WO2001017761A1 - Apparatus for stitching and seaming elastomeric fillers to tire beads - Google Patents

Abstract

A device that automatically performs a complete cycle of stitching and seaming an apex to a tire bead. A microprocessor controller is initially programmed by an operator of the present device with certain parameters relating to the bead and apex to be joined. The device is essentially comprised of three assemblies: a bead winding assembly, an apex delivery assembly, and a stitch and seam assembly.

Description

For: Apparatus for stitching and seaming

Elastomeric Fillers To Tire Beads

Background of the Invention

The present invention relates to the art of pneumatic tire construction, and more particularly to an apparatus and method for stitching and seaming an elastomeric filler material to a tire bead.

In the construction of vehicle tires it is the ususal practice to incorporate a stiffening bead at both the inside and outside opening where the tire is to be mounted upon a rim. To prevent air from becoming entrapped in the annular space formed internally of the edge of the bead and tire carcass, it is common to have an additional strip of elastomeric material joined to the outer peripheral edge of the bead. This additional strip is known as a filler or apex and typically is of triangular cross-section to correspond to the cross-section of the space formed between the bead and tire carcass that is folded thereover.

Devices and methods are known for attaching the apex to a bead, but most consume much time and are labor intensive. The prior art includes apparatus for wrapping an apex around a bead, while other apparatus has been designed to seam the free ends of the apex together once it has been wrapped around the bead. In addition, prior art machines and methods generally require user intervention between the steps of wrapping the apex around the bead an joining the ends of the bead, and also to securely stitch or weld the entire apex to the bead. Thus, prior art devices and methods require time consuming, laborious efforts to complete each strip stitch and seam cycle . Summary of the Invention

The present invention is generally comprised of a device that automatically performs a complete cycle of stitching and seaming an apex to a tire bead. A microprocessor controller is initially programmed by an operator of the present device with certain parameters relating to the bead and apex to be joined. For instance, the operator programs the beads ' s internal diameter (e.g., 430-620 mm), bead width (e.g., 0 - 24.4 mm), bead height (e.g., 0 - 19.05 mm), bead taper angle (e.g., 0° - 15°), and type of bead construction (e.g. single wire hexagonal) . Once these parameters are programmed in the controller by an operator, the entire stitch and seam process is automatic.

The device is essentially comprised of three assemblies: a bead winding assembly, an apex delivery assembly, and a stitch and seam assembly. Once the microprocessor controller is programmed, a bead delivery apparatus is loaded with an assembled bead, and is driven via a pneumatic cable cylinder along a pair of rails towards the bead winding assembly. The loading mechanism lowers the bead onto the winder assembly which accepts the bead. The load mechanism then retreats from the winder assembly to its remote position where it is loaded with another bead.

Once the winder assembly receives the bead, the apex delivery assembly is actuated via the controller, and pulls a strip of apex through a series of rollers, and moves radially towards the bead. Upon the end of the apex contacting the bead, the winder assembly is actuated to rotate the bead about its central axis. The outward force applied to the apex by the guide wheels, coupled with the tackiness of the elastomeric bead and apex, causes the apex to wrap around and bend to the bead as it rotates. After a pre-determined length of apex has been sensed by an optical sensor, the winder assembly is de-energized. An ultra-sonic cutter is then actuated which cuts through the apex at a predetermined bias, thereby forming the trailing edge of the apex (and the leading edge of the next apex to be wrapped about a bead) . The winder assembly is then actuated again causing the remainder of the apex to wrap around the bead, except for the leading and trailing edges which need to be spliced together prior to being stitched to the bead. At this juncture, the apex delivery system is moved along a pair of rails via a pneumatic cable cylinder to its remote position. The stitch and seam assembly is then actuated via the controller which moves the assembly via a pneumatic cylinder along a pair of rails into laterally aligned relation with the apex and bead. A pair of gripper assemblies are then rotated via respective servo-motors until each gripper assembly senses (via optical sensors) a respective end of the apex. Pneumatic cylinders operatively attached to each of the gripper assemblies are then actuated to move them in a horizontal plane towards the ends of the apex. When the assemblies reach their terminal positions, a pair of vertically opposed grippers mounted to each of the assemblies are then moved towards one another, thereby clamping the ends of the apex therebetween. The gripper assemblies are then driven towards one another via their respective servo-motors, until the ends of the apex contact and are butt-spliced to one another. The gripper assemblies are then driven horizontally towards the bead, thereby forcing the spliced ends of the apex into the bead and stitching the two together. Each of the grippers are then moved vertically away from the apex, the gripper assemblies moved horizontally away from the bead, and the stitch and seam assembly returned to its home position. An unload mechanism is then actuated to pick up the assembled bead and apex, and carry it to a storage bine. The operation then begins, again with a new bead being beaded into bead winder assembly.

Brief Description of the Drawings

Figure 1 is a front elevational view of the present application;

Figure 2 is a perspective view of the present invention with a portion of the support frame removed; Figure 3 is a perspective view of the present invention with the upper portion of the support frame removed;

Figure 4a is a perspective view of the winder assembly portion of the present invention prior to a tire bead being supported thereon;

Figure 4b is a perspective view of the winder assembly portion of the present invention with a tire bead supported thereon;

Figure 5 is a perspective view of the apex delivery assembly portion of the present invention;

Figure 6 is a perspective view illustrating an apex being advanced towards a tire bead;

Figure 7 and 8 are perspective views of the stitch and seam assembly portion of the present invention;

Figure 9 is an enlarged perspective view of a gripper assembly; and

Figure 10 and 11 are perspective views of the stitch and seam assembly separated from the supporting apparatus.

Detailed Description Referring now to the drawings, wherein like reference numerals refer to like parts throughout, there is seen in Fig. 1 an apparatus, denoted generally by reference numeral 10, for stitching and seaming on elastomeric filler (hereinafter "apex") 12 to a tire bead core 14. Apparatus 10 is generally comprised of three primary assemblies arranged on a platen 11: namely, a tire bead guiding and winding assembly, denoted generally by reference numeral 16, an apex delivery assembly, denoted generally by reference numeral 18, and a stitch and seam assembly, denoted generally by reference numeral 20. Although the present invention is most directly concerned with stitch and seam assembly 20, all three assemblies will be described in sufficient detail for understanding the entire system. Each of assemblies, 16, 18 and 20 will be described in sequential order of use in performing the stitch and seam operation.

The stitch and seam process begins at bead guiding and winding assembly 16. A load mechanism 22 lifts bead 14 from a standard input conveyor 24. Load mechanism 22 is then driven along the Z-axis on rails 26 via a pneumatic cable cylinder 28 which receives its air supply from a compressed air source 29 (a signal received by source 29 from microprocessor controller 46 effects actuation of cylinder 28, and all other cylinders present in apparatus 10, as will be described hereinafter) . Bead 14 is then lowered by load mechanism 22 into laterally spaced relation with a winder assembly, denoted generally by reference numeral 30.

Winder assembly 30 is generally comprised of three, triangularly arranged, vertically extending bead support shafts 32, 34 and 36. Each of support shafts 32, 34 and 36 include a guide wheel 38, 40 and 42, respectively, positioned at the upper end thereof. Guide wheels 38, 40 and 42 are appropriately positioned to engage the inner edge of a bead and thereby support the bead in a horizontal plane, vertically spaced above platen 11. Shaft 32 is attached to a servo-motor 44 which receives signals directly from microprocessor controller 46, causing it to rotate a predetermined amount about its vertical axis, for reasons that will be explained and become apparent hereinafter. Shafts 34 and 36 are mounted on rails 48 and 50, respectively, which extend along axes A-A and B-B, respectively, and are also attached to respective pneumatic cylinders 52 and 54 which effect movement thereof along rails 48 and 50 in response to signals received from controller 46. Shafts 34 and 36 are initially positioned such that the circumference of a circle on which the shafts would lie is less than the circumference of bead 14. Once bead 14 is lowered by loading mechanism 22 into lateral alignment with guide wheels 38, 40 and 42, controller 46 sends a signal through source 29 to pneumatic cylinders 52 and 54, thereby effecting movement of shafts 34 and 36 along rails 48 and 50 in order to position guide wheels 38, 40 and 42 in tight supporting relation to the inner edge of bead 14. Load mechanism is then moved via cylinder 28 along rails 26 to its "home" position, remote from assembly 16.

Prior to operation of apparatus 10, the inside diameter of bead 14 is programmed into controller 46 (as is the bead width, bead height, bead taper angle, and bead construction), thus permitting controller 46 to properly sequence its instructions to the various cylinders and motors, including the pneumatic cylinders 52 and 54 which adjust the positions of shafts 34 and 36 an appropriate distance for engaging bead 14.

With bead 14 securely positioned on guide wheels 38, 40, and 42, apex delivery assembly 18 is then actuated to advance apex 12 to bead 16. Apex 12 is introduced to assembly 18 from a standard apex supply, such as an extruder 55. Assembly 18 is essentially comprised of a set of rollers 56 on top of which apex 12 is initially supported, each of which extend in spaced parallel relation to one another in a common plane; a first carriage assembly 58 on which a first set of clamping rollers 60 (between which apex 12 is securely held) and a first pair of opposed guide wheels 62, 64 are each mounted; and a second carriage assembly 66 on which a second set of clamping rollers 68 (between which apex 12 is securely held) and a second pair of opposed guide wheels 70, 72 are mounted. A servo-motor 74 drives second carriage assembly 66 via a ball screw 76 along rails 78 which extend along the X-axis. Second carriage assembly 66, in turn, causes first carriage assembly 58 to move along rails 78 via a pneumatic cylinder 80. Assembly 18 further includes an ultra-sonic cutter 82 that extends through an opening 84 formed through platen 11, and is driven vertically along the Y-axis via a pneumatic cylinder 86, and a mandrel 88. Mandrel 88 is positioned in a common vertical plane with cutter 82 and is pivotally movable via a pneumatic cylinder 90 into engaging relation with apex 12 (during the cutting operation) , and out of engaging relation with apex 12 (at all other times) . In operation, after bead 14 is properly positioned on assembly 16, and load mechanism 22 moves to its "home" position, apex 12 is delivered to assembly 18. Apex 18 slides over the top surface of rollers 56, between clamping rollers 60, between guide wheels 62 and 64, between clamping rollers 68 and between guide wheels 70 and 72. Each of rollers 56, 60 and 68 are rotatably mounted on shafts and are coated with a commercially available non-stick substance or coating, such as a plasma coating, nylon, or the like, thereby permitting apex 12 to pass thereover with minimal friction. Guide wheel pairs 62, 64 and 70, 72 each include slightly outwardly directed facing beveled surfaces (also coated with the non-stick coating) which engage apex 12 and are separated from one another by a distance slightly less than the thickness of the apex, thus creating a force fit of the apex therebetween. Consequently, guide wheels 62, 64 and 70, 72 apply a slight pressure to apex 12 to assist in the stitching operation, as will be explained in greater detail hereinafter.

After apex 12 is positioned between the rollers and guide wheels, servo-motor 74 is energized via controller 46. Consequently, ball screw 76 rotates, thereby causing carriage 66 to move along rails 56, pulling apex 12 along with it, towards stitch and seam assembly 20 until it reaches its terminal position which positions the leading end of apex 12 in contacting relation to bead 14. Simultaneously, pneumatic cylinder 80 causes carriage 58 to follow. Servo-motor 44 is then energized via controller 46, thereby causing bead 14 to rotate about its central axis . Due to the tack of the elastomeric material and the slight outwardly directed pressure applied to the apex by guide wheels 62, 64 and 70, 72, a bond is formed between apex 12 and bead 14, thereby causing apex 12 to wrap around bead 14 as it rotates about its central axis. Apex 12 continues to wrap around bead 14 until it reaches a predetermined length which is sensed by an optical sensor 92 which is mounted on platen 11 in a common vertical plane with cutter 82. At that instant, carriages 58 and 66 are pushed back to their starting positions by pneumatic cylinder 80 and servo-motor 74, respectively. Mandrel 88 is then pivoted via pneumatic cylinder 90 into engaging relation with the upwardly facing surface of apex 12, and pneumatic cylinder 86 is actuated, causing ultra-sonic cutter 82 to move vertically upwardly and cut through apex 12 at a predetermined bias. Cutter 82 and mandrel 88 then retract to their remote positions. Servo-motor 44 is then actuated once again, causing apex 12 to wrap entirely around bead leaving the two ends of apex 12 free from bead 14.

Once carriage 66 is fully retracted to its beginning position, stitch and seam assembly 20 is moved along rails 78 via pneumatic cable cylinder 94 (which is actuated by controller 46) into operable position with respect to the free ends of apex 12. Assembly 20 is generally comprised of a carriage 95 on which the other components of the assembly are mounted, and which is slidable along rails 78, a pair of gripper assemblies designated generally by reference numerals 96 and 98, respectively, and a semi-circular rail 100 on which gripper assemblies 96 and 98 travel via actuation of servomotors 102 and 104, respectively. Gripper assemblies 96 and 98 each serve to grip and splice the ends of apex 12 together, and then stitch and seam the joined ends of apex 12 onto bead 14, as will be described hereinafter.

Gripper assemblies 96 and 98 are identical in construction and for that reason will be described using common reference numerals, the only difference being that the parts of assembly 98 will be designated on the drawings with a ' symbol. Each gripper assembly 96 and 98 includes a base plate 106, 106' having a concentric bearing 108, 108' mounted on its upper surface and multiple concentric bearing 110, 110' mounted on its lower surface. The upper bearings 108, 108' are engaged by respective trunnions 112, 114 which are attached to the ball screws 116, 118 of servo-motors 102 and 104, respectively. Lower bearings 110, 110' engage rail 100, and upon actuation of servo-motors 102, 104, upper bearings 108, 108' slide within trunnions 112, 114, thereby causing base plates 106, 106' to travel around rail 100 until each senses a free end of apex 12 via optical switches 115, 115' which are mounted on gripper assemblies 96, 98, respectively, at which point each will stop.

The remainder of gripper assemblies 96 and 98 include a cylinder mounting plate 120, 120' attached to base plate 106, 106', and extending in a vertical plane, a horizontally oriented pneumatic cylinder 122, 122' slidably attached to cylinder mounting plate 120, 120'; a bearing plate 124, 124' attached to plate 120, 120' and to the end of pneumatic cylinder 122, 122'; a pair of vertically oriented pneumatic cylinders 126, 126' and 128, 128' fixedly secured to plate 120, 120' and slidably attached to bearing plates 130, 130' and 132, 132', respectively; a pair of gripper mounting brackets 134, 134' and 136, 136' fixedly attached to plates 130, 130', and 132, 132', respectively; and a pair of grippers 138, 138' and 140, 140' (all coated with the non-stick coating) pivotally attached to brackets 134, 134' and 136, 136', respectively.

Once each gripper assembly 96 and 98 is positioned in vertically and laterally aligned relation to the ends of apex 12, pneumatic cylinders 126, 126' and 128, 128' are actuated, causing grippers 138, 138', and 140, 140' to move down and up, respectively, until the ends of apex 12 are securely clamped therebetween. Servo-motors 102 and 104 are then actuated again, causing gripper assemblies 96 and 98 to move along track 100 towards one another. This movement is continued until the two ends of apex 12 are securely butt-spliced together, at which point the servo-motors are de-energized. At this point, pneumatic cylinders 122, 122' are actuated, causing grippers 138, 138' and 140, 140' (and associated structures) to move in a horizontal plane until the ends of apex 12 contact bead 14. The pressure produced between apex 12 and bead 14 serves to stitch the joined ends of apex 12 to bead 14, thereby completing the physical process of joining an apex to a bead.

Once the apex has been stitched to the bead, pneumatic cylinders 126, 126' and 128, 128' are actuated to pull gripper assemblies 96, 96' and 98, 98' outwardly away from apex 12. Servo-motors 102, 102' and 104, 104' are then energized to move gripper assemblies 96, 96' and 98, 98' to their rearmost positions. Cable cylinder 94 is then actuated to move carriage 95 to its remote position. The completed apex/bead is then engaged by an unload mechanism 142 which is movable along rails 26 upon actuation of pneumatic cable cylinder 144. Support shafts 34 and 36 are then moved radially inwardly via actuation of pneumatic cylinders 52 and 54, respectively, to cause winder assembly 30 to release the completed bead/apex. Unload mechanism 142 is then free to remove the apex/bead and place it in any conventional storage bin.

Claims

What Is Claimed Is:

1. An apparatus for assembling elastomeric fillers onto a vehicle tire bead wherein a vehicle tire bead and tire apex are joined together for forming a vehicle tire comprising: a support platen for carrying thereupon a tire bead guide and winding assembly, a tire apex delivery assembly, and a stitch and seam assembly; a tire bead guide and winding assembly carried by said support platen and including a load mechanism for receiving a tire bead of a predetermined diameter and forwarding the tire bead into a position laterally spaced from a winding assembly; a winding assembly carried by said support platen in a position for receiving the tire bead forwarded by said load mechanism; said winding assembly including guides positioned to engage an inner edge of the tire bead received by said winding assembly to support the tire bead in a horizontal plane vertically spaced above said platen; a tire apex delivery system carried by said support platen for advancing a tire apex into contacting relation with the tire bead supported in a horizontal plane vertically spaced above said platen, and cutting the tire apex to a length corresponding to the length of the tire bead; and a stitch and seam assembly carried by said support platen for applying pressure to the tire bead and tire apex when in a contacting relation to form a bond therebetween, and including a gripper for gripping the ends of the tire apex and the tire bead to join the ends thereof in abutting relation to form an endless loop.

2. A method for joining a tire bead having an inner edge to a tire apex for forming a vehicle tire comprising the steps of: forwarding a tire bead of predetermined diameter along a path of movement into a predetermined position relative to a tire bead receiving guide means; supporting said tire bead on said tire bead receiving guide means in a horizontal plane by an inner edge thereof; forwarding tire apex into contacting relation with said tire bead; applying a pressure to said tire bead and said tire apex when in said contacting relation stitching said tire bead to said tire apex; severing said tire apex, forming a length thereof equal to the circumference length of said tire bead; and gripping the ends of said stitched tire bead and tire apex and applying pressure thereto, thereby butt-splicing the ends thereof to form an endless loop.