Shoulder assembly for a tire building machine and inflatable and collapsible tire building drum - Patent Application 20070122997

Abstract

A shoulder assembly for attachment to a tire building drum is provided, the shoulder assembly including a plurality of sections configured to interlock to form a shoulder ring that attaches to the tire building drum when the tire building drum is in an inflated state, and a plurality of magnetic elements disposed relative to a surface of the shoulder ring that is configured to contact a side of the tire building drum. The magnetic elements correspond to retaining magnetic elements disposed on the tire building drum. The shoulder ring is configured to maintain contact with the tire building drum during formation of the tire carcass, and the shoulder ring is configured to maintain its shape and retain on the formed tire carcass when the tire building drum is collapsed.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Patent Application Serial No. 63 / 013,867, filed April 22, 2020, the contents of which are incorporated herein by reference.

[0002] SUMMARY OF THE INVENTION The present general inventive concept relates to a tire building machine and, more particularly, to a shoulder assembly that is attached to the tire building machine to form the outer ridge of a tire carcass. [Background technology]

[0003] Manufacturing vehicle tires generally involves forming a tire carcass, forming the belt and tread portions of the tire separately from the carcass, and then bonding the belt and tread portions of the tire to the carcass to form a "green" tire. The green tire is then processed to form the tread and various other features of the tire and to vulcanize the rubber component of the tire.

[0004] Formation of the various portions of a tire is typically accomplished using one or more tire building drums of a type that defines a cylindrical working surface. For example, formation of the carcass portion of a tire is typically accomplished on a rotatable, inflatable, and collapsible tire building drum, commonly referred to as a "first stage drum" or "carcass drum." Certain carcass drum designs are designed to be radially inflatable and collapsible and are sometimes referred to as "radially inflatable / collapse" or "REC" drums. In a typical carcass drum, the rotatable drum is composed of multiple segments that define the drum's periphery. The segments that form the drum's periphery are adapted to be driven between an inflated position, where the tire carcass can be formed on the drum, and a collapsed position, where the formed carcass can be removed from the tire building drum.

[0005] With the carcass drum configured in the expanded position, it is rotated about its central axis. As the carcass drum rotates, the individual components of the tire carcass are laid on the drum's periphery to form multiple cylindrical layers. At least one, and sometimes multiple, rigid or semi-rigid rings called "beads" are positioned to surround each opposing circumferential end of the tire carcass layer. The circumferential ends of the tire carcass layer are then wrapped over the respective beads and bonded to the inner surface portions of the tire carcass layer to form the finished outer circumferential end of the tire carcass.

[0006] A typical carcass drum has rounded outer peripheral edges of the drum's working surface, often referred to as "shoulders." These outer drum shoulders are typically contoured to allow the beads and outer circumferential edges of a finished tire carcass to wrap over the drum's outer working surface and extend slightly radially inward. Thus, when a tire carcass is formed and finished on the carcass drum's outer working surface, the radially inward extension of the beads and outer peripheral edges of the finished tire carcass serves to "trap" the carcass drum within the finished tire carcass. In other words, as long as the carcass drum is in the expanded position, the tire carcass is form-fitted to the outer working surface and inwardly curved shoulders and therefore cannot be removed from the carcass drum. However, when driven to the collapsed position, the finished tire carcass can be removed from the carcass drum and transported to a subsequent tire building drum for further operations in tire production.

[0007] As a tire carcass is transported from one carcass drum to another for continued tire manufacturing, it is not uncommon for the tire carcass to deform, causing at least a portion of the tire carcass to form imperfections, such as crimps, bulges, thin spots, etc. As a finished tire containing these imperfections rolls over a surface, the repeated contact of the portion of the tire containing the tire component imperfections with the surface can, under certain circumstances, result in undesirable performance characteristics of the finished tire, such as, for example, vibration and / or resonance of the rolling tire. Such vibration and / or resonance can result in undesirable noise and / or shudder in the tire, increased tire wear and shortened tire life, and, in some extreme cases, catastrophic failure of the tire.

[0008] For these and other reasons, various prior art designs for carcass drums include removable shoulder rings that are secured to the circumferential edge of the inflated carcass drum's outer working surface to define shoulder portions of the carcass drum while the tire carcass is being formed, and that can be unwound from the circumferential edge of the carcass drum's outer working surface to allow the carcass drum's outer working surface to collapse. The completed tire carcass may then be removed from the carcass drum with the removable shoulder rings positioned on the tire carcass's inner circumference. The tire carcass can then be transported with the shoulder rings retained within the tire carcass on the inside of the bead edges so that the shoulder rings continue to support the tire carcass' bead edges in a substantially circular configuration during transport. Each shoulder ring typically defines multiple segments secured together to form the rounded working surface of the carcass drum shoulder. Thus, when the tire carcass is ready to be placed on a subsequent tire building drum for subsequent tire production, each shoulder ring can be disassembled and removed from within the tire carcass.

[0009] Some prior art shoulder ring designs employ threaded fasteners, such as screws or bolts, to fasten the segments together to form the shoulder ring and to fasten the shoulder ring to the corresponding end of the outer working surface of the carcass drum. For designs employing such threaded fasteners, the time required to physically fasten and unfasten the removable shoulder ring from the carcass drum, as well as physically disassembling each shoulder ring to remove it from within the tire carcass, can lead to significant downtime during the tire building process. Furthermore, this process creates significant additional labor associated with the repeated disassembly and reassembly of the shoulder rings and their repeated fastening and unfastening to the carcass drum. Therefore, a need exists for improved carcass drum and removable shoulder ring designs for carcass drums to increase the efficiency of tire carcass construction and tire building processes. Summary of the Invention [Means for solving the problem]

[0010] In accordance with various exemplary embodiments of the present general inventive concept, a shoulder assembly is provided that is easily attached to a tire building drum without fasteners and maintains its position within the tire carcass when the tire building drum collapses.

[0011] Additional aspects and advantages of the present general inventive concepts will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the present general inventive concepts.

[0012] The foregoing and / or other aspects and advantages of the present general inventive concept can be achieved by providing a shoulder assembly for attachment to a tire building drum, the shoulder assembly comprising: a plurality of sections configured to interlock with one another to form a shoulder ring for attachment to the tire building drum when the tire building drum is in an inflated state; and a plurality of magnetic elements disposed on a surface of the shoulder ring configured to contact a side of the tire building drum, the magnetic elements corresponding to retaining magnetic elements within the tire building drum; the shoulder ring configured to maintain contact with the tire building drum during formation of the tire carcass, and the shoulder ring configured to maintain its shape and remain with the formed tire carcass when the tire building drum is collapsed.

[0013] Other features and aspects will be apparent from the following detailed description, drawings, and claims. [Brief explanation of the drawings]

[0014] The following exemplary embodiments are representative of exemplary techniques and structures designed to carry out the objectives of the present general inventive concepts, but the present general inventive concepts are not limited to these exemplary embodiments. In the accompanying drawings and illustrations, the size and relative size, shape, and quality of lines, objects, and areas may be exaggerated for clarity. A wide variety of additional embodiments will be more readily understood and appreciated through the following detailed description of exemplary embodiments, with reference to the accompanying drawings therein. [Figure 1] FIG. 1 shows a perspective view of a simplified representation of a carcass drum including a pair of shoulder assemblies according to one exemplary embodiment of the present general inventive concept, the carcass drum shown in an expanded position. [Figure 2] FIG. 2 is a perspective view of a simplified representation of the carcass drum and shoulder assembly of FIG. 1, with the carcass drum shown in a collapsed position. [Figure 3] FIG. 3 shows a partial perspective view of the circumferential edge of the cylindrical outer working surface of the carcass drum of FIGS. [Figure 4] FIG. 4 is a perspective view of a shoulder assembly in accordance with an exemplary embodiment of the present general inventive concept. [Figure 5] 5 is another side perspective view of the shoulder assembly of FIG. 4. FIG. [Figure 6] FIG. 6 is a cross-sectional view of the upper section of the shoulder assembly of FIG. 5 attached to an arcuate segment of a carcass drum. [Figure 7] FIG. 7 shows the shoulder assembly of FIG. 5 with the upper section exploded from the shoulder assembly. DETAILED DESCRIPTION OF THE INVENTION

[0015] Reference will now be made to exemplary embodiments of the present general inventive concepts, which are illustrated in the accompanying drawings and illustrations. Exemplary embodiments will be described herein for the purposes of explaining the present general concepts with reference to the figures.

[0016] The following detailed description is provided to help the reader comprehensively understand the structures and fabrication techniques described herein. Accordingly, various changes, modifications, and equivalents of the structures and fabrication techniques described herein will be suggested to those skilled in the art. However, the described progression of fabrication operations is merely an example, and the type of order of operations is not limited to that described herein and can be changed as known to those skilled in the art, except for operations that necessarily occur in a certain order. In addition, descriptions of well-known functions and structures may be simplified and / or omitted for clarity and conciseness.

[0017] It should be noted that spatially relative terms, such as "up," "down," "right," "left," "beneath," "below," "lower," "above," and "upper," may be used herein for ease of description to describe the relationship of an element or feature to other elements or features as shown in the figures. The spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures is flipped or rotated, an element described as "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the exemplary term "below" can encompass both an orientation above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations), and the spatially relative descriptors used herein would be interpreted accordingly.

[0018] In accordance with various exemplary embodiments of the present general inventive concept, a shoulder assembly for use with a tire building machine is provided, the shoulder assembly being configured to attach to a carcass drum when the drum is inflated and to remain within the tire carcass and separate from the drum when the drum is collapsed. It is understood that a pair of shoulder assemblies (one of which may be referred to herein simply as a "shoulder") in accordance with the present general inventive concept may be provided, one shoulder secured to each of two opposing sides of the carcass drum during formation of the tire carcass. However, for clarity, only one (i.e., one side) of the pair of shoulder assemblies will typically be described and illustrated herein. Additionally, the terms "drum," "tire building drum," and / or "carcass drum" may be used interchangeably herein.

[0019] 1 and 2 are perspective views of a simplified representation of a carcass drum 11 including a pair of shoulder assemblies 10 constructed in accordance with one exemplary embodiment of the present general inventive concept. It will be appreciated that the shoulder assemblies of the present general concept may be used in conjunction with any of a wide variety of tire building drum designs. However, the simplified representation of the carcass drum 11 shown in FIGS. 1 and 2 is provided to illustrate various components of the carcass drum 11 that may be provided for use in conjunction with the shoulder assemblies 10 of the present general concept. In this regard, the carcass drum 11 shown in FIGS. 1 and 2 includes a generally elongated central hub assembly 13 and a plurality of substantially arcuate segments 15 supported relative to the hub assembly 13 in a substantially cylindrical configuration and configured for expansion and contraction movement between an expanded position (see FIG. 1) and a collapsed position (see FIG. 2). 1, the segments 15 are arranged in an edge-to-edge configuration such that the segments 15 cooperate to form a substantially smooth, cylindrical outer working surface 17 having a pair of opposing circumferential edges 23 defined by the cooperating edges of the arcuate segments 15. In the collapsed position shown in FIG. 2, the segments 15 are drawn toward the central hub assembly 13 in a substantially overlapping configuration such that the entire carcass drum 11 has a relatively small overall diameter compared to the diameter of the outer working surface 17 defined when the drum is in the expanded position.

[0020] It will be appreciated that additional mechanical connections and internal components 19 of the carcass drum 11 are provided to effect attachment of the segments 15 of the carcass drum 11 to the central hub assembly 13 and to effect movement of the segments 15 between the collapsed and expanded positions. However, a description of the specific details of such mechanical connections and internal components 19 is not necessary for an understanding of the general inventive concept of the present invention. Accordingly, for the purposes of this description, these additional internal mechanical connections and internal components 19 are illustrated in simplified form in FIGS. 1 and 2. Those skilled in the art can understand the structure and operation of the various mechanical connections and internal components 19 of a carcass drum with consideration of several publications, such as U.S. Pat. No. 8,272,417 issued to Painter. However, it will be understood that numerous other designs and configurations of tire building drums may be used without departing from the spirit and scope of the general inventive concept of the present invention.

[0021] Figure 3 is a perspective view of one of the circumferential edges 23 of the cylindrical outer working surface 17 of the carcass drum 11 of Figures 1 and 2. In accordance with various exemplary embodiments of the present general inventive concept, each of the circumferential edges 23 of the carcass drum 11 is slightly offset radially inward from the outer working surface 17 of the carcass drum 11 and defines a circumferential lip 25 that extends axially outward from the outer working surface 17 of the carcass drum 11. Each circumferential lip 25 defines an axially outward-facing annular planar surface 27. As described further below, a plurality of magnetic elements 29 are spaced apart from the circumferential lip 25, each embedded in the lip 15 and facing axially outward along the annular planar surface 27 of the lip 25. As described in more detail herein, each shoulder assembly 10 can be configured to be attached to a corresponding outer circumferential edge 23 of the carcass drum 11 via a plurality of magnetic elements 29 positioned relative to the circumferential edge 23 of the carcass drum 11 and via an additional plurality of magnetic elements positioned relative to the shoulder assembly 10. Thus, the shoulder assemblies 10 can be attached to the carcass drum 11 in an assembled state, or can be assembled by attaching the shoulder assemblies 10 to the carcass drum 11 one by one.

[0022] Referring now to FIG. 4, a single shoulder assembly 10 according to one exemplary embodiment of the present general inventive concept is shown. As seen in FIGS. 1 and 2, the view depicted in FIG. 4 is of the outer side of the shoulder assembly 10 facing away from the carcass drum 11 when mounted thereon. As depicted in FIG. 4, the shoulder assembly 10 includes a plurality of arcuate, interconnected sections. In this exemplary embodiment, four sections are provided, which for purposes of this description may be referred to as an upper section 12, a lower section 14, a first side section 16, and a second side section 18. Each of the sections 12, 14, 16, and 18 is formed of a substantially rigid material, such as, for example, steel, aluminum, plastic, polyurethane, or the like. In various exemplary embodiments, each of the sections 12, 14, 16, and 18 may be formed of a non-magnetic material, such as, for example, polyurethane or other plastics, aluminum, or the like. In certain more modest embodiments, one or more of the sections of the shoulder assembly may be formed of polyurethane.

[0023] Each of the sections 12, 14, 16, 18 defines a substantially smooth, arcuate outer surface 20, and as described in further detail below, each section 12, 14, 16, 18 is adapted to releasably couple to an opposite adjacent section 12, 14, 16, 18 in an end-to-end configuration such that the sections 12, 14, 16, 18 cooperate to form a toroidal shape. In this configuration, the various outer surfaces 20 of the sections 12, 14, 16, 18 cooperate to define a substantially cylindrical outer working surface 34 of the shoulder assembly 10. Additionally, each section 12, 14, 16, 18 defines an outermost edge 22 having a rounded shape such that when the sections 12, 14, 16, 18 are connected in an end-to-end configuration, the various outer edges 22 of the sections 12, 14, 16, 18 cooperate to define a substantially smooth, rounded contour that defines a radially inwardly curved shoulder surface suitable for use in forming the finished outer periphery of a tire carcass. In various exemplary embodiments of the present general inventive concept, the outer working surface 34 of the shoulder assembly 10 is formed to be substantially flush with the outer cylindrical working surface 17 of the carcass drum 11 when the carcass drum 11 is in the expanded position (see FIG. 1 ).

[0024] Figure 5 is a perspective view showing the inside of the shoulder assembly 10 of Figure 4. As previously explained, Figure 4 illustrates the side of the shoulder assembly 10 that faces away from the carcass drum 11 when mounted thereon. Thus, Figure 5 illustrates the side of the shoulder assembly 10 that faces and contacts the outer peripheral edge 23 of the carcass drum 11 when the shoulder assembly 10 is mounted thereon. The shoulder assembly 10 is formed such that the innermost circumferential edge 24 of the outer working surface 34 of the shoulder assembly 10 defines a lip 31 that is sized and shaped to fit over the circumferential lip 25 of the corresponding edge 23 of the carcass drum 11 when the shoulder assembly 10 is mounted thereon. Therefore, when the shoulder assembly 10 is placed on the outer circumferential edge 23 of the carcass drum 11 with the circumferential lip 25 of the drum 11 fully received within the lip defined by the circumferential edge 24 of the outer working surface 34 of the shoulder assembly 10, the two lips engage with each other to position and maintain the outer working surface 34 of the shoulder assembly 10 flush and coaxial with the outer working surface 17 of the carcass drum 11.

[0025] 5, the shoulder assembly 10 includes an axially inwardly facing annular plane 26 offset axially inward from and extending radially inward from the lip 31 defined by the circumferential edge 24 of the outer working surface 34. This radially inwardly extending annular plane 26 is configured to contact the aforementioned outer side surface 27 of the circumferential edge 23 of the carcass drum 11 when the lip 31 defined by the circumferential edge 24 of the outer working surface 34 of the shoulder assembly 10 is fully received on the circumferential lip 25 of the corresponding edge 23 of the carcass drum 11. The radially inwardly extending annular surface 26 of the shoulder assembly 10 includes a plurality of magnetic elements 28 disposed thereon, which correspond to the magnetic elements 29 provided for the outer side surface 27 of the circumferential lip 25 of the carcass drum 11. Therefore, when the carcass drum 11 is moved to the expanded position and the shoulder assembly 10 is positioned on the outer circumferential edge 23 of the carcass drum 11 with the circumferential lip 25 of the drum 11 fully received within the lip defined by the circumferential edge 24 of the outer working surface 34 of the shoulder assembly 10, each of the magnetic elements 28 of the shoulder assembly 10 magnetically couples with and attracts a corresponding one of the magnetic elements 29 of the carcass drum 11 to establish a releasable magnetic connection, thereby releasably securing the shoulder assembly 10 at a position along the axial edge 23 of the carcass drum 11.

[0026] FIG. 6 shows a cross-sectional view of the upper section 12 of the shoulder assembly 10 of FIG. 5 mounted on one of the arcuate segments 15 forming the outer working surface 17 of the carcass drum 11. As shown in FIG. 6, in various exemplary embodiments, the magnets 28, 29 of the shoulder assembly 10 and carcass drum 11 may be housed in aluminum shells 38, 40 with adjustable magnet positions so that the magnetic attraction to the shoulder assembly 10 can be optimally varied. For example, in the illustrated embodiment, each of the magnetic elements 28, 29 is defined by a magnetic steel plug housed in a correspondingly sized aluminum shell 38, 40 disposed in a blind bore defined in the corresponding shoulder assembly 10 or carcass drum 11. In the illustrated embodiment, each magnetic element 28 of the shoulder assembly 10 is fixed within the corresponding aluminum shell 38 via a frictional connection, adhesive, or the like. However, the magnetic element 29 of the carcass drum 11 is slidably received within the corresponding aluminum shell 40. The adjustable set screw 42 is disposed within a through bore 44 defined by the arcuate segment 15 of the carcass drum 11 and is configured to extend into the aluminum shell 40 and threadingly engage the corresponding magnetic element 29. Thus, the adjustable set screw 42 can be rotatably adjusted to extend the magnetic element 29 of the carcass drum 11 toward or away from the magnetic element 28 of the shoulder assembly 10. In this manner, when the shoulder assembly 10 is attached to the periphery of the carcass drum 11, the distance between the corresponding pair of mated magnetic elements 28, 29 can be adjusted, thereby adjusting the attractive force between each of the mated pair of magnetic elements 28, 29 to achieve an optimal force. This arrangement of the magnetic elements eliminates the need for any other fastening / mounting device to hold the shoulder assembly 10 on the carcass drum 11.

[0027] In the illustrated embodiment of FIG. 6 , the magnetic element 28 of the shoulder assembly 10 is shown as fixed, while the set screw 42 and adjustable magnetic element 29 are shown in relation to the arcuate segment 15 that forms the outer working surface 17 of the carcass drum 11. However, this arrangement may be reversed without departing from the spirit and scope of the general inventive concept of the present invention. That is, in other exemplary embodiments, the magnetic element 28 of the shoulder assembly 10 may be adjustable, while the magnetic element 29 of the carcass drum 11 may be fixed. In various other exemplary embodiments, each of the magnetic elements 28, 29 of the shoulder assembly 10 and carcass drum 11 may be fixed within a corresponding shell or blind bore defined in the corresponding shoulder assembly 10 or carcass drum 11. In still other embodiments, a carcass drum may be used that does not have a magnetic element thereon, and in which the magnetic element 28 of the shoulder assembly 10 is configured to magnetically couple directly to the arcuate segment 15 that forms the outer working surface 17 of the carcass drum 11.

[0028] It will be appreciated that in various embodiments similar to those shown in FIGS. 1-6 , a tire carcass can be formed on the carcass drum 11 and shoulder assembly 10 when the carcass drum 11 is in an inflated state and the shoulder assembly 10 is mounted thereon and held in place by the magnetic elements 28, 29. When the carcass drum 11 collapses (depresses), the associated shoulder assembly 10 remains in place within the tire carcass. Separation of the carcass drum 11 from the shoulder assembly is relatively easy because the magnetic elements 28 of the shoulder assembly 11 and the magnetic elements 29 of the carcass drum 11 face each other when the carcass drum is in an inflated state, and when the carcass drum collapses, the carcass drum segments 15 move in a “wiping” or “shearing” radial force, separating the paired magnetic elements 28, 29 in an easier manner than would be encountered if the elements were pulled axially away from each other.

[0029] FIG. 7 illustrates the shoulder assembly of FIG. 5 with the top section 12 disassembled from the shoulder assembly 10. As shown in FIG. 7, the top section 12 of the shoulder assembly 10 is formed with tongues or tenons 30 extending from each end, which correspond to grooves 32 formed in the upper ends of both the first and second side sections 16, 18. Similarly, the bottom portion 14 of the shoulder assembly 10 is formed with tenons 30 extending from each end that correspond to the grooves 32 formed in the bottom ends of the first and second side sections 16, 18. In various exemplary embodiments, the tenons 30 and grooves 32 may be configured with substantially the same curvature as the outer diameter 20 of the shoulder assembly 10. Thus, as shown in FIG. 7, assembly of the top portion 12 to the first and second side portions 16, 18 is accomplished by moving the top portion 12 laterally to slide the tenons 30 into the grooves 32. This configuration allows for convenient and relatively easy assembly and disassembly, allowing the shoulder assembly 10 pieces to rotate with the drum without spinning off due to spinning forces during tire carcass formation. In various exemplary embodiments, the tenons 30 and corresponding grooves 32 may be formed at an angle to the outer diameter 20 or may be formed to increase in width or thickness from one end to the other. In various exemplary embodiments, the tenons 30 may be configured with various other connection profiles, such as hooks, T-shaped profiles, or jigsaw profiles, to secure the shoulder assembly 10 pieces so that they can spin with the drum without spinning off due to spinning forces. These tenon 30 interlocks may, in various exemplary embodiments, be separate bolt-on components that couple with the sides of the shoulder assembly 10. Such a configuration may improve wear, ease of manufacturing, maintenance, and the like. In various exemplary embodiments, the shoulder segments may be formed of polyurethane or aluminum. In various exemplary embodiments of the present general inventive concept, the shoulder assembly may be formed without a lip on the innermost edge 24 and may rely solely on magnetic elements to retain the shoulder assembly on the tire building drum.

[0030] Various exemplary embodiments of the present general concept may provide a "loose shoulder" concept that does not use retaining fasteners and relies solely on the magnetic elements described above to secure the shoulder to the carcass drum. The purpose is to reduce de-centering time when building triple- and double-bead tires, typically aircraft, agricultural, and off-the-road (OTR) tires. Various exemplary embodiments may use polyurethane shoulder segments held in place on the drum by magnets. The shoulder segments themselves are tenons joined together to form a complete ring, and the tenons act as a safety feature to prevent the segments from radially displacing as the drum rotates. Corresponding magnets in the drum may be housed within an aluminum shell, and the magnets may be adjustable in position to optimize the magnetic force required to hold the shoulder in place but also allow the drum to collapse. Various exemplary embodiments of the loose shoulder may have an embedded steel plug or magnet that aligns with the retaining magnet in the aluminum shell, thus providing shoulder alignment.

[0031] Unlike conventional shoulders, the shoulder of the present general inventive concept can remain within the carcass while the tire drum collapses and the carcass, complete with the shoulder, is removed from the tire building machine. The drum collapses away from the shoulder, destroying the magnetic effect through a wiping action instead of a linear pull-off, which requires more force. The shoulder may be divided into four sections. The steel shoulder is divided into six sections, each weighing approximately 10 kg. The polyurethane sections of the present general inventive concept may weigh only approximately 5 kg each. In various exemplary embodiments, there may be two parallel cut key shoulders, which mate with tenons that pass through the key shoulders to form a shoulder ring assembly. The same key segments can then be pulled inward along with the tire carcass, encasing the shoulder assembly, until the tire carcass is removed from the tire building machine with the shoulder, with the shoulder locked in place by the tire carcass register.

[0032] Various exemplary embodiments of the present general inventive concept may provide a shoulder assembly for attachment to a tire building drum, the shoulder assembly including a plurality of sections configured to interlock with each other to form a shoulder ring attached to the tire building drum when the tire building drum is in an inflated state, and a plurality of magnetic elements disposed against a surface of the shoulder ring configured to contact a side of the tire building drum. The magnetic elements correspond to retaining magnetic elements within the tire building drum, and the shoulder ring is configured to maintain contact with the tire building drum during formation of the tire carcass, and the shoulder ring is configured to maintain its shape and retain with the formed tire carcass when the tire building drum is collapsed. One or more of the sections may be formed from or include polyurethane. The shoulder assembly may further include a lip extending to cover a portion of the circumference of the tire building drum when the shoulder ring is attached to the tire building drum. The sections may be interlocked at each end with connecting tenons and grooves configured to prevent radial displacement of the sections as the tire building drum rotates.

[0033] One major advantage of the present general inventive concept is reduced decore time compared to conventional methods of tire building. Conventional shoulder methods require manual intervention to remove each section before the drum collapses. Various exemplary embodiments of the present general concept can eliminate such manual intervention at this early stage of production, as the drum simply collapses, leaving the shoulder ring in place. In various exemplary embodiments, the use of polyurethane, aluminum, etc., presents the opportunity to have lighter and / or fewer shoulder assembly parts, and as such, reassembly of the shoulder after removal from the carcass is quicker than with conventional systems.

[0034] Numerous variations, modifications, and additional embodiments are possible, and accordingly, all such variations, modifications, and embodiments are deemed to be within the spirit and scope of the present general inventive concept. For example, notwithstanding anything in this application, unless expressly specified to the contrary, there is no requirement in this specification or any application claiming priority from this application to include any particular described or illustrated acts or elements, any particular order of such acts, or any particular interrelationship of such elements. Furthermore, any act may be repeated, any act may be performed by multiple entities, and / or any element may be duplicated.

[0035] It should be noted that the simplified diagrams and figures contained herein do not show all connections and assemblies of the various components; however, one skilled in the art would understand, using sound engineering judgment, how to make such connections and assemblies based on the illustrated components, diagrams, and descriptions provided herein. Numerous variations, modifications, and additional embodiments are possible, and therefore, all such variations, modifications, and embodiments are deemed to be within the spirit and scope of the present general inventive concept.

[0036] The present general inventive concept has been illustrated by the description of several exemplary embodiments, and while the exemplary embodiments have been described in detail, it is not the applicant's intention to limit, or in any way restrict, the scope of the general inventive concept to such descriptions and illustrations. Instead, the description, drawings, and claims herein are to be regarded as exemplary in nature and not restrictive, and additional embodiments will readily appear to those skilled in the art upon reading the above description and drawings. Additional modifications will readily appear to those skilled in the art. Accordingly, departures may be made from such details without departing from the spirit or scope of applicant's general inventive concept.

Claims

1. 1. A shoulder assembly attached to an inflatable and collapsible tire building drum, comprising: a plurality of arcuate sections configured to interlock with one another to form a shoulder ring that is mounted on the tire building drum when the tire building drum is in an inflated condition; a first plurality of magnetic elements disposed near a surface of the shoulder ring and configured to magnetically secure the shoulder ring to a side of the tire building drum; the shoulder ring is configured to maintain contact with the tire building drum during formation of the tire carcass; the shoulder ring is configured to maintain its shape and to disengage from the tire building drum when the tire building drum is collapsed; Shoulder assembly.

2. the first plurality of magnetic elements are spaced apart near the shoulder assembly to correspond to a second plurality of magnetic elements within the tire building drum; The shoulder assembly of claim 1 .

3. one or more of the sections comprises polyurethane; The shoulder assembly of claim 1 .

4. the sections are joined to each other at each end by tenon and groove connections configured to prevent radial displacement of the sections when the tire building drum rotates. The shoulder assembly of claim 1 .

5. 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; The shoulder assembly of claim 1 .

6. a lip extending over a portion of the circumference of the tire building drum when the shoulder ring is mounted on the tire building drum; The shoulder assembly of claim 5 .

7. the lip is sized to maintain an outer working surface of the shoulder ring flush with the outer working surface of the tire building drum. The shoulder assembly of claim 6 .

8. the shoulder ring further defines an annular outer edge having a curved surface; The shoulder assembly of claim 5 .

9. the curved surface defines a radially inwardly curved shoulder surface suitable for use in forming the finished outer periphery of a tire carcass; The shoulder assembly of claim 8 .

10. a plurality of arcuate segments supported relative to a central hub and configured to move between an expanded position and a collapsed position, wherein in the expanded position the segments cooperate to define a central portion of a cylindrical working surface having a pair of oppositely disposed circumferential edges; a shoulder assembly for defining an end of the work surface, the shoulder assembly having a plurality of arcuate sections configured to interlock with one another to form an outer portion of the cylindrical work surface; the shoulder assembly is removably magnetically securable to one of the circumferential edges of the central portion of the work surface; Inflatable and collapsible tire building drum.

11. The method further comprises a first plurality of magnetic elements provided against a surface of the shoulder ring, the first plurality of magnetic elements being configured to form a magnetically fixed element pair with one of a second plurality of magnetic elements provided against a corresponding circumferential edge of a central portion of the working surface; 11. The inflatable and collapsible tire building drum of claim 10.

12. Each pair of magnetically secured elements has an adjustable magnetic attraction force; 12. The inflatable and collapsible tire building drum of claim 11.

13. movement of the plurality of arcuate segments to the recessed position results in displacement of each pair of magnetically secured elements relative to one another in a direction perpendicular to the magnetic attraction of the pair of magnetically secured elements.

13. The inflatable and collapsible tire building drum of claim 12.

14. at least one of the magnetic elements of each pair of magnetically secured elements has an adjustable position relative to the other of the magnetic elements, said adjustment of position resulting in a change in the force of attraction between the pair of magnetically secured elements; 13. The inflatable and collapsible tire building drum of claim 12.

15. the sections of the shoulder assembly are coupled to each other at each end with tenon and groove connections configured to prevent radial displacement of the sections when the tire building drum rotates; 11. The inflatable and collapsible tire building drum of claim 10.

16. an outer portion of the cylindrical work surface defining a cylindrical surface and an adjacent curved outer edge that defines the shape of the tire carcass; 11. The inflatable and collapsible tire building drum of claim 10.

17. the arcuate segments cooperate to define a first annular lip disposed radially inward from a central portion of the working surface and extending axially outward from a corresponding circumferential edge of the central portion of the working surface; 11. The inflatable and collapsible tire building drum of claim 10.

18. the shoulder assembly further includes a second annular lip extending over the first annular lip when the shoulder assembly is magnetically secured to a corresponding circumferential edge of the central portion of the work surface; 18. The inflatable and collapsible tire building drum of claim 17.

19. the first annular lip and the second annular lip cooperate to maintain an outer portion of the work surface flush with a central portion of the work surface; 20. The inflatable and collapsible tire building drum of claim 18.

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