For: Apparatus for stitching and seaming
Elastomeric Fillers To Tire Beads Application Of: Robert Kolb, Jesse Carpenter, Kevin Razy,
Ethan Wilson and Raymond Davis Cross Reference to Related Applications
The present application claims priority to Applicant ' s co-pending applications U.S. Serial No. 09/390,422, filed September 3, 1999, and PCT International Application No. , filed August 30, 2000. 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 openings 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 and 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 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 rest of the 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 positions the bead onto the winding assembly which accepts the bead. The load mechanism then retreats from the winding assembly to its remote position where it is loaded with another bead.
Once the winding 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 the apex tangentially towards the bead. Upon the end of the apex contacting the bead, the winding 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, cause the apex to wrap around and bond to the bead as it rotates.
After a pre-determined length of apex has been stitched to the bead, its leading edge is sensed by an optical sensor and the winding assembly is de-energized. A cutter is then actuated to cut through the strip of 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 winding assembly is then actuated again causing the
remainder of the apex to wrap around the bead, except for the leading and trailing edges which form a V-shaped notch and ultimately need to be spliced together. 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 a carriage, to which each of the gripper assemblies are mounted, are then actuated to move the carriage in a vertical plane towards the leading and trailing ends of the apex. When the carriage reaches its terminal position, a pair of grippers mounted to respective plates are then moved towards the plates, thereby clamping the leading and trailing ends of the apex therebetween. The gripper assemblies are then pivotally driven towards one another via respective servo-motors, until the leading and trailing ends of the apex contact and are butt-spliced to one another. If necessary the gripper assemblies are then driven in a vertical plane 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 in respective horizontal planes away from the apex, and the carriage moved along its rail.
An unload mechanism is then actuated to pick up the assembled bead and apex, and place it in a storage bin. The operation then begins, again with a new bead being loaded onto bead winder assembly.
Brief Description of the Drawings Figure 1 is a front elevational view illustrating the platen and components mounted thereon of the present invention;
Figure 2 is a front elevational view of the present invention illustrating the apex being advanced towards the
bead ;
Figure 3 is a front elevational view of the present invention illustrating the apex initially being stitched to the bead; Figure 4 is a magnified portion of the portion of the present invention where the apex is initially stitched to the bead;
Figure 5 is a front elevational view of the bead winder assembly portion of the present invention; Figure 6 is a front elevational view of the present invention illustrating the Mof the apex being stitched to the bead;
Figure 7 is a perspective view illustrating the stitching wheel assembly of the present invention; Figure 8 is a perspective view illustrating a portion of the winder assembly of the present invention;
Figure 9 is a magnified view of the stitching wheel assembly of the present invention (without an apex shown) ;
Figure 10 is a magnified, side elevational view of the stitching wheel assembly of the present invention (without an apex shown) ;
Figure 11 is a perspective view of the rear of the present invention;
Figure 12 is a perspective view of the servo-motor that drives the winder assembly of the present invention;
Figure 13 is a perspective view illustrating the chair and sprocket assembly of the present invention;
Figure 14 is another perspective view thereof;
Figure 15 is a perspective view of the orientation guide of the present invention;
Figure 16 is another perspective view thereof;
Figure 17 is a perspective view of the final stitch and seam assembly of the present invention (without the apex shown) ; Figure 18 is a perspective view of the gripper assemblies of the present invention (without the apex shown) ;
Figure 19 is another perspective view thereof (without
the apex shown) ; and
Figure 20 is an illustration of an apex and bead prior to its final stitching process.
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 an elastomeric filler (hereinafter "apex") 12 to a tire bead core ("bead") 14. Apex 12 may be of single, duplex or other conventional construction, and generally includes a height dimension greater than its width, a generally triangular cross-section, and an inwardly facing surface adapted for secure attachment to bead 16. Apparatus 10 generally comprises three primary assemblies arranged on or in relation to a platen 16 which extends in a vertical plane: namely, tire bead winder assembly, denoted generally by reference numeral 30, an apex delivery assembly, designated generally by reference numeral 20, and a final stitch and seam assembly, designated generally by reference numeral 22. A microprocessor controller 24 is utilized to control the assembly process.
Prior to operation of apparatus 10, the inside diameter of bead 16 is programmed into controller 24, as is the bead width, bead height, bead taper angle, and bead construction. Knowing these parameters and coupled with sensors that will be described hereinafter, controller 24 is able to properly sequence its instructions to the various cylinders and motors present in the system.
The process begins at bead guiding and winder assembly 30. A "pick and place" type load mechanism, designated generally by reference numeral 26 lifts bead 14 from a standard input conveyor 28 and places bead 14 into engaged relation with a winder assembly.
Winder assembly 30 generally comprises five support shafts 32, 34, 36, 38, and 40 each of which longitudinally extends along a horizontal axis. Each support shaft 32, 34, 36, 38, 40 includes a guide wheel 42, 44, 46, 48, 50,
respectively, mounted at their distal ends. Guide wheels 42, 44, 46, 48, 50 are appropriately positioned to engage the inner circumferential surface of bead 16, and thereby support the bead in a vertical plane, laterally spaced from platen 16. Shaft 32 is operatively attached to a servo-motor 52 which receives signals directly from microprocessor controller 24, causing it to rotate about its longitudinal, horizontally extending axis, for reasons that will be explained and become apparent hereinafter. Shafts 34 and 36 are mounted to blocks 35, 37, respectively, that are manually adjustable relative to platen 16 and are coupled to shaft 32 via a chain and sprocket assembly, designated generally by reference numeral 54, thereby causing these two shafts to rotate at the same rate and at the same time as shaft 32. The additional "drive" shafts 34, 36 reduce slippage of bead 16 as it rotates around winder assembly 30.
Shafts 38 and 40 are mounted on rails 56 and 58, respectively, which extend along axes A-A and B-B, respectively, and are also attached to respective pneumatic cylinders 60 and 62 which effect movement thereof along rails 48 and 50 in response to signals received from controller 24. Shafts 38 and 40 are initially positioned such that the circumference of a circle on which the shafts would lie is less than the circumference of bead 16. Once bead 16 is positioned by loading mechanism 26 into engaged relation with shafts 32, 34, and 36, controller 24 sends a signal through a pneumatic control center 64 to pneumatic cylinders 60 and 62, thereby effecting movement of shafts 38 and 40 along rails 56 and 58 until guide wheels 48 and 50 securely engage the inner surface of bead 16. Load mechanism 26 is then moved to a "home" position, remote from apparatus 10.
With bead 16 securely engaged by guide wheels 42, 44, 46, 48, and 50, apex delivery assembly 20 is then actuated to advance apex 12 tangentially towards bead 14. Apex 12 may be of a single, duplex, or other construction, and is introduced to assembly 20 from a standard source, such as an extruder 66 (and extruder 68 if of duplex construction) . From extruders
66 and 68, apex 12 is initially moved in a horizontal plane by a conveyor 70 and through a series of conventional accumulators (if desired) 72. After accumulating, the leading edge of apex 12 is passed to an orientation guide, designated generally by reference numeral 74, which converts the orientation of apex from extension in a horizontal plane to extension in a vertical plane.
Orientation guide 74 comprises a plurality of roller pairs 76 between which apex 12 extends. Each successive roller pair 76 is incrementally oriented from extension along a horizontal axis (the leading roller pair) to extension along a vertical axis (the trailing roller pair) .
After passing through orientation guide 74, apex 12 enters apex delivery assembly 20. The first portion of apex delivery assembly 20 encountered by apex 12 is a support plate 78 on which is mounted a plurality of rollers 80 which rotate about vertical axes and which engage the inwardly facing sidewall of apex 12, and a plurality of laterally spaced apart guide wheels 82 positioned vertically below rollers 80 and which rotate about respective horizontal axes, and which engage the bottom surface of apex 12 which ultimately is attached to bead 16.
A carriage 84 is movably positioned in vertically spaced relation above support plate 78 and includes a horizontally extending elongated rod 86 rigidly attached thereto. A horizontally extending elongated bar 88 is vertically spaced from and attached to rod 86 for pivotal movement about the longitudinal axis along which rod 86 extends.
When apex 12 comes off of orientation guide 74 it passes between rollers 80 and bar 88, and is supported on its bottom by wheels 82. Once positioned between bar 88 and rollers 80, a pneumatic cylinder 90 positioned on carriage 84 is actuated, thereby causing bar 88 to pivot about rod 86 towards apex 12. When bar 88 securely engages the outwardly facing sidewall of apex 12, carriage 84 is driven horizontally along rails 92 toward assembly 18 via a ball screw (or pneumatic piston) 94. Due to the secure engagement of apex 12 by bar 88, apex 12 is
pulled along with carriage 84 towards bead winder assembly 30. Apex 12 next passes between a set of guide rollers 96 and a pair of laterally spaced apart guide wheels 98, 100. Wheels 98 and 100 are mounted to the ends of and rotate about the longitudinal axes of rods 102, 104, respectively, which are attached to pneumatic motors 106 and 108, respectively. Motors 106, 108 effect pivotal movement of rods 102, 104, respectively, about an axis that perpendicularly intersects the axes along which rods 102 and 104 extend. Rods 102 and 104 extend along axes that are slightly diagonal. Thus, wheels 98, 100, rotate about non-vertical, diagonal axes. Although other orientations of wheels 98, 100 would work, this orientation causes the apex 12 passing therethrough to be forced at an angle which effectively stitches apex 12 to bead 14.
Once the leading edge of apex 12 passes over roller 96, motors 106, 108 are actuated to pivot rods 102, 104 (and hence wheels 98, 100), respectively, until wheels 98, 100 engage apex 12. Apex 12 is continuously advanced tangentially towards bead winder 30 via carriage 84 (driven by lead screw 94) until its leading edge passes between a pair of stitch wheels 110, 112 which are positioned in vertically spaced relation above winder assembly 30, and contacts bead 14. At this point a mandrel 114 is pneumatically driven via cylinder 116 along its longitudinal axis which extends in an essentially vertical direction, and the U-shaped opening in mandrel 114 engages the leading edge of apex 12. Mandrel 114, which is positioned between guide wheels 98, 100 and stitch wheels 110, 112, forces the leading edge of apex 112 downwardly against bead 14, thereby forming the initial stitching of apex 12 to bead 14. Mandrel 114 then retracts upwardly away from apex 12.
Stitch wheels 110, 112 are movable via pneumatic cylinder 117 along a longitudinal axis that is essentially parallel to the axes of rods 102, 104, and the lateral spacing between stitch wheels 110, 112 is manually adjustable, but is preferably set at a distance that is slightly less than the
thickness of apex 12, thereby causing apex 12 to be forced therebetween. Stitch wheels 110, 112 also include opposing outwardly beveled surfaces that further add to the effective forcing of apex 12 onto bead 14. The surface of wheels 110, 112 (and all rollers and other surfaces that contact apex 12) may be coated with a commercially available non-stick coating so as not to cause apex 12 to peel away from bead 14 after detaching from any of the surfaces, which would detract from the force being applied to the apex 12. At this stage in the process servo-motor 54 is actuated, thereby causing shaft 32 to rotate about its longitudinal axis (and, consequently, shafts 34, 36 also rotate through the chain and sprocket coupling 54) . As shaft 32 rotates, bead 14 also rotates and due to the stitching of the leading edge of apex 12 to bead 14, apex 12 is correspondingly moved. As apex 12 is rotated with bead 14, its length continuously passes between stitch wheels 110, 112 which effects the stitching of apex 12 to bead 14. In addition, as apex 12 winds around winder assembly 30, it is further supported by plates 115 which extend in a common vertical plane and include rollers 119 attached thereto. Plates 115 are positioned along the circular path that apex 12 follows. Although not specifically limited to any particular positions, it is effective to position plates 115 from about the 90 degree position to about the 225 degree position relative to the top of winder assembly 30 as measured in a clockwise direction. Plates 115 prevent apex 12 from coming into contact with other parts of apparatus 10 as it winds around assembly 30.
Servo-motor 54 drives apex 12 and bead 14 until the leading edge of apex 12 passes an optical sensor 118 attached to platen 16 and positioned at about 225 degrees around the circumference of bead 16 as measured in a clock-wise direction from its top where apex 12 is stitched to bead 14. When apex 12 passes sensor 118, servo-motor 54 is deactivated, thereby ceasing the motion of bead 14. A cutter 120 (the cutter may be a conventional heated blade, an ultrasonic cutter, or any other conventional blade) positioned adjacent guide rollers 80
is then driven via a pneumatic cylinder 122 to cut through the length of apex 12 at a predetermined bias, thereby forming the trailing edge of apex 12 (and forming the leading edge of the next strip of apex 12) . Once cutter 120 retracts from apex 12, servo-motor 54 is once again actuated and the stitching of the remainder of apex 12 to bead 14 is completed.
Due to the geometry of apex 12 as it is wound around bead 14, when the stitching of apex 12 to bead 14 is completed on winder assembly 30, a V-shaped notch 124 exists between the leading and trailing edges of apex 12. To close this notch 124, apex 12 (and bead 14) is rotated a predetermined distance via servo-motor 54 until it is positioned adjacent stitch and seam assembly 22. After apex 12 is rotated such that notch 124 is positioned in alignment with stitch and seam assembly 22, a carriage 127, on which all the components of the stitch and seam assembly 22 are assembled, is driven via a pneumatic cylinder 128 along a rail 126 towards apex 12 and bead 14. An optical sensor 129 mounted to carriage 127 senses when assembly 22 is appropriately positioned relative to apex 12 (i.e., apex 12 breaks the beam of light generated by sensor
129) , at which point pneumatic cylinder 128 is deactivated.
When stitch and seam assembly 22 is appropriately positioned relative to apex 12, the leading and trailing edges of apex 12 will be positioned between a plate 130, 132 and a gripper 134, 136, respectively. Plates 130, 132 are interconnected for pivotal movement relative to one another about a shaft 138 which is positioned forward of grippers 134, 136. Grippers 134, 136 are mounted to plates 130, 132, respectively, and are movable relative thereto along horizontally extending axes via pneumatic cylinders 140, 142, respectively .
Once apex 12 is sensed by sensor 129, pneumatic cylinders 140, 142 are activated, thereby causing grippers 134, 136, respectively, to move along their respective horizontally extending axes and clamp the leading and trailing edges of apex 12 between plates 130, 132 and the bottom surfaces of grippers 134, 136, respectively. After the leading and
trailing edges of apex 12 are securely clamped in position, pneumatic cylinders 144, 146 pivotally drive plates 130, 132, respectively, towards one another, while the forward ends pivot about shaft 138. Through this motion, grippers 134, 136 also move towards one another, thereby causing the V-shaped notch 124 to close and the leading and trailing edges of apex 12 to be stitched together. At this point bead 14 and apex 12 are entirely stitched together. If desired, the entire bead/apex assembly can be further treated by manually using conventional stitching rollers and rolling the seam between the apex and bead.
Pneumatic cylinders 140, 142 are activated once again, causing grippers 134, 136 to disengage apex 12, and carriage 127 moves assembly 22 to it's "home" position, remote from apex 12. Shafts 38 and 40 are then driven along rails 56, 58, respectively, via cylinders 60, 62, respectively, out of engagement with bead 14. An unload mechanism, denoted generally by reference numeral 148, is then actuated to automatically pick the completed bead/apex assembly off of apparatus 10 and place it on a rack.
It should be pointed out that the effectiveness of apparatus 10 at stitching and seaming apex 12 to bead 14 is further enhanced by performing the operation when the apex material is "hot," i.e., immediately following apex 12 coming out of extruder 66 (and 68) . By not permitting the apex material to cool off, the tack of the material and consequently its ability to bond to bead 14 is at its peak. Accordingly, the bond formed between apex 12 and bead 14 is far stronger than would otherwise be the case if the process was performed after the apex material was given the opportunity to decrease in temperature.