RU2829640C1 - Shoulder assembly for tire building machine - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: group of inventions relates to a shoulder assembly mounted on an expandable and compressible tire building drum, as well as a expandable and compressible tire building drum. Shoulder assembly comprises a plurality of sections interconnected to form a shoulder ring mounted on the tire building drum when the tire building drum is in an extended state. Shoulder assembly comprises a plurality of magnetic elements located on the surface of the shoulder ring, which are configured to contact the side of the tire building drum. Magnetic elements correspond to the retaining magnetic elements in the tire building drum. Shoulder ring is made with possibility to maintain contact with tire assembly drum during tire carcass formation, and the shoulder ring is configured to maintain its shape so that it remains with the formed tire carcass when the tire building drum is compressed.

EFFECT: higher efficiency of tire carcass assembly.

20 cl, 7 dwg

Description

Cross-reference to related applications

The application claims priority to U.S. Provisional Patent Application No. 63/013,867, filed April 22, 2020, the contents of which are incorporated herein by reference in their entirety.

Field of technology

The general idea of the invention relates to a tire building machine and, more particularly, to a shoulder unit for attachment to a tire building machine for forming the outer edges of a tire carcass.

Prior art

The production of vehicle tires typically involves the steps of forming the tire carcass, forming the breaker section and tread of the tire separately from the carcass, and then joining the breaker section and tread of the tire to the carcass to form a green tire. The green tire is then processed to form the tread and a number of other tire components and vulcanize the rubber components of the tire.

The forming of the various sections of the tire is usually performed by one or more tire building drums of a type that is defined by a cylindrical working surface. For example, the forming of a section of the tire carcass is usually performed on a rotary expanding and contracting tire building drum, commonly referred to as a "first stage drum" or "carcass drum". Certain designs of carcass drums are designed to be radially expanding and contracting and may be referred to as a "radially expanding/contracting" drum or "PPC" drum. In conventional carcass drums, the rotating drum comprises a plurality of segments defining the outer periphery of the drum. The segments forming the outer periphery of the drum are adapted to be driven between an expanded position in which the tire carcass can be formed on the drum and a contracted position in which the formed carcass can be removed from the tire building drum.

The carcass drum in the extended position rotates about the central axis. During the rotation of the carcass drum, the individual components of the tire carcass overlap on the outer periphery of the drum to form a plurality of cylindrical layers. At least one and in some cases a plurality of rigid or semi-rigid rings, called "beads", are arranged so that they surround each opposite circumferential end of the tire carcass layers. The circumferential ends of the tire carcass layers are subsequently wrapped on the corresponding beads and connected to the more internal portions of the surface of the tire carcass layers to form the finished outer circumferential edges of the tire carcass.

Conventional carcass drums often have rounded outer circumferential edges of the drum running surface, called "shoulders". These outer shoulders of the drum are profiled so that the beads and the outer circumferential edges of the finished tire carcass can be wrapped and continue slightly radially inward on the outer running surface of the drum. Thus, when the tire carcass is being formed and finished on the outer running surface of the carcass drum, the radially inward extension of the beads and the outer circumferential edges of the finished tire carcass serve to "catch" the carcass drum inside the finished tire carcass. In other words, as long as the carcass drum remains in the extended position, the tire carcass is conformed in shape to the outer running surface and the inwardly curved shoulders and thus cannot be removed from the carcass drum. However, after the drum has been moved to the compressed position, the finished tire carcass can be removed from the carcass drum and transported to subsequent tire building drums for further tire manufacturing operations.

When a tire carcass is transported from a carcass drum to subsequent drums to continue manufacturing the tire, the tire carcass is often deformed, causing at least a portion of the tire carcass to acquire defects, such as folds, bulges, thin sections, etc. When the finished tire having said defects rolls on a surface, repeated contact with the surface of the tire sections having tire component defects, under certain circumstances, leads to the occurrence of undesirable operational characteristics of the finished tire, such as vibration and/or resonance of the rolling tire. Such vibration and/or resonance can lead to undesirable noise and/or shaking of the tire, increased wear and reduced service life of the tire, and in some cases to destruction of the tire structure.

For these and other reasons, a number of existing designs for carcass drums include shoulder rings that can be attached to the circumferential edges of the outer surface of the extended carcass drum to limit the shoulder portions of the carcass drum when forming a tire carcass, and which can be detached from the circumferential edges of the outer working surface of the carcass drum, providing the ability to compress the outer working surface of the carcass drum. After this, the finished tire carcass together with the removable shoulder rings located in the inner periphery of the tire carcass can be removed from the carcass drum. The tire carcass can then be transported with the shoulder rings retained in the tire carcass inside the bead edges, so that during transportation the shoulder rings continue to support the bead edges of the tire carcass, essentially in a circumferential configuration. Each shoulder ring limits a number of segments fastened to each other to form a rounded working surface of the shoulder of the carcass drum. Thus, once the tire carcass is prepared for placement on the next tire building drum to continue tire manufacturing, each shoulder ring can be disassembled and removed from inside the tire carcass.

Some existing designs of shoulder rings use threaded fasteners such as screws, bolts, etc. to perform the fastening of segments and the formation of a shoulder ring, as well as to perform the fastening of the shoulder ring to the corresponding edge of the outer working surface of the carcass drum. In designs where such threaded fasteners are used, the time required to perform the fastening and detachment of the removable shoulder rings from the carcass drum, as well as the disassembly of each shoulder ring to remove the shoulder ring from the tire carcass, can lead to significant downtime during the tire manufacturing process. In addition, this process leads to significant additional labor costs associated with repeated disassembly and assembly of the shoulder rings, as well as their repeated fastening and detachment from the carcass drum. Thus, there is a need to improve the design of the carcass drum and the removable shoulder ring for the carcass drum to improve the productivity of the tire carcass assembly and the efficiency of the tire manufacturing process.

Disclosure of invention

In a number of example embodiments of the general idea of the invention, a shoulder assembly is proposed that can be easily installed on a tire building drum without fasteners and maintain its position within the tire carcass when the tire building drum is compressed.

Additional aspects and advantages of the general idea of the invention are presented in part in the following description and in part will become clear from the said description or can be learned from practical implementation of the general idea of the invention.

The above-described and/or other aspects and advantages of the general idea of the invention can be provided by means of a shoulder unit, which must be mounted on a tire building drum, wherein the shoulder unit comprises a plurality of sections, made with the possibility of mutual connection with each other to form a shoulder ring, which must be mounted on a tire building drum, when the tire building drum is in the extended state, and on the surface of the shoulder ring a plurality of magnetic elements are arranged, which are made with the possibility of contact with the side of the tire building drum, wherein the magnetic elements correspond to the holding magnetic elements in the tire building drum, wherein the shoulder ring is made with the possibility of maintaining contact with the tire building drum during the formation of the tire carcass, and the shoulder ring is made with the possibility of maintaining its shape so that it remains with the formed tire carcass, when the tire building drum is compressed.

Other features and aspects will become apparent from the following detailed description, drawings and claims.

Brief description of the drawings

The following examples of embodiments characterize examples of technologies and structures developed to perform the tasks related to the general idea of the invention, but the general idea of the invention is not limited to the mentioned examples of embodiments. In the drawings, the dimensions and relative sizes, shapes and characteristics of lines, objects and areas may be exaggerated for clarity. A large number of additional embodiments will become more understandable from the following detailed description of the examples of embodiments with reference to the drawings.

Fig. 1 shows a simplified view of a frame drum comprising a pair of shoulder assemblies according to an example embodiment of the general idea of the invention, wherein the frame drum is shown in an extended position, in a perspective view;

Fig. 2 shows a simplified view of the frame drum and the shoulder assemblies from Fig. 1, with the frame drum shown in a compressed position, in perspective;

Fig. 3 shows a part of the circumferential edge of the cylindrical outer surface of the drum for the frame of Figs. 1 and 2, a perspective view;

Fig. 4 - a shoulder unit according to an example of an embodiment of the general idea of the invention, perspective view;

in Fig. 5 - the shoulder joint from Fig. 4, a perspective view from the other side;

Fig. 6 is a sectional view of the upper section of the shoulder assembly of Fig. 5 attached to the arcuate segment of the frame drum; and

Fig. 7 shows the shoulder assembly from Fig. 5 with the top section removed from the shoulder assembly.

Embodiments of the invention

Further reference will be made to explanatory embodiments of the general idea of the invention, examples of which are presented in the drawings and in the description. These examples of embodiments are presented in the application to explain the general idea of the invention with references to the drawings.

The following detailed description allows a comprehensive understanding of the structures and assembly technology presented in this document. Accordingly, various changes, modifications and equivalents of the structures and assembly technologies described in this document will be presented to those skilled in the art. The sequence of assembly operations described is given only as an example, but the type of the sequence of operations is not limited to the described type and can be changed as is known in the art, except for the operations necessarily performed in a certain order. In addition, the description of well-known functions and structures may be simplified and/or omitted for brevity and greater clarity.

It should be noted that spatial relative concepts such as "up", "down", "right", "left", "under", "below", "lower", "above", "upper" and the like may be used herein to conveniently describe the relationship of one element or feature to another element(s) or feature(s) shown in the figures. Spatial relative concepts serve to describe various orientations of the devices during use or operation in addition to the orientation shown in the figures. For example, if the device in the figures is inverted or rotated, elements described as "below" or "under" other elements or features will be oriented above the other elements or features. Thus, the explanatory concept "below" may refer to an orientation both above and below some element or feature. The device may be oriented differently (rotated 90 degrees or oriented differently), and the spatial relative concepts used herein are construed accordingly.

In a number of exemplary embodiments of the general idea of the invention, a shoulder unit is provided that is to be used with a tire building machine, wherein the shoulder unit is configured to be attached to a carcass drum when the drum is extended, but remains in the tire carcass and is separated from the drum when the drum is compressed. It should be understood that according to the general idea of the invention, there may be a pair of shoulder units, one of which may be referred to simply as a "shoulder", wherein one shoulder is attached to each of two opposite sides of the carcass drum during the formation of the tire carcass. However, for the sake of clarity, only one of the pair of shoulder units (i.e. on one side) will be described and only one shoulder unit will be shown. In addition, the terms "drum", "tire building drum" and/or "carcass drum" may be used in the present description on an equal basis.

In Fig. 1 and 2, a simplified view of a carcass drum 11 is shown, comprising a pair of shoulder assemblies 10 designed according to an example of an embodiment of the general idea of the invention, in a perspective view. It should be noted that the shoulder assembly according to the general idea of the invention can be used with any of the drums for building tires of different designs. At the same time, the simplified view of the carcass drum 11 shown in Fig. 1 and 2 serves to explain the various components of the carcass drum 11, which can be present for use together with the shoulder assemblies 10 according to the general idea of the invention. In this regard, the carcass drum 11 shown in Fig. 1 and 2, comprises a generally elongated central hub assembly 13 together with a plurality of substantially arcuate segments 15 supported around the hub assembly 13 in a substantially cylindrical configuration and configured to extend and retract between an extended position (see Fig. 1) and a compressed position (see Fig. 2). In the extended position shown in Fig. 1, the segments 15 are arranged end to end so that the segments 15 cooperate and form a substantially smooth cylindrical outer working surface 17 having a pair of opposite circumferential edges 23 limited by the cooperating end edges of the arcuate segments 15. In the compressed position shown in Fig. 2, the segments 15 are drawn toward the central hub assembly 13, essentially in an overlapping configuration, so that the entire frame drum 11 has a relatively small outer diameter compared to the diameter of the outer working surface 17, determined in the extended position of the drum.

It should be noted that there are additional mechanical connections and internal components 19 of the drum 11 for the carcass for performing the installation of the segments 15 of the drum 11 for the carcass relative to the central hub assembly 13 and the movement of the segments 15 between the compressed position and the extended position. However, a description of the characteristic features of such mechanical connections and internal components 19 is not necessary for understanding the general idea of the invention. Thus, for convenience of description, these additional internal mechanical connections and internal components 19 are shown in Figs. 1 and 2 in a simplified manner. A person skilled in the art will understand the design and operation of various mechanical connections and internal components of the drum for the carcass, taking into account numerous publications, for example, patent US8272417, issued to an applicant named Painter. However, it should be understood that numerous other designs and arrangements of drums for building tires can also be used without departing from the spirit and scope of the general idea of the invention.

Fig. 3 shows one of the circumferential edges 23 of the cylindrical outer working surface 17 of the frame drum 11 from Figs. 1 and 2, in a perspective view. According to various examples of embodiments of the general idea of the invention, the circumferential edges 23 of the frame drum 11 define a circumferential projection 25, which is slightly offset radially inward from the outer working surface 17 of the frame drum 11 and extends axially outward from the outer working surface 17 of the drum. Each circumferential projection 25 defines an axially outward facing annular flat surface 27. As described below, a plurality of magnetic elements 29 are arranged at equal distances from each other on the circumferential projection 25, wherein each magnetic element 29 is embedded in the projection 25 and faces outward in the axial direction along the annular flat surface 27 of the projection 25. As described in more detail herein, each shoulder assembly 10 can be mounted so as to be attached to a corresponding outer circumferential edge 23 of the frame drum 11 by means of a plurality of magnetic elements 29 arranged on the circumferential edge 23 of the frame drum 11 and a further plurality of magnetic elements arranged on the shoulder assembly 10. Thus, the shoulder assembly 10 can be mounted on the frame drum 11 in an assembled state or it can be assembled by mounting one part of the shoulder assembly 10 at a time on the frame drum 11.

In Fig. 4, a shoulder unit 10 according to an example of an embodiment of the general idea of the invention is shown separately. As can be seen in Fig. 1 and 2, the view in Fig. 4 is a view from the outside of the shoulder unit 10, which faces away from the frame drum 11, when the shoulder unit is installed on the drum. As shown in Fig. 4, the shoulder unit 10 comprises a plurality of arcuate and interconnected sections. In this example of an embodiment, there are four sections, which for convenience of description can be called an upper section 12, a lower section 14, a first side section 16 and a second side section 18. Each section 12, 14, 16, 18 is made of a sufficiently rigid material, such as steel, aluminum, plastic, polyurethane, etc. In some embodiment examples, each section 12, 14, 16, 18 may be made of a non-magnetic material such as polyurethane or other plastic, aluminum, etc. In some embodiments, one or more sections of the shoulder assembly may be made of polyurethane.

Each of the sections 12, 14, 16, 18 defines a substantially smooth arcuate outer surface 20, and, as described in detail below, each section 12, 14, 16, 18 is adapted for butt-to-butt releasably joining with each of the adjacent sections 12 14, 16, 18, so that the sections 12, 14, 16, 18 interact and form a circular ring. In this configuration, the various outer surfaces 20 of the sections 12, 14, 16, 18 cooperate and define a substantially cylindrical outer working surface 34 of the shoulder assembly 10. In addition, each section 12, 14, 16, 18 defines an outermost edge 22 having a rounded shape, so that when the sections 12, 14, 16, 18 are connected end-to-end, the various outer edges 22 of the sections 12, 14, 16, 18 cooperate and define a substantially smooth rounded profile defining a radially inwardly directed curved shoulder surface suitable for use in forming the final machined outer circumferential edge of the tire carcass. In a number of examples of embodiments of the general idea of the invention, the outer working surface 34 of the shoulder unit 10 is formed so that it is substantially flush with the outer cylindrical working surface 17 of the frame drum 11 when the frame drum 11 is in the extended position (see Fig. 1).

Fig. 5 shows the inner side of the shoulder unit 10 from Fig. 4, in perspective view. As described above, Fig. 4 shows the side of the shoulder unit 10, which faces away from the frame drum 11, when the shoulder unit is mounted on the drum. Thus, Fig. 5 shows the side of the shoulder unit 10, which faces the outer circumferential edge 23 of the frame drum 11 and contacts it, when the shoulder unit 10 is mounted on the frame drum 11. The shoulder unit 10 is designed such that the innermost circumferential edge 24 of the outer working surface 34 of the shoulder unit 10 defines a projection 31, the size and shape of which correspond to the corresponding circumferential projection 25 of the corresponding edge 23 of the frame drum 11, when the shoulder unit 10 is mounted thereon. Thus, when the shoulder unit 10 is located on the outer circumferential edge 23 of the drum 11 for the frame with the circumferential projection 25 of the drum 11, completely located inside the projection defined by the circumferential edge 24 of the outer working surface 34 of the shoulder unit 10, the two projections are in engagement with each other, ensuring the location and retention of the outer working surface 34 of the shoulder unit 10 flush and coaxial with the outer working surface 17 of the drum 11 for the frame.

As shown in Fig. 5, the shoulder unit 10 has an axially inwardly facing annular flat surface 26, which is offset inward in the axial direction from the projection 31 defined by the circumferential edge 24 of the outer working surface 34, and which extends radially inward from the projection 31. This radially inwardly extending annular surface 26 is configured to contact the above-mentioned outer side surface 27 of the circumferential edge 23 of the frame drum 11, when the projection 31 defined by the circumferential edge 24 of the outer working surface 34 of the shoulder unit 10 is completely located on the corresponding circumferential projection 25 of the corresponding edge 23 of the frame drum 11. The radially inwardly extending annular surface 26 of the shoulder unit 10 comprises a plurality of magnetic elements 28 arranged thereon, which correspond to the magnetic elements 29 arranged on the outer side surface 27 of the circumferential projection 25 of the frame drum 11. Thus, when the frame drum 11 is moved to the extended position and the shoulder unit 10 is arranged on the outer circumferential edge 23 of the frame drum 11 with the circumferential projection 25 of the drum 11 completely arranged inside the projection defined by the circumferential edge 24 of the outer working surface 34 of the shoulder unit 10, each of the magnetic elements 28 of the shoulder unit 10 can magnetically connect and be attracted by a corresponding one of the magnetic elements 29 of the frame drum 11 to form a detachable magnetic connection, thereby securing the shoulder unit 10 in the required position in the axial direction along the entire edge 23 of the frame drum 11.

Fig. 6 shows the upper section 12 of the shoulder unit 10 from Fig. 5, attached to one of the arcuate segments 15, forming the outer working surface 17 of the drum 11 for the frame, a sectional view. As shown in Fig. 6, in a number of example embodiments, the magnets 28, 29 in the shoulder unit 10 and the drum 11 for the frame can be placed in aluminum casings 38, 40, in which the position of the magnets can be adjusted, so that the force of magnetic attraction on the shoulder unit 10 can be changed to an optimal force. For example, in the embodiment shown, each of the magnetic elements 28, 29 is an insert made of magnetic steel, placed in an aluminum casing 38, 40 of a corresponding size, mounted inside a blind hole formed in the corresponding shoulder unit 10 or the drum 11 for the frame. In the embodiment shown, each magnetic element 28 of the shoulder unit 10 is secured inside the corresponding aluminum casing 38 using a friction connection, glue, etc. The magnetic element 29 of the drum 11 for the frame is placed inside the corresponding casing 40 with the possibility of sliding. Inside the through hole 44 defined by the arcuate segment 15 of the frame drum 11, an adjusting locking screw 42 is installed, which is designed to pass into the aluminum casing 40 and form a threaded connection with the corresponding magnetic element 29. Thus, the adjusting locking screw 42 can be adjusted with the possibility of rotation and move the magnetic element 29 of the frame drum 11 toward the magnetic element 28 of the shoulder unit 10 or move the magnetic element 29 of the frame drum 11 away from the magnetic element 28 of the shoulder unit 10. Thus, the distance between the corresponding pairs of mating magnetic elements 28, 29 can be adjusted when the shoulder unit 10 is attached to the circumferential edge of the frame drum 11, thereby adjusting the attractive force between each pair of mating magnetic elements 28, 29 to achieve an optimal force. With such an arrangement of the magnetic elements, no other fastening devices are required to hold the shoulder unit 10 on the frame drum 11.

In the embodiment shown in Fig. 6, the magnetic element 28 of the shoulder unit 10 is shown in a fixed form, while the locking screw 42 and the adjustable magnetic element 29 are shown in connection with the arcuate segment 15 forming the outer working surface 17 of the frame drum 11. However, this arrangement can be changed to the opposite without deviating from the essence and scope of the general idea of the invention. In other words, in other examples of embodiments, the magnetic elements 28 of the shoulder unit 10 can be adjustable, while the magnetic elements 29 of the frame drum 11 can be fixed. In a number of other examples of embodiments, each of the magnetic elements 28, 29 in the shoulder unit 10 and the frame drum 11 can be fixed inside a corresponding casing or inside blind holes formed inside the corresponding shoulder unit 10 or the frame drum 11. In other embodiments, a frame drum may be used in which there are no magnetic elements, and in which the magnetic elements 28 of the shoulder assembly 10 are designed to be magnetically connected directly to the arcuate elements 15 forming the outer working surface 17 of the frame drum 11.

It should be noted that in a number of embodiments similar to the embodiments shown in Figs. 1 - 6, when the drum 11 for the carcass is in the extended state, and the shoulder unit 10 is mounted on it, which is held in place by magnetic elements 28, 29, a tire carcass can be formed on the drum 11 for the carcass and the shoulder unit 10. When the drum 11 for the carcass is compressed, the mutually connected shoulder unit 10 remains in place inside the tire carcass. The separation of the frame drum 11 from the shoulder unit is relatively easy, since the magnetic elements 28 of the shoulder unit 10 and the magnetic elements 29 of the frame drum 11 face each other when the frame drum is in the extended state and when the frame drum is in the compressed state, and the segments 15 of the frame drum are moved under the action of a "sliding" or "shearing" radial force, which separates the paired magnetic elements 28, 29 more easily than if this were accomplished by retracting the magnetic elements from each other in the axial direction.

Fig. 7 shows the shoulder assembly of Fig. 5 with the upper section 12 removed from the shoulder assembly 10. As shown in Fig. 7, the upper section 12 of the shoulder assembly 10 is formed with a tongue or tenon 30 that extends from each end, the tenon 30 corresponding to a groove 32 formed in the upper ends of the first and second side sections 16, 18. Similarly, the lower section 14 of the shoulder assembly 10 is formed with tenons 30 that extend from each end and correspond to grooves 32 formed in the lower ends of the first and second side sections 16, 18. In a number of example embodiments, the tenons 30 and grooves 32 may be formed with substantially the same curvature as the outer diameter 20 of the shoulder assembly 10. Thus, as shown in Fig. 7, the assembly of the upper section 12 with the first and second side sections 16, 18 is performed by lateral movement of the upper section 12 and insertion of the studs 30 into the grooves 32. Such a design provides convenience of assembly and disassembly, which can be performed relatively easily, and the components of the shoulder assembly 10 can rotate with the drum during the formation of the tire carcass without unscrewing under the action of the rotational force. In a number of example embodiments, the studs 30 and the corresponding grooves 32 can be formed at an angle relative to the outer diameter 20 or can be formed with an increase in width or thickness from one end to the other. In a number of example embodiments, the studs 30 could have a profile for using a number of other connections, for example, a hook profile, a T-shaped profile, a sawtooth profile, etc. for fastening the components of the shoulder assembly 10 so that they can rotate with the drum without coming out under the action of the rotational force. The fasteners of said studs 30 in a number of example embodiments may be a separate bolt on the part that must be connected to the side sections of the shoulder unit 10. Such configurations may reduce wear, increase ease of manufacture, facilitate maintenance, etc. In a number of example embodiments, the shoulder segments may be formed from polyurethane or aluminum. In a number of example embodiments of the general idea of the invention, the shoulder unit may be formed without a projection of the innermost edge 24 and may rely only on magnetic elements for holding the shoulder unit on the tire assembly drum.

A number of example embodiments of the general idea of the invention may suggest the idea of introducing a "freely mounted shoulder" that does not use fixed fasteners and relies only on the above-described magnetic elements to attach the shoulders to the drum for the carcass in order to reduce the assembly time of triple and double bead tires, mainly tires for aircraft, agricultural machinery and off-road tires (OTR). In a number of example embodiments, polyurethane shoulder segments can be used, which are held in place on the drum by magnets. The shoulder segments themselves are connected to each other by studs and form a complete ring, and the studs act as a safety device to prevent radial displacement of the segments when the drum rotates. The corresponding magnets in the drum can be placed inside aluminum casings, and the magnets can be adjusted in the desired position to optimize the magnetic force required to hold the shoulder in place, as well as to ensure compression of the drum. Various exemplary embodiments of free-standing arms may comprise an embedded steel insert or magnet, wherein the inserts or magnets align with holding magnets in the aluminum housings and thus provide alignment of the arm.

Unlike traditional shoulders, the shoulders according to the general idea of the invention may remain in the carcass when the tire building drum is compressed and the carcass complete with shoulders is removed from the tire building machine. The drum will be compressed away from the shoulders, eliminating the magnetic effect by sliding instead of being directly pulled away, which would require applying more force. The shoulders may consist of four sections. Steel equivalent shoulders contain six sections, each weighing approximately 10 kilograms. Polyurethane sections according to the general idea of the invention may weigh approximately 5 kilograms each. In a number of exemplary embodiments, there may be shoulders with two sections with grooves with parallel cuts, wherein the parallel cut is connected to the tenon, which provides passage through the shoulders with grooves and forms a shoulder annular assembly, after which the same segments with grooves can be retracted inwardly with the tire carcass covering the shoulder assembly until the tire carcass is removed from the shoulders from the tire building machine, and the shoulders are held in place by a tire carcass retainer.

A number of example embodiments of the general idea of the invention may provide a shoulder unit that is to be mounted on a tire building drum, wherein the shoulder unit comprises a plurality of sections configured to be mutually connected to each other to form a shoulder ring that is to be mounted on the tire building drum when the tire building drum is in an extended state, and a plurality of magnetic elements located on the surface of the shoulder ring that are configured to contact the side of the tire building drum, wherein said magnetic elements correspond to the holding magnetic elements in the tire building drum, the shoulder ring is configured to maintain contact with the tire building drum during the formation of the tire carcass, and the shoulder ring is configured to maintain its shape so that it remains with the formed tire carcass when the tire building drum is compressed. One or more sections may be formed from polyurethane or contain polyurethane. The shoulder unit may also comprise a projection extending to close a portion of the periphery of the tire building drum when the shoulder ring is mounted on the tire building drum. The sections may be interconnected with each other at each end by means of tongue and groove joints configured to prevent radial displacement of the sections when the tire building drum rotates.

The main advantage of the general idea of the invention is the reduction of assembly time compared to traditional methods of tire assembly. Traditional methods of assembling the shoulders require manual intervention to remove each section before the drum is compressed. A number of example embodiments of the general idea of the invention provide for the elimination of such manual intervention at the initial stage of production, when the drum is simply compressed, leaving the shoulder ring in place. In a number of example embodiments, the use of polyurethane, aluminum, etc. makes it possible to use lighter sections of the shoulder assembly in smaller quantities, and thus, reassembly of the shoulders after removing the carcass will be faster than with traditional systems.

Numerous changes, modifications and additional embodiments are possible, and accordingly all such changes, modifications and embodiments should be considered within the spirit and scope of the general concept of the invention. For example, regardless of the content of any part of the application, unless expressly stated otherwise, there is no requirement to include in any claim of this document or in any application having priority over this document any specific act or element described or explained, any sequence of such acts or any mutual relationship of such elements. In addition, any act may be repeated, any act may be performed by a plurality of objects, and/or any element may be duplicated.

It should be noted that the simplified diagrams and drawings included in this application do not show all the connections and assemblies of a number of components, but those skilled in the art should understand how such connections and assemblies can be implemented based on the illustrated components, figures and descriptions provided herein, through careful technical evaluation. Numerous changes, modifications and additional embodiments are possible, and accordingly, all such changes, modifications and embodiments should be considered within the spirit and scope of the general idea of the invention.

Although the general idea of the invention has been presented by describing several exemplary embodiments, and the illustrated embodiments have been described in detail, it is not the purpose of the present application to limit the scope of the general idea of the invention in any way to such descriptions and explanations. On the contrary, the descriptions, drawings and claims presented herein are to be considered as illustrative and not limiting, and those skilled in the art will be able to easily understand additional embodiments after studying the above description and drawings. Those skilled in the art will be able to easily understand additional modifications. Accordingly, deviations from such detailed description are possible without departing from the spirit or scope of the general idea of the invention presented by the applicant.

Claims (28)

1. A shoulder unit mounted on an expanding and contracting tire assembly drum and comprising: a plurality of arcuate sections configured to be interconnected with one another to form a shoulder ring mounted on the tire building drum when the tire building drum is in an extended state; and a first plurality of magnetic elements located on the surface of the shoulder ring, which are adapted to magnetically attach the shoulder ring to the side of the tire drum; wherein the shoulder ring is configured to maintain contact with the tire assembly drum during formation of the tire carcass, and the shoulder ring is configured to maintain its shape and to be detached from the tire building drum when the tire building drum is compressed. 2. The shoulder assembly of claim 1, wherein the first plurality of magnetic elements located at a distance from each other on the shoulder assembly correspond to a second plurality of magnetic elements in the tire building drum. 3. The shoulder assembly of claim 1, wherein one or more sections comprise polyurethane. 4. The shoulder assembly of claim 1, wherein the sections are interconnected at each end by tenon and groove joints configured to prevent radial displacement of the sections when the tire building drum rotates. 5. The shoulder assembly of claim 1, wherein the shoulder ring defines a cylindrical outer working surface having a diameter substantially equal to the diameter of the outer working surface of the tire building drum. 6. The shoulder assembly according to claim 5, further comprising a projection extending to cover a portion of the periphery of the tire building drum when the shoulder ring is mounted on the tire building drum. 7. The shoulder assembly of claim 6, wherein the projection is sized to maintain the outer working surface of the shoulder ring flush with the outer working surface of the tire building drum. 8. The shoulder assembly of claim 1, wherein the shoulder ring defines a cylindrical outer working surface having a diameter substantially equal to the diameter of the outer working surface of the tire building drum. 9. The shoulder assembly of claim 8, wherein the shoulder ring also defines an annular outer edge having a curved surface. 10. The shoulder assembly according to claim 9, wherein the curved surface defines the shape of the outer section of the sidewall of the tire carcass. 11. An expandable and compressible drum for assembling tires, comprising: a plurality of arcuate segments supported around a central hub and movable between an extended position and a compressed position, wherein in the extended position the segments interact and define a central portion of a cylindrical working surface having a pair of opposite circumferential edges; and a shoulder assembly for defining an end section of the working surface, wherein the shoulder assembly comprises a plurality of arcuate sections configured to be interconnected with each other to form an outer section of the cylindrical working surface; wherein the shoulder unit is magnetically connected in a removably manner to one of the circumferential edges of the central section of the working surface. 12. An expandable and compressible tire assembly drum according to claim 11, also comprising: a first plurality of magnetic elements located on the surface of the shoulder ring, wherein each magnetic element from the first plurality of magnetic elements is configured to form a pair of magnetically connected elements with one of the second plurality of magnetic elements located on the corresponding circumferential edge of the central section of the working surface. 13. An expandable and compressible tire assembly drum according to claim 12, wherein each pair of magnetically connected elements creates an adjustable magnetic attractive force. 14. An expandable and compressible tire assembly drum according to claim 13, wherein moving the plurality of arcuate segments into the compressed position results in each pair of magnetically connectable elements being displaced relative to each other in a direction perpendicular to the magnetic force of attraction of the pair of magnetically connectable elements. 15. An expandable and compressible tire assembly drum according to claim 13, wherein at least one of the magnetic elements of each pair of magnetically connectable elements has a position that is adjustable relative to the other of the magnetic elements, wherein the adjustment of the position leads to a change in the attractive force between the pair of magnetically connectable elements. 16. An expandable and compressible tire building drum according to claim 11, wherein the shoulder assembly sections are interconnected at each end by tenon and groove joints configured to prevent radial displacement of the sections when the tire building drum rotates. 17. An expandable and compressible tire building drum according to claim 11, wherein the outer portion of the cylindrical working surface defines a cylindrical surface and an adjacent curved outer edge defining the shape of the tire carcass. 18. An expandable and compressible tire building drum according to claim 11, wherein the arcuate segments interact to define a first annular projection located radially inward from the central portion of the working surface and extending outward in an axial direction from a corresponding circumferential edge of the central portion of the working surface. 19. An expandable and compressible tire building drum according to claim 18, wherein the shoulder assembly also comprises a second annular projection extending to cover the first annular projection when the shoulder assembly is magnetically attached to respective circumferential edges of the central portion of the working surface. 20. The expandable and compressible tire assembly drum of claim 19, wherein the first and second annular projections cooperate to hold the outer portion of the working surface flush with the central portion of the working surface.