WO1991004186A1

WO1991004186A1 - Cleat for snowmobiles and the like

Info

Publication number: WO1991004186A1
Application number: PCT/US1990/005390
Authority: WO
Inventors: Joseph Berto
Original assignee: Individual
Current assignee: Individual
Priority date: 1989-09-20
Filing date: 1990-09-20
Publication date: 1991-04-04
Anticipated expiration: 1992-03-20

Abstract

This invention relates to cleats (10) mountable on endless tracks or treads (12) to improve both traction and braking under adverse lateral forces producing skidding and loss of traction wherein each cleat includes a gripping flange portion (17) which is characterized by the outer edge being formed as a pair of planar surfaces (18, 20) that diverge outwardly and backwardly from a central portion (26) of the cleat relative to the normal driving direction of a vehicle.

Description

Cleat for snowmobiles and th_ like planar flanges for either compacting or pressing against soft or powder snow. However, little or no regard appears to have been given to more severe problems that such cleats can create on surfaces of widely varying hardness or compaction to resist skidding, as during turns, or traversing hilly or mountainous terrain, or during braking. In fact, many such cleats aggravate problems of skidding or sliding during forward traction, by reducing surface area contact of the drive track and the ability of a vehicle to resist turning forces crossing or climbing side hills These problems become even more severe and may lead to tragedy to an operator or the machine under braking conditions due to the inability of the cleats to resist forces lateral to their attachment to the vehicle drive track or tread. Further, the surface area of spikes may be too small to be effective on ice surfaces that are too hard for the spikes to penetrate. Likewise spikes are relatively ineffective on powder snow. Planar cleats, whether vertical or canted forwardly or backwardly from the direction of travel, may reduce ground contact area on icy surfaces and have little or no resistance to lateral forces, such as those induced by side hills, turns or uneven braking.

In accordance with the present invention my cleats include a traction increasing flange which resists lateral forces imposed on the vehicle by inertial forces or gravity during turning or skidding, or due to changes in terrain or the degree of compaction of its surface. The flanged portion of each cleat resists such lateral forces by including a pair of terrain engaging planar flanges, or blade portions, which diverge outwardly and backwardly from a central portion of the cleat with respect to the driving direction of the vehicle whether mounted on an endless track as on a snowmobile, or a rotatable tread, as on an all-terrain vehicle. With such configuration, the diverging planar surfaces are at an obtuse angle to each other from the central portion of the base plate of the cleat so that the central portion of the blades, whether solid between the surfaces, or gapped, strike the ground first in normal forward drive. This action exerts a downward and backward compression of unconsolidate ground or snow to lift the tread and the vehicle as they move forwardly. At the same time any tendency of the tread or vehicle to slip sideways is resisted by both diverging planar surface converting the lateral force components acting on the flange to a normal component in the direct line of drive or braking, whether traveling on a side- or down-hill and over areas of firmer ground or snow. Further, on braking of the vehicle, the two angled, planar surfaces tend to pack the surface both forwardly and latterly toward the central area between the two planes. This substantially improves braking of a vehicle in addition to increasing safety by reducing skidding or side slipping, on harder plane surfaces or on hilly terrain.

Summary of the Invention;

In a preferred form the cleat of the present invention is an article of manufacture connectable to an endless track or to a broad cylindrical tread of a land vehicle. In a preferred embodiment it includes an elongated base plate having a width and configuration, flat or curved, for mounting on a link of an endless track or tire. An integral flange portion extends generally longitudinally along the base plate, and includes at least a pair of generally upstanding blade portions which angularly diverge latterly from the central portion of the cleat toward the outer ends of the base plate. The blade portions have an obtuse angle therebetween so that in normal drive, the central portions the flange first contacts the terrain surface, during propulsion of the links of the endless track or cylindrical tread and thereby increase the longitudinal and lateral resistance of the track or tread to slippage transverse to the direction of travel on surfaces of varying hardness or inclination.

In another aspect of the invention, each cleat is an article of manufacture for increasing traction between an endless track and the earth's surface, wherein the cleat has an elongated base plate forming one surface mountable on a drive link of an endless track or the like and the drive surface of the base plate has a paddle portion extending longitudinally therealong which includes at least a pair of blade sections extending laterally from the central area of the drive surface so that they form an obtuse angle therebetween.

In a further embodiment of the invention the central portion of the two flanges or blade portions may be formed with a gap or a space therebetween. Alternatively, they may be joined together, with or without, a reinforcing rib along the intersection plane. Desirably the ground engaging edges of each blade or flange may include serrations. Desirably the edges of the flange or blades are tilted from perpendicular to the base plate so that they lag their lines of attachment to the base plate at an angle of from zero to 30*, as measured from the direction of drive of the base plate when affixed to a link of an endless track or to a rotary tread. Further objects and advantages of the present invention will become apparent from the following detailed description of the preferred embodiments taken together with the drawings which form an integral part of this specification.

Brief Description of the Drawings;

Fig. 1 is a perspective view showing a plurality of cleats, in accordance with the present invention, mounted on several links of an endless track to drive of a snowmobile.

Fig. 2 is an enlarged perspective view of a preferred embodiment of the cleats, as seen at the exposed end of the snowmobile track in Fig. 1.

Fig. 3 is a vertical cross-sectional view in the direction of arrow 3-3 in Fig. 1 through the cleat and its attachment to a portion of a link of the endless track, or drive belt.

Fig. 4 is a bottom plan view taken in the direction of arrows 4-4 in Fig. 1 showing a preferred arrangement of a plurality of cleats of this invention mounted on different links of the track so they are spaced laterally and longitudinally from each other across the width and length of the endless track.

Fig. 5 is an end view of the cleat shown in Figs. 6 and 7 with the direction of drive indicated by an arrow. Fig. 6 is a front elevation view of the forward side of another embodiment of the cleat wherein the direction of drive is out of the plane of the drawing and showing the blades not joined together at the center of the cleat.

Fig. 7 is a top plan view of the cleat of Fig. 6, with the direction of drive toward the top of the drawing.

Fig. 8 is a view similar to Fig. 5 of a short (mini or pony) cleat including carbide tipped "picks" or studs, which are particularly suitable for attachment to a rotary drive tread or tire, or to provide wider or closer spacing of cleats across a tread or track, or to improve traction on ice or hardpacked trails.

Fig. 9 is a front elevation view, similar to Fig. 6 of the cleat of Fig. 8.

Fig. 10 is a top plan view of the assembled pick and cleat of Fig. 8.

Fig. 11 is an end view of a further embodiment of a cleat in accordance with the invention, similar to Fig. 7.

Fig. 12 is a front elevation view of the cleat of Fig. 11, similar to Fig. 9, but with the pair of diverging blades joined at the center of the cleat and including a reinforcing rib.

Fig. 13 is a top plan view of the cleat of Fig. 11, similar to Fig. 10. Preferred Embodiments of the Invention;

Referring now to the drawings and in particular to Fig. 1, cleats 10 constructed in accordance with present invention are mountable on individual links 11 which form endless track 12 for driving snowmobile 14 over the surface of snow of varying compaction, density, water content or the like. Cleat 10 is particularly formed to resist lateral forces that may be imposed on the vehicle during turning, skidding, braking or by a sloped terrain. Such resistance to lateral forces is accomplished by surface-engaging flange 17 being formed integrally with baseplate 16, including a pair of generally upstanding and diverging blade portions 18 and 20. As shown in Fig. 2 blades 18 and 20 diverge outwardly and backwardly relative to the direction of drive from the center of base plate 16. Preferably they form an obtuse angle 22 between them with an included angle of from about 150* to about 175A Such an angle of divergence has been found to be particularly advantageous to maintain forward acceleration along the intended drive line by substantially reducing lateral skidding or sideways motion on a crusted or icy snow surface. Additionally the diverging blades greatly improve braking characteristics of the vehicle to maintain a straight line by converting lateral force components on both blades to a single force directly in line with the motion of the vehicle. Further, due to the surfaces of the blades being rearwardly angled, during braking they effectively compact the snow or ground between this obtuse angle.

Additionally, as best seen in Fig. 3, blades 18 and 20 are canted or tilted (with respect to the direction of drive) at their junction with base plate 16 so that they form an angle between the blades and the base plate of from about 90* to 45* and preferably from about 60* to 75A Such tilted attitude of the blades permits the leading central portions of the blades to "knife" into the snow with the resultant forces on both blades acting along the center line of the cleat and normal to its length.

As indicated by the arrows in Fig. 1., (and in the bottom plan view of Fig. 4,) rotation of belt or track 12 is counterclockwise for forward drive of snowmobile 14. This direction, as shown by the mounting of cleats 10 on belt 12, brings the center portions of blades 18 and 20 into initial contact with the snow, or other yielding surfaces, so that the outer edges, preferably including ground gripping serrations 32, "lag" relative to the junction or intersection of the blades with baseplate 16 at an angle of from 0* to 45', preferably 15* to 30A An additional advantage of such a lag angle is the "lifting" effect upon contact with the ground which tends to raise the forward end of the vehicle during acceleration. The opposite action of the cleats in turn occurs upon braking by effectively "dipping" the front end of the vehicle to increase the braking effect.

I have found that in operation of a vehicle, such as snowmobile 1 , a particular advantage of forming flange 17 with blades 18 and 20 diverging outwardly toward the outer ends of cleat 10 and backwardly from the direction of travel lies in the unexpected substantial improvement in all aspects of traction and braking where the snow is crusty or icy and particularly in hilly terrain, such as during crossing of a side hill. In such conditions the tendency of a vehicle to slide sideways either due to natural or induced gravitational forces presents special perils to both vehicle and operator. These forces are strongly resisted by the mutual angular divergence between the blades relative to the direction of drive. Distribution of cleats 10 on belt 12, as by spacing them apart longitudinally on separate links 11, and laterally across the width of belt 12, as shown in Fig. 4, assures adequate contact with snow of varying degrees of compaction and roughness.

In a preferred form, central junction 26 of blades, or paddles, 18 and 20 includes a reinforcing rib 28 which acts not only to protect the central or leading edges of the diverging paddles from under wear, but also serves as a snow breaker or "slicer" to penetrate icy crusts or other hard surfaces and improves the purchase of each blade on the ground.

Alternatively, depending upon the degree of consolidation of the ground surface, such as soft snow, or mud, paddle, or blade, portions 18 and 20 forming flange 17 may be spaced or gapped apart at their leading edges, 19 and 21, at the apex of obtuse angle 22 at the central or impact points of flange 17. Such a construction is illustrated in Figs. 5, 6, and 7, which are generally similar to Figs. 2 and 3. As indicated central, or forward, edges 19 and 21 of blades 18 and 20 are spaced apart by gap or slot, 30, as best seen in fig. 6.

A further embodiment of the invention is shown in Figs. 8 to 10 in the form of a mini-cleat 50 which is particularly suitable for mounting on tire treads or narrow belts. More particularly however, as shown in Fig. 8, they provide a versatile mounting arrangement for studs or picks 52 with hardened points, such as carbide tips 54. As shown, the length of studs 52 may be shimmed as by washers 56, so that tips end slightly below the tips of teeth 32. Because cleats 50 are molded of plastic, teeth 32 are sufficiently resilient under load on ice so that they flex to add traction to group of stud 54 on ice or hard snow. Further blades 18 and 20 still retain the advantages of resisting lateral slipping or skidding for a vehicle either for traction or side hill traversing, on a broad flat surface, such as links 11. In this embodiment of the invention, I have found that for icy surface operation, cleats 50 are preferably mounted so that obtuse angle 22, between blades 18 and 20, is directed so that the outer ends contact the drive surface first, or backwardly from the direction of drive, for maximum effectiveness. Where these cleats are used on ice, or other hard surfaces, compaction of snow or the like, within the obtuse angle between the blades is not a problem. Thus, the advantages of the present invention are available on balloon tire treads, in unconsolidated or hard surfaces, to improve both braking and forward propulsion of a vehicle.

A further advantage, particularly in racing, is obtained by use of cleats constructed in accordance with the present invention, because of the "lift" they provide to the forward end of a snowmobile, as produced both by the canted edge of rib 28, which is generally perpendicular to central junction 26, and the lagging, serrated edges of blades 18 and 20, during forward propulsion. Such lift is achieved by mutual and counter lateral forces on blades 18 and 20 which react to exert a major force component normal to the center of the cleat. This force enhances the grip of the drive tread on the ground for direct forward thrust by the vehicle against the ground. Similarly, upon braking of the vehicle during turning, or in traversing tilted, or side hill terrain, these reaction forces when equal apply the resultant force components from the equal angular blades to straight ahead braking.

Preferably each cleat 10 is attached to a link 11 by bolts 36 which pierce link 11 through a cylindrical bore 35 each of which corresponds in location to conical bores 33 through base plate 16. The axis of bore 33 is desirably canted toward the forward surface of blades 18 and 20 to facilitate mounting on a link 11 of belt 12 without removal of the latter from the endless track of snowmobile 14. For example, a shape for holes 33 or 52 aids installation on a link, without access to either the flat upper or lower surfaces of belt 12. Bolts 36 are secured, as by nuts 38 and lock washers 40.

Desirably cleats of the present invention are cast as a unit in a single mold from thermoplastic polyurethane, or polyether, having a Shore hardness of about 90A to 50D molecules of stiffness up to about 100,000 psi and a tensile strength of about 5,000 to 10,000 psi and at temperatures down to -20*C.

The arrangement of Figs. 11 to 13 illustrates a further embodiment of the invention wherein the paddle or blade portions, 18 and 20, are wider or longer so that they are more flexible, relative to the dimensions of base plate 16.

In summary the present invention provides cleats with improved driving and braking characteristics for all terrain vehicles, including snowmobiles and the like, by positioning a pair of generally planer blades so that they complementarily slant away from normal relative to the direction of travel of the vehicle and diverge both backwardly and outwardly from a central area of a baseplate and with respect to the forward direction of travel of a vehicle over unconsolidate or irregular terrain.

Various modifications and changes in the illustrative examples and their equivalents will occur to those skilled in the art from the foregoing detailed description of preferred embodiments of the present invention. All such modifications or changes coming within the scope of the appended claims are intended to be included therein.

Claims

Claims;

1. A cleat for increasing traction of a snowmobile endless track or the like, said cleat being formed by an elongated base plate having a width adapted to mount on a link of an endless track, a flange portion having one edge thereof integral with the surface of said base plate and extending generally longitudinally along said surface, said flange portion further including at least a pair of generally upstanding, and angularly diverging blade portions extending from the central portion of said base plate toward the outer ends thereof and said blade portions having an obtuse angle therebetween, said base plate being mountable on the links of an endless track so that during propulsion thereof said blade portions frictionally engage a snow surface to resist both longitudinal and lateral slippage either in the direction of travel of the track or transverse thereto.

2. An article in accordance with Claim 1 wherein said blade portions stand at a rake of from about 90* to about 60* to said drive surface of said cleat.

3. A cleat in accordance with Claim 1 wherein said blade portions are joined at said central area of the base plate.

4. A cleat in accordance with Claim 3 wherein said blade portions include a reinforcing rib which extends along the location of joinder and which projects perpendicular to the junction.

5. A cleat in accordance with Claim 1 wherein said blade portions of said pair are spaced apart at the center of said cleat.

6. An article of manufacture consisting of a cleat for increasing traction between an endless track or tread and an unconsolidated traction surface, said cleat having a base plate having one surface mountable on an endless track or tread and an opposing drive surface having a generally upstanding paddle portion extending longitudinally therealong, said paddle portion including at least a pair of blades, each of which provides a generally planar surface which slants from normal to the direction of travel and at an obtuse angle to each other so as to diverge backwardly and outwardly from a central area of said cleat relative to a selected direction of drive of a vehicle over an unconsolidated traction surface.

7. An article of manufacture in accordance with Claim 6 wherein additionally the outer edges of said blade portions are at an obtuse angle at their connection to said base plate with respect to the direction of drive of a vehicle.

8. As an article of manufacture, a cleat for increasing traction between an endless tread or track and a traction surface, said cleat having an elongated base plate having one surface mountable on a drive link of such an endless track and a drive surface said drive surface including a generally upstanding flange portion extending longitudinally therealong having at least a pair of blade sections extending generally laterally and at an obtuse angle to each other, from the central area of said base plate so that said central area will initially contact the surface of a terrain in normal drive to compress the surface rearwardly and laterally from the center of said flange to resist lateral slippage during driving or braking of said endless tread or track with a traction surface.

9. A cleat in accordance with Claim 8 wherein the adjacent ends of said blade portions are joined and said joined ends of said paddle portion have a length so that the apex of said obtuse angle formed therebetween initially contacts a traction surface in the normal drive direction of said cleat.

10. A cleat in accordance with Claim 8 wherein the adjacent central edges of said blade portions are spaced apart to form a gap therebetween.

11. A cleat in accordance with Claim 8 wherein the outer edges of each of said pair of blade portions are canted relative to their connection to said base plate at an angle acute or obtuse to the direction of drive of said cleat.