern of conic studs of moderate relief;

FIG. 55 is a forward-looking perspective view of perforated interleaving for optional interposition between the forefoot chassis and the corrugated sole plate;

FIG. 56 is a perspective view depicting a flexural forefoot chassis having curvilinear beams and using external tabs two pivots incorporating discontinuous annular snap features;

FIG. 57 shows a perspective view of a forefoot platen having a variety of peripheral bosses, a subset of which include overhanging flanges devised to partially entrap the peripheral tabs incorporated in the chassis of FIG. 56, and furthermore in which mounting of a forefoot chassis is enabled by shoulder bolts installed in compatible threaded mold inserts; FIG. 58 is a perspective view of a flexural heel chassis including a central discontinuous annular snap feature, and also including tabs both internally and externally integral with bladed studs;

FIG. 59 is a perspective view of a heel platen having a variety of peripheral bosses, a subset of which include overhanging flanges devised to partially entrap the peripheral tabs incorporated in the chassis of FIG. 58, also including relief features to restrict rotary motion of the central region of the flexural heel chassis of FIG. 58, and furthermore in which operational linkage of a heel chassis is enabled by shoulder bolts installed in compatible threaded mold inserts;

FIG. 60 illustrates a modular forefoot platen using a flexural corrugation that employs a mounting plate, a base layer, and raised platform such that a peripheral flange is generated about its perimeter, the platen including a leading pivot feature having a recessed ring and an annular detent, and also including a trailing pivot having a recessed ring and a central threaded insert;

FIG. 61 is a perspective view of a chassis compatible with the mountings included in the forefoot chassis shown in FIG. 60, the chassis having a medial beam, medial stud, and a surrounding serpentine beam network incorporating convoluted loops connecting the medial components to a set of peripheral studs, furthermore including tabs and keepers that engage with the undercut channel between the mounting plate and the raised platform;

FIG. 62 is an underside perspective view of the chassis shown in FIG. 61;

FIG. 63 shows a lobed chassis integrated as a component in the modular system that permits diverse traction chassis to be installed or interchanged on the platen shown in FIG. 60;

FIG. 64 is an underside view of the lobed chassis shown in FIG. 63;

FIG. 65 shows a heel platen having a keyed annular recess so that the center of a compatible chassis can be discouraged from rotation about its center point;

FIG. 66 shows an external perspective view of a bladed serpentine heel chassis devised to be mountable on the heel platen of FIG. 65;

FIG. 67 is an underside perspective view showing a keyed ring commensurate with the keyed annular recess at the center of the heel platen shown in FIG. 65;

FIG. 68 is a cutaway perspective view of a preparatory computational model for a crowned chassis, in which a volume has been derived by sweeping a curved figure about a medial racetrack- shaped path; FIG. 69 is a cutaway underside perspective view of the same preparatory computational model shown in FIG. 68;

FIG. 70 is a schematic perspective view of the geometrical model of the volume FIG. 68 and FIG. 69 interposed with a preparatory computational volume derived for a serpentine chassis;

FIG. 71 is a schematic perspective view of a preparatory volume derived by the intersection of the serpentine volume with the crowned volume;

FIG. 72 is a perspective view of a threaded insert devised for use within the disclosed footwear system in which the insert includes a tapered extension that allows the insert to serve as an intrinsic mechanical spacer, as in the exemplary system depicted in the immediately succeeding figures;

FIG. 73 is an external perspective view of a convolute forefoot chassis having both discontinuous annular snap fittings and leading and trailing arcuate operational linkage features, in which its crowned beam geometry has been directly derived by the computational sequence schematically described in FIGS. 68 through 71 inclusive;

FIG. 74 is an underside perspective view of the convolute forefoot chassis shown in FIG. 73;

FIG. 75 is perspective view of a convolute heel chassis incorporating both bladed and conic stud geometries;

FIG. 76 is perspective underside view of the convolute heel chassis shown in FIG. 75;

FIG. 77 is a perspective view of a sole plate monolithically integrating a fore plate and heel plate, the fore plate and heel plate being compatible with the chassis illustrated in the immediately preceding figures;

FIG. 78 is a perspective view showing the forefoot chassis of FIGS. 73 and 74 and the heel chassis of FIGS. 75 and 76 installed on the monolithic sole plate shown in FIG. 77;

FIG. 79 is a perspective a variant of a demountable monolithic fore plate formed within the disclosed footwear system which uses only integral polymeric features for operational linkage, including a snap receiver toward the trailing send of the fore plate;

FIG. 80 is an underside perspective view of the demountable fore plate shown in FIG. 79; FIG. 81 is a perspective view of a serpentine chassis compatible with the forefoot fore plate shown in FIGS. 79 and 80, in which the leading end of the chassis includes an arcuate fender and front cover shields, and the trailing end includes a flexible yoke carrying a snap tab;

FIG. 82 is an underside perspective view of the demountable fore plate shown in FIG. 81;

FIG. 83 is a perspective view illustrating a lobed chassis compatible with the monolithic demountable fore plate shown in FIGS. 79 and 80, having an arcuate snap fitting mounted on a yoke at its trailing end;

FIG. 84 is an underside perspective view of the lobed chassis shown in FIG. 83;

FIG. 85 is a perspective view of an embodiment of the disclosed footwear system, the embodiment including a forefoot chassis which employs a kinetic bayonet mount toward the leading end of the chassis, and an array of serpentine beams intermediate between a leading panel and a trailing panel, in which both the leading panel and the trailing panel carry triangulate studs, in which the panels can rotate independently of one another, and in which the leading panel includes a conformable annular corrugation formed about the bayonet mounting feature so that the panel and central bayonet mounting feature are permitted compliance with the shape and movement of the footwear during use;

FIG. 86 is an underside perspective view of the bayonet-mountable chassis shown in FIG. 85;

FIG. 87 illustrates a perspective view of a forefoot bayonet mounting platen compatible and commensurate with the bayonet-mountable chassis shown in FIGS. 85 and 86;

FIG. 88 is an underside perspective view of the bayonet-mountable forefoot chassis shown in FIG. 87;

FIG. 89 is a perspective view showing a first location in a process of mounting or demounting the bayonet-mountable forefoot chassis and the bayonet mounting forefoot platen from one another, showing the unlocked position, the arrow indicating the direction of rotation followed to safely engage the chassis on the platen;

FIG. 90 is a perspective view showing a second location in a process of mounting or demounting the bayonet-mountable forefoot chassis and the bayonet mounting forefoot platen from one another, showing a locked position, the arrows indicating the diverse expressed motion effects owing the interplay of the articulating components; FIG. 91 is an oblique view of a variation of a chassis compatible with the bayonet mounting system in which the bladed studs have an overt rotational bias, and in which two rounded conic studs are included upon the pivot locations;

FIG. 92 is a reverse oblique view of the bayonet-mountable chassis shown in FIG. 91;

FIG. 93 is a perspective view of a compact interchangeable chassis having static triangulate studs operationally compatible with the kinetic bayonet-mountable chassis illustrated in the preceding figures, in which the compact chassis is devised to be captured by the action of a pair of opposing flexural prongs posed against a receiving platen;

FIG. 94 is an underside perspective view of the compact flexural pronged chassis shown in FIG. 93;

FIG. 95 is a perspective view of a compact receiving platen including relief elements that reliably capture the compact flexural pronged chassis shown in FIGS. 93 and 94;

FIG. 96 is an underside perspective view of the compact receiving platen shown in FIG. 95;

FIG. 97 is a perspective view of a compact flexural pronged chassis statically mounted on its receiving heel platen;

FIG. 98 is a plan view of a compact flexural pronged chassis statically mounted on its receiving platen, showing a second and alternate position that occurs during mounting and demounting, at which the chassis is retained on the receiving platen by outward spring force exerted in the field plane, but at which it can be readily freed from the plate by lifting the chassis out of the field plane;

FIG. 99 is a perspective view of a molded perform for an overmolded bayonet-mountable forefoot chassis component, depicting the appearance of the preform after an initial molding operation;

FIG. 100 is a perspective view an overmolded bayonet-mountable forefoot chassis, after a secondary molding operation, in which a secondary mold and secondary material have been introduced to impart material, features, and properties that differ from those provided through the initial molding process;

FIG. 101 is a perspective underside view the overmolded bayonet-mountable forefoot component shown in FIG. 100; FIG. 102 is a sectional perspective view of the overmolded bayonet-mountable forefoot component illustrated in the preceding figures, illustrating the boundaries of between a first material and a second material;

FIG. 103 is a perspective view showing that by the use of the same installation routine; the overmolded bayonet-mountable forefoot component can be interchangeably substituted in a modular- fashion for the studded components using the common mounting platen depicted in FIGS 87 and 88;

FIG. 104 is a perspective view of an overmolded heel chassis that can be modularly installed on receiving heel platen of FIGS. 95 ad 96 in combination with the overmolded bayonet-mountable forefoot component and in place of the flexural pronged heel chassis shown in FIGS. 93 and 94;

FIG. 105 is a top perspective view of a compact pocket tool that can used to release the bayonet-mountable forefoot chassis from its mounting;

FIG. 106 is an underside perspective view of the simple pocket tool shown in FIG. 105;

FIG. 107 shows an integrated molded sole plate incorporating a bayonet mounting on the forefoot area and a sliding catch on the heel area, the drawing furthermore illustrating the positioning of a fill panel expressly devised to occupy voids in the consolidated molded sole plate;

FIG. 108 shows a forefoot chassis having a cantilevered tab at the leading end that includes a shielding flange that excludes potential contaminants, and aids part alignment;

FIG. 109 shows a forefoot chassis having leading and trailing panels outfitted with pluralities of inserts, such that individual studs with threaded shanks can be installed in a user- selected arrangement;

FIG. 110 shows an external perspective view of a heel chassis having shields on its prongs that substantially cover the gap between the flexible prong and the inner frame of the chassis, so that contaminants are prevented from blocking user-initiated movement of the prongs, and all including an terminal catch tab;

FIG. I l l shows the heel chassis of FIG. 110 from an internal oblique perspective;

FIG. 112 shows a cut away partial perspective view of a heel region of a sole plate devised to receive a pronged heel chassis in which the receiving posts are shaped to substantially fill the catching recess in a compatible pronged chassis, an in which the mounting operation is achieved by sliding the chassis toward the front of the article of footwear;

FIG. 113 is a plan view a forefoot chassis expressly modified to increase transverse stud displacement, in order to mitigate injurious forces encountered during a side collision or lateral impact;

FIG. 114 is a perspective view of the side-impact forefoot chassis of FIG. 113;

FIG. 115 is a graph of the measured torsional resistance, in newton-meters, of the forepart of an exemplary forefoot chassis expressed during clockwise and counterclockwise rotation of the forepart on a shoe devised within the disclosed footwear system for the right foot;

FIG. 116 is a table of proposed scale quantizations to economically serve a variety of footwear sizes, footwear users, and footwear uses;

FIG. 117 is an external perspective view of a forefoot chassis having an infill panel in the middle section, such that orbital relative motion of the traction features is suppressed;

FIG. 118 is and internal perspective view of the forefoot chassis of FIG. 117;

FIG. 119 is a schematic model showing how an apertured flange formed on an initial molded precursor can be used to mechanically interlock a secondary material with a premolded initial material;

FIG. 120 is a perspective view of a schematic model of a discrete bladed flexural traction element employed in a variant of the disclosed footwear system in which flexural blades are individually interchangeable, and in which the array of flexural articulating beams is integrated with prongs that capture the traction features upon a forefoot platen;

FIG. 121 is a perspective view of a schematic model showing a set of discrete traction elements installed in a compatible forefoot platen assembly, in which the forefoot platen assembly provides a discrete housing for each discrete bladed flexural traction element; and

FIG. 122 is a reverse partially cut away view of the arrangement shown in FIG. 119, in which the cover layer is cut away to show how the four prongs on each traction element are caught by corresponding elements integral to the housed platen assembly.

DETAILED DESCRIPTION

Referring now to the individual drawings in sequence, FIG. 1 shows a sketch of the counter-rotational forces encountered during on-field play that commonly lead to knee injury. Planted foot at arrow Z results in an effective counter-rotational force between the fixed lower leg R1 and the turning upper leg R2. Because the studded shoe is entrapped in the turf and cannot turn, a destructive level of force can be imposed at the knee.

It is widely accepted that any shoe that allows the foot to rotate while its studs are firmly planted might mitigate this stress and reduce the frequency of injury. The disclosed footwear system provides a chassis comprising articulating strut arrays that provide reliable and responsive traction during regular play. Studs are structurally permitted a shift of 1 cm or more in either rotational direction during high-risk maneuvers, such as abrupt stopping or turning.

The disclosed footwear system thereby provides an elastic or cushioning effect in any activity expressed within the plane of the field, but requires only a compact chassis comprising an array of stiff but flexible polymeric struts. The chassis is light in weight and adds only a few millimeters of thickness to the assembled shoe structure.

Furthermore, the traction system of the disclosed footwear system provides a natural progressive resistance to applied linear or rotational force, and therefore emulates the torsional behavior of the biological structures of the limbs of the lower body. The application of the disclosed footwear system to practical use therefore is intuitive and aligned with the body’s innate proprioception.

A parallel-beam flexural chassis represents a subclass of such monolithic structures that provide pseudopantographic motion without any real mechanical pivot points. In FIGS. 2, 3, and 4, respectively, relaxed compound strut 2, right-shifted compound strut 4, and left-shifted compound strut 6 indicate three operational states of the same flexural element. In each state, the strut includes stud 10, first beam 12, first base joint 14, second beam 16, and second base joint 18. The strut is constrained at the base so that the stud can shift sideways in one plane, but is discouraged from out-of-plane motion.

FIG. 2 is a schematic of relaxed twin-beam compound strut 2 formed according to the disclosed footwear system, having two beams and carrying a single stud, showing its default, relaxed state. FIG. 3 shows a schematic of a twin-beam compound strut formed according to the disclosed footwear system, showing a condition in which the stud is displaced to the right by an applied force. FIG. 4 shows a schematic of a twin-beam compound strut e formed according to the disclosed footwear system, showing a condition in which the stud is displaced to the left by an applied force. These illustrations are explanatory. In the diverse realizations of the disclosed footwear system, beams can be straight or curved in their default state, and can include diverse internal ancillary beam components between or within a compound strut, so long as their design and disposition does not prevent articulation.

It may be appreciated that the schematic module shown in the preceding figures can be integrated into an array within a chassis that can fit onto the sole of a field shoe. FIG. 5 shows an external plan view of flexural chassis 20 designed for operational linkage to a compatible sole plate. Flexural chassis 20 including a distributed array of seven articulating studs. The geometry of flexural chassis 20 may be more completely appreciated by concurrent reference to the perspective views of the part in FIG. 6 and FIG. 7.

Viewed from the bottom of the shoe, and proceeding toward the trailing end, the flexible members of flexural chassis 20 include long center front stud beams 22, leading stud beams 24, middle stud beams 26, and trailing stud beams 28. The array of beams connects to spine 30 either directly, or in the case of center front stud beams 22 and leading stud beams 24, by intermediate yoke 32 and intermediate neck 34. Through holes 36 and bevels 38 provide mechanisms for holding the chassis on the sole plate.

Beam pairs connect to front stud 40, leading studs 42, middle studs 44, and trailing studs 46. Arcuate center stud 48 has a convex leading side and a concave trailing side. Center stud 48 is braced by stud buttress 50.

The six bladed studs on the sides are longitudinally asymmetric, in that the leading edge of the blade has a more acute angle than the trailing edge. This asymmetry allows optimized traction during the player’s forward travel, but releases easily from the field when the foot is lifted. The studs shown are lofted ellipsoids, having an average leading edge rake of approximately -45°, and a trailing edge rake of approximately -10°.

The blunt rake on the trailing edges of side studs, in combination with the broad faces of front stud 40 and arcuate middle stud 48, conspire to engage with the field surface and prevent slippage during forward travel. Whenever the athlete is running in a straight line, this arrangement provides aggressive linear traction.

Beams in flexural chassis 20 are straight and parallel, with the exception of bilaterally symmetrical leading stud beams 24. Leading stud beams 24 are outwardly convex to impart a buckling bias in one direction upon the imposition of compression stress. The imposed design curvature prevents overloading of the beams and abrupt catastrophic failure. Instead, the beams progressively bend away from one another in the field plane as front stud 40 accepts a load, for example, during rapid deceleration.

Flexural chassis 20 furthermore includes flexural structures interconnecting and regulating the motion of studs 40 and 42. These include yoke 32 and bridge 34. These additional features allow the foremost set of three studs to move both independently and collectively. Leading stud beams 22 carrying front stud 40 are symmetrically bowed to invite a buckling action upon compression of the beams.

Arcuate middle stud 48 includes buttress 50 and has an acute curvature in order to provide a high-traction scooping action during running, while also providing a torque-reducing coring action when the athlete pivots on the foot. Arcuate middle stud 48 essentially presumes an approximate pivot location, and may be variously located according to the demands of the sport or the athlete. It may also be eliminated when it is desirable for any pivot point to remain indefinite.

Flexural chassis 20 is devised to reside upon a compatibly formed sole plate. FIG. 8 shows a rear oblique perspective view of a sole plate commensurate and compatible with the flexural chassis shown in FIGS. 5 through 7. Sole plate 60 includes sole plate platen 70, which roughly conforms to the shape of the anticipated shoe assembly, including, for example, a shoe last and shoe upper. Arcuate alignment posts include leading posts 62, middle posts 64, and trailing posts 66, which extend from sole plate 60 at the forefoot. Heel plate 80 is superposed on sole plate 60.

Fixed integral heel studs including angled side studs 84 and heel transverse stud 86 extend from heel platen 80 on sole plate platen 70. Countersunk heel mounting holes 88 are formed at the heel. Plain mounting holes 68 are formed at the forefoot.

FIG. 9 shows the assembly of the chassis and the sole plate. It may be seen that flexural chassis 20 slips over arcuate alignment posts 62, 64, and 66 such that flexural chassis 20 bears against sole plate platen 82. Spine 30 is held in place by operational linkage hardware 90. Operational linkage hardware 90 is here represented by flathead Phillips type screws. In the installed configuration, the crossbars carrying the studs are free to move orbitally over a distance of several millimeters relative to sole plate 60. Beveled realizations of threaded operational linkage hardware 90 can be stopped by the bottom a blind hole so that the head docs not meet and compress or expand the bevels of the countersunk mounting holes. This elective condition prevents destructive spreading of the molded chassis component, while not compressing or clamping the chassis against the sole plate. This loose but closely confined condition also permits articulation stresses to be distributed more sympathetically in the chassis.

FIG. 10 shows the characteristic deformation of the flexural chassis under rotational stress, as when the athlete’s foot is planted and turned. FIG. 11 shows the characteristic deformation of the struts within the chassis under axial stress, as when the athlete’s travel is linear and the foot is abruptly planted to decelerate.

Momentary deformation of the illustrated embodiment can be 12 mm or more in each direction while not imparting permanent deformation. Irrespective of the local displacement, the studs remain within the perimeter of sole plate platen 82. The bladed studs shown are 16 mm long, 5 mm wide, and 12.5 mm deep.

The sectional proportion for the illustrated beams is a width of 2 mm, a depth of 3.5 mm, and a length of 22.5-25 mm. These proportions provide a functional maximum of approximately 15 mm of displacement in the field plane in each direction before permanent deformation or breakage occurs. Such operative thresholds depend on both the design and material, and the identified values are presented to characterize the utility of the disclosed footwear system.

The proportions of the beams may be widely varied according to design requirements. In general, it is preferable in the disclosed footwear system to provide beams that are deeper than they are wide. Sectional aspect ratios of 1:1.2 to 1:2 are typical within the disclosed footwear system. For example, a low-profile version of a chassis includes compound struts having six to eight beams per strut, each beam having a depth of 1.2 mm and a width of 0.8 mm. Beam proportions can also be guided by practicalities such as mold fabrication, or the How of the molten polymer during injection.

It may be appreciated from FIG. 10 that rotation of the planted foot results in the studded struts on one side of the shoe traveling in curved arcs toward the toe of the shoe, with studded struts on the opposite side of the shoe traveling in curved arcs away from the toe. In either circumstance, progressive resistance is encountered as the torsion increases. In natural turf, the elliptical or other elongate blades will begin to furrow soil and cut thatch and blades of grass. As the foot is lifted from an engaged state with the turf, the blades ramp out and return to their relaxed home position.

FIG. 11 shows the chassis deformations encountered when a foot is planted during linear deceleration. In this case, the leading strut and the two sets of side struts are collectively pushed toward the heel. The beams obtain bowed or serpentine shapes as the force of deceleration is applied against the leading faces of the studs. Sympathetic articulation is encouraged by intermediate yoke 32 and intermediate neck 34, such that studs in the foremost region of the array exhibit both a degree of independent articulation and a degree of interdependent articulation. The arrangement has been found to distribute operational stress more broadly in the part and increase durability.

The accommodative and sympathetic behavior of the part should be understood to induce a more gradual force gradient to the athlete temporally as well as spatially. A less temporally acute force gradient reduces shock to the knee and other joints, prevent sudden slacking, buckling, and straining of connective tissue, and can cushion the athlete’s momentum to reduce the chance the mass of the upper leg will overshoot the lower leg as the athlete abruptly stops. The chassis design can be derived to address particular axes of concern.

The preceding examples presume that the heel is lifted from the turf during extreme inertial or torsional events, as when running at speed and turning or stopping. While this is often the case, there are instances, such as when the athlete makes a sudden cold start, where the entire foot is planted flat when the shoe upper is turned.

FIG. 12 shows a modification of the disclosed footwear system in which the heel includes an independent flexural heel chassis 110 rather than fixed studs, so that the heel studs are moveable in the same fashion as the studs on the forefoot.

Compatibly, agile heel sole plate 100 includes arch bridge 102 integrally connecting agile heel forefoot platen 104 to agile heel sole platen 106. Agile heel sole plate 100 also includes agile heel sole plate arcuate posts 108. Agile heel sole plate arcuate platen serve to locate the two chassis including flexural heel chassis 110 on agile heel sole plate 100. Here, flexural heel chassis 110 includes four symmetrical struts 114 carrying studs 112. Countersunk heel mounting hole 114 allows hardware, such as a screw, to be used to centrally constrain flexural heel chassis 110 to agile heel sole plate 100, while leaving a degree of free play at the extremity of the struts where the studs are located. In the broad application of the disclosed footwear system, it may be appreciated that the function of keeping a chassis seated upon a compatible sole plate in a stable position within the field plane may be conceptually and structurally separated from the function of keeping the chassis held in intimate proximity to the sole plate.

In practical embodiments that still allow articulation, the mechanical interferences provided between the sole plate and chassis must limit sliding of the comprehensive part in the field plane, and also limit lifting of the chassis in the axis perpendicular to the field plane, such that the extremities of the chassis are permitted local or pervasive flexural motion in the field plane. In the disclosed footwear system, these two discrete constraining functions can be diversely expressed in cooperating physical structures, and may be separated or conjoint.

For example, In the preceding example, the hardware in the form of threaded fasteners, provides the properties of both retention and restriction, as defined above. The head of the fastener extends over the chassis and holds the chassis against the sole plate. It also prevents longitudinal or lateral displacement of the chassis.

In general practice of the disclosed footwear system, the close proximity of the chassis to the sole plate is preserved by permitting the internal surface of the chassis and the external surface of the sole plate to contact one another locally dynamically during use of the footwear. It is generally useful to hold the chassis and sole plate in intimate proximity, so that field debris cannot wedge under the chassis.

Those conditions are diversely provided within the disclosed footwear system by the mechanical expression of both a retentive property, namely, a mode of interference that holds the chassis to the sole plate in relative proximity, preventing their separation on an axis perpendicular to the field plane, and a restrictive property, namely, one that prevents a flexural chassis from departing in any direction from a known location within the field plane.

At least one retentive connector is included within the engagement mechanism that provides an interfering retentive relationship between the sole plate and chassis, in order to make the chassis mountable upon the article of footwear through the influence of the retentive connector, such that the chassis is held in meaningful conformity with the external surface of the sole plate.

At least one restrictive connector is also included within the engagement mechanism in order to provide an interfering restrictive relationship between the sole plate and chassis, the chassis being mountable upon the article of footwear through the influence of the restrictive connector, such that the chassis is substantially deterred by the restrictive connector from comprehensive displacement relative to the sole plate in any radial direction within the field plane. The restrictive connector may provide a pivoting or centering function, and can be disposed to allow sliding and prevent jamming of the articulating extremities.

In the disclosed footwear system, articulating studs are typically located so that they are inset slightly from the perimeter of the sole plate. It is appreciated that the potential range of travel will depend on a distance of the stud from points of connection with a sole plate. The weighting of the foot at the stud locations is also a design consideration.

The prospective application of the disclosed footwear system is diverse, and, accordingly, the illustrated examples are not meant to disclose the full range of imagined realizations. In particular, the disclosed footwear system envisions disparate combinations and arrangements of motile flexural beam arrays; it furthermore envisions disparate combinations and arrangements of chassis structures so that a chassis can be deformatively manipulated on and off a sole plate or a demountable platen.

The assembly in FIGS. 13 through 16 inclusive shows one modification of the disclosed footwear system disclosing four-beam flexural struts within a chassis, in which retention clips are devised to permit a degree of in-plane rotation to each strut within the chassis, and in which each stud is provided with four beams and a retention clip at its outermost extremity.

Increasing the number of beams provided per stud while reducing their individual cross- sectional depth allows shallower beams to be used for a given value of flexural resistance in the field plane. This thinning of the compound beam arrays permits a lighter part weight and increases intimacy of the foot with the ground.

Chevron stud flexural chassis 200 is devised to be mounted upon dimensionally compatible conic stud sole plate 220. Chevron stud flexural chassis 200 is installed upon conic stud sole plate 220 without the need for loose hardware or any installation tool. A combination of snapping and other plastic deformation ensures that the flexural chassis remains in place during vigorous play.

More specifically, this variation also includes operational linkage features that clip around posts integrally formed in the sole plate. The stud-bearing flexural struts can be momentarily deformed so that they fit into undercut guide channels. The design integrates both structural articulation stops and operative articulation stops.

A structural articulation stop is a physical post or other raised feature on a platen or sole plate that is disposed so that the articulating chassis component bears against the stop at an extremity of its deformation in the field plane. An operative articulation stop is a functional condition in which struts attain a state of resistance to forces encountered in field conditions such that the studs can no longer be meaningfully displaced by the active athlete. An operative beam stop, for example, can involve indirect contact, progressive wedging or jamming against a static component, or the cumulative force resulting from the abutment of flexural chassis elements against one another. Advance reference to the graph in FIG. 155 exemplifies an embodiment in which structural stops are substantially coincident with operational stops, so that overloading of structural stops is avoided.

An operative beam-stopping state may be encountered when the spatial frequencies of the beams and the spaces between them are knowingly proportioned so that the beams contact one another in the vicinity of the transitory tangencies of the serpentine curves. This geometrical condition can occur when the beams are relatively closely spaced. The condition may be appreciated by the following theoretical case.

If the beams are set in a relaxed state and each is 2 mm wide, and the space between them is 0.82 mm, the movement of the integral stud will be stopped when the beams bear against one another at their midpoints when the transitional tangencies of the serpentine curves reach 45°. This intrinsic stopping effect owes to the obliquity of the beams as measured across the deformed beam set being proportional to their diagonal measure at the limiting design angle.

In this case, the diagonal measure is derived from the square root of two. The midpoints of the beams will bear against one another at the design angle when the sum of obliquely measured widths across the midpoints at their flexural extremity is equal to the sum of the beams and their intermediate spaces across their midpoints in the relaxed state.

At 45°, the proportion of the beam to the sum of the beam, and the space between a given beam and its neighboring beam. In the preceding geometric condition, the ratio of the beam relaxed width W to the deformed beam width at the beam midpoints is 1 :A/2. The gap that results in intrinsic stopping at 45° is therefore (W) 1- 2. When W=2 mm, the requisite space between beams is approximately 0.82 mm. In this condition, further deformation is prohibited, as the beams bear against one another at their midpoints. This paragraph does not make sense, specifically the first sentence.

Operative stops can be integrated across diverse networks of beams, limbs, lobes, struts and spines. Any amenable situation where one flexing element bears against another flexing element owing to deformation of the elements should be understood as an intentional implementation of the disclosed footwear system.

It may be appreciated also that the stopping effect may be local, and that articulation relative to the sole plate may continue due to flexing, pivoting, sliding, or other motions allowed in the design. Stops can also be conscientiously used to regulate forces and stresses along the beams during deforming events, such that the articulation is regulated at a point or along a length of the articulating feature.

Such stops can be complex, have specific bearing or spacing protrusions, or be carried on discrete or dedicated beams. The application of these principles should be broadly understood to be a general adaptability of the disclosed footwear system, and that such features will be applied according to the needs of an individual design.

In the example embodied in FIGS. 13 through 16, additional beams collectively serve as an armature that intermediates displacement between struts, so that upon imparted inertial or torsional forces, a degree of that force is transferred from one beam set to another via the intermediating beams composing the armature. The bends in the intermediating beams act as operative stops at extremity of articulation, as the struts move relative to one another and the sole plate, and the spaces between the beams close. The chassis essentially coils onto itself, and acquires a secondary and self-bracing flexural state.

The relevant motion in this example is not limited to flexural behavior, as a degree of rotation in the clips about the posts is intentionally permitted. The coordinated and complementary effect of rotation and deformation increases the achievable range of motion, while reducing stress at critical locations in the struts within the monolithic chassis.

In the illustrated design, beams are effectively prestressed by the provision of a default serpentine shape. In this case, beams can only obtain a straight and parallel condition only at a specific moment after force is applied against the studs in a rearward direction. Beyond that point, the serpentine beams will be flexed into a reverse serpentine shape. The potential displacement of the studs during use depends on the shape, length, and orientation of the beams. FIG. 14 shows a studded sole plate including articulating chevron studs and fixed conic studs, and in which a subset of the conic studs is devised to capture the retention clips shown in FIG. 13. The permissive interfitting of chevron stud flexural array 200 and conic stud sole plate 220 may be further apprehended by reference to the perspective views of the assemblies depicted in FIG. 15 and FIG. 16.

Chevron stud flexural chassis 200 includes a plurality of clips 202, beams 204, and chevron studs 206. Conic stud sole plate includes a defining conic sole plate platen 222, and three types of fixed conic studs. The conic studs are shorter relative to the extension of flexural chevron studs 206 and are provided with generous fillets so that the studs provide a degree of traction, yet can ramp out of the turf when the foot is rotated without unduly stressing the player’s joints. In contrast, chevron studs 206 provide deep engagement with the turf, but provide protection of the player’s joints by being actively displaceable.

Heel studs 224 blend geometrically with the sole plate. Stopping studs 226 have a cylindrical section against which a flexural beam bears at a predetermined limit of deformation. Pivot studs 228 have undercut recesses so that clips 202 in chevron stud flexural array 200 can be fit around a cylindrical post. Keystone stops 230 permit a degree of rotational motion, but limit relative rotation of the clips about the posts formed in pivot studs 228.

The assembly of the four-beam flexural chassis to the studded sole plate allows chevron studs to be closely retained against the sole plate by the cooperative effect of tabs 208 and guide channels 232. Intermediating shoulder beam 210 integrates the flexural activity of the independent stmts so that a degree of applied force is transferred between beam sets during deformative events. The proportions of intermediating shoulder beam 210 can be freely elected to promote the amount of independence or coordination of the flexural action of the discrete beam arrays. Forefoot mounting holes 234 and heel mounting holes 236 express an operational linking mechanism to connect the sole plate with the shoe upper and last.

The exemplary cases illustrate beam arrays in which the sectional proportions of the beams remain substantially consistent along their lengths. FIGS. 17 through 20 inclusive depict useful departures from this paradigm. Beams can be widened or attenuated, for example, to reduce stress, tailor resistance, extend part lifetime, or steer studs along a modified path.

FIG. 17 shows a studded chassis having symmetrical beam attenuations, which may be used to reduce stress at key locations and promote pseudopantographic motion. Symmetrically attenuated stud chassis 250 includes local attenuations 252 such that beams are narrowed near their points of connection.

FIG. 18 shows a studded strut having asymmetrical beam attenuations. Asymmetrically attenuated strut 260 includes two pantographic attenuations 262 on one beam. Distal knuckling attenuations 264 and middle knuckling attenuation 266 are formed on the opposite beam. This modification allows the travel of the stud to deviate from a restrictive pantographic path. This strategy may be implemented, for example, when it is desirable to prevent the stud from extending beyond the sole plate during extreme flexural events.

FIG. 19 shows a studded strut having symmetrical knuckling beam attenuations in which a buckling bias is preformed in the beam length. Folding stud strut 270 includes distal buckling attenuations 272 and medial buckling attenuations 274. This configuration may be implemented to promote compression and extension along the longitudinal axis of the strut.

FIG. 20 shows an optimized studded strut 280 having symmetrical, continuous beam attenuations. Continuously attenuated beam 282 may be thinned continuously toward their midlengths in a parabolic or other curvature. Such attenuation is known in certain instances to distribute stress more efficiently along the beam, so that the desired strut displacement can be achieved with a maximized part lifetime.

It may be appreciated that these detailed examples are schematic in nature, and that the intent of these descriptions is to outline a suite of solutions that can be spontaneously creatively realized in the derivation chassis with complex strut arrays within the scope of the disclosed footwear system.

Tabs and guide channels can be variously integrated with molded shoe structures. FIG. 21 shows a schematic sectional view of an internal guide channel integrally formed on the underside of the sole plate. Internally guided chassis shoe 300 includes internally-guided chassis shoe upper 310 and internally-guided chassis shoe sole plate 320. Internally-guided strut array 330 includes a plurality of agile flexural studs 332. Internally-guided chassis shoe retaining channel 322 holds studs 332 close to the sole plate during flexural activity.

FIG. 22 shows a schematic sectional view of an external guide channel integrally formed in the side edge of the sole plate. Externally-guided chassis shoe 340 includes externally-guided chassis shoe upper 350 and externally-guided chassis shoe sole plate 360. Externally-guided chassis shoe sole plate 360 includes a plurality of agile flexural struts 372. The structural interplay of externally-guided chassis shoe retaining channel 374 and integral sole plate guide 364 holds flexural struts 372 close to sole plate during flexural activity.

The following series of illustrations depict implementations of embodiments of the disclosed footwear system applying the preceding principles. Particularly, the illustrated systems provide for the convenient installation and removal of modular chassis components. A range of implementations is progressively presented. The embodiments differ in detail, but have many features in common, or which operate interchangeably.

FIGS. 23-55 inclusive relate to systems in which chassis are entrained about a flanged platen, and therefore conform to the general schema shown in FIG. 22. Accordingly, FIG. 23 is an oblique external view of platen sole plate 400 provided with a main plate 402 and two integral surmounted platens. The purposes of sole plate features may be appreciated by anticipatory reference to compatible chassis illustrated in FIGS. 26 through 31 inclusive.

Returning to FIG. 23, forefoot platen 404 includes forefoot platen base 406 and forefoot platen cap 408. The difference in spatial extent between forefoot platen base 406 and forefoot platen cap 408 generates forefoot flange 410 and discontinuous front flange 414. Forefoot platen cap 408 is formed with underside bevels 412 on its flanges. Chassis tab bypasses 416 form two symmetrical insets in forefoot platen cap 408. The gap between the forefoot flanges and main plate 402 identifies forefoot channel 418 suitable for the introduction of an anticipated chassis. Arcuate pinion cavity 420 and round pinion cavity 422 are disposed on the longitudinal centerline of forefoot platen 404.

Heel platen 424 includes heel platen base 426 and heel platen cap 428. The difference in spatial extent between heel platen base 426 and heel platen cap 428 identifies three heel platen flanges 430, each separated from the next flange by a space of approximately 60°. Heel platen flanges 430 include heel platen underside bevels 432. The radially symmetrical configuration generates three undercut channels 434 and three inset bypasses 436. Trefoil heel platen recess 436 is indented in heel platen 424.

The forefoot platen can electively be corrugated to modify the flexural behavior of the sole plate. FIG. 24 is an oblique external view of corrugated sole plate 440. Corrugated sole plate 440 includes exterior sole plate face 442. External sole plate face 442 is provided with coiTugated forefoot platen 450 and compatible heel platen 470. Corrugated forefoot platen 450 includes corrugated forefoot platen base 444 and corrugated forefoot platen cap 446. Corrugating channels 448 intrude through corrugated forefoot platen base 444 and corrugated forefoot platen cap 446 to the level of the external sole plate face 442. Partitioned flanges 448 extend beyond corrugated forefoot platen base 444.

Leading flange 454 extends from the front of forefoot platen 450. Intermittent channels 458 include are formed beneath partitioned flanges 452. Partitioned flanges 452 are provided with intermittent chamfering 464 on their undersides. Corrugated chassis tab bypass 466 forms a break in the series of partitioned flanges 452. Recessed features of corrugated forefoot platen 450 include arcuate guide recess 460, and blind pinion hole 462. Pivot ramp 468 serves to guide a pivotable relief feature into a pivotable recessed feature such as blind pinion hole 462. Guide ramps may be implemented pervasively within the disclosed footwear system.

Compatible heel platen 470 includes compatible heel platen base 472 and compatible heel platen cap 474. The difference in spatial extent between compatible heel platen base 472 and compatible heel platen cap 474 creates undercut heel flanges 476. Heel tapering bevels 478 are formed on each flange. The space between exterior sole plate face 442 and undercut heel flanges 476 identifies three heel plate channels 480 alternating with heel plate bypasses 482. Compatible center heel Y recess 484 is formed into the outer face of compatible heel platen 470. Instructional embossments 486 on the part indicate installation procedures.

FIG. 25 is an oblique reverse view showing the internal side of the sole plate illustrated in FIG. 24. Corrugated sole plate underside 488 includes forefoot hollow 490. Forefoot hollow 490 is accompanied by elongate corrugation shells 492, which are geometrically offset from corrugated channels 448 to produce molded corrugated partitions with substantially constant wall thickness. Underside pinion boss 494 analogously corresponds to blind pinion hole 462. Compatible heel recess 496 surrounds compatible heel boss 498.

FIGS. 26 and 27 show two views of platen-mountable chassis 500. FIG. 26 is a forwardlooking perspective view of a bladed forefoot chassis formed according to the disclosed footwear system. FIG. 27 is a rearward-looking perspective view of a bladed chassis of FIG. 27. Platen- mountable chassis 500 includes eight studs. Seven studs are disposed on an approximately elliptical plan at the perimeter of the chassis. One stud is located at the center toward the front of the chassis. Seven mountable struts 502 are convergent on connective spine 504. Each of the seven mountable struts 502 include mountable beams 506 and mountable crossbars 508. Studs include six side studs 510, one leading stud 512, and one core stud 514. Mountable struts further include keepers 516. Crossbars 508 and keepers 516 include tabs 518.

Side studs 510 include leading blade edge 550 and trailing blade edge 522. Core stud 514 has a more arcuate curvature than the studs carried by mountable struts 502.

Lift tab 524 includes lifter hook 526 which extends from lift tab 524 toward the anticipated sole plate.

Numerical mark 528 matches the chassis to the sole plate. Directional marking 530 indicates axes of mounting and removal. Acronymic mark 532 indicates a recommended playing surface. Flexural index 534 denotes the nominal relative mechanical resistance of the chassis during a metered condition of deformation. Arcuate pinion 536 and round pinion 538 are located on the underside of connective spine 504, and dimensionally correspond to recesses arcuate guide recess 460 and blind pinion hole 462 in corrugated sole plate 440.

FIG. 28 is a top oblique view of mountable heel chassis 550 carrying three bladed struts 552. FIG. 29 is an underside view of the heel chassis of FIG. 28. Three mountable heel struts 552 are laid out with radial symmetry about a center point. Mountable heel struts 552 include mountable heel beams 554, mountable heel crossbars 556, and mountable heel studs 558.

Three mountable beveled heel tabs 560 extend inward from mountable heel crossbars 556 and include mountable beveled heel tab bevels 562. Three heel lift tabs 564 are disposed radially about the center of heel chassis 550. Heel lift tabs 564 include heel lift hooks 566. Hub index 568 identifies part class or category. Mountable heel Y pinion 570 includes three pinion arms 572 extended outward from the center of mountable heel chassis 550.

FIG. 30 is a forward-looking perspective view of an assembled traction system including corrugated sole plate 440, mountable forefoot chassis 500 and mountable heel chassis 550. FIG. 31 is a rearward-looking perspective view of the assembly shown in FIG. 30. The following installations are applicable to platen sole plate 400 and corrugated sole plate 440. The references and figures employ corrugated sole plate 440.

Installation of mountable forefoot chassis 500 is obtained by local out-of-plane flexure of the chassis such that the five foremost tabs are slid under partitioned flanges 452, while the rearmost pair of tabs are disposed to ride momentarily on the top surface of forefoot platen cap 446.

FIGS. 11 and 12 depict characteristic deformations of the struts of a flexural chassis. In accordance with these exemplary deformations, serial flexure of the two rearmost mountable heel struts 502 is enacted so that their associated tabs are successively aligned with corrugated chassis tab bypasses 466.

Concurrently, arcuate pinion 536 is seated in arcuate guide recess 460, and round pinion 538 blind pinion hole 462. The angular extent of arcuate guide recess 460 is greater than that of arcuate pinion 536, so that a degree of expressly delimited angular motion is permitted.

The flexed tab is then lowered against the external face of platen sole plate 440. The release of the strut allows the rearmost tabs to slide under the influence of spring force beneath partitioned flanges 452, where they are then captured and retained within the undercut channel, but exhibit a degree of permissible motion in the field plane.

In the geometrical layout of mountable forefoot chassis 500, relative to the perimeter of corrugated forefoot platen base 444, the inner extent of mountable chassis tabs 518 is offset outward from the outer perimeter of corrugated forefoot platen base 444 by 1 mm to 1.5 mm when the chassis is in its resting state. Arcuate pinion 536 and round pinion 538 inherently equalize local departures of this offset during the deformative articulation of mountable forefoot chassis 500.

This offset leaves a gap so that disparities between the arcuate travel of the struts and the arcuate shape of the platen do not result in unwanted jamming or limitation of movement. In knowing implementations of the disclosed footwear system, these arcuate disparities are nevertheless used to expressly limit the range of motion and the amount or resistance exhibited in a given state of chassis deformation, constituting operative stops, as previously defined.

Mountable heel chassis 550 is installed on platen sole plate 440 by initially locating the tabs in alignment with the interstices between undercut heel flanges 476. Mountable heel beams 554 are then deflected out of the field plane to contact the surface plane of external sole plate face 442. Mountable heel chassis 550 is then rotated so that the three beveled heel tabs 540 slip under the three undercut heel flanges 476.

In this process, mountable heel Y pinion 570 bears against the external face of compatible heel platen cap 474 until mountable heel Y pinion 570 aligns and engages with compatible center heel Y recess 484. Mountable heel chassis 550 is then safely retained on corrugated sole plate 440, while mountable heel struts 558? arc permitted a degree of useful flexural displacement in the field plane.

Sole plates and chassis formed in accordance with the disclosed footwear system can serviceably use undercut channels typically around 1.8 mm in height and undercut by about 3 mm. Tabs are accordingly between 1.3 mm and 1.8 mm in thickness, and locally beveled at pitches between 1:8 and 1:16, so that they are easy to entrain about the platen, and are freely displaceable within the undercut channels. Flanges are also typically beveled at equivalent pitches, with similar intent. Undercut flanges can be usefully provided with a thickness that tapers from about 1.5 mm to about 1.3 mm at the outer extent of its bevel.

FIGS. 32-38 illustrate a traction system having many features corresponding to the traction system described in previous figures, with additional features making the traction system amenable for use with a cooperating tool. It also includes stops for constructively inhibiting the movement of the chassis struts. FIG. 39 and 40 show two views of the tool. FIGS. 41 and 42 show two differing uses of the tool in conjunction with chassis within the traction system.

FIG. 32 is a forward-looking perspective view of a corrugated tool-readied sole plate having relief stops and accommodations for installation and removal with a dedicated tool. Tool- readied sole plate 580 includes tool-readied sole plate outer face 582, bearing tool-readied forefoot platen 584. Tool-readied forefoot platen 584 includes tool-readied forefoot platen base 586 and tool-readied forefoot platen cap 588, and tool-readied corrugating channels 590. The extension of tool-readied forefoot platen cap 588 beyond tool-readied forefoot platen base 586 engenders tool-readied forefoot flanges 592. As in previous examples, tool-readied forefoot flanges 592 carry underside bevels 594.

In this sole plate design, undercut bypass notch 596 includes both an inset in the perimeter of tool-readied forefoot platen cap 588 and a deeper inset into the perimeter of tool- readied forefoot platen base 586. This configuration creates an undercut that can be used as a catch for capturing snap fittings formed in a variety of modular traction components.

Leading pinion hole 598 and trailing pinion hole 600 are located along the centerline of tool-readied forefoot platen 584. Tool pivot holes 602 are disposed symmetrically about the platen centerline. Numerical size indicator 604 is recessed in the top surface of the forefoot platen. Incused instructional markings 606 are recessed in the top surface of tool-readied forefoot platen 584.

Relief strut stops 608 are located so that movement of the rearmost pair of struts on tool- readied forefoot chassis 640 will be arrested at an elected limit of travel, but which nevertheless allows the momentary disposition strut tabs into a position within undercut bypass notch 596 where they may be entered under tool-readied forefoot flanges 592.

Tool-readied heel platen 610 includes tool-readied heel platen base 612 and tool-readied heel platen cap 614. Tool-readied heel platen cap 594 includes heel flange sectors 596 and heel bypass sectors 598. Heel flange sectors 616 include heel flange sector bevels 600. Trefoil recess 622 is inset into the top surface of the platen. Wedge-shaped stop key 624 is located ahead of the platen and is devised to interfere with removal once a compatible heel chassis is installed.

FIG. 33 shows a bottom view of the sole plate of FIG. 32. The internal side of tool- readied sole plate 580 is interrupted by corrugating well 626. Shell ribs 628 spatially surround tool-readied corrugating channels 590 formed in the external surface of tool-readied forefoot platen 584. Leading hole boss 630 and joined hole bosses 634 provide surrounding material so that holes formed into the external side do not intrude through the sole plate.

Flexure control dome 634 increases the underside thickness around the center of tool- readied forefoot platen 584. The heel area includes heel well 636 and trefoil boss 638.

Of particular note in applications of the disclosed footwear system using corrugated sole plates, it has been observed in the use of the disclosed footwear system that the sole plate geometry exhibits an asymmetric and atypical response to bending. When a simple flat strip of any material is sharply bent, it naturally obtains a mathematical saddle shape, in which the outward face of the bend is convex in the long axis, but slightly concave in the short axis. As expected, this geometry is reversed if the bending radius is reversed.

In the disclosed footwear system, the unexpected result of the particular corrugation shown is that this underside concavity occurs, irrespective of the direction of the bend in the sole plate. This allows a chassis to more closely follow the platen than would be expected. This property also provides a secondary effect in the particular circumstance when the forefoot is in a state of plantar extension, as when a football player is executing an instep kick.

When the foot is in plantar extension and contacts the ball with significant force, the inertial mass of the ball can momentarily recurve the extended forefoot. In this condition, the centerline of the corrugated sole plate of the disclosed footwear system abruptly shifts toward the ball, while its outer margins move back. In essence, velocity is added to the centerline of the forefoot and removed from the outer edges of the forefoot at the moment of impact.

This property is characteristically nodal but not bistable, so the effect is of an abrupt flexural impulse, followed by a relative plateau of deformative movement. When the forefoot is bent backward, the sole plate, with its internal side bearing against the foot, becomes momentarily convex in the transverse axis, as well as the longitudinal one. The effect reverses, through the same nodal spring force gradient, as soon as the kicked ball leaves the foot.

Transverse curvatures imparted by flexure of the sole plates using the illustrated corrugations typically have greater curvature at the center than at the margins of the sole plate, as in a bilaterally symmetrical hyperbolic or catenary curve.

In the illustrated examples, this centerline convexity has been measured to be 4 mm at the transverse apex of the sole plate. The nodal spike in the flexural gradient occurs as a peak in the rate of curvature change once the transverse arc height reaches about 2 mm. The transition from 2 mm to 4 mm of arc height is relatively abrupt.

Flexure control dome 634 is included in the preceding design to conscientiously regulate this nodal effect. The dome thickens the sole plate wall at the center by about 0.5 mm. This adds strength to the sole plate at a stress point, and marginally equalizes the nodal behavior, providing it with a more intuitive onset. The observed effect, upon ball contact of sufficient extremity to reflex the sole plate, is the addition of an incremental expression of force, or resistance to recoil, along the centerline of the instep.

FIGS. 34 and 35 illustrate tool-readied forefoot chassis 640 devised to be fitted on tool- readied sole plate 560. Seven tool-readied chassis struts 642 include tool-readied chassis beams 644 and tool-readied chassis crossbars 646. The two rearmost beams join at yoke 648. The seven tool-readied chassis struts 642 converge upon tool-readied armature spine 650. Beams in the illustrated chassis are tapered in depth, decreasing in depth with distance from the chassis centerline.

In addition to the surface-engaging grip of studs or equivalent features, an open beam and armature fretwork acts as a tread pattern to further promote traction. If a chassis’ studs are fully engaged in the turf, the chassis fretwork will be pressed against the top layer of the turf. The top layer of natural or artificial turf is typically composed of fibrous material. The fine chassis fretwork structure inherently crimps exposed fibrous material, owing to the highly local applied forces.

On their downward-facing ground contact faces, beams may be provided with peaks or bevels to provide traction on fibrous material such as natural or synthetic blades of grass. Synthetic grass differs from living plant matter in that its blades typically do not break or tear. Acute bevels on the beams within the chassis will pinch and fold the strands of polymer grass about the sharp beam vertices, reducing slippage on the field of play.

Traction ribs 652 are formed on the outward-facing side of tool-readied chassis beams 644 and tool-ready armature spine 650. Tool-readied chassis lifter 654 bridges two forward beams. Six tool-readied side studs 656 are formed integrally with tool-readied chassis crossbars 646. Two abbreviated front studs 658 are earned on a shared strut. The tops of the side studs and front are convex and sloped forward. Tool-readied center stud 660 is located transversely to tool- readied armature spine 650. Tool-receiving undercuts 662 are formed into the leading edge of the rearmost pair of struts.

Leading stud edges meet the top side stud faces at approximately 45°. Trailing stud edges meet top side stud faces 662 at approximately 20°. Side edges of tool-readied center stud 660 converge on center stud 648 at about 35°. These properties facilitate exit from turf and discourage accidental tripping. Tool-readied crossbar tabs 664 extend from tool-readied chassis crossbar's 646. Tool-readied keeper tabs 666 extend from spring-loaded keepers 668.

The underside of tool-readied forefoot chassis 630 includes front annular pinion 672 and rear annular pinion 674. Each of the tool-readied chassis crossbars 646 including their associated tabs is shaped with stud base concavities 676. The leading pair of concavities have an arc height of approximately 0.2 mm, the middle pair of concavities have an arc height of 0.4 mm, and the trailing concavities an arc height of 0.2 mm. These concavities anticipate flexure of the sole plate that occurs both during bonding into a curved state against a shoe upper, and during the footwear’s active use. This concave surface modification prevents binding or entrapment of the tabs in their receiving channels during extremities of sole plate deformation.

Integral crossbars, studs, and pinions are here formed with integral hollows. Hollows are typified by stud hollows 678. Hollows and recesses can reduce cycle time during injection molding by equalizing local mold volumes. Hollows and recesses can thereby discourage sinking and warping, and improve part consistency and surface finish, particularly in polymers that exhibit relatively high shrinkage rates, and may therefore be taken as a general practical modification within the disclosed footwear system.

The combined effect of these modifications is to ease extraction of the bladed studs from the turf, encourage rotary cutting or displacement of the real or synthetic soil, and discourage accidental tripping. The orientation and scaling of stud faces also reduces risk to other players.

FIG. 36 and FIG. 37 depict locking heel chassis 680. Locking heel chassis 680 includes three locking heel struts 682, each having two locking-heel chassis beams 684, one locking-heel crossbar' 686, and one locking-heel stud 688. Locking-heel chassis 680 also includes trefoil center stud 690. Locking-heel crossbars 686 integrate locking-heel tabs 692. One of the three locking-heel struts 694 integrates heel detent notch 696. Trefoil center stud 690 integrates trefoil post 698 on its internal side.

FIG. 38 is a perspective view of an assembly of the tool-readied sole plate 560 and tool- readied forefoot and heel chassis of the preceding figures. Tool-readied forefoot chassis 640 is mounted in a manner analogous to the method applied in the previous example. Locking heel chassis 680 is also mounted in an analogous fashion, except that the foremost strut is momentarily deformed away from the sole plate at its extremity, so that the stud is tilted and wedge-shaped stop key 604 is then captivity engaged within heel detent notch 696. Heel detent notch 696 has a greater dimensional extent than heel stop post, so that the chassis is allowed a degree of angular travel or deformation before the sidewalls of heel detent notch 696 encounter wedge-shaped stop key 604.

In this example, the tool-readied forefoot chassis 640 and locking heel chassis 680 differ in height. Specifically, tool-readied forefoot chassis 630 is made so that the bladed studs stand 12 mm above the top of tool-readied forefoot platen 560, while locking heel chassis 680 extends about 15 mm above tool-readied heel platen 590. Conscientiously imparted chassis design variances of this sort can mitigate the risk of achilles tendon hyperextension, and can be implemented according to the athlete’s anatomy, condition, or preference.

The high spatial density of the heel studs, including trefoil center stud 690, also discourages excessive ground penetration during an aggressive heel strike. It may generally be appreciated that sole plates can be geometrically complex, and vary in shape such that mounting heights and angles of platens and chassis are dependent upon the location and orientation of local sole plate surfaces. FIG. 39 is a perspective view showing one side of installation tool 700 expressly devised for use with the tool-readied components and assemblies in the preceding figures. FIG. 40 is a perspective view showing the opposite side of the same tool. Installation tool 700 includes symmetrical features so that the tool can be inverted and used for the right and left sides of the shoe. Installation tool 700 can be used for both installation and removal of chassis.

One end of installation tool 700 includes stop collar’s 702 and positioning pins 704. Positioning pins 704 includes pin hollows 706. Tool shank 708 connects with broader tool body 710. Raised tool ridges 712 strengthen the tool. Beveled stud lifters 714 are devised to engage with tool-receiving undercuts 662 formed in the rearmost pair of struts in tool-readied forefoot chassis 630. Trefoil socket 716 is commensurate in shape and dimension with the base end of trefoil center stud 690. Maintenance hooks 718 can be used to clean out platen channels, and for any necessary prying action in the interoperation of the chassis and sole plate.

FIG. 41 is a perspective view of the tool readied for deflecting and lifting a rear bladed strut in the process of removal of the forefoot chassis. Installation tool 700 is inserted into the chassis platen such that one positioning pin 704 occupies tool pivot hole 582 with its associated stop collar 702 resting against the top surface of the platen. The tool can then be pivoted about positioning pin 704 so that beveled stud lifters 714 engage with one tool-receiving undercut 662.

The tool is devised with axial geometrical and flexural tolerances so that the stud can be moved with considerable force toward the rear of the sole plate, and then lifted by 3 mm- 5 mm toward the limit of its field-plane travel so that the rearmost tabs can be passed over the platen and the forefoot chassis slid forward and off the sole plate.

FIG. 42 is a perspective view of the tool in place for lifting and deflecting the foremost bladed strut in the process of removal of the heel chassis. In this use of installation tool 700, trefoil socket 716 is set over trefoil center stud 690. Technical advantage is then applied to both rotate locking heel chassis 680 and locally lift the leading stud over wedge-shaped stop key 604. In this operation, at a threshold force, trefoil post 698 ramps against the sidewalls of companion trefoil recess 602.

The illustrated embodiment is provided with sidewall bevels of 12°. This angle has been found to allow a degree of free angular play that returns the heel chassis to its resting state, unless the complex set displacing actions is imposed by the operated tool. The depth, shapes, and sidewall angles of recesses and posts and companion recesses can be idiosyncratically devised within the disclosed footwear system to impose limits on mechanical actions.

Once the foremost crossbar is heel detent notch 696 is raised above wedge-shaped stop key 604, locking heel chassis 680 is effectively unlocked, and can be rotated through 120° so that its tabs bypass the flanges on the heel platen. At this relative location, locking heel chassis 680 is mechanically separable from tool-readied forefoot chassis 630.

Remaining FIGS. 43-55 inclusive illustrate diverse complementary components that have been derived to extend the modular utility of the flanged sole plates described in accordance with the disclosed footwear system. FIGS. 43-47 illustrate covers which are both slid and snapped onto a flanged sole plate.

Elastomeric forefoot cover 720 and heel cover 740 are devised to quickly mount and demount from a flanged sole plate. The soles of athletic shoes are commonly a lamination of a relatively hard-surface elastomer and an expanded elastomer, such as a polymer foam. Forefoot cover 720 and and heel cover 740 include a relatively hard and abrasion-resistant external surface, and an internal face carrying an array of quatrefoil spurs 738 formed monolithically with the covers. Each quatrefoil spur is divided into four axially divergent tines that act as minute, independent leaf springs when placed against a meeting surface.

FIG. 43 is a top perspective view of a ribbed, resilient forefoot pad 720 compatible with sole plates formed within the disclosed footwear' system. FIG. 44 is an underside perspective view of the same part. Resilient forefoot cover 720 includes forefoot cover primary wall 722 and relief traction ribbing 724. Forefoot cover lift tab 726 extends beyond rear wall 728 of the part. Forefoot cover sidewall 730 is formed to substantially encompass the anticipated forefoot platen. The sidewall carries forefoot flange 734 and setback flange 736 on its interior face. The internal face of forefoot cover primary wall 722 includes a rectangular array of quatrefoil spurs 738.

Forefoot flange 734 is shaped and dimensioned in regard of the material hardness so that it can be slid onto the platen, while setback flange 736 is shaped and dimensioned so that it can be elastically deformed and pressed into an engaged state by bypassing the platen flange. The cover is in effect serially slid onto, and then snapped onto, the receiving platen.

The process is readily reversed by gripping and lifting forefoot cover lift tab 726 so that the rearward section of elastomeric forefoot cover 720 is bent upward and disengaged from the platen, and the slid forward to a position where it is fully free of the geometrically associated platen flange.

FIG. 45 is a top perspective view of ribbed resilient heel pad 740. FIG. 46 is an underside perspective view of the same heel pad, showing an array of integrally molded resilient spurs 758 on its internal face. Ribbed resilient heel pad 740 includes resilient heel pad primary wall 742, resilient heel pad ribbing 744, and heel pad lift tab 746. Heel pad size marking 748 promotes matching with a predetermined platen size.

Heel pad sidewall 750 is formed integrally with heel pad slide-on flanges 752, heel pad slide-on flanges 754, and heel pad snap-on flange 756, heel pad bypass flanges 756. The interior face of heel pad primary wall 742 is formed with quatrefoil heel pad spurs 758. As with quatrefoil spurs 738 in resilient forefoot pad 720, each spur includes four tines that extend obliquely from the interior face of the pad’s principal wall.

FIG. 47 is a perspective view of the ribbed, resilient pads of the preceding figures mounted on tool-readied sole plate 560. It may be appreciated that an elective modification of the shoe can be useful when transitioning from field play on turf to court play or casual wear.

FIG. 48 is a perspective view of an overmolded chassis having resilient pads molded onto its compound struts. In this embodiment, overmolded chassis 760 includes differing materials which have been structurally integrated through sequential molding. Overmolded struts 762 include rigid chassis 764 and elastomeric chassis overmolding 766. Elastomeric chassis overmolding 766 provides a gripping surface that can engage with substantially flat contact surfaces such as wood, composite, or concrete. The overmolded chassis provides a degree of articulation of the footwear upon impenetrable surfaces.

FIG. 49 is a perspective view of a modification of a forefoot chassis having additional surface-engaging blades integrated into the chassis to improve traction in soft grounds. FIG. 50 is a plan view of modification of the same soft-ground forefoot chassis. Soft grounds include mud, sand, and saturated or disrupted turf. These grounds are loose and easily displaced.

Soft ground forefoot chassis 770 includes a pair of side struts 772, a pair of middle struts 774, a pair of front struts 776, and a lead strut 778. Side bladed studs 780 are formed on the three pairs of struts. Lead end bladed studs 782 are formed on lead strut 778. Soft ground forefoot chassis 770 also includes one soft ground center stud 784, and two bilaterally disposed intermediate studs 786. Bilaterally disposed intermediate studs 786 are disposed transversely to the forefoot chassis work in cooperation with soft ground center stud 784 to form a baffle providing added traction in soft or fragmented grounds. Beam spars 788 connect each soft ground intermediate stud 786 to its associated beams. The flexural property of beam spars 784 permits each intermediate stud 786 to move in concert with the other elements of its associated struts.

FIG. 51 is a perspective view of lobed flexural chassis 800 having a pattern of low-relief surface-engaging elements formed on its limbs. FIG. 52 is an underside perspective view of the same chassis. In this realization, each limb, instead of being an open strut, is a closed lobe that is allowed independent displacement about two pivotal centers. Relative flexural displacement is allowed by the cooperative effects of divided lobes 802, intermediating channels 804, traction raised lands 806, and positioning pinions 818.

The incursions of intermediating channels 804 identifies a linear array of flexural attenuations 808 along the medial axis of the chassis. The collective effect of attenuations 808 is to provide the effect of an articulating spine, so that the side and front lobes are given a degree of regulated displaceability in the field plane. Lobed flexural chassis 800 is retained and guided by resilient tabs 810.

Mounting and demounting can be obtained through any combination of geometrical features previously described. Lobed flexural chassis 800 includes rear tailpiece 812, which carries representative beveled grip 814 upon its upper face. Rear tailpiece wall 816 includes two symmetrical engagement rims 818.

When mounted, the chassis is captured by undercuts in the platen in such a way that the lobes are retained, but displaceable. Rear tailpiece 812 is captured, but is elastically connected to divided lobes 802, so that local displacement of the lobes can occur.

It may be appreciated that engagement and disengagement can be implemented through diverse structures, engagements and manipulations, such as sliding, snapping, lifting, and twisting, as have been previously detailed. It may be further appreciated that the forms of such elements and actions are dictated by the elastic limits of the selected material.

Lobed flexural chassis 800 is mounted on a commensurate sole plate so that positioning pinions 820 and 822 are seated in compatible holes. When in contact with a ground surface, divided lobes 802 are permitted movement until they are stopped, normally by contact with a neighboring lobe. Lobed chassis of the general form exemplified by lobed flexural chassis 800 can be molded from rubbers, silicones, or elastomers which often have intrinsic gripping properties. An internal interleaving layer can be inserted to reduce inter-surface gripping and promote articulation. The part can also employ the overmolding of differing polymers, as representatively characterized FIG. 48.

Various traction patterns can be devised that use a common modular format. By way of example, FIG. 53 is a perspective view of a flexural chassis having a pattern of concave conic surface-engaging elements formed on its displaceable lobes. FIG. 54 shows the internal side of the same part. The plain template of conic stud chassis 830 is interrupted by intermediating continuous channels 834 and discontinuous channels 836.

The channels separate conic stud chassis 830 into a set of lobes that includes foremost studded lobe 836, side studded lobes 838, rear catch lobes 840, and tailpiece lobe 842. Intermediating continuous channels 834 and discontinuous channels 836 intersect conic stud chassis 830 such that a series of colinear spans 844 is disposed along a median axis. A median axis can be medial, i.e., exhibiting a property of being equidistant, but can be diversely curved, sinuous, or offset, depending on the intended function and the chosen plan of the chassis.

By definition, concave conic studs are solids of rotation in which the generative profile includes a concave curve. In the geometry shown, Two front conic studs 846 are formed upon the foremost lobe of conic stud chassis 830. Two front conic studs 846 are 10 mm in diameter and have a height of 3 mm.

Thirteen primary conic studs 848 are formed so that each stud perimeter is 12 mm in diameter and 4 mm high. All conic studs in conic stud chassis 830 tangent at all points of their circular perimeters with the external surface of the chassis so that they blend continuously with the outer surface.

Mounting and demounting can be obtained through variants of previously described features. Lobed flexural chassis 800 includes conic stud tailpiece lobe 842. Stud tailpiece lobe 850 is geometrically extended to include tailpiece grip tab 850, which in turn carries beveled grip ridge 852 upon its upper face.

Tailpiece wall 854 extends toward the anticipated sole plate, forming a partition between stud tailpiece lobe 850 and stud tailpiece grip tab 850. A symmetrical and opposed pair of snap rails 856 in this example are spatially divided from tailpiece wall 854. Snap rails 856 carry snap rims 858.

Conic stud chassis 830 includes a surrounding set of conic stud chassis offset tabs, collectively represented by leading guide tab 860, side slide tabs 862, and rear catch tabs 864. Rear catch tabs 864 include integral alignment keys 866.

In a manner analogous to previous descriptions, lobed flexural chassis 800 is first entrained about a platen by sliding. Stud tailpiece lobe 850 is then elevated by lifting tailpiece grip tab 850 so that alignment keys 866 can be introduced into a passage such as bypass notch 576 on a platen.

Once the tabs are entrained about a mating platen, flexural chassis 800 and conic stud chassis 830 can be snapped into undercut recesses owing to the rims extending from their tailpieces. Snap rims 850 in lobed flexural chassis 800 are integral to a continuous rear wall, while snap rims 850 are on discrete snap rails 848.

The partition of the snap rail from the back wall permits readier elastic displacement of snap rims 850. This modification adapts the conic studded exemplar design to relatively more rigid materials, which, absent such partition, may not possess sufficient elongation in a continuous rear chassis wall to repeatedly stretch over the rear region of the platen.

Athletic activity includes a wide range of athletic surfaces. Conic stud chassis 830 is suited to athletic play on relatively shallow synthetic turf, on resilient tracks or trails, or wherever deeper studs cannot effectively penetrate, but where a degree of impression is nevertheless anticipated.

Conic studs and low-relief studs are generally observed to be less injurious than deep bladed studs. Nevertheless, the illustrated lobed conic stud forefoot chassis articulates to rotationally differentiate foot location from stud location, so that meaningful relief of rotational stress is provided in the targeted venues.

FIG. 55 is a forward-looking oblique view of perforated interleaving 900 for optional interposition between a forefoot chassis and a corrugated sole plate. For clarity of description, drawings in this specification omit depictions of the optional interleaving. However, its positioning between chassis and sole plates, as well as similar interleaving shaped for placement at the heel, can readily be envisioned throughout the relevant descriptions. Perforated interleaving 900 includes front perforation 902, rear perforation 904, and tool pivot perforations 906. The contour generally follows the form of the relevant platen.

Interleaving can be fabricated from sheet material having friction-reducing properties, such as PTFE or graphite, or may provide a barrier against soiling or fouling of the corrugating channels.

Interleaving 900 can also be reverse-printed or printed by dye sublimation for branding, decoration, or personalization of the product. It may be made of pre-existing materials, and can be devised to exhibit any desired graphic or textural effect. Interleaving can amenably be fabricated from sheet material having thicknesses between 0.25 and 1.00 mm. The chassis and sole plate can include a tolerance in anticipation of interleaving.

In the remaining examples of the disclosed footwear system, a principle is widely applied in which at least one pivot location on the forefoot chassis is left free to turn about its center during bowing of the one or more regulating flexural beams to which it is structurally linked. This foundational structure permits an arrangement of traction elements on the forefoot chassis to rotate clockwise or counterclockwise about the defined center.

A configuration expressly embodied in the disclosure includes a second pivot location so that at least one beam located between the pivots is permitted to articulate. The conscientious application of these principles allows the beam or beams to compress or extend as the pivots orbit about their centers, such that orbital relative stud displacement permitted in the chassis, and such that the articulated traction elements reliably return to a home position when the deformative load is removed.

Realizations are disclosed in which the regulation is provided by a unitary, longitudinal regulating flexural beam. In other embodiments, the regulating function is served by arrays of beams of either straight or curved form. Envisioned embodiments exhibit a variety of oblique orientations and convolute forms. Realizations are therefore also disclosed in which the regulating effect is saved by compound arrays of flexural beams.

In the present workable and exemplary application of the disclosed footwear system, the pinion points are set apart from one another by 30 mm. An effective range for the disclosed class of solutions for a common distribution of adult shoe sizes is 20-60 mm. This spatial interval has been found to usefully divide elastic deformation of the forefoot chassis so that the chassis is reliably retained within the perimeter of the sole plate. This geometrical configuration holds the chassis in close spatial correlation with its mounting, and constrains the stud position to the weighted region under the athlete’s foot.

FIGS. 56-67 inclusive relate to chassis and compatible mounting systems which include an anchoring shoulder bolt. A shoulder bolt is a threaded hardware fastener having an integral collar that has a wider dimension than the threaded shaft. The spatial stopping effect of the collar allows the shoulder bolt to be used as an axle or compression limiter.

The disposition of the threaded component in the assembly and the proportioning of the component parts allows a compatibly devised fore plate chassis to articulate freely upon the imposition of external force. The arrangement provides reliable spatially restrictive mounting, but which also permits a degree of movement, rather than securing the chassis or any of its members to the sole plate.

The exemplary system includes an equivalent shoulder bolt used in anchoring a heel plate. In this instance, the shoulder bolt can either allow a degree of rotational movement, or may hold the center point of the chassis close to its support. In the illustrated examples, threaded metal inserts are structurally fused within a molded polymeric platen or sole plate by the practice of insert molding. Insert molding is widely used in conjunction with adaptable traction systems, such as cleats for turf sports, and spikes for track-and-field events.

A shoulder bolt is a threaded fastener which includes an unthreaded collar as well as a threaded shank. The diameter of the collar is typically greater than the outer thread diameter, so that the threaded shank can be passed through a hole that is compatibly dimensioned so that the collar is seated in the hole and can act as an axle.

The exemplary shoulder bolts in the illustrated example are provided with a 5 mm long M4 thread, and have a collar diameter of 5 mm, a collar length of 4 mm, and have a recess formed in the head to receive a 2.5 mm hexagonal tool. In the disclosed footwear system, the hole length in a receiving polymer part is formed to be 3.8 mm long for when the effect of a rotating axle is desired, and a receiving hole length of 4.2 mm is provided when the parts are to be clamped in a fully fixed relationship.

In the latter case, the collar serves to limit the pressure off the screw head against the polymeric part. This allows the part to be repeatedly installed and removed without locally degrading the polymer. In effect, the compression of the polymer is kept with the range where full elastic recovery of the polymer can occur. The collar of the shoulder bolt also deters bellying of the cylindrical hole, which can cause the polymer part to bind against the collar of the typically metallic bolt.

In this application of the disclosed footwear system, bolts whose heads are provided with a flat underside are preferred, as any bevel on the underside will impart potentially destructive expansive force. Such expansive force can ultimately fissure or split the polymeric material. Low-profile bolt heads are typically preferred in the disclosed footwear system, as extraction forces expressed against the head are relatively small in the targeted uses.

For additional durability, bushings can be insert-molded within relevant locations within the chassis, such that a metal bushing bears against a metal shaft during deformative events. Provision for such added durability can be made according to the projected maximum force imparted during anticipated boundary events experienced by the athlete in the practice of the given sport.

Specific realizations of the disclosed footwear system both headed, threaded hardware fasteners and annular snap fittings within the chassis, in which the snap fittings are disposed about identified pinion points. FIGS. 56 through 59, as well as FIGS. 65 through 74, illustrate forefoot and heel components which are equipped in accordance with this conception within the disclosed footwear system, in which discontinuous annular fittings snap over headed posts located, either on discrete forefoot and heel platens, or on an integral sole plate.

The annular' snap fittings are partly or wholly encompassed by an annular retention feature such as a relief ring. The encompassing relief rings carry the rotational loading during active flexural events, and thereby deter the deflection or inadvertent release of the snap fitting prongs. The necessarily flexible prongs of the snap fittings on the chassis provide a convenient means of operational linkage between the chassis and the rest of the article of footwear, yet the deflectable prongs are shielded from any forces exerted in the field plane during active use of the footwear.

The deflectable prongs are effectively immobilized except during deliberate installation or removal of the chassis on an axis substantially perpendicular to the sole plate. This cooperation of a geometrically divided snap fitting and a geometrically continuous annular pinion therefore provides a convenient and functional result that cannot be achieved by either element alone. FIGS. 56 and 57 illustrate a system accommodating a chassis having paired curved beams and two snap fittings. The chassis is mounted by bending the chassis along its length so that it is sufficiently foreshortened so that tabs can be introduced into undercut recesses. The two discontinuous annular snap fittings are then pressed onto shoulder preinstalled shoulder bolts.

FIG. 56 is a perspective view depicting a flexural forefoot chassis having curvilinear beams and using external tabs two pivots that incorporate discontinuous annular snap features. Rings that extend from the underside of the chassis are installed in commensurate recesses in the mounting platen, and carry any load exerted in the field plane. As a result, snap features are shielded from the experience of any operational stresses beyond their deflection during mounting.

Still referring to FIG. 56, snap-on chassis 910 carries one central leading tab 912 and four opposing side tabs 914. Concave finger grips 916 are located on opposite sides where lifting occurs in the middle to extract the tabs from their end recesses. Radial snap fittings 918 are disposed within discontinuous annular snap fitting 920. Snap fitting flexible beam 922 is located between the two discontinuous annular snap fittings 920. Paired curved beams 924 connect canted studs 926 to the central snap fitting flexible beam 922.

A plurality of canted studs 926, here having a bladed form, are distributed about the perimeter of curved-beam snap-on chassis 910. The top faces of the studs are sloped toward the leading end of the chassis, so that the grip in turf is more pronounced when running forward than when running backward. On the internal side of the chassis, annular pivot rings 928 are connected to discontinuous annular snap fitting 920 by contiguous cylindrical part geometry.

FIG. 57 shows a perspective view of snap-catch forefoot platen 930 having a variety of peripheral bosses, a subset of which includes overhanging flanges devised to partially entrap the peripheral tabs integrated in curved-beam snap-on chassis 910. Snap-catch forefoot platen 930 has external face 932 from which a plurality of open-ended undercut bosses 934 extend. Forefoot platen 930 also includes undercut stopped bosses 936 which are closed at one end to restrict movement of curved-beam snap-on chassis 910 at the chassis’ four opposing side tabs 914, when the curved beams are at a designated limit of deformation.

Blank bosses 938 are located at the sides of snap-catch forefoot platen 930, and serve to provide balance to the wearer and prevent damage to other relief features in the event of inadvertent weighting of the platen when no chassis is mounted on the article of footwear. Counterbored forefoot platen mounting holes 940 are located near the perimeter of snap-catch forefoot platen 930.

Pivot ring recesses 942 are commensurate with annular pivot rings 928 in curved-beam snap-on chassis 910. Flush molded-in threaded inserts 944 receive shoulder bolts 946. Shoulder bolts and threaded inserts within the disclosed footwear system are typically metallic in composition.

FIG. 58 shows flexural heel snap-on chassis 950 that includes one traverse tab 952 and two longitudinal tabs 954. Curved heel snap fitting beams 956 connect central discontinuous annular heel snap feature 958 to bladed snap-on heel studs 960.

FIG. 59 is a perspective view of snap-on heel platen 970 having primary heel platen face 972 and a set of undercut bosses extending outward therefrom, including symmetrical undercut internal bosses 974, transverse undercut boss 976. Blank side bosses 978 are included for stability in case the article of footwear is worn absent any chassis.

The set of overhanging heel flanges is devised to partially entrap the peripheral tabs incorporated in flexural heel snap-on chassis 950. Arcuate blank bosses 980 extend from primary heel platen face 972 and occupy a portion of the open loops of flexural heel snap-on chassis 950 so that arcuate blank bosses 980 restrict rotary motion of the central region of flexural heel snap- on chassis 950. Snap-on heel platen ring recess 982 in concentric with molded-in threaded heel insert 984.

Heel shoulder screw 986 is installed in molded-in threaded heel insert 984, and for convenience can be of the same dimensions as shoulder bolts 946 used in the preceding forefoot assembly.

Snap-on chassis arrows 988 indicate the instructive direction for chassis mounting. Chassis icon 990 indicates the correct relative chassis orientation for installation. Numerical indicator 992 identifies the heel platen type in series where the heel platen is interchangeable on the shoe. Counterbored heel holes 994 allow mounting of the platen to an amenably devised sole plate. An amenable sole plate would typically carry molded-in threaded inserts at locations corresponding to counterbored heel holes 994 and forefoot platen mounting holes 940.

To prepare installation of the chassis, snap-catch forefoot platen 930 and flexural heel snap-on chassis 950 are mounted on an amenable sole plate via their countersunk mounting holes. It may be appreciated that any application of the disclosed footwear system using separate a detachable platens may equally be formed monolithically into a continuous sole plate, may be ovcrmoldcd of differing materials, or, equally and alternately, may be of separate components that are permanently assembled into an article of footwear by welding, adhesion, stapling, staking or other accepted means.

To operate the forefoot component of the preceding implementation of the disclosed footwear system, curved-beam snap-on chassis 910 is manipulated into an arched tape so that its absolute longitudinal dimension is foreshortened to a chord less than its original length. Central leading tab 912 and four opposing side tabs 914 are then slipped under open-ended undercut bosses 934 and undercut stopped bosses 936.

At this stage interference between radial snap fittings 918 and shoulder bolts 946 leaves curved-beam snap-on chassis 910 in a deflected state, with radial snap fittings 918 and shoulder bolts 946 in concentric and aligned positions. Radial snap fittings 918 are then pressed over the heads of shoulder bolts 946 into an engaged state. Annular pivot rings 928 become seated in pivot ring recesses 942.

In use on the field, annular pivot rings 928 carry the preponderance of any load imposed in the field plane, as when the chassis is articulating in response to a turned foot. The two- dimensional restraint at two pivot points allows snap fitting flexible beam 922 to bend, which relieves stresses on the relatively longer and lighter paired curved beams 924. Undercut stopped bosses 936 actively delimit the travel of the flexed extremities of the chassis, and deter overextension of the articulating studs which could lead to premature part fatigue.

Flexural heel snap-on chassis 950 is mounted on snap-on heel platen 970 by introducing transverse tab 952, two longitudinal tabs 954, beneath undercut internal bosses 974 transverse undercut boss 976. The chassis is manipulated through a slight deflection and rotation, and the prongs of central discontinuous annular heel snap feature 958 pressed over heel shoulder screw 986. The heel chassis can then articulate as the heel of an active athlete is moved while the heel is engaged in the ground.

The configurations embodied in FIGS. 56-59 employ internal and external tabs in combination with snap fittings. An aspect of discontinuous tabs so formed that the mounting system does not require a raised central platen. The system can therefore be made to conform to a lower assembly profile, and thereby provide a relatively intimate connection with the playing surface. FIG. 60 illustrates modular intersected forefoot platen 1000 that includes a partial sectioning applied to a raised, undercut platen so that a compatible chassis can be flexural entrained about the resulting separate and nearly contiguous flanges. Modular intersected forefoot platen 1000 includes platen foundation plate 1002, intersected forefoot platen base layer, and raised platform such that a peripheral flange is generated about its perimeter, the platen including a leading pivot feature having a recessed ring and an annular detent, and also including a trailing pivot having a recessed ring and a central threaded insert.

In principle, modular intersected forefoot platen 1000 follows the conceptual model of mounting platens illustrated in FIGS. 24, 25, 32, and 33. The current example differs in part in that the trailing edge of the cap plate is convexly arcuate in the field plane, so that arcuate mounting features can be entrained about the cap so that arcuate motion about a pivot located toward the trailing end of the assembly is permitted. This configuration allows degrees of freedom of motion within a diverse set of envisioned modular traction components.

As shown, modular intersected forefoot platen 1000 includes intersected forefoot platen external face 1002, intersected forefoot platen mounting holes 1004, intersected forefoot platen mounting stepped countersinks 1006, intersected forefoot platen base 1008, intersected forefoot platen cap 1010.

The contour of the base and cap includes an extended tab at the front and a slight waist toward the middle of the generally oblong shape. The extended tab allows articulating front studs on the installed chassis to bypass articulating side studs. The waist anticipates modes of chassis operation. In particular, the waist allows a subset of articulating side studs to shift transversely upon a side impact, or upon a complex flexure of an installed chassis.

Platen intersections 1012 divide the layers exemplified by intersected forefoot platen base 1008, intersected forefoot platen cap 1010 into divided lands 1014 so that the platen is made flexible. Leading recessed ring 1016 is accompanied by relatively shallow indented ring detent 1018. Intersected forefoot platen insert 1020 is molded into the polymeric platen to provide internally-tapped metal threads to receive a compatibly dimensioned shoulder bolt. Trailing recessed ring 1022 is given a larger diameter than leading recessed ring 1016 so that during installation of the chassis on the platen the larger ring will not prematurely engage in a receiving recess or embossed detent. Size indicia 1024 allows a maker, assembler, or end user to match a demountable platen to a shoe size. Embossed unlock icon 1026 indicates the direction of displacement required to decouple the chassis from the platen. Numbered instructional arrows indicate the steps required to engage or disengage the chassis from the platen.

FIG. 61 is a perspective view of a chassis compatible with the mountings included in the forefoot chassis shown in FIG. 60. The chassis includes a medial beam, a medial stud, and a surrounding serpentine beam network incorporating convoluted loops connecting the medial components to a set of peripheral studs. FIG. 62 is an underside perspective view of the chassis shown in FIG. 61.

Convolute bladed chassis 1030 includes canted side blades 1032, canted leading blades 1034, and medial arcuate bladed stud 1036. Countersunk bolt through-hole 1038 is located at the trailing end of flexural spine beam 1040. Upper guides 1042 and lower guides are structurally separate but devised to be able to bypass one another during active articulation of the chassis.

Flexible keepers 1046 are devised to intermittently engage with the undercut channel between the mounting plate and bear against the cantilevered edge of intersected forefoot platen cap 1010. In use, the keepers carry a light spring force which keeps them in a relatively constant position relative to the platen cap. Integral keeper tabs 1048 engage with the undercut channel and assist in keeping the chassis in close but structurally guided relationship with the receiving platen.

Convolute beam array 1050 includes a series of discrete loops 1052 arranged into a substantially continuous arrangement. Stub beams 1054 connect discrete loops 1052 within convolute beam array 1050 to canted side blades 1032 and canted leading blades 1034. Bell- curved yoke 1056 is provided at the trailing end of the chassis to allow for reduced stress and increased transverse articulation. Beam marking 1058 here indicates a spring force value, so that the approximate relative flexural resistance of the component can be readily identified or referenced.

Tool channel 1060 is formed across the chassis components so that a bladed removal tool such as a screwdriver is directing into a prying position, with the shank of the tool seated in a concave channel, and the flat blade seated in a rectangular recess under medial arcuate bladed stud 1036. Raised leading pivot ring 1062 is centered about concentric hollow 1064. Raised trailing pivot ring 1066 surrounds the underside exit of countersunk bolt through-hole 1038. Stud hollows 1068 reduce weight, accelerate molding, and discourage the warping and surface defects that can occur as result of excessive wall volumes. Stud hollows also reduce friction between articulating elements when the product is in active use.

In the operation of the preceding embodiment of the disclosed footwear system, all tabs except the rearmost pair are slid under the cap in the direction indicated by unlock icon 1026, deforming and elevating the center of the chassis under a spring force. Convolute bladed chassis 1030 is then slid past its final position, as suggested by the first numbered directional arrow. At this stage, the leading ring bypasses its commensurate recess and is momentarily held by annular ring detent 1018 by the inward spring force.

In this momentary relationship, the rearmost tabs can be flexed outward and under the cap, as suggested by the second instructional arrows. The chassis is then moved forward until the rings are sprung into their captive position by the release of chassis’ spring force. A shoulder bolt is passed through countersunk bolt through-hole 1038 and made captive by the internal threads of intersected forefoot platen insert 1020. The chassis is then reliably but moveably captive upon the platen.

The relatively constant curvature of convolute beam array 1050 decreases the ratio of compression and extension imposed on opposite sides of the flexural beams. This configuration increases the maximum force that can be usefully imposed on the chassis for a material of a given flexural modulus and elongation at break.

The examples shown predominantly accommodate rotational foot motion, but provide some mitigation of side impact forces. This conceptual template can be used to derive diverse chassis patterns that differ in the orientation of the loops and their mounting locations relative to corresponding mounting features in the given chassis.

FIG. 63 and FIG. 64 provide two descriptive views of lobed snap-on chassis 1070 devised as a component in the comprehensive modular system. The comprehensive system enables diverse traction chassis to be installed or interchanged on modular intersected forefoot platen 1000 shown in FIG. 60. This conceptual foundation encompasses chassis exhibiting diverse forms and employing diverse material compositions. FIGS. 63 and 64 show a ribbed traction chassis having lobes which include integral ribs, devised so that they can be mounted on the same fore plate as that provided for the anchorablc fore plate chassis of FIGS. 56 and 57. The studs exhibit a shape that is colloquially referred to in the making of athletic footwear as a chevron. Chevrons can have an overt V or Y shape, but the class generally includes any stud exhibiting an abrupt or conspicuous geometrical deviation in its profile. Chevron studs are generally perceived as intermediate in aggressiveness between conic studs and bladed studs.

Lobed snap-on chassis 1070 includes a set of snap-on chassis lobes 1072. Lobed snap-on chassis 1070 is bilaterally asymmetrical to conform to the asymmetries of the human foot. Snap- on chassis lobes 1072 are disposed about medial bending beam 1074. Lobed snap-on chassis 1070 is surmounted by integral brachiate ribbing 1076. Raked chevron studs 1078 are located along each side of the chassis. Two low blunted front studs 1080 are located on the foremost lobes. Two stellate pegs 1082 are located along medial bending beam 1074.

The trailing region of lobed snap-on chassis 1070 includes tail lobe 1084, tail extension 1086 and a set of tail grip ridges 1088. Tail lobe wall 1090 integrates three snap tabs 1092 that extend inward toward medial bending beam 1074. Leading alignment ring 1094 and trailing alignment ring 1096 dimensionally correspond to leading recessed ring 1016 and trailing recessed ring 1022 in modular intersected forefoot platen 1000. Inward-facing tabs 1098 are disposed about the front and sides of lobed snap-on chassis 1070.

To install lobed snap-on chassis 1070 on modular intersected forefoot platen 1000, all inward-facing tabs 1098 except the rearmost pair are slid under the undercut extension of intersected forefoot platen cap 1010. Tail lobe 1084 is lifted, and each of the rearmost lobes is flexed about medial bending beam 1074 so that each of the rearmost tabs is successively introduced into the platen channel.

Three snap tabs 1092 are then pressed over the rearmost region of the cap. The gaps between the tabs allow the tabs to independently deflect. Depending on the rigidity of the polymer composition, gaps can be electively extended to partition tail lobe wall 1090. The tail lobe is snapped in place, and its location provides an operational boundary that prevents overextension of the lobes that might induce accidental release of the mounted chassis.

The geometry of tail lobe wall 1090 is specific, in that its arcuate shape devised to be concentric with trailing alignment ring 1096. In the active articulation of the lobed chassis, medial bending beam 1074 obtains various curved states that cooperatively induce local and momentary rotations about trailing alignment ring 1096. The concentricity of tail lobe wall 1090 and its associated structures exemplified by snap tabs 1092 allows the tail lobe to articulate in an unobstructed fashion. This configuration therefore reduces internal stresses and provides the assembled flexural mechanism with greater attainable angular range.

Corresponding heel components can be provided within the disclosed footwear system for any forefoot configuration, although the smaller area can impose design constraints. It may be appreciated from the examples disclosed in this specification that diverse pairings of heel and forefoot components are enabled.

FIG. 65 shows kinetic heel platen 1100 for compatible use with convolute heel chassis 1120 having a keyed annular recess so that the center of a compatible chassis can be discouraged from rotation about its center point. As in previous examples of the disclosed footwear system, a chassis and platen are mutually manipulated so that a flexural chassis is dependably captured upon the affiliated platen.

This process typically involves imposing a degree of deformation to the chassis, but can also involve deformation of a monolithic sole plate or attached platen components. Chassis formed according to the disclosed footwear system can be mounted by two-dimensional distortions in the field plane, but commonly involves localized lifting and deformation of a chassis out of the field plane. In the disclosed footwear system, intentional interferences momentarily require a manually imparted deformative force until interfering relief elements are aligned and a more relaxed mutual state is obtained. The articulating component is then enabled to operate while retained in a captive condition. Manipulation of this kind may occur directly by hand or indirectly by the use of a tool.

In accordance with the foregoing principles, FIG. 65 depicts keyed heel platen 1100. FIG. 66 shows an external perspective view of a bladed serpentine keyed heel chassis 1120 devised to be mountable and demountable on keyed heel platen 1100 by a specific process of three- dimensional deformation in combination with a rotating action. FIG. 67 is an underside perspective view showing keyed ring 1122 geometrically commensurate with the keyed annular recess 1112 at the center of the keyed heel platen 1100.

Features of keyed heel platen 1100 in FIG. 65 include external platen face 1102, keyed platen base 1104, and keyed platen cap 1106. Keyed platen base 1104 provides a spacer so that undercut keyed platen cap 1106 stands off from external platen face 1 102. Keyed platen base 1104 also includes stops that reinforce keyed platen cap 1106 and expressly limit articulation of the installed chassis. Keyed platen mounting holes 1108 provides a mechanism of operational engagement. As generally noted, platens have been routinely realized within the disclosed footwear system as integrally molded features within a monolithic or composite sole plate.

Keyed platen threaded insert 1110 is captured in the molding process with sufficient adhesion and interferences that a suitable dimensioned shoulder bolt can be repeatedly installed and removed without disengagement of the molded-in metal part from the surrounding polymeric volume. Keyed annular recess 1112 includes a circular trough and a linear trough extension extending from the circular region. Instructional indicia include orientation insignia 1114, unlock insignia 1116, and directional insignia 1118.

FIGS. 66 and 67 illustrate details of serpentine keyed heel chassis 1120. At its center, keyed heel chassis 1120 includes shoulder bolt through-hole 1122. Keyed heel chassis convolution array 1124 includes an arrangement of individual but interconnected looped heel beams 1126. As in other examples, beams are furnished with beveled edges 1128 that promote crimping and gripping of natural or artificial grass blades by the network of flexural beams.

Keyed chassis blades 1130 are proportioned for useful traction laid out at effective locations. Keyed chassis tabs 1032 extend inward from keyed chassis blades 1130. Stud bridge 1134 includes heel tool channel 1036. Tool recess reinforcement 1138 is proportioned to receive the blade of a tool such as a screwdriver. Keyed ring 1140 includes an annular key portion 1142 and linear key extension 1144. Keyed heel stud hollows 1146 reduce weight and wall thickness.

In the operation of this implementation of the disclosed footwear system, serpentine keyed heel chassis 1120 is located against keyed heel platen 1100 in the orientation suggested by the pointed end of unlock insignia 1116. Keyed chassis blades 1130 are deflected downward about the heel cap, and the chassis turned until keyed ring 1140 aligns and engages with keyed annular recess 1112 under the release of the spring force that has been momentarily imposed. Lineal' key extension 1144 discourages any significant rotation of the chassis relative to the chassis.

Once engaged, the joined parts can be held in intimate proximity by a retaining shoulder bolt. M4 shoulder bolts with a 4 mm shoulder have been successfully used in combination with various chassis within the disclosed footwear system. Threaded shanks extending 4-5 mm from the shoulder provide a suitable connection with inserts molded into a polymeric platen. As noted earlier, the spatial stopping effect of the collar of a counterbored hole allows the shoulder bolt to be used either as an axle or compression limiter. In an articulating forefoot mechanism, the chassis is commonly intended to turn about such a pivot.

In a heel mechanism embodiments such as the current example, it can be useful to affix the chassis at a center point. This can be realized by providing the shoulder-receiving portion of shoulder bolt through-hole 1122 with differing lengths. A hole length of 3.8 mm has been found suitable for allowing motion in bolts with a 4 mm shoulder, while a hole length of 4.2 mm allows the head of the shoulder bolt to impart a clamping effect, without overstressing or fracturing the material surrounding the hole. This differentiation of the hole length allows a single bolt size to conveniently provide two distinct functions.

To separate the chassis from the platen, the security bolt is removed. A tool such as a bladed screwdriver is inserted into tool recess reinforcement 1138 and turned toward unlock insignia 1116 in following the arrows provided by directional insignia 1118. Contact between beveled walls of keyed ring 1140 and keyed annular recess 1112 induces the central region of keyed heel chassis 1120 to elevate out of the field plane, until the chassis can be turned under the influence of the tool blade and shaft. Once the chassis has been turned to align with directional insignia 1118, the chassis will clear keyed platen cap 1106 and the chassis separated from the platen.

It may be generally understood that the implementation of disclosed footwear system yields a range of molded components that are deliberately devised either to impart or receive spring forces during installation, operation, or disassembly of the disclosed footwear system’s constituent parts. Furthermore, it has been found useful in the interest of the consistency of performance for the joined parts to remain in intimate proximity. To serve this end, it has been found useful to implement complex geometries that provide a fluidity of articulation.

In the interest of enablement, the following schematic figures illustrate methods for deriving freeform geometries that have been usefully applied within the disclosed footwear system. The geometrical forms can be informed by both anatomical and technical parameters, as the geometry of the human foot is complex, and its shape within an article of footwear fluctuates during use. Accordingly, it can be a challenge to derive adaptive sole plate geometries that actively and responsively conform to the changing foot configuration. The disclosed footwear system as detailed in the preceding depictions has included diverse adaptations providing for such conformity. The immediately following descriptive figures specifically illustrate one exemplary sequence of geometrical originations that have been found constructive in the practical implementation of the disclosed footwear system.

In this method, the construction of the foundational model includes the two steps of generating a first volume and a second volume and computationally intersecting those volumes to identify a third volume. This derived volume then serves as a foundational substrate for traction features and other functional components.

An example of a first volume may be understood by reference to the sectioned shell illustrated in FIGS. 68 and 69. The complete shell is shown in FIG. 70. The figures collectively represent a preparatory computational model in the form of crowned shell 1150, in which a first volume has been derived by sweeping a curved figure 1154 about a medial racetrack-shaped path 1152.

The first volume can be a simple bounded shell having a constant thickness. However, in accordance with diverse design targets, bounded shells in the disclosed footwear system have been intentionally originated to exhibit variations in shell thickness commensurate with the anticipated functional demands of the static or articulating part.

The designation of flat medial areas allows radial relief features to be raised from the flat areas set aside for that use. The remainder of the crowned volume is then free to be tailored to other design requirements. In realized embodiments, the flat area is given a “racetrack”, “stadium”, or “discorectangular” shape. All of these terms refer to an elongate-shape defined by two semicircles connected by two uncrossed lines. This shape is useful within the disclosed footwear system, as it inherently provides flat lands for two pivot locations.

Other generative shapes can be used as the path for a swept volume. An ellipse is formally defined as a shape having two foci, an oval or ovate shape is a mathematically indefinite bilaterally symmetrical elongate shape of continuous but varied curvature exhibiting more acute curvature at one end than the other. Path profiles consisting of tangent arcs or splines can also serve within the disclosed footwear system.

For most applications, the presence of two arcs disposed to express bilateral symmetry about a line connecting their centers has been considered to provide a sufficient and workable basis for enabling the pivoting features that regulate the flexural operation of the chassis. This shape is useful within the disclosed footwear system, as it also provides natural centers for two pivot locations.

In the particular example shown, the computational sweeping process expressly defines an oblong shell having varied thickness. In the example, the sheet is thicker toward the center and exhibits a curved, continuously tapered reduction in thickness toward the perimeter. Oblong filler extrusion 1156 is geometrically continuous with crowned shell 1150, but has parallel faces, and so provides a flat volumetric region of constant thickness in the central region of the shell.

Crowned shell 1150 therefore defines a body which includes a first face that is externally convex, and a second face that is externally concave. A first volume is enclosed by the definition of a finite edge that bridges the two major faces.

Any component in which any section displays a domed shape such as the one example typified by crowned shell 1150 may be termed a crowned component. The definition includes any three-dimensional volume that has an externally convex sectional contour opposed with an externally concave sectional contour.

The broader definition therefore includes mathematical volumes incorporating saddle shapes, toroidal surfaces, bell shapes, and other surfaces blending or integrating locally convexities and concavities. Practical implementations within the disclosed footwear system include volumes with parallel faces, regions with skewed faces, and volumes with convex geometrical surfaces blended with regions of flat or concave geometry.

Such shells in implementations of the disclosed footwear system have included local thicknesses from 1 mm to 8 mm. The local thickness can be even greater, for example, if the designer intends to later develop relatively deep traction features by computational subtraction from this first volume. More typically, a foundational chassis preform is derived having beam thicknesses between 2 mm and 4 mm.

FIG. 70 is a schematic perspective view of the geometrical model of the volume illustrated in FIGS. 68 and 69 interposed with a second computational volume in the form of convolute extrusion 1160, here derived for a serpentine chassis. FIG. 71 is a schematic perspective view of subtractive computational volume 1070 identified by the intersection of convolute extrusion 1160 with the combined contiguous volumes of crowned shell 1150 and oblong filler extrusion 1156. The generative profile of the second volume can include curves and lineations anticipativc of beams, lobes, armatures, or other contours relating to the eventual locations of pivots or studs.

Convolute extrusion 1160 is generated by computationally extruding such a chassis preform profile through an elected --axis dimension. The second volume can be extruded in either a linear or tapered fashion. In the disclosed footwear system, a taper between 1° and 5° is commonly applied to this second volume in order to generate an intrinsic draft angle for efficient mold extraction. When the chassis is apertured, the taper is normally applied independently to the sidewalls of each aperture. Tapering is typically generated to yield a consistent wall angle in the model based on the relevant aperture or contour.

Returning to the model illustrated in FIG. 71, subtractive computational volume 1170 defines oblong center land 1172, convolute array model 1174, convolute model loops 1176, trailing yoke model 1180, leading bar model 1082, and leading bridge model 1084. These model shapes anticipate features of the physical product. Subtractive computational volume 1070 serves as a foundation for additive or subtractive volumes relating to additional features.

For example, additional beam stiffness can be locally built onto this foundational armature by the addition of a ribbed structure so that the eventual beam depth is between 3 mm and 6 mm. Among the effects of such beam array crowning is that, once installed, the chassis perimeter bears with a spring force against the bottom of the shoe.

In such cases, in use, the peripheral region of the part is drawn down against the shoe, typically by the cooperative influence of such means as restrictive structural interleaving of tabs and flanges, or by fittings such as snaps, screws, or bolts. Advance reference to FIGS. 73, 7477, and 78 provide an example of a crowned chassis using two cooperating central snaps to hold the chassis substantially flush with its chassis throughout a range of sole plate flexure and chassis articulation.

The exemplary forefoot chassis being derived includes a yoke at the trailing end that provides a mounting mechanism and efficient accommodation of elongation stress. The yoke is intermediate in the transverse axis between the rearmost pair of studs, and free of direct connection with the spine of the anchored forefoot chassis.

This configuration allows the yoke to travel both flexurally and slidingly within a permitted spatial range. This arrangement allows the chassis to be steadily drawn down against a platen, while providing a mounting strategy that relieves stresses that would be imparted by any sort of absolute fixation. The trailing portion of the chassis is free to rotate, so long as the yoke and its receiving catch are arcuate and concentric with a predetermined pivot location.

A useful aspect of providing a catch on a flexural yoke is that the gripping force between the chassis and platen can be arranged to increase when the sole plate is flexed. This effect draws the chassis tight against the sole plate at moments of activity when it is most exposed to stresses that might result in accidental release. Once active deformation is relieved, the chassis typically returns to its rest state, and so does not suffer the degrading effects of a part held in a state of protracted strain.

Applied more generally, by conscientious initiation of the constituent and generative curves, paths, and axes, the real-molded volume can be derived so that it bears against the sole plate at certain preferred locations and under certain conditions. Contact locations between the chassis and the sole plate can be made to occur such that the assembled components meet and are held in a substantially relaxed state.

Alternately, the geometrical relationship can be devised so that meeting surfaces at chosen locations of the chassis bear against the sole plate under a precalculated spring force. The geometry can be chosen so that a spring force exerts a static or dynamic load. Creep-resistant semicrystalline polymers are often chosen when a part is held in a loaded state over a period of extended duration.

Because there is a degree of independence of the surfaces in contact, such effects can include rotation, rolling, sliding, deflection, entrapment, or stopping within the same progressing event involving the relevant meeting surfaces. The onset of a given effect may be made gradual by the geometry of the design, so that footwear applying serial phased resistance will not necessarily be perceived by the athlete as having a stepped or quantized resistive action.

When the chassis is preformed to a curved shape by crowning, stress is typically reduced throughout the chassis during its active articulation and deformation. The chassis can be shaped so that it is prestressed, namely, so that its curvature exceeds that of the part in its static condition, such that the part exerts a constant spring force in its entrapped but inactive state.

Shaping of the chassis can reduce or equalize frictional forces at locations which involve sliding or rotating movement expressed between engaged pails. Results that are attainable by the application of a crowned flexural chassis include increased exclusion of contaminants and reduced risk of part lifting, separation, or breakage.

Expressly-imposed crowning curvature can also impart useful local deflection, for example, to tabs, flanges, or any other such internally or externally retentive, so that the chassis can be easily aligned and mounted on the commonly curved bottom of the shoe. The crowning curvature can be devised to reduce the amount of deflection or deformation needed to manually mount the chassis on the footwear.

Crowning also reduces the athletic effort needed to deflect the composite sole assembly, so can increase responsiveness and reduce bodily fatigue. Accordingly, chassis crowning by the approach described can be enlisted to increase comfort and extend effective part life.

It may be noted that the crowning of the chassis can be performed so that it does not interfere with the mold extraction or ejection. The studs may be geometrically extruded or lofted from the relevant surface of the chassis so that their sloped sides exhibit adequate draft. In such cases, the stud prominences may possess a slight obliquity to the crowned surface in order to provide sidewalls having consistent draft angles. It may also be noted that parts can be obliquely or flexurally extracted from a mold, and that a halved injection mold with a linear closure is only one of many forming options to which the disclosed footwear system is amenable.

The flat medial region of constant thickness enables operational functionality within the disclosed footwear system. The opposing internal and external faces of the flat medial region are locally parallel, but their outer bounds are locally tangent to, and geometrically continuous with, the curved surfaces that define the crowned geometrical volume. The practical result of this geometrical configuration is that any mutually engaged pivot features having radial concentricity, if located within the flat medial region, can be induced to rotate freely despite the compound curvature of the surrounding surfaces.

FIG. 72 is a perspective view of a threaded insert devised for use in injection molding within the disclosed footwear system. The illustrated insert component integrates a threaded insert with a tapered standoff. Threaded standoff insert 1190 includes cylindrical standoff collar 1192, standoff internal thread 1194, conic external surface 1196. Knurled tabs 1198 conspire to discourage rotation or extraction of the insert.

Metal inserts are typically designed to be flush with the molded part so that the insert acts as a shutoff to prevent injected polymer from filling the inner threaded volume. The disclosed footwear system extends this utility by providing an external taper that can serve as a shutoff by tooling a compatible recess in the mold to match its taper. The insert then acts somewhat as a self-aligning mold pin, which prevents the metal insert from marring the facing mold half.

Shoulder bolts are typically individually machined to produce a precise shoulder.

Because the insert includes a tapered extension that allows the insert to serve as an intrinsic mechanical spacer, standard screws, in combination threaded standoff insert 1190 can be used in place of shoulder bolts and conventional threaded inserts. In this role, the tapered inserts can be used both as axles and as compression limiters, depending on the exact part design.

FIGS. 73-84 illustrate variations of platens and chassis demonstrating variations of the principles detailed in previous examples. These designs employ annular snap fittings within the chassis which are disposed about identified pinion points.

The subset of these designs described in FIGS. 73-78 inclusive illustrate forefoot and heel components which are equipped with discontinuous annular snap fittings that snap over headed posts located on platens or on an integral sole plate.

The annular snap fittings are partly or wholly encircled by annular retention feature such as a relief ring. The encompassing relief rings carry the rotational loading during active flexural events, and thereby deter the deflection or inadvertent release of the snap fitting prongs. The necessarily flexible prongs of the snap fittings on the chassis provide a convenient means of connection between the chassis and the rest of the article of footwear, yet are shielded from any potentially distortive forces exerted in the field plane during active use of the footwear.

Deflectable prongs are effectively immobilized except during deliberate installation or removal of the chassis on an axis substantially perpendicular to the sole plate. This cooperation of a geometrically divided snap fitting and a geometrically continuous encircling pinion therefore provides a convenient and functional result that cannot be achieved by either element alone.

FIGS. 73 and 74 illustrate quadruple snap forefoot chassis 1200. Quadruple snap forefoot chassis forefoot 1200 includes both discontinuous annular snap fittings and leading and trailing arcuate operationally linking features. Its crowned beam geometry has been directly derived by the computational sequence schematically described in FIGS. 68 through 71 inclusive.

Quadruple snap forefoot chassis 1200 is furnished with paired front studs 1202 connected by chassis bridge 1204. Six longitudinally oriented studs 1206 are located at the periphery of the chassis. Front fender 1208 is arcuate and serves to cover the foremost undercut opening in the accompanying platen during articulation. Compound coil array 1210 imparts in-plane compliance to paired front studs 1202 and longitudinally oriented studs 1206 via coils 1212 and beveled pinch rib 1214.

Each snap ring 1216 includes six sectional beams 1218 shaped and oriented to surround and capture a rounded screw head. Flexural connector beam integrally joins two snap rings 1216. Trailing yoke 1222 carries first arcuate button 1224. Second arcuate button 1226 is located on compound coil array 1210 between first arcuate button 1224 and the rearmost of snap rings 1216. Outer yoke catch tab 1228 extends forward from trailing yoke 1222. Inner yoke catch tab 1230 extends rearward toward outer yoke catch tab 1228.

Annular pivot collars 1232 extend from the undersurface of quadruple snap forefoot chassis 1200. Front guide tab 1234 includes guide catch 1236. Front fender 1208, front guide tab 1234 and guide catch 1236 are all arcuate and concentric with the foremost of the two annular pivot collars 1232. Mold hollows 1238 are formed in the underside of paired front studs 1202 and longitudinally oriented studs 1206.

FIGS. 75 and 76 depict combination heel chassis 1250. Combination heel chassis 1250 incorporates both bladed and conic stud geometries. Heel coil set 1252 includes individual heel coils 1254 disposed in an array. Conic posts 1256 are integrally formed with bridge blades 1258. Core snap fitting 1260 is located at the functional center of the part. Wide bridge tab 1262 and short bridge tabs 1264 provide a capture structure . Heel guide collar 1266 encircles core snap fitting 1260.

FIG. 77 shows molded integrated sole plate 1270 which includes integral fore plate 1280 and integral heel plate 1290. Integral fore plate 1280 and integral heel plate 1290 are respectively interoperable with quadruple snap forefoot chassis 1200 and combination heel chassis 1250.

Integrated sole plate 1270 includes forefoot support 1272, heel support 1274, arch support 1276, and seating rim 1278. Perimeter spacer posts 1282 intermittently surround integral fore plate 1280. Undercut nosing 1284 is located at the front of integrated sole plate 1270. Recessed centration annuli 1286, surround cup-shaped annuli 1288 which extend above the primary plane of integral fore plate 1280. Each cup-shaped central annulus 1288 is thermoplastically coupled with an instance of metal threaded standoff insert 1190.

The mounting mechanism include two-sided forefoot internal catch flange 1292 and heel external catch flanges 1294. Cylindrical anti-rotation posts 1296 act as stops to prevent unwanted tuming of a compatible heel chassis such as combination heel chassis 1250. Round head hex screws 1298 arc installed in threaded standoff inserts 1190 to provide three discrete linkage locations.

To mount combination quadruple snap forefoot chassis 1200 upon integrated sole plate 1270, front guide tab 1234 is introduced into undercut nosing 1284 so that its top surface is briefly pushed up so that guide catch 1236 engages the void beneath the nosing. At this stage, the chassis is lightly captive on the platen, and is readily aligned so that sectional beams 1218 within snap rings 1216 can be made to expand over the convex heads of round head hex screws 1298 by applied pressure.

Combination heel chassis 1250 is held in its retained and relaxed state in an analogous fashion. Wide bridge tab 1262 and short bridge tabs 1264 are introduced into heel external catch flanges 1294. Chassis heel coils 1254 are fitted over anti-rotation posts 1296 to complete the mounted configuration shown in FIG. 78.

FIG. 79 shows demountable fore plate 1300 which uses only integral polymeric features for operational linkage. FIG. 80 is an underside perspective view of the demountable fore plate shown in FIG. 79. Demountable fore plate 1300 includes demountable fore plate panel 1302, demountable fore plate mounting holes 1304, demountable fore plate posts 1306, and tool fulcrum post 1308. Demountable fore plate nosing 1310 includes nosing undercut cap 1312 and front molding port 1314. Demountable fore plate catch 1316 includes fore plate catch lip 1318. The economical formation of catch lip 1318 is aided by catch lip port 1320 which is formed through the part. Tool fulcrum post 1308 includes concave tool fulcrum 1322 in axial alignment with fore plate catch 1316.

In this instance of the disclosed footwear system, circular guides include circular post 1324, intermediate circular channel 1326, and concentric relief ring 1328. Circular post 1324 and concentric relief ring 1328 are raised relative to demountable fore plate panel 1302.

On the underside, reinforcing perimeter land 1330 adds depth and strength so that screws or bolts can have their heads countersunk to an extent that they do not interfere with the in-plane movement of an articulating chassis. Namely, the top of the heads of the threaded hardware sits below the external face of demountable fore plate panel 1302.

Island reinforcements 1332 provide local structural support for demountable fore plate catch 1316 and one mounting hole 1304. Two spacer rings 1334 assist in preventing the two sets of circular guides from receding in response the weighting of the foot during active exercise of the footwear prevents demountable fore plate panel 1302.

The recommended hardware for the illustrated operational linkage method includes the broad class fasteners having a head with a flat underside. Threaded fasteners having heads bearing beveled undersides are known to impart a ramping effect that spreads the surrounding material if overtightened. This ramping can lead to premature failure of a polymeric part. Accordingly, the term countersunk should therefore be understood throughout these discussions to include any hardware configuration that seats any pail of the head of a fastener into a receiving volume of material.

As in prior realizations, the part is aligned with prevailing molding and operational advantages by local reductions of polymeric mass. Molded internal offset 1336 and molded internal voids 1338 are provided at suitable locations.

FIGS. 81 and 82 illustrate a convolute chassis compatible with the demountable fore plate shown in FIGS. 79 and 80. Shielded convolute chassis 1340 mirrors previous examples in many aspects, but integrates additional functional features.

The leading end of the exemplary shielded convolute chassis 1340 includes features regularly proposed within the disclosed footwear system such as coupled front studs 1342, and independent side studs 1344. In general, articulating structures, unlike fixed structures, tend to naturally loosen debris owing to the constant reforming of their geometry.

In certain circumstances, for example, in damp, loose, natural turf - relatively larger openings can lead to packing of plugs of material into the chassis that exceed the scale that is otherwise ejected. In this embodiment, obstructive features are included that discourage the accumulation of debris in the larger interstices of the chassis’ convolutions.

Here, front excluder 1346 is formed integrally in the vicinity of coupled front studs 1342. Side excluders 1348 are integrated in dependent side studs 1344. Both are provided with convex, geometrically blended surfaces so that any momentarily trapped material is directed outward from the chassis. High pivot stud 1350 and low pivot stud 1352 surmount the pivot points of the chassis. A numerical resistance rating and an alphabetical turf abbreviation adjacent to the central studs guide the user in selecting an appropriate chassis for the field condition.

Convolute beam network 1354 includes a collection of alternating loops 1356 that arc surmounted by tread ridge 1358. Axial flex beam 1360 extends between high pivot stud 1350 and low pivot stud 1352. As in previous examples, the chassis arrangement incorporates a matrix of beams that geometrically and operationally intermediates between spatially separated relief traction features.

Flexible yoke 1362 carries integral elongate push button 1364 and lifter reinforcement 1366. At the leading end of shielded convolute chassis 1340, soil fender 1368 is functionally complemented by soil shields 1370. Leading tab catch 1372 serves positioning and guiding functions, as described in analogous realizations of the disclosed footwear system.

Features that assist in rotary motions about the two pivot locations include post hollows 1372, flush guide collars 1374, and inset ring channels 1376. These features are located and dimensioned so that they may respectively engage with circular post 1322, intermediate circular channel 1324, and concentric relief ring 1326 in demountable fore plate 1300. Blade hollows 1378 lighten the part, reduce material cost, ensure surface quality, and abbreviate mold cycles.

An aspect of the disclosed footwear system is its provision of the ability to interchange diverse components within an organized and preconceived modular system. FIGS. 83 and 84 show lobed yoke chassis 1400 which can be interchangeably mounted on demountable fore plate 1300. Irrespective of the base plan of the chassis, any realization of the disclosed footwear system may integrate a variety of stud forms, heights, and layouts.

Lobed yoke chassis 1400 includes lobed panel 1402 in which an array of panel lobes 1404 are defined by interruptions in the perimeter at a roughly regular spatial frequency. Flexural connector beam 1406 links surrounding panel lobes 1404 and joins the lobes in a volumetrically continuous array. Brachiate spline 1408 surmounts lobed yoke chassis 1402 and loosely follows its layout.

Chevron traction features 1412 are functionally alternated about the chassis perimeter with conic traction pegs 1414. Crescent-shaped midline studs 1416 complete the set of discrete traction units. Resistance marker 1418 identifies the relative flexural resistance value of the chassis component. This value can relate to a specific testing unit, or to an abstract or synthesized scale.

Panel lobes 1404 are shaped so that each lobe is deflected over the same given distance by the same force exerted against the lobe when in active use. In this implementation, the lobes progressively bear against one another, and so accumulate a combined resistance as the athlete’s engaged foot is turned in the ground. Split front tab 1428 provides an instance where this principle is applied. The two lobed features can turn in concert about a front pivot location, but arc also allowed to articulate relative to one another. Under greater relative stress, they can come into contact. The configuration therefore provides a degree of damping to a transversely applied force, as might be experienced in a side impact to the leg or foot. Guiding catches 1430 retain the front of the chassis in front molding port 1314 located below nosing undercut cap 1312.

Arcuate alignment features may be seen to correspond to previous descriptions. Lobed chassis yoke 1422 has an arcuate region that carries lobed chassis button 1424 and reinforced tool recess 1426. Arcuate lobed chassis snap tab 1428 extends forward from lobed chassis yoke 1422 and is concentric upon circular pivot features including lobed chassis post hollows 1434, lobed chassis flush guide collars 1436, and lobed chassis inset ring channels 1438.

As in the example of shielded convolute chassis 1340, circular relief registration features are located and dimensioned so that they may respectively engage with circular post 1322, intermediate circular channel 1324, and concentric relief ring 1326 in demountable fore plate 1300.

Lobed chassis neck 1440 extends the flexural function of flexural connector beam 1406. The proportioning of flexural notching 1442 tailors the bending of the lobes to an intended purpose. As in prior examples, Lobed chassis chevron hollows 1444 and peg hollows 1446 lighten the part, reduce material cost, ensure surface quality, and abbreviate mold cycles.

The variants of the disclosed footwear system shown in FIGS. 56 through 84 inclusive illustrate applications of the disclosed footwear system that prospectively provide serial phasing of flexural resistance effects. Serial resistance phasing, in this sense, involves a succession of resistive effects that are, by design, induced to occur at successive stages of deformation.

An example of a self-resistant progression of flexural effects initially involves the simple elastic deformation of the part, but then additionally includes one or more stages of operation in which deformed elastic elements of the part come into contact with one another, and then deform in accordance with a further discrete and expressly-devised phase of flexural resistance.

In realized versions of this principle, the relative geometrical disposition of the elements is conscientiously arranged to provide resistant effects that may include, for example, guiding, slippage, flexure, jamming, or stoppage, depending upon the relative geometry and the momentary operational condition. This broad understanding has diverse applications within the disclosed footwear system. For example, the longevity of a flexed polymeric component typically relates to the stress induced by elastic compression on one side of the flexed region, and elastic extension on the other. In applications of the disclosed footwear system, the greatest stresses are commonly expressed at connection points of ribs, struts, or beams within a chassis. Locations within the part can be devised to become self-resistant at an anticipated phase of deformation. This practice allows, for example, deformed beams to come into contact in such a way that stress is transferred toward the middle of the beam length, and therefore away from the acute connection points that would otherwise carry the preponderance of deformative stresses.

This phased effect can be devised to provide progressive resistance in the chassis, while reducing local polymeric compression and elongation at the juncture of beams, spines, or other flexible elements. The reduction in severity of these stress events, which are repetitious in anticipated use in the field, functionally extends the projected lifetime and reliability of the chassis component.

The serial phasing of resistance by such means may be understood to provide a further equalization of stress within the part during operation. It can also provide discrete or ancillary outcomes as diverse as the steering of a displaced element along a preferred path, the selfclearing or cleaning of an element or surface, the mitigation of perceived functional nonlinearities of resistance, or reduction of noise from the rubbing of components under load and in relative motion. Features exhibiting this property can also be applied within the disclosed footwear system with diverse design intent, including component weight reduction, ease of molding, suitability to the targeted user, cosmetic advantage, or product differentiation.

The preceding disclosed applications of the articulating footwear system have shown that the principles of its teachings can be diversely applied. Namely, it has been exhibited that the resistant spring force imparted by a mechanically retained flexural beam can be divided, configured, or oriented in a diversity of patterns to suit the purpose of protecting the lower limbs from axial or rotational injury.

In a separate set of embodiments, the principle of structural interference between sliding flanges is applied to a version of a bayonet mount combined with additional arcuate flanges arranged about the perimeter of the shoe. The conscientious disposition of these arcuate elements allows controlled rotation of studded panels. In this configuration, a plurality of studded panels is intermediated by serpentine beams that collectively act both as an expansion joint, and as a type of spatially-separated leaf spring array that permits rotation in the field plane.

FIGS. 85-105 inclusive illustrate another embodiment of a footwear system that further displays its reach and utility. Concurrent reference to FIGS. 85-90 inclusive explain the structure and use of a discrete forefoot sole plate assembly that, in one embodiment, includes a forefoot chassis and a forefoot platen.

The particular implementation shown employs a cyclical pivotable kinetic bayonet mount toward a leading end of the chassis, and a cyclically pivotable annular component located toward a trailing end of the chassis. An array of serpentine beams is positioned intermediate between a leading panel and a trailing panel. In the first chassis illustrated, both the leading panel and the trailing panel carry geometrically similar triangulate studs. Owing to this configuration, the two stud-carrying panels are free to rotate independently but interactively, and reliably return to a home position upon the removal of the rotational load.

As described herein, a bayonet mount in the broadest sense is one in which parts are mechanically engaged by a first step of axial insertion and a second step of in-plane rotation, namely, without helical features such as threading that advance the parts toward one another in a z-plane.

Bayonet mounts used in the disclosed footwear system represent a subset of this category, in which fractional arcuate extensions are devised to intentionally interfere with one another so that, once mechanically engaged, mating parts are retained within a desired functional relationship.

Bayonet mounts desired in reference to the following figures represent a further subset of bayonet mounts, in which, rather than fully stopping or detaining the mated parts, the geometry of the mounting intentionally allows a degree of flexural angular motion about the mounting.

Bayonet mounts in the following example represent an even more specific apparatus, namely, one in which a captive component is held within a plane, but is permitted to move under flexural resistance in opposite rotational directions, depending on the applied force. The captive blade of the bayonet, when at rest, is therefore without mechanical obstruction in the field plane, so that upon flexural activation, it can move within an unobstructed volume. The permitted reciprocating angular range may be symmetrical or asymmetrical about the resting position, according to the needs of the application. The bayonet mounts used in combination with attributes of the present disclosure of a footwear system therefore differ in principle from the conventional class of bayonet mounts. Conventional bayonet mounts normally only involve turning the engaged mutually rotating elements until they reach a stopped position. In the present example, the position reciprocation of the bayonet mounting is influenced by its connection to a set of flexible serpentine beams.

In the following realizations, the serpentine beam array not only imparts spring force, but also acts as an expansion coil, so that the two physically engaged pivot locations can remain consistently operational through flexures of the forefoot. In effect, any differential in the center- to-center distance between the assembled parts is accommodated by the self-adjusted length of the serpentine chassis beams.

The implementation includes a variety of structural adaptations that allow the chassis component to follow the continual bending and twisting of the wearer’s foot during active play. For example, the leading panel includes a conformable annular corrugation formed about the bayonet mounting feature, so that, during use, the panel and central bayonet mounting feature are permitted continually shifting compliance with the shape and movement of the footwear. As in preceding examples, the mounting platens can be either removable or intrinsically integrated in a comprehensive sole plate. No description of one embodiment in this specification should be taken to exclude the other.

Referring now to the drawings, bayonet-mount chassis 1500 depicted in FIG. 85 is geometrically derived for a right foot, and designed to be mounted on bayonet-mount platen 1540 shown in FIG. 87 and FIG. 88. Bayonet-mount platen 1540 is a commensurate and complementary bilaterally asymmetrical platen. The left foot configuration is a mirror image of the right foot configuration.

Bayonet-mount chassis 1500 includes leading panel 1502 and trailing panel 1504. Outside convolute beam 1506 and inside convolute beam 1508 flank serpentine beam array 1510. Annular corrugation 1512 includes concentric grooves on its inner and outer faces that are offset, on the inner and outer face, by the half the regular frequency of the grooves, and assigned a depth and curvature such that a corrugation of substantially consistent thickness is formed. The detail of this structure may be visualized by reference to the sectional drawing in FIG. 102, which depicts a si milar corrugated structure in a different but geometrically related pail. Bayonet flange 1514 extends outward from the leading pivot center. The sector angle of bayonet flange 1514 is about 75°. Quadrant tab array 1516 is divided into a plurality of quadrant tabs 1518 to permit compliance with the flexing sole of the shoe, and has an arcuate form concentric with the leading pivot center. The sector angle of quadrant tab array 1516 is about 90°. The sector angle of the individual quadrant tabs 1518 is about 10°. The recited angular values are included for completeness of description, but do not represent limitations on the range of envisioned embodiments.

Middle tab 1520, visible in FIG. 86, and trailing tab 1522 have arcuate forms concentric with the trailing pivot center. Triangulate studs 1524 are disposed on leading panel 1502 and trailing panel 1504. Triangulate studs 1524 are filleted to blend into leading panel 1502, in order to promote release from the ground during use and deter soil adhesion.

External panel basins 1526 reduces the thickness of the panels where structurally permissible. Internal panel basins 1528 reduces the thickness of the panels where structurally permissible on the opposite and internal faces of the panels. Bayonet collar 1530 surrounds leading pivot center cavity 1532. Trailing pivot features comprise alternating rings 1534 and alternating annular grooves 1536. Triangulate hollows 1538 are formed within each triangulate stud 1524.

FIGS. 87 and 88 illustrate bayonet-mount platen 1540. Bayonet-mount platen 1540 includes bayonet-mount base panel 1542, undercut nose tab housing 1544, undercut intermediate tab housing 1546, middle undercut tab housing 1548, and trailing undercut tab housing 1550. Undercut perimeter flanges 1552 have ported apertures 1554 beneath their undercuts to provide cost-effective mold and part production. Countersunk bayonet platen holes 1556 extend through bayonet-mount base panel 1542.

Recessed pivot ring array 1558 includes negative volumes corresponding to alternating rings 1534 in bayonet-mount chassis 1500. Cylindrical bayonet center plug 1560 is provided with a moderate side wall draft. Bayonet entry port 1562 is formed commensurate with bayonet flange 1514 and bayonet collar 1530. Bayonet buttress 1564 includes undercut flange guard 1566. The sector angle of flange guard 1566 is about 120° . The 120° sector angle permits more than ±15° rotation for the 75° sector angle of bayonet flange 1512. Instructional icon 1568 shows the tool axis for disengagement of an installed chassis. Bayonet chassis perimeter rim 1570 surrounds bayonet-mount base panel 1542 and countersunk bayonet platen holes 1556. Inset base region 1572 locally reduces platen thickness. Trailing pivot land 1576 accommodates recessed pivot ring array 1558. Center plug hollow removes unnecessary material from cylindrical bayonet center plug 1560. Bayonet flange guard port 1578 enables undercut flange guard 1566.

FIG. 89 shows the initiating installation position of bayonet-mount chassis 1500 upon bayonet-mount platen 1540. Bayonet flange 1514 has been located in the arcuate receptive region of bayonet entry port 1562, and circular leading pivot relief features engaged. The chassis is then rotated in the rotational direction indicated by arrow D.

In the process of turning, alternating rings 1534 on the underside will ride on bayonetmount base panel 1542. Quadrant tab array 1516, middle tab 1520, and trailing tab 1522 are manually guided into their receiving undercuts, deforming the parts as necessary, until alternating rings 1534 fully seats in and engages with recessed pivot ring array 1558.

FIG. 90 represents the installed state. Pivot ring array 1558 and its mating features can be assigned depths between 1 mm and 3 mm, and sidewall angles between 0° and 30°, depending on the intended ease of release for the targeted user and application.

The particular implementation of the disclosed footwear system captures the chassis at three locations along the lateral side of the foot, at two locations the leading and trailing ends of the forefoot, and, at the bayonet mount, in the vicinity of the first metatarsal and the medial side of the foot. The plurality of captive but motile locations hold the chassis firmly to the sole plate or forefoot platen during physical activity, but allows ready removal by the insertion of lifting tool from the medial side between the two operational pivots.

In the installed state, the chassis is free to rotate about the leading and trailing pivot locations. The motion of one pivot can be complex. Most commonly, a rotational force imposed on one rotating panel will impart a counter-rotational force upon the other. This action can be a reciprocating or alternating one, as suggested by the bidirectional arrows.

In use on the field, this arrangement has been found to yield a regulating effect depending on the relative weighting and engagement of the two operationally distinct sets of studs. Because studs on the leading panel are located farther from the pivot center, typically there is relatively greater leverage exerted on them when the foot is turned in the ground. In situations where all studs are equally engaged, the leading studs are more prone to rotate, as the trailing panel of studs provide resistance owing to their induced counter-rotation. The athlete experiences the combined effect as an articulation to a large turning arc, as suggested by the diverging arrows marked “R” and “L”.

As the athlete’s weight is shifted forward, the regulating influence of studs on the rear panel is reduced, and the articulation of the front panel becomes increasingly unencumbered. The comprehensive result is that the rotational freedom of the foot in the ground increases in a manner that is proportionate to the natural habits of the body.

Specifically, an article of footwear equipped with an articulating chassis becomes easier to turn at the later phase of each stride. Rotational responsiveness of the mounted traction system also increases as the athlete’s overall pace escalates, as a faster pace normally results in an extended stride and forward bias in the foot strike.

The bending of the chassis component upon the platen to sole plate to which it is mounted inherently results in a fluctuating differential in the center-to-center distance between the respective pivots as the sole components of the shoe are flexed during active play. A curved or actively flexed condition can also prevail in the assembled shoe’s rest state.

Accordingly, when the parts are molded in a flat state, it is useful in the disclosed footwear system to provide a disparity between the center-to-center dimensions so that the assembled parts will optimally engage and operate. In the practical application of the disclosed footwear system, this value depends on the center-to-center distance and the expected range of forefoot flexion. Typical adjustment values are between 0.5 mm and 2.0 mm.

For example, pivot features on a flat-molded sole plate part may have a 59.2 mm, while a functionally matched flat-molded chassis part may have an optimized center-to-center distance of 60.0 mm. When the parts are mutually engaged and made convex, the center-to-center- distance varies according to the parts’ momentary centers of curvature, such that, in some known or predicted state of mutual flexure, their pivotable centers directly align.

Diverse stud patterns can be implemented for differing conditions and preferences. FIGS. 91 and 92 depict a chassis directly compatible with the bayonet mounting system in which the bladed studs have an overt rotational bias, and in which two rounded conic studs are included upon the pivot locations. Bladed bayonet chassis 1580 shares its main functional features with bayonet-mount chassis 1500. Such foundational features include major panel 1582 and minor panel 1584. The panels are connected by a serpentine beam set 1586 and have set back tabs 1588 directly corresponding to those in bayonet-mount chassis 1500.

Rotationally biased bladed studs 1590 surround rounded conic posts 1592. Rounded conic posts 1592 are concentric with pivot points of the chassis. Arcuate bayonet blade 1594 and corrugated groove array 1596 mirror corresponding features in bayonet-mount chassis 1500, and ensure the interoperability of the components. The intentional standardization allows different types of forefoot traction chassis to be reliably installed and removed.

In order to provide a functionally coherent article of modular footwear, it is anticipated that a heel component would generally be provided to correlate with an articulating forefoot system. It is nevertheless an aspect of the disclosed footwear system that heel and forefoot components are functionally and esthetically separable. Accordingly, a traction system devised for the heel can take many forms and still meet the preferences of the user.

FIGS. 93-98 inclusive illustrate a functionally complementary compact mounting system in which the studs remain static. The interacting chassis and platen exploit flexural structure to enable rapid and reliable mounting and demounting of the interchangeable chassis. The implementation therefore highlights the discrete value within the disclosed footwear system of components that provide interchangeability, and that this property independently provides a preventative benefit.

The studs are held in an immobile state relative to the balance of the shoe. Heel rotation is less often implicated in rotational joint injury than the anchored planting of the forefoot, and it is not either essential or mandatory for the structure and operation to precisely mirror that of the forefoot component. The exemplary compact chassis and platen are amenable to use at the heel, but are not limited to that use.

Heel studs can accordingly be permanently molded into the sole plate, may be interchangeable but static, or may be interchangeable and kinetic. They can be devised with stud forms and positions that are directed to the mitigation of anatomical proclivities, such as heel overextension or foot hypersupination.

For example, the sinking of the heel in soft or wet ground has been implicated in ruptures of the Achilles tendon. Habitual or incidental hypersupination is believed to play a role in ankle injury. The specialized fitting of a heelpiece formed according to the disclosed footwear system, in view of immediate field condition or the athlete’s clinical history, can reasonably be foreseen to diminish the chance of injury or reinjury to connective tissue.

FIGS. 93-98 collectively illustrate a compact interchangeable chassis having triangulate studs that remain substantially immobile once installed. The compact chassis is operationally and cosmetically compatible with the kinetic bayonet-mountable chassis illustrated in the preceding figures, in which the compact chassis is devised to be captured by the symmetrical action of a pair of opposing flexural prongs against cooperating relief features on a receiving platen.

The example is dimensioned to serve as a companion heel component to the articulating forefoot system shown in FIGS. 95-98 inclusive. Because the design of connecting flexural parts requires complex geometrical interactivity, the cooperative structural features may be most thoroughly appreciated by concurrent reference to the full suite of relevant drawings, in which compact chassis 1600 is slidingly engaged and flexurally coupled with compact platen 1630.

Referring now to the chassis illustrated in FIGS. 93 and 94, compact chassis 1600 includes compact chassis base panel 1602 which includes static center frame 1604. Ridge beam 1606 follows the forked shape of compact chassis 1600. Bilaterally symmetrical compact chassis flexural prongs 1608 integrate material from ridge beam 1604 and chassis base panel 1602. The compact chassis flexural prongs 1608 have a complex inner profile that anticipates their flexure and their seating, in their laterally deflected state, against the outer profile of static center frame 1604.

Four static studs 1610 extend from compact chassis base panel 1602. Internal seating flange 1612, side seating flanges 1014, and external seating flanges 1016 are recessed relative to the foundational thickness of compact chassis 1600 ,so that they can be slidingly engaged with companionable cantilevered features in compact platen 1630. External flange 1016 includes a plurality of recessed locations that are spatially discontinuous, but which mutually engage with corresponding flanges on cantilevered tailpiece 1640 located on compact platen 1630.

Center lift tab 1618 extends from static center frame 1604 and is proportioned so that it can be manually flexed upward out of the field plane. Center lift tab 1618 is shown here having a cardioid shape, with a recessed center region.

Compact chassis flexural prongs 1608 are contiguous with pin catch heads 1620. Pin catch heads 1620 are proportioned so that they can be conveniently and comfortably deflected by the joint action of the thumb and forefinger. Pin catch heads 1620 are designed with a relatively low profile to discourage accidental release of the chassis when the shoe is in active use.

As compact chassis flexural prongs 1608 are manually flexed in an inward direction, pin catch heads 1620 will follow a substantially arcuate path that is only completely defined by the exact volumetric geometry of flexural prongs 1608 and the properties of the material itself in response to an applied force. However, the deflected location of pin catch heads 1620 can be approximated by the assumption of a center of rotation in the vicinity of the connected end of the beam.

Accordingly, pin catch traps 1622 provide symmetrical open hollows presenting two short arcuate channels conforming to the anticipated flexural translation of the beams. The shape and length of the pin catch traps is also dimensionally correlated with the channels separating chassis prongs 1608 from the relatively static center frame 1604.

Chassis prongs 1608 are thereby permitted sufficient travel to disengage from their locked state in the position where they are stopped by contact between chassis prongs 1608 and the outer margin of static center frame 1604. Cardioid land 1624 extends in relief from the underside center lift tab 1618. Triangulate voids 1626 form internal hollows in static studs 1610.

FIGS. 95 and 96 show compact receiving platen 1630 including relief elements that reliably capture the compact flexural pronged chassis shown in FIGS. 93 and 94. As in previously disclosed examples, the part is equally envisioned as a demountable component, as illustrated here, and as a component that is integrally encompassed within a formatively integral sole plate.

Compact receiving platen 1630 includes compact platen panel 1632, compact platen mounting holes 1634. Compact platen internal flange 1636, compact platen side flanges 1638, and T-shaped compact platen external flange 1640 anticipate respective mechanical engagement with internal seating flange 1612, side seating flanges 1614, and external seating flange 1616 in chassis compact chassis 1600. Molding pass-throughs 1642 permit the forming of undercuts in an economical two-part mold.

In the embodiment, catch posts 1644 are cylindrical in shape and extend in relief from compact platen panel 1632. Catch posts 1644 are located in joint consideration of the dimension and flexure of chassis prongs 1608 within compact chassis 1600, and more particularly with pin catch heads 1620 and their pin catch traps 1622. Tab indentation 1646 serves as a stop for the vertex of center lift tab 1618. Tab detent 1648 is cardioid in shape and proportioned to receive cardioid land 1624. Tab detent 1648 and cardioid land 1624 can be chamfered or filleted at elective angles or curvatures to regulate their resistance to mutual disengagement.

FIGS. 97 and 98 illustrate the interoperation of compact chassis 1600 and compact receiving platen 1630. FIG. 97 shows the two components in a mutually engaged state. The parts are fully engaged so that both parts obtain a relaxed and as-molded state. FIG. 98 is an explanatory plan view of a flexural pronged heel chassis statically mounted on its receiving heel platen, showing a second and alternate compact chassis position 1601 that occurs as a result of flexural manipulation during mounting and demounting.

In the mounted condition, internal seating flange 1612, side seating flanges 1614, and external seating flange 1616 on chassis compact chassis 1600 are held beneath compact platen internal flange 1636, compact platen side flanges 1638, and T-shaped compact platen external flange 1640. Cardioid land 1624 on the underside of center lift tab 1618 is seated in tab detent 1648.

Catch posts 1644 are entrapped catch traps 1622 formed in pin catch heads 1620. The inclined geometry of pin catch heads 1620 similarly interferes with the inclined face of compact platen side flanges 1638. In each case, the ramping of sloped contact faces results in deeper engagement of the parts rather than withdrawal, owing to the slightly hooked configuration of the features. Absent active deflection of chassis prongs 1608, the parts cannot be separated except by breakage.

An useful property of the illustrated assembly design is that the compact chassis is retained on the platen even in its disengaged state. This condition is obtained by devising the chassis and platen so that pin catch heads 1620 on chassis prongs 1608 bear against compact platen side flanges 1638 such that the vertex of center lift tab 1618 bears against tab indention 1646.

The spring forces exerted in the field plane in this state conspire to hold the chassis on the platen until the operator elects to lift the chassis away from its mounting. This property facilitates the handling of the unlocked part during the exchange of modular components.

Deflected pin catch head position 1621 depicts pin catch heads 1620 displaced mutually inward, owing to the bending of chassis prongs 1608. In this illustrated flexural phase, indicated by the dashed outline, compact chassis 1600 has been released from catch posts 1644 and has bypassed side flanges 1638 and moved into chassis position 1601.

In the relative phase of operation identified by chassis position 1601, the chassis is retained on the receiving platen by outward spring force exerted in the field plane without manual influence by the operator. The chassis can nevertheless be freed from the plate by lifting the compact chassis away from the platen and out of the field plane.

A variety of designs can be realized by modification of the preceding general plan. For example, center lift tab 1618 and tab detent 1648 can be provided with steep draft angles that require direct manual lifting to disengage the parts, or angles that allow the tab to ramp out of its recess under an indirect sliding force. Compact platen internal flange 1636 and be eliminated, or replaced by a molded hook on the chassis that fits into an undercut on the chassis, so that the prongs progressively ramp against side flanges 1638 in a simple in-plane sliding installation.

While the exemplary design is scaled and proportioned so that it may be located in the heel region, the use of the compact modular system is not limited to that purpose. The device or a similar one can be readily proportioned, for example, so that three components can serve as the traction system on a shoe, two serving the forefoot, and one the heel. Devices using the exemplary mounting mechanism can also be molded in tandem arrangements, in which a plurality of paired catches operate in unison within a volumetrically continuous part.

In view of the foregoing disclosures, an athlete may spontaneously interchange stud patterns, for example, when shifting from a venue that uses natural turf to one that use artificial turf, or even in the event of the ground becoming wet or disturbed in the course of a game. The exchange itself provides a preventative effect to the wearer, equivalent to results that currently require a complete change in footwear.

Low-relief, overmolded traction components using two or more bonded materials may employ a different range of polymers than those used for chassis optimized for wet or muddy field conditions. Accordingly, chassis materials for street, court, or indoor wear can integrate polymeric materials differing in their physical properties, which are expressly chosen for their ability to chemically bond to one another.

Overmolding, or two-shot molding, typically involves injecting a first shot of polymer between two mold halves to form a part preform, and then switching one of the mold halves for another, so that one or more open volumes are left between the mated halves and the captive part. A second polymer is injected then into the voids so that the two differing materials are inherently joined in course of a two-step molding operation.

The overmolding operation is useful within the disclosed footwear system, since it offers footwear designer a palette of effects providing both operational diversity and visual variety. It is well established that the preference for a particular article footwear is a function of both its technical result and its visual appeal.

Overmolding is most commonly performed so that a resilient material such as TPU or TPE is molded onto a more rigid substrate, and widely enables the use two materials having differing performance properties, or exhibiting contrasting colors or textures. FIG. 99 is a perspective view of a molded perform for an overmolded bayonet-mountable forefoot chassis component, depicting the appearance of the preform after an initial molding operation.

Molded chassis substrate 1660 illustrates the form of a rigid part after the first injection cycle. Molded chassis substrate 1660 includes leading frame 1662, trailing frame 1664, and intermediating elongation components 1666. Frame quadrant tab array 1668, frame short tab 1670, and frame arc tab 1672 directly correspond to features in bayonet-mount chassis 1500 and bladed bayonet chassis 1580.

After the initial molding cycle, frame windows 1674 leave temporary openings through leading frame 1662 and trailing frame 1664. Attachment lips 1676 increase the contact area and mechanical engagement between the two polymers. Resilient corrugation zone 1678 surrounds one of two circular windows 1680. Circular windows 1680 include circular lips 1682 to secure the second polymer to the first. Frame bayonet blade 1684, frame bayonet collar 1686, and frame guide rings 1688 mirror corresponding features in previously detailed chassis. Frame bayonet blade 1684 has a sector angle of about 75°, or about two-thirds of sector angle of flange guard 1566, so that ±15° of rotation is enabled.

FIGS. 100, 101, and 102 depict the component after the second injection cycle has filled the windows with resilient traction pads of a thermoplastic elastomer. Overmolded pad system 1690 includes five resilient pads faced with a pattern of cups 1692 and linear ridges 1694. Two resilient buttons carry concentric raised rings. The pads and buttons are molded so that they stand proud of the top surface of molded chassis substrate 1660, as may be seen in the sectional drawing in FIG. 102. FIG. 103 illustrates that the overmolded bayonet-mountable forefoot component can be interchangeably substituted in a modular fashion for the studded components using the common mounting platen depicted in FIGS. 87 and 88. The manner of mounting and the potential traction modes of operation correlate with the explanations that accompany FIGS. 89 and 90. However, the overmolded chassis can be installed for wear on courts and other flat playing surfaces, and delivers a level of joint protection to the athlete, owing to the frictional resistance between the floor and the resilient pads inducing rotation and relative motion in the structurally contiguous leading frame 1662 and trailing frame 1664.

The preceding forefoot chassis provides progressively resistive rotation over ± 15°, relative to the foot held in a fixed shoe upper. The precise range is established by the radial dimensioning of the bayonet faster, the relative location of arcuate chassis tabs and their arcuate receiving channels, and the flexural resistance of functionally influential beam structures. In actual use upon a fibrous or granular field material, such as natural turf, this angular range can be practically extended by the complementary effect of conscientiously-designed stud arrays.

When a traction chassis is deformed by a torsional load, any sufficiently engaged traction elements will either be driven closer together or farther apart, depending upon their position in the array. In either case, the relief traction elements compress any compressible field material ahead of their path of motion. This compression provides increased grip in the field plane relative to that provided by the conventional action of dragging a cleated shoe in the turf.

The preceding chassis examples include a set of features that enable the continued functioning of the articulating traction component during flexure of the sole plate. For example, in the routine operation of the disclosed footwear system, annular corrugation 1512 obtains a domed form, and also obtains flexural states in which bayonet collar 1530 and bayonet flange 1514 are skewed relative to the surface of leading panel 1502.

Other features promoting general flexural compliance features include its serpentine beams, its notched tabs, its thinned regions, and the use of overmolded elastomers. It should be understood that is in the reach of the disclosed footwear system that these properties are foreseen as interchangeable. For example, flat, thinned regions may alternately be corrugated or filled with elastomer at any location in the chassis.

Similarly, elastomeric or corrugated connective structures may in whole or in pail be substituted for intermediating serpentine beams, so long as they serve the function of returning a set of traction elements to a home position. The beam arrays illustrated depict a subset of the range of solutions. The flexural bridge that imparts the spring force to the traction elements may therefore be, or integrate, beams, meshes, grids, reticulations, or other geometrical forms. It may include materials selected either for their rigidity or their compliance, depending on their use within the design. The bridge structure may include a woven fabric of either mineral or organic origin, or may comprise a composite.

It may be appreciated that there is correspondence between the version of the disclosed footwear’ system shown in FIGS. 15 and 16, and the recited bayonet-mounted scenarios, in that each includes a plurality of pivot points interconnected by serpentine beams. However, there is also an indeterminate range of intermediate realizations that would serve a particular functional or visual interest.

FIG. 104 illustrates overmolded compact chassis 1700. Overmolded compact chassis 1700 can be modularly installed on receiving heel platen of FIGS. 95 and 96, foreseeably in combination with the overmolded bayonet-mountable forefoot component, and in substitution for the flexural pronged compact chassis shown in FIGS. 93 and 94.

Overmolded heel chassis 1700 included compact overmolding frame 1702, compact overmolding frame insets 1704, frame prongs 1706, frame prong heads 1708, and prong head catches 1710. Compact chassis pad 1720 carries mixed grip pattern 1722 comprising cups and raised ridges.

The bayonet-mounted chassis described above can be released by any bladed tool of suitable length and thickness by inserting the tool along the dashed guideline, beginning at the unlock symbol. This lifting action disengages the mated sets of relief rings so the pails can be induced to slide rotationally about the bayonet components, and ultimately lifted apart.

In the interest of completeness, the disclosed footwear system provides a simple and lightweight pocket tool that can safely and conveniently be used to flexurally elevate the chassis to a releasable height, without any risk of marring or straining of a polymeric chassis. FIGS. 105 and 106 show a dedicated lifting tool for use with the bayonet mounting system disclosed in the preceding examples.

Lifting tool 1730 includes perimeter rim 1732, upper panel 1734, locker hook opening 1736, branding 1738, ramped blade face 1740, blunt tip 1742, plain underside panel 1744, and ramped blade hollow 1746. The tool is gradually introduced under the chassis near the trailing pivot features to flex and lift that region, and decouple the engaged parts at that location. In the illustrated embodiments, local lifting by 2-3 mm is adequate to permit the chassis to be rotationally and slidably disengaged from its mounting.

The tool illustrated is 120 mm in length, and is effective with all envisioned sizes of the relevant components. Its rounded edges allow it to be comfortably kept loose in the pocket of an article of clothing. The specific length is a matter of convenience, and can, for example, be made larger for large hands, or so small that it can serve as a key fob.

The tool can include picks for loosening and dislodging any accumulation of soil, as previously demonstrated in the exemplary installation tool 700. If desired, the tool and chassis can be modified so that the tool has one or more ridges that engage and follow, in a collinear manual operation, one or more commensurate channels recessed in the bayonet platen.

FIG. 107 shows consolidated molded sole plate 1750 incorporating a bayonet mounting on the forefoot area, and a sliding catch on the heel area. FIG. 107 also shows the axis of installation of relief fill panel 1760.

Consolidated molded sole plate 1750 includes sole plate perimeter foot cup 1752, consolidated sole plate fore plate 1754, consolidated sole plate midsole 1756, and consolidated heel plate 1758. The relief features of these components correspond to the set of cooperating mounting structures on previously illustrated bayonet-mountable chassis.

Rather than being mounted by loose hardware, consolidated molded sole plate 1750 is made structurally continuous, such that no constituent element can be separated from any other constant element without the application of destructive force. Nevertheless, consolidated molded sole plate 1750 can be materially inhomogeneous, and can accordingly incorporate a range of polymeric injectates, fillers, foams, webs, fabrics, matrices, inserts, or laminations. The design can include intricate incursions or projections, to fulfill either practical or esthetic ends.

Relief fill panel 1760 is derived so that it occupies recesses and voids in the consolidated molded sole plate 1750. Voids apertured through a layer of the part can result from the exigencies of economical molding of undercut features. Recesses can result from the limitations on wall thickness for a given polymer and targeted mold cycle.

Accordingly, relief fill panel 1760 includes primary fill panel 1762 is surmounted by first fill lands 1764 and second fill lands 1766. Port fill plugs 1768 are dimensioned to fit into apertures formed beneath overhanging tabs, such apertures generally owing to the requisite geometry of mold halves used to form consolidated molded sole plate 1750.

Shoes can benefit from filling and leveling by such a secondary molded part. A fill panel can serve a secondary function in the shoe, such as cushioning or shock absorption, and ca be composed accordingly.

FIGS. 108 and 109 illustrate useful modifications of fore plate chassis. FIG. 108 shows a forefoot chassis having a cantilevered tab at the leading end that excludes potential contaminants and aids alignment. Wet ground, in particular, can force mud and debris into crevices between moving parts. Shielded chassis 1770 includes shielded chassis studded leading lobe 1772, shielded chassis midsection 1774, and shielded chassis studded trailing lobe 1776. Leading cantilevered shield 1778 extends from the front of the chassis such that it overlays the retention features on a bayonet-mount chassis. Leading cantilevered shield 1778 serves to provide extra shielding at a location where, depending upon conditions, a shoe may engage forcefully with muddy ground.

FIG. 109 shows a forefoot chassis having leading and trailing panels outfitted with pluralities of inserts, such that individual studs with threaded shanks can be installed in a user- selected arrangement. Customizable forefoot chassis 1780 includes customizable forefoot front panel 1782 and customizable forefoot rear panel 1784. Customizable forefoot front panel 1782 and customizable forefoot rear panel 1784 are each outfitted with arrays of flush threaded inserts 1786. Customizable forefoot front panel 1782 and customizable forefoot rear panel 1784 are flexurally intermediated by outer flexural rails 1788 and inner flexural rails 1790. Peripheral tabs 1792 correspond to analogous features on preceding embodiments.

Discrete stud 1794 has molded body 1796 and threaded shank 1798 such that each example can be tightened into a corresponding flush threaded insert 1786 at any of the available locations. This assembly allows individual sites to be customized for the stud pattern, and the pattern to be locally individuated for stud shape and length. Such customization can be applied to general use, or to adaptive or remediate athletics.

FIGS. 110 and FIG. I l l show two perspective views of shielded heel chassis 1800. Heel chassis 1800 is structurally compatible with center-catch sole plate 1820, which is represented in FIG. 112 by a partial view of its heel area. The figures depict variants of mounting features for a pronged array. Shielded heel chassis 1800 has inner frame 1802 and flexible prong arms 1804. Inner frame 1802 and flexible prong arms 1804 arc integrally formed with capture flanges 1806. Middle lift tab 1808 is located within inner frame 1802. Flexible prong arms 1804 carry gap shields 1810 that substantially cover the gap between inner frame 1802 and flexible prong arms 1804 and of the chassis. Heel cleats 1812 extend from inner frame 1802. Center hook 1814 extends from the internal side of inner frame 1802 and includes center hook flange 1816. Catch hollows 1818 are formed into the medial and lateral margins of shielded heel chassis 1800.

FIG. 112 shows a partial view of center-catch sole plate 1820 detailing the area around the heel. Center-catch sole plate 1820 includes center-catch heel plate 1822, which carries mounting features integrally formed with center-catch sole plate 1820. Mounting features include leading catch 1824, side detent catches 1826, and oblong posts 1828. Dual recessed detents 1830 are axially aligned on center-catch sole plate 1820. Tail end undercut 1632 is formed into the rearmost region of center-catch sole plate 1820. Midsole extension 1834 connects the arch area of the sole plate to a forefoot traction region.

The mutual mounting of shielded heel chassis 1800 and center-catch sole plate 1820 departs from the heel mounting system in that the axial orientation is reversed, such that shielded heel chassis is installed by sliding the chassis toward the leading end of the sole plate. Dual recessed detents 1830 conspire with flexible prong arms 1804 and side detent catches 1826 to provide a first mild hold position and a second locked hold position. Center hook flange 1816 tail end undercut 1632 engaged when shielded heel chassis 1800 approaches its locked position.

Flexible prong arms 1804 are surmounted by gap shields 1810 so that the space between flexible prong arms 1804 and heel chassis frame 1806 is substantially covered, with only enough of a space left to prevent the formation of flashing between gap shields 1804 heel chassis inner frame 1802 during molding. The chassis can electively be devised so that in its installed state a degree of residual spring force remains, so that flexible prong arms 1804 bear outwardly against the relief features of flexible prong arms 1804. In this arrangement, gap shields 1810 are deflected such that they substantially cover the gap between inner frame 1802 and flexible prong arms 1804.

When used on a loose granular to fibrous surface, gap shields 1804 prevent contaminants from obstructing ready removal of the compact interchangeable chassis. This modification includes oblong posts 1828 that are shaped to substantially fill catch hollows 1818. Center hook flange 1816 engages tail end undercut 1632 such that a strong hold is provided at the location where a heel strike typically occurs. Relative to the version of the compact traction system shown in FIGS. 93 to 98, this modification frees more of the internal area of the chassis frame for other modular components within the comprehensive system. It is generally recognized that embodiments of the invention can be realized with fewer features, and not all illustrated features devices are necessary to every application.

FIGS. 113 and 114 show side impact forefoot chassis 1840. Side impact forefoot chassis 1840 has open regions in the midsections between the perimeter and pivot locations so that beams can move both away from and toward the center of the foot. Owing to this modification, the studs are transversely displaceable with respect to one another, and the chassis better mitigate side impact forces.

Side impact forefoot chassis 1840 includes features that parallel preceding examples, including leading side impact forefoot panel 1842, leading side impact forefoot panel 1844, inside loop 1846, outside loop 1848, middle beams 1850. Chassis ligature 1852 is located at a relative stasis point, such that little shear is expressed between the connected beams during articulation of the flexural members.

Displaceable front tab 1854, displaceable middle tab 1856, and displaceable rear tab 1858 are devised to a degree of in-plane movement relative to the platen channels into which they are received. Laterally cantilevered studs 1860 are permitted transverse displacement owing to the relatively deep incursions of laterally cantilevering channels 1862. Orbital lead stud 1864 is also permitted to shift transversely upon impact, owing to orbital motion about the leading pivot point.

The comprehensive and interoperable components of the modular system characterized within FIG. 85 to FIG. 114 inclusive, and their envisioned extensions, provide the athlete with a diversity of adaptive effects that can mitigate joint injury. The responsive behavior of the articulating chassis can also have more subtle experiential effects. For example, the anticipation of incipient injury owing to the neural signaling of stress can diminish the player’s confidence and style of play. Reducing that stress can improve competitiveness. In essence, the naturalistic flexure of the chassis aligns with the body’s inherent proprioception.

The ease of installation and removal has pragmatic benefits as well. In practice, the installation of an individual chassis component takes 1 to 5 seconds. A complete exchange of a set chassis on a pair of shoes can be obtained in less than 30 seconds, whether the shoes are loose, or remain mounted on the feet.

Because the installation and dismounting of the components is a quick and simple process, the parts can be quickly and conveniently separated for routine inspection, cleaning, or maintenance. No parts are inaccessible or hidden from the inspector.

The chassis that are the subject of this disclosure are expressly devised to prohibit accidental release from the shoe. The forefoot chassis illustrated in FIGS. 85-92, in FIGS. 113 and 114, and in FIGS. 117 and 118 are expressly devised to require active intervention with a bladed tool. This requirement is implemented in pail to provide the athlete with a high degree of confidence in the reliable retention of the forefoot chassis, where operational stresses are greatest. The pronged chassis are irreversibly mounted unless a special sequence of actions is imparted. It is also understood that, in the absence of the dedicated plastic tool, any appropriately-dimensioned generic bladed tool can be substituted in its place.

The chassis components in the comprehensive system can be codified by reference to benchmark values. FIG. 115 is a schematic graph of the measured torsional resistance, in newton-meters, expressed during clockwise and counterclockwise rotation of the foremost chassis panel, as observed from the underside of the shoe, over an angular range on a shoe devised within the disclosed footwear system for the right foot. The graph relates to FIGS. 85, 86, 89, 90, 91, 92, 99, 100, 101, 102, 103, 108, and 109, which share a common chassis configuration.

In one embodiment, the chassis and compatible sole plate can be scaled for a US10/EUR44 size shoe. Clockwise rotation is functionally and structurally limited at +15°. Counterclockwise rotation is functionally limited at approximately -20° by the compression of convoluted beams against one of their own sidewalls. It may be appreciated that the torsional resistance curves are essentially asymptotic with the angular design limits of the physical parts. This condition minimizes the likelihood of destructive force being applied to a chassis or sole plate.

The graph is included to characterize the fluctuating and sympathetic properties of an exemplary embodiment, and the range of embodiments is not limited by any recited value or measure. The graph represents only the torsional resistance of an otherwise unloaded studded front panel. Tn practice, the loading is intermodulated with the composition of the playing surface, and the cooperative effect of any interoperating set of studs.

A first state of engagement includes the static heel chassis, in which the planted foot can orbit over only a few degrees. As the heel is lifted, the forefoot’s flexural mechanism is permitted an increasing orbital articulation. When the forefoot is planted with both its sets of studs equally trapped in firm ground, an exemplary attainable orbital range of approximately ±10° occurs. This angular range increases as the weight is shifted forward, such that an orbital range of ±30° or more is permitted. At each phase of the stride, the torsional resistance increases as the foot is turned toward the extremes of the chassis’ angular displacement. In practice, these phases occur, both orbitally and axially, as a continuum rather than as discrete steps.

The polymeric test pieces possessed an elastic modulus of 1800 MPa. The torsional resistance can be increased through the use of polymer formulations having higher elastic moduli, for example, copolymeric polyoxymethylenes, which have typical elastic moduli in the range of 2400-2700 MPa, and homopolymeric polyoxymethylenes, which have typical elastic moduli in the range of 3000-3600 MPa. Reinforced or alloyed acetals can have elastic moduli as high a 10,000 MPa, while more compliant polyamides amenable for use in the invention can have elastic moduli as low as 800 MPa.

The torsional resistance profile can be tailored to the anticipated user and use, for example, by the election of a particular polymer, and by the proportioning of the flexural beams. It can also be tailored by scaling the entire chassis model. A scaled, geometrically similar version in which the components differ in scale scaled by a factor of 0.85 in all dimensions, exhibited torsional resistance values of 0.5 times that represented in the 1.0 scale version represented in the graph. The 0.85 scale is dimensionally amenable to a shoe size of US W7/US M5.5/EUR 38.

FIG. 116 is a table of proposed scale values derived to economically serve a variety of pragmatic applications. The scaling of components at quantized intervals allows the number of stocked components to be minimized. The scale factors of 0.8, 0.9, 1.0, 1.1, and 1.2 cover a wide range of users. Specific designs are expected to nevertheless expected to vary by material composition, and include individuation that departs from absolute geometric similarity.

While a primary purpose of the disclosed footwear system is to provide motility, in the field plane, to relief traction elements, it is understood that in certain circumstances it may be purposeful to suppress the orbital motion of the relief traction features while still providing a chassis that can be flcxurally mounted and demounted within the modular system.

FIG. 117 is an external perspective view of paneled forefoot chassis 1870 having an infill panel in the middle section, and throughout the part, such that orbital relative motion of the traction features is substantially inhibited in the field plane. FIG. 118 is an internal perspective view of the forefoot chassis of FIG. 117.

Paneled forefoot chassis 1870 includes forefoot chassis frame 1872 which supports and surrounds continuous chassis panel 1874. Continuous chassis panel 1874 is represented as a plurality of subpanels enclosed locally by elements of forefoot chassis frame 1872. Chassis frame 1872 is structurally continuous with triangulate cleats 1876 and recessed tabs 1878.

Continuous chassis panel 1874 pervades the surface of the chassis, including interstices between trapped beams 1880. Cover plaquette 1882 surmounts forefoot chassis frame 1872 and deters the direct incursion of field debris. Cautionary mark 1884 indicates the subversion of any safeguarding orbital articulation in the part.

The paneled forefoot chassis 1870 is installed in a sequence analogous to previous components of the modular system, namely, by locating the blade of its bayonet mounting feature into its corresponding recess on the sole plate and rotating through about 90°, while bending the chassis slightly so that its tabs fit into undercut receiving flanges In its installed state, the chassis is held in place upon the sole plate, but not secured to the sole plate at any location, so that that the chassis is both demountable between athletic sessions, and structurally disengaged and independent of the sole plate during use.

In its mounted state, the disengaged condition allows the entire chassis to slide relative to the sole plate, so that any spatial disparities owing to the slight difference in radius of curvature to which the forefoot is conformed during active use is taken up by the relative sliding action. The sliding action can be complemented by increasing the draft angle of the pivoting relief features, such that any ramping effect that occurs between the chassis and sole plate, owing to the actively varying differential in the center-to-center distance between their pivot points, expresses a mutual force that returns the chassis to a seated relationship with the sole plate.

Because the chassis is permissively bound to the sole plate throughout its length, and is held captive by both the bayonet mount in its middle and by flanges at its leading and trailing extremities. The combination of the static sole plate and the agile chassis effectively acts as a layered spring when flexed out of the field plane. The expressly permitted slippage between the operatively separate parts allows the chassis to flex with more responsiveness and less internal strain than if it were secured to the sole plate.

The local and momentary slippage permitted by the decoupling of the chassis from the sole of the footwear therefore not only allows stud displacement in the field plane when the foot is held in the same field plane, but allows that protective effect to persist throughout transitory states of dorsiflexion, planar flexion, inversion, or eversion of the foot.

To enhance such flexibility, or for any other purpose, panels or subpanels in any embodiment can be provided with complex patterning such as fractal patterns, reticulations, auxetic structures, or matrices having null Poisson ratios. They can also be formed of material of different composition than the rest of the chassis, as is the typical case in two-shot overmolding.

Polymer formulations having low surface energy which are of use within the disclosed footwear system can be suboptimal candidates for conventional overmolding. FIG. 119 shows a schematic model showing how an apertured flange formed on an initial molded precursor frame can be used, in an overmolding operation, to mechanically engage a secondary material with a preliminary material that is resistant to chemical bonding.

Schematic chassis window 1890 includes schematic window frame 1892, frame connector 1894, frame rail 1896, and frame bridge links 1898. Bridge links 1898 connect frame rail 1896 schematic window frame 1892 at a plurality of locations.

The apertures left between bridge links 1898 further increase the mechanical interference and are spatially arranged to make a more secure surface bond between the two polymers. The principle can be extended to any plurality of rails and bridge links. A given window can be fully occupied by a flexible mesh made of thin sections of rigid material. The overmolding can provide a visually continuous exterior elastomeric field that is invisibly reinforced by the internal patterned mesh.

Preceding embodiments described systems using a geometrically continuous chassis. Each engaged traction element therefore influences the operation of the others to which it is structurally linked. The further and discrete embodiment details a modification in which six structurally and operationally independent studs are clipped into individual housings. Each bladed stud is monolithically molded with a specially devised snap fitting. FIG. 120 depicts a schematic model of a discrete bladed flexural traction element employed in a variant of the disclosed footwear system in which flexural blades arc individually interchangeable. The traction elements each include an array of flexural articulating beams are also serve as mounting prongs in a snap fitting arrangement. FIGS. 121 and 122 show the capture of the traction features upon a compatible forefoot platen.

Individual bladed chassis 1900 includes upright blade 1902, fork bridge 1904, inner prongs 1906, and outer prongs 1908. Inner prongs 1906 include inward-facing catches 1910. Outer prongs 1908 include outward-facing catches 1912.

FIG. 121 illustrates a schematic model including a set of discrete traction elements installed in a compatible forefoot platen assembly, in which the forefoot platen assembly provides a discrete housing for each discrete bladed flexural traction element. FIG. 122 is a reverse partially cut away view of the arrangement of shown in FIG. 120, in which the molded cover layer of the housings is shown cut away in order to show how the four prongs on each traction element are caught and retained by corresponding elements integral to the housed platen assembly.

Housed forefoot platen 1920 includes housed platen base 1922. Hardware holes 1924 permit mounting and demounting of housed forefoot platen 1830 to a compatibly fabricated sole plate. Housing walls 1926 extend from housed platen 1920 in bilaterally symmetrical pairs. Where permissible, neighboring housing walls 1926 are conjoined for compactness and durability.

Internal walls 1928 are located at the midline between each pair of housing walls 1926. Housing covers 1930 are materially continuous with housed platen 1920, housed platen base 1922, and housing walls 1926, and are conjoined into one or more cover substructures.

Fill plate 1940 is formed in a separate molding operation and occupies the molding ports left in order to enable molding of the hollow housings. As it fills openings left as a consequence of the use of a simple two-piece mold, fill plate 1940 serves a purpose somewhat analogous to relief fill panel 1760 in FIG. 107. Both housed platen 1920 and fill plate 1940 can be molded in two-part molds, without any complex mechanical actions.

FIG. 122 reverses the perspective orientation of FIG. 121, and visually cuts away housing covers 1930 to illustrate how the four prongs on each traction element are caught by corresponding elements integral to the housed platen assembly. The reliability of the capture of individual bladed chassis 1900 within housed platen 1920 depends on the differentiation of the structure and operation the array of prongs.

Specifically, inward-facing catches 1910 are furnished with a negative rake, while outward-facing catches 1912 are furnished with a positive rake. Snap fittings with a sufficiently negative rake at their meeting faces can be separated by a pulling force, while snap fittings with a positive rake can only be separated by direct disengagement of the mutually hooked features, or destruction.

The illustrated assembly includes both types of catches. To install the set of individual bladed chassis 1900, the chassis are slid under and into housing covers 1930 until inward-facing catches 1910 and outward- facing catches 1912 respectively engage with corresponding retentive internal walls 1928 and retentive features on housing walls 1926.

To release the chassis without damage, it is necessary to advance the pair of outwardfacing catches 1912 on outer prongs 1918 toward one another through short arcuate paths, in an interaction similar to that described in reference to compact chassis 1600 and compact platen 1630 in FIGS. 93-98.

To fully extract each individual bladed chassis 1900, a degree of outward force is manually applied to the inner face of upright blade 1902, while at the same time drawing the outer prongs toward one another in the field plane. Only then can the chassis be slid out of its operative position without damage to one pail or the other.

The outer two prongs are hooked in order to resist accidental release, effectively exhibiting a moderately-curved positive rake. The inner two prongs have faces with faces beveled to approximately 20°, effectively exhibiting a moderate negative rake. As noted above, absent other interference, a negatively raked snap fitting can be pulled free from its catch owing to the ramping faces. In principle, a positive hook results in a destructive fit, unless the hook is actively released by a user actively deflecting the hook from its aligned condition.

In the installation process, the four prongs deflect more or less concurrently as the component is pushed into its recess. At the terminus of the allowed travel, the heads of the prongs engage with retentive features formed integrally with the forefoot plate. Once installed and engaged, the prongs substantially return to their relaxed, unloaded state.

Each housing shell furthermore encloses a dividing and retentive internal wall 1928 that guides the prongs into their intended direction. In the field plane, the divider and sidewalls are curved away from the shape of the discrete stud component. This allowance allows pscudopantographic deformation of the prongs in cither direction within the field plane during athletic activity.

The disposition of the four prongs deters any part of the curved divider and walls from acting as a fulcrum during the dynamic deformation of the element. The component therefore resists being inadvertently pried loose by the leverage of the turf.

The heads of the two outer prongs extend beyond the housing so that they remain visible and manually accessible. When the elements are to be removed, an operator deflects the exposed heads of the two outer prongs so that the positive-rake hooks bypass their catches. Applying an outward force to the stud from its inward face can disengage the central pair of ramped, negative rake faces.

While this fastening arrangement is intended to permit only deliberate removal, convenient dismounting is enabled by providing a stop on the housing so that the deflection of the outer pair of prongs is arrested at a position where the inner pair of prongs is still allowed to deflect into an unoccupied volume by an indirect pulling force. In the illustrated example, the outer prongs are provided with greater length so that they are stopped through contact with internal walls 1928.

Absent the stop, the unrestricted deflection of the outer prongs would trap the oppositely- disposed captive head of the inner prong against its commensurate catch. In order to extract the component, the operator would need to estimate the requisite degree of deflection of the outer prongs, and then knowingly deflect the prongs only to that point.

In the illustrated design, the outer prongs are deflected by direct manual force, while the inner prongs are deflected by indirect manual force. Each pair of neighboring prongs is given just enough allowance between the center guide and an outer wall for passage of the deflected pair of heads.

Further envisioned modifications of the disclosed footwear system include plurality of pronged chassis monolithically or separately connected in a chain, which may electively integrate fenders that cover the openings of the housings. The chassis using these features can be intentionally disposed to influence one another’s operation. The illustrated example should therefore be taken as implicitly inclusive of hybrid and intermediate solutions in view of the full range of preceding examples. In other versions of this system, the housings can be deliberately disposed in the design so that prongs obstruct one another unless a particular order of removal is enacted. This sequence adds a further level of safety to their mounting. In this circumstance, the necessary sequence can be instructively marked on the sole plate.

This completes the discussion in direct relation to the drawings. The following section includes further details and commentary regarding particular implementations of the preceding designs.

Athletes typically exhibit a rolling gait that transfers weight increasingly toward the tip of the foot. This cycle influences the flexural response of the chassis. In general, the chassis follows the gross directional movement of the athlete when the sole is relatively evenly engaged in the surface, but becomes more permissive of acute rotation as the athlete’s weight is shifted forward.

Within the disclosed footwear system, this progression is, in exemplary cases, enabled by a dual-pivot arrangement. When both rotational poles of the chassis are deformatively activated, the two pivotable locations drive the deformation of the chassis via forces transferred from the cleats to the elastically resilient longitudinal features. This causes the spine, spine array, or other longitudinally disposed chassis feature to deform into a relatively shallow arc.

As the weight is shifted forward, the trailing elements progressively disengage from the turf, while the leading elements engage more deeply. As the bias is shifted forward, the concentration of torsional force about the leading pivot increases, while the corresponding force about the trailing pivot decreases.

The comprehensive effect is that the athlete experiences an increase in ease and attainability of rotation toward the finish of the stride. The experienced turning radius effectively becomes smaller as a normal running pace progresses. This accommodation provides relief to the leg joints at certain unstable moments, as when executing an abrupt maneuver at speed.

In general, it may be appreciated that forefoot components are expressly devised to retain their articulation when the chassis is momentarily formed by an athlete’s rolling stride into a curved state. The forefoot assemblies in the following examples can be routinely bent to an included angle of 90°, without inducing disengagement or inoperability of the traction chassis. Forefoot assemblies in the disclosed footwear system have been found to remain torsionally functional even when subjected to a longitudinal out-of-plane twist of 20°. Mechanically conjoined elements have been found to bend or twist throughout their intended operational range while exhibiting gaps no greater than 1 mm at any location between the chassis and fore plate. This owes in pail to detailed influences imparted by the teachings of the disclosed footwear system, such as conformal concavities in the contact faces of the chassis, and locally induced spring forces. These intentional structures and interactions ensure that the mated components remain in contact throughout a range of states of flexion.

The preceding descriptions have described a multiplicity of structurally distinct methods of installing and removing articulable chassis within a modular traction system. A first form uses alignment of a flexural chassis using relief features on a sole, and mounting the chassis using discrete hardware components, such as threaded metal bolts. A second form uses clips or snaps on the chassis that are captured by posts on the sole plate. The third form provides mutual alignment of the articulating chassis and sole through the use of positional pinions in collaboration with sliding tabs and channels.

A fourth form employs a primary pinion, and rotates into a captive but orbitally displaceable relationship with the sole plate, owing to the complementary retention of a set of cantilevered tabs and one or more circular or annular pinions. A relevant subset of solutions within the fourth form includes an arcuate bayonet feature that is allowed to reciprocate in two opposing rotational directions about an intermediate resting position. The torsional resistance in the two directions need not be equal in either resistive force or angular range.

A fifth form of the disclosed footwear system uses one or more prongs that can be deflected along an arcuate path in order to catch receptive posts located on a mating part. A useful form of this implementation employs a pair of oppositely-disposed prongs that are reversibly captured by posts on their compatible sole plates.

These forms of the disclosed footwear system may be used in any combination or number upon articles of footwear. For example, an article of footwear can include a repetition of bayonet-type rotary mounted chassis, so that a set of identical parts can be mounted on the heel and forefoot. A single chassis may encompass both the forefoot and heel regions.

Pinions governing a pivoting action can have a whole or segmented shape, and accordingly can have a round, annular, arcuate, elongate, triangular, keyhole, hourglass, or bowtie shape, so long as their influence serves the application of the disclosed footwear system. They can vary in number, and differ in depth and draft angle to accommodate ready installation and removal. The disclosed footwear system expressly encompasses embodiments intermediate between those shown in the necessarily explicit figures, including diverse modes of manually or mechanically deforming an articulating chassis so that it is made both captive and motile upon the article of footwear.

Beams within an articulating chassis can be computationally derived, in any dimension, proportion, position, or spatial frequency, to integrate logarithms, progressions, or matrices that yield sets of values that regulate or optimize their individual or collective effect.

Within current practice, shoes for use on artificial turf are designed and designated for such use, and may differ depending upon the properties of the synthetic field surface. Play on hard surfaces such as compacted soil, concrete, or wood are also widely practiced. Accordingly, nominal class designations in current use for football alone include FG, SG, HG, AG, MG, TF, TT, ID, IC, and IT, and have colloquial design guidelines within the trade. Arrays within the disclosed footwear system can be expressly engineered for individual sports, players, styles of play, field surfaces, or field conditions.

It is an express intention of the foregoing disclosures and descriptions of footwear systems that they provide an ongoing esthetic palette for the designer of the chassis components, as it is visual variety, as well as technology, that is known to drive the adoption and commercial appeal of footwear.

The diversity of attainable variants is expected to enhance the overall value of the comprehensive footwear system. Accordingly, the disclosed footwear system should not be considered to be limited in any aspect of body color, tactile quality, imprinting, or surface finish. Complementary insignia or decorations may be inlaid or onlaid. Coloring and labeling can be originated to express solidarity with amateur or professional teams.

The existence of an active secondary market for athletic shoes is also recognized, as is the vital role of esthetics and identity in establishing and preserving value in that market. Athletic shoes produced with this community in mind are often produced in intentionally limited runs. This circumstance increases the imperative of generating a multiplicity of design variants, even if the footwear is never intended for field wear.

Accordingly, flexural mechanisms formed within the disclosed footwear system may be directed toward the visual or conceptual appeal of their real or imagined movements, as well as their static appearance. Articulating chassis within the range of the disclosed footwear system can foreseeably integrate non-functional mechanical actions, such as animated gearing and linkages, solely for the wearers’ contemplation of their operation.

Sports with high degrees of physical contact, such as rugby, lacrosse, and North American football, side hits are a common source of injury. The thicknesses and curvatures of the beams can be devised so that the stud buckles, deflects, or breaks away at an applied- force threshold. When studs are individually removable, they may exhibit the diversity of properties of such components already disclosed in the prior art.

Spoils using relatively shallow traction features, such as those for indoor athletics, track and field, training, and trail running, can also make use of the disclosed footwear system. On outdoor terrain, such systems may be used to mitigate the stresses of ascent or descent without requiring thick foams to cushion shear forces.

The ready separability of the chassis from the sole plate allows the use of a polymer material in the chassis that cannot be reliably adhered. The separability of the components therefore allows the use of low surface energy polymers and silicones which would otherwise be precluded from footwear design. Low surface energy polymers often provide low wear and friction, while discouraging soil adhesion. The separability of the chassis from its mounting also allows a degraded monolithic traction chassis to be removed and recycled.

The open chassis designs illustrated in the specification are generally provided with draft and shutoff angles so that they can be cost-effectively molded in two-part molds, without sliding pins, plates, or cores. Alternate designs having closed limbs and unrelieved undercuts can be molded using molds with sliding or collapsible cores.

A dense, rigid polymer may be used for the flexural chassis, and be infilled with a closedcell foam or elastomeric membrane. Elastomeric or rigid materials can be finely corrugated or apertured so that they can expand and contract with the articulations of the moving chassis or sole plate. A sole plate platen can carry a variety of shaped prominences or recesses to accommodate differing chassis pinion positions.

Flexural arrays formed according to the disclosures of the articulating footwear system can be used for medical, remedial, therapeutic, or orthopedic reasons, and may accordingly be selected or devised for a particular set of physical conditions, or for the idiosyncratic or incidental needs facing the individual athlete. In general, it may be appreciated that the relative positions of interfitting assembly features such as snaps and catches, grooves and tabs, or holes and posts, can often be reversed, and any descriptions should be understood to encompass any such similar inversions, dispositions, or transpositions.

By decoupling the foot position from the emplacement of the shoe’s engaged traction elements, the disclosed footwear system provides a way to mechanically buffer the forces imparted on the feet during athletic activity, and by inference mitigate the forces imposed upon the athlete’s bones, musculature, and connective tissue. The system is adaptable to easy customization for the player’s age, size, weight, style of play, physical condition, or state of physiological remediation. The disclosed footwear system nevertheless preserves the desirable traction effects that are essential to competitive play.

Footwear designed according to the preceding instructions responds resiliently to a force applied to the traction features in the field plane, and returns the momentarily displaced traction features to their original position when the force is removed. The deformable traction elements combine preventative properties with energy-storing and releasing effects.

The modular aspect of the comprehensive disclosed footwear system provides a variety of functional options, personal choices, and practical economies. Traction chassis or other compatible coverings may be interchanged to suit circumstances within the bounds of a sport, or provide any alternation of functionality between activities employing the foundational footwear. Degraded or otherwise disfavored traction systems can be readily repaired, revised, or upgraded.

Although the totality of circumstances leading to a leg injury can be elusive, excessive torsion applied to the knee is a known contributor to many anterior cruciate ligament (ACL) injuries, due to the unnatural angular displacement between the planted foot and the momentum of the athlete’s rotationally displaced body mass. The disclosed footwear system provides perceptible and measurable relief from torque in such athletic postures.

As the fear of injury has a broadly inhibitory effect on general athletic practice, any system that succeeds in quantifiably reducing the risk of injury invites increased participation by novice, aging, intermittent, or anxious athletes, as well as preserving the health and well-being of competitive or elite players.

Also, the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. Any references to examples, embodiments, components, elements or acts of the systems and methods herein referred to in the singular may also embrace embodiments including a plurality, and any references in plural to any embodiment, component, element or act herein may also embrace embodiments including only a singularity. References in the singular or plural form are not intended to limit the presently disclosed systems or methods, their components, acts, or elements. The use herein of “including,” “comprising,” “having,” “containing,” “involving,” and variations thereof is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. References to “or” may be construed as inclusive so that any terms described using “or” may indicate any of a single, more than one, and all of the described terms. In addition, in the event of inconsistent usages of terms between this document and documents incorporated herein by reference, the term usage in the incorporated reference is supplementary to that of this document; for irreconcilable inconsistencies, the term usage in this document controls.

Having thus described several aspects of at least one example, it is to be appreciated that various alterations, modifications, and improvements will readily occur to those skilled in the art. For instance, examples disclosed herein may also be used in other contexts. Such alterations, modifications, and improvements are intended to be part of this disclosure, and are intended to be within the scope of the examples discussed herein. Accordingly, the foregoing description and drawings are by way of example only.

What is claimed is:

Claims

1. A system to provide traction to an article of footwear including a sole, the system comprising: a platen provided on the sole, the platen including a mount-receiving feature; and a chassis configured to be releasably secured to the platen, the chassis including a mountengaging feature configured to releasably engage the mount-receiving feature of the platen to secure the chassis with respect to the platen, wherein the chassis further includes a plurality of relief traction features disposed upon and extending from the chassis and at least one flexural beam mechanically continuous with at least one traction feature of the plurality of relief traction features.

2. The system of claim 1, wherein the mount-engaging feature of the chassis and the mount-receiving feature of the platen are configured to include mutually engageable relief features on the chassis and platen, the mutually engageable relief features collectively providing both a retention function and a restriction function.

3. The system of claim 2, wherein the mutually engageable relief traction features are proportioned and disposed such that a force applied to the relief traction features imparts a deformation to the beam and such that the relief traction features are displaced and the beam momentarily loaded with spring force.

4. The system of claim 3, wherein the mutually engageable relief features include features derived from circular geometry.

5. The system of claim 4, wherein the mutually engageable relief features include snap fittings.

6. The system of claim 5, wherein the snap fittings include a pair of prongs that are displaceable within a field plane that is coplanar with the platen.

7. The system of claim 6, wherein each snap fitting is configured to fit around a headed post on the platen.

8. The system of claim 5, wherein the snap fittings include an array of displaceable prongs oriented perpendicular to a field plane that is coplanar with the platen in a discontinuous annular pattern.

9. The system of claim 8, wherein each snap fitting is configured to fit over a headed post on the platen.

10. The system of claim 2, wherein the mutually engageable relief features arc mutually engaged in response to a spring force upon the alignment of the mutually engageable relief features.

11. The system of claim 2, wherein the beam is a spine disposed between two mutually engageable relief features having at least one of a restrictive function and a retentive function.

12. The system of claim 1, wherein the chassis is crowned on an internal side of the chassis.

13. The system of claim 1, wherein the chassis is mounted on the platen by the momentary deformation of a portion of the chassis out of its relaxed state.

14. The system of claim 13, wherein the deformation includes deforming the chassis out of a field plane that is coplanar with the platen.

15. The system of claim 13, wherein the deformation includes deforming the chassis in a field plane that is coplanar with the platen.

16. The system of claim 1 , wherein each of the chassis and the platen includes undercut structures.

17. The system of claim 16, wherein the chassis includes extensions that fit into the undercut structures, and removing the chassis from the platen includes deforming the chassis and releasing the extensions under the undercut structures.

18. The system of claim 1, wherein the beam is a member of a plurality of beams within a strut.

19. The system of claim 18, wherein each beam of the plurality of beams is configured to be one of straight, curved, serpentine, or in form a loop.

20. The system of claim 18, wherein a beam of the plurality of beams within the strut is configured to cause flexure of the plurality of beams when flexed.

21. The system of claim 1, wherein the beam is member of a plurality of struts within the chassis.

22. The system of claim 21, wherein a strut of the plurality of struts is configured to cause flexure of the plurality of struts when flexed.

23. The system of claim 1, wherein the beam is a flexural lobe extending from a flexural spine.

24. The system of claim 23, wherein each flexural lobe includes an undercut.

25. The system of claim 1, wherein the mount-receiving feature includes a slot and the mount-engaging feature includes a tab configured to be received in the slot and retained by the mount-receiving feature upon rotating the tab within the slot.

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26. The system of claim 25, wherein the mount-receiving feature includes an annular ring raised relative to the slot.

27. The system of claim 25, wherein the mount-receiving feature and mount-engaging feature include complementary interlocking arcuate elements.

28. The system of claim 27, wherein the arcuate elements are located in a central forefoot region of the sole.

29. The system of claim 27 , wherein the arcuate elements are located along a lateral forefoot region of the sole.

30. The system of claim 27, wherein the arcuate elements are located in a central forefoot region of the sole and along a lateral forefoot region of the sole.

31. The system of claim 25, wherein the mount-receiving feature and the mountengaging feature further include complementary interlocking elements spatially separate from the slot such that the interlocking elements releasably engage one another by deformation of the chassis.

32. The system of claim 31, wherein the interlocking elements have a circular geometry.

33. The system of claim 25, wherein the chassis is releasably engaged with the platen by a first step of rotating the tab within the slot and a second step of deforming complementary interlocking elements.

34. The system of claim 33, wherein a combination of the mount-receiving feature and the mount-engaging feature permits a degree of local rotational motion when the mountreceiving feature and the mount-engaging feature are in a mutually engaged state.

35. The system of claim 34, wherein local rotational motion within the mounted chassis is permitted at two locations.

36. A slide-in traction assembly for a traction system to provide traction to an article of footwear including a sole, the assembly comprising: a platen provided on the sole, the platen including a slide-receiving feature; a chassis configured to be releasably received to the platen, the chassis including a slide- in feature configured to releasably receive the slide-receiving feature of the platen; and a sliding connector assembly configured to releasably secure the chassis to the platen, the sliding connector assembly including a chassis connector component associated with the slide-in feature of the chassis and a platen connector component associated with the slide-receiving feature of the platen.

37. The assembly of claim 36, wherein the sliding connector assembly further includes at least one undercut feature on the platen and at least one underfitting flange on the chassis to position the chassis with respect to the platen when the slide-in feature of the chassis is received within the slide-receiving feature of the platen.

38. The assembly of claim 37, wherein the at least one undercut feature includes a plurality of undercut features on the platen, and the at least one underfitting flange on the chassis includes a plurality of underfitting flanges on the chassis.

39. The assembly of claim 36, wherein the chassis further includes at least one laterally displaceable beam that is deflectable at one end.

40. The assembly of claim 39, wherein the at least one laterally displaceable beam includes a recess formed in an internal side of the at least one laterally displaceable beam, the recess being located toward an unsupported end of the at least one laterally displaceable beam.

41 . The assembly of claim 40, wherein the platen further includes a post formed therein, the post dimensionally corresponding in width to the recess formed in the unsupported end of the at least one laterally displaceable beam.

42. The assembly of claim 41, when the slide-in feature of the chassis is received within the slide-receiving feature of the platen, the at least one laterally displaceable beam bears against the slide-receiving feature of the platen in a ramping action so that the at least one laterally displaceable beam is momentarily deflected to enable the post to be received within the recess.

43. The assembly of claim 39, wherein a free end of the at least one laterally displaceable beam faces a leading end of a soleplate of the sole of the article of footwear.

44. The assembly of claim 39, wherein a free end of the at least one laterally displaceable beam faces a trailing end of a soleplate of the sole of the article of footwear.

45. The assembly of claim 39, wherein the at least one laterally displaceable beam includes two laterally displaceable beams that are deflectable at one end.

46. The assembly of claim 45, wherein the two laterally displaceable beams are mutually opposed to one another.

47. The assembly of claim 45, wherein the two laterally displaceable beams are bilaterally symmetrical.

48. The system of claim 36, wherein the platen is integrally formed with a soleplate of the sole of the article of footwear.

49. The system of claim 36, wherein the platen is removably installed on a soleplate of the sole of the article of footwear.

50. The system of claim 36, wherein the platen is located at a heel of a soleplate of the sole of the article of footwear.

51. The system of claim 36, wherein the slide-receiving feature of the platen includes a recess formed therein and the slide-in feature of the chassis includes an outwardly deflectable tab with a boss on an internal side of the deflectable tab, the recess being configured to receive the boss of the deflectable tab when the slide-in feature of the chassis is received within the slide-receiving feature of the platen.

52. A system to provide traction to an article of footwear, the system comprising: a chassis configured to be releasably secured to the article of footwear, the chassis including a mount-engaging feature configured to releasably engage the chassis with respect to the article of footwear, the mount-engaging feature including two pivotable centers having circular relief geometry; at least one flexural beam mechanically continuous with the two pivotable centers, wherein the chassis further includes a plurality of relief traction features disposed upon and extending from the chassis, the at least one flexural beam being mechanically continuous with at least one traction feature of the plurality of relief traction features.

53. The system of claim 52, in which the at least one flexural beam is located between the pivotable centers.

54. The system of claim 52, wherein the at least one flexural beam is located between a first pivotable center of the two pivotable centers and a relief traction feature of the plurality of relief traction features.

55. The system of claim 52, wherein the chassis includes an undercut flange.

56. The system of claim 55, in which the undercut flange is mechanically continuous with a first pivotable center of the two pivotable centers, the undercut flange having a circular relief geometry.

57. A slidc-in traction component for a traction system to provide traction to an article of footwear, the traction component comprising: a chassis configured to be releasably received upon article of footwear, the chassis including at least one laterally displaceable beam, wherein the at least one laterally displaceable beam includes a recess formed in an internal side of the at least one laterally displaceable beam, the recess being located toward an unsupported end of the at least one laterally displaceable beam, and wherein at least one laterally displaceable beam is deflectable at the unsupported end, such that the at least one laterally displaceable beam is permitted displacement from a first position to a second position upon the application of a lateral force.

58. The traction component of claim 57, further comprising a primary external face and at least one underfitting flange recessed from the primary external face.

59. The traction component of claim 58, wherein the at least one underfitting flange includes a plurality of underfitting flanges on the chassis.

60. The traction component of claim 57, wherein the at least one laterally displaceable beam includes two laterally displaceable beams.

61. The traction component of claim 60, wherein the two laterally displaceable beams are oppositely disposed.

62. The traction component of claim 57, wherein the recess is arcuate.