Abstract
The invention relates to a transfer wheel and a method for transferring a tire component to a tire building drum, wherein the transfer wheel defines a circumferential surface extending about a transfer wheel axis, wherein the transfer wheel comprises a pusher segment arranged at a first segment position along said circumferential surface, wherein the pusher segment comprises a segment body that is configured to be flush with the circumferential surface and at least one push-off member in said segment body movable relative to the segment body in a push-off direction facing radially outward relative to the transfer wheel axis.
Claims
1-18. (canceled)
19. A transfer wheel for transferring a tire component to a tire building drum, wherein the transfer wheel defines a circumferential surface extending about a transfer wheel axis, wherein the transfer wheel comprises a pusher segment arranged at a first segment position along said circumferential surface, wherein the pusher segment comprises a segment body that is configured to be flush with the circumferential surface and a plurality of push-off members arranged adjacent to each other in a lateral direction parallel to the transfer wheel axis in said segment body movable relative to each other and the segment body in a push-off direction facing radially outward relative to the transfer wheel axis between a flush position in which the plurality of push-off members are flush with the circumferential surface and a push-off position radially outside of said circumferential surface.
20. The transfer wheel according to claim 19, wherein the plurality of push-off members define a shape of the circumferential surface that is adaptable to a contour of the tire component when transferring said tire component to the tire building drum.
21. The transfer wheel according to claim 19, wherein the plurality of push-off members are pneumatically driven.
22. The transfer wheel according to claim 19, wherein the segment body comprises a plurality of slots for receiving the plurality of push-off members, wherein the segment body further comprises a duct for connecting the plurality of slots to a source of compressed air or partial vacuum.
23. The transfer wheel according to claim 19, wherein the pusher segment comprises at least ten push-off members.
24. The transfer wheel according to claim 19, wherein the transfer wheel comprises a mounting body, wherein the pusher segment is detachably mounted to the mounting body in said first segment position.
25. The transfer wheel according to claim 19, wherein the transfer wheel comprises a plurality of retaining segments distributed about the transfer wheel axis in a plurality of further segments positions along the circumferential surface for retaining the tire component to said circumferential surface, wherein the pusher segment is exchangeable with any one of the retaining segments in any one of the further segment positions.
26. A method for transferring a tire component to a tire building drum with the use of the transfer wheel according to claim 19, wherein the method comprises the steps of: moving the at least one push-off member in the push-off direction to separate the tire component from the transfer wheel at the first segment position; and applying the tire component to the tire building drum with pressure exerted onto said tire component by the at least one push-off member.
27. The method according to claim 26, wherein the tire component has a contour with a varying thickness in a cross section at the first segment position, wherein the plurality of push-off members are configured to match the contour of the tire component when moving in the push-off direction.
28. The method according to claim 26, wherein the method further comprises the step of: retracting the plurality of push-off members in a retraction direction opposite to the push-off direction independently of the contact between the plurality of push-off members and the tire component.
29. The method according to claim 26, wherein the tire component is a side wall.
30. The method according to claim 26, wherein the method comprises the steps of: applying a first side wall to the tire building drum and forming a first splice between a leading end and a trailing end of said first side wall at a first splice position on the tire building drum; applying a second side wall to the tire building drum and forming a second splice between a leading end and a trailing end of said second side wall at a second splice position on the tire building drum; wherein the second splice position is offset in a circumferential direction of the tire building drum with respect to the first splice position.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0071] The invention will be elucidated on the basis of an exemplary embodiment shown in the attached schematic drawings, in which:
[0072] FIG. 1 an isometric view of a tire building drum with a cover according to a first exemplary embodiment of the invention;
[0073] FIG. 2 shows an isometric view of a detail of the tire building drum with the cover according to FIG. 1;
[0074] FIG. 3 shows a cross section of the tire building drum at the cover according to line III-III in FIG. 2;
[0075] FIGS. 4A and 4B show a top view of a closing valve of the cover in an open state and a closed state, respectively;
[0076] FIG. 5 shows a cross section of an alternative cover according to a second exemplary embodiment of the invention;
[0077] FIG. 6 shows a side view of the tire building drum according to FIG. 1 and a transfer wheel for transferring a tire component to said tire building drum;
[0078] FIG. 7 shows an isometric view of a detail of the transfer wheel according to FIG. 6;
[0079] FIG. 8 shows a cross section of the transfer wheel cooperating with the tire building drum according to FIG. 6;
[0080] FIG. 9 shows a cross section of an alternative transfer wheel cooperating with the tire building drum according to FIG. 6;
[0081] FIG. 10 shows a cross section of the tire building drum according to FIG. 3, cooperating with a clip bar;
[0082] FIG. 11 shows a side view of an applicator according to a second exemplary embodiment of the invention for applying a tire component to a tire building drum;
[0083] FIG. 12 shows a cross section of the applicator according to the line XII-XII in FIG. 11; and
[0084] FIG. 13 shows an isometric view of an alternative tire building drum with a cover according to a third exemplary embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0085] FIG. 1 shows a tire building drum 1 for shaping one or more tire components into a green or unvulcanized tire.
[0086] The tire building drum 1 is rotatable about a drum axis D. The drum axis D defines an axial direction A, a circumferential direction C about said drum axis D and a radial direction R perpendicular to said drum axis D. The tire building drum 1 has a center section 10 for shaping a carcass portion of the one or more tire components. The tire building drum 1 is further provided with a first drum half 11 and a second drum half 12 on opposite sides of said center section 10 in the axial direction A, for turning-up one or more tire components 9, including a side wall, against the shaped carcass portion. The tire building drum 1 also comprises a plurality of bead-lock segments 2 for retaining bead. The bead-lock segments 2 are located in the axial direction A between the first drum half 11 and the center section 10 and between the second drum half 12 and the center section 10.
[0087] Each drum half 11, 12 is provided with a plurality of turn-up arms 3 which are distributed in the circumferential direction C and which are movable relative to the drum axis D between an arms-down position and an arms-up position for turning-up the parts of the tire components at a side of the bead-lock segments 2 facing away from the center section 10 against the shaped part of the tire components at the center section 10. Each turn-up arm 3 comprises an elongate arm body 30 and a turn-up roller 31 at the distal end of said arm body 30. The turn-up process is known per se from WO 2018/111091 A2 and incorporated herein by reference.
[0088] As shown in FIG. 1 and in more detail in FIG. 2, the tire building drum 1 further comprises a cover member, a cover part or a cover 4 according to a first exemplary embodiment of the present invention and a plurality of further covers 13. Each cover 4, 13 is arranged in the gap between a pair of adjacent turn-up arms 3 in the circumferential direction C for at least partially bridging, spanning or covering said gap. The cover 4 according to the present invention is located in one cover position P only. The further covers 13 are conventional covers. Alternatively, one or more of the further covers 13 or all of the covers 13 may be replaced by the cover 4 according to the present invention.
[0089] The cross section of FIG. 3 shows the cover 4 according to the first exemplary embodiment in more detail. The cover 4 is formed as a cover plate. In particular, the cover 4 comprises a plate body 40 with a support surface 41 for supporting a tire component 9 on said plate body 40 and a back surface 42 for mounting the plate body 40 on the tire building drum 1. The tire component 9 is preferably a side wall that is applied directly onto the tire building drum 1 at the position of the cover 4. The plate body 40 extends in a longitudinal direction L, parallel or substantially parallel to the axial direction A. The longitudinal direction L of the plate body 40 is also parallel or substantially parallel to the longitudinal of the turn-up arms 3 when said turn-up arms 3 are in the arms down position, as shown in FIG. 3. The plate body 40 is configured to at least partially cover the turn-up rollers 31 of the adjacent turn-up arms 3. The cover 4 is further arranged to remain behind in the arms-down position when the turn-up arm 3 is moved from the arms-down position towards and/or into the arms-up position.
[0090] As shown in FIG. 3, the tire building drum 1 comprises a cover base 14 for mounting the cover 4 on the respective drum half 11, 12 between the pair of adjacent turn-up arms 3. In particular, the back surface 42 of the plate body 40 is arranged to be mounted to said cover base 14. The further covers 13 are mounted on similar cover bases (not shown) distributed circumferentially about the drum axis D. Each cover base 14 is movable in a retraction direction K parallel to the longitudinal direction L of the cover 4 and/or the axial direction A and in a return direction H opposite to the retraction direction K. The retraction direction K faces away from the center section 10. The cover base 14 is movable between a cover position in which the plate body 40 at least partially covers the turn-up rollers 31 at the distal ends of the respective adjacent turn-up arms 3 and a retracted position in which the plate body 40 at least partially expose the turn-up arms 3, in particular the turn-up rollers 31 at the distal ends thereof, prior to turning-up said at least one turn-up arms 3.
[0091] The tire building drum 1 further comprises a pressure chamber 15 for driving the retraction of the cover base 14 in the retraction direction K with compressed air and driving a return of the cover base 14 in a return direction H opposite to the retraction direction L with a partial vacuum.
[0092] The cover 4 differs from the further covers 13 in that it comprises at least one retaining element 5 in the support surface 41 for retaining the tire component 9 to said cover 4. In this exemplary embodiment, the cover 4 comprises a plurality of retaining elements 5 in the support surface 41 for retaining the tire component 9 to said cover 4. The further covers 13 are solely configured for supporting the tire component 9, but not for retaining.
[0093] As further shown in FIG. 3, the plurality of retaining elements 5 comprises a plurality of first suction openings 51 and a second suction opening 52. In this example, the plurality of first suction openings 51 are grouped into an array, in particular a linear array. In other words, the plurality of first suction openings 51 are positioned in a single file, one behind the other, parallel to the axial direction A. The second suction opening 52 is located at the end of the array of first suction openings 51 closest to the center section 10. Each first suction opening 51 defines a first surface area for applying suction to the tire component 9. Similarly, the second suction opening 52 defines a second surface area. In this example, the second surface area is larger than the first surface area. Moreover, in this example, the first suction openings 51 and the second suction opening 52 are circular. Alternatively, the suction openings 51, 52 may have a different shape.
[0094] The cover 4 further comprises a closing valve 6 at each first suction opening 51. In this example, the second suction opening 52 does not have such a closing valve 6. In this example, the closing valves 6 are located at, near, close to or flush with the support surface 41. Alternatively, the closing valves 6 may be in a recessed position relative to the support surface 41. Each closing valve 6 is operable, movable and/or switchable between an enabled or open state, as shown in FIG. 4A, in which the respective first suction opening 51 is open and a disabled or closed state, as shown in FIG. 4B, in which the respective first suction opening 51 is closed. In the open state, the first suction opening 51 can be brought into fluid communication with a source of partial vacuum. In the closed state, the first suction opening 51 can be disconnected from the source of partial vacuum. The closing valves 6 are independently and/or individually switchable with respect to each other. In other words, one or more closing valves 6 may be switched to the closed state, while others remain in the open state.
[0095] In this specific embodiment, the closing valves 6 can be manually switched between the open state and the closed state. In other words, the states of the closing valves 6 are not controlled automatically. The operator may switch the closing valves 6 by directly interacting with said closing valves 6, or by using a manually operated tool, such as a screwdriver, that is not part of the tire building machine 1 and/or the cover 4.
[0096] As shown in FIGS. 4A and 4B, the closing valves 6 are slide valves, in particular rotary slide valves. In particular, each closing valve 6 comprises a circular base plate 60 that fits in the respective first suction opening 51. The base plate 60 has four ports 61, 62 that allow for fluid communication through said base plate 60. The closing valve 6 further comprises a circular closure cap 63 that is concentrically mounted over and rotatable with respect to the base plate 60. The closure cap 63 comprises two apertures 64, 65 which are arranged to be aligned with the four ports 61, 62 in two angular positions of the closure cap 63, one-hundred-and-eighty degrees apart. The number of ports 61, 62 and the number of apertures 64, 65, their shapes and relative positions may be chosen differently. In this example, the closure cap 63 can be rotated over ninety degrees to switch the closing valve 6 between the open state of FIG. 4A and the closed state of FIG. 4B. The closure cap 63 is provided with an elongate slot 66 for receiving the tip of a screwdriver to enable the previously mentioned, manual switching.
[0097] Depending on the width of the tire component 9 that has to be retained by the cover 4, the tire component 9 may not cover all of the first suction openings 51. Anticipating this situation, the operator can disable one or more first suction openings 51 which will not be covered by the tire component 9 in use by switching the corresponding closing valves 6 to the closed state prior to the tire building operation. Hence, pressure loss and/or leakage through said uncovered first suction openings 51 during the subsequent tire building operation can be prevented. In the embodiment as shown, there is only one cover 4 per drum half 11, 12. Hence, the manual operation, although relatively slow compared to an automated version, can still be completed sufficiently quickly to prevent any significant downtime when switching over to a different tire component 9.
[0098] As best seen in FIG. 3, the cover 4 further comprises a duct 7 for connecting the plurality of retaining elements 5 to a source of partial vacuum. The duct 7 comprises a first duct section 71 extending in said back surface 42. The first duct section 71 can establish fluid communication between any one of the first suction openings 51 and the source of partial vacuum. In particular, the first duct section 71 is common to or interconnects each of the first suction openings 51. The first duct section 71 is closed or sealed when the plate body 40 is mounted on the cover base 14 of the respective drum half 11, 12. The duct 7 comprises a second duct section 72 extending internally in the plate body 40 in particular in the thin portion of said plate body 40 that projects towards the center section 10 from the cover base 14. The second duct section 72 can establish fluid communication between the second suction opening 52 and the source of partial vacuum.
[0099] The tire building drum 1, the respective drum half 11, 12 or the cover 4 further comprises a main one-way valve or check valve 16 in or communicating with the duct 7. In this example, the main check valve 16 is positioned between the pressure chamber 15 and the suction openings 51, 52 to stop flow of compressed air from the pressure chamber 15 to the suction openings 51, 52 when the pressure chamber 15 is used to drive the cover base 14 in the retraction direction K and to allow flow of a partial vacuum between the suction openings 51, 52 and the pressure chamber 15 when the pressure chamber 15 is used to return the cover base 14 in the return direction H. The partial vacuum may be maintained or regenerated after the cover base 14 has been returned, to generate suction at the suction openings 51, 52 for retaining of the tire component 9 to the cover 4 during a subsequent tire building cycle.
[0100] FIG. 5 shows an alternative cover 104 according to a second exemplary embodiment of the invention, which differs from the previously discussed cover 4 in that the switching of the closing valves 106 between the open state and the closed state can be automated. This is convenient when more than one cover 4 per drum half 11, 12 is used or when the states need to be changed quickly without operator intervention. In this example, the closing valves 106 are push-to-open check valves that are switchable from the closed state to the open state when the tire component 9 is received on the alternative cover 104 through direct contact with said tire component 9. In other words, the push-to-open check valves are operated solely by the weight of the tire component 9 exerted thereon, provided that the alternative cover 104 is in an upwardly facing receiving position to receive the tire component 9 with at least a component of its gravitational force exerted on the alternative cover 104 in a downward direction. Alternatively, the switching of the closing valves 106 may be automated mechanically, for example by using actuators, servos, solenoids or the like.
[0101] Alternative types of closing valves may be used with the same effect, such as linear slide valves, gate valves, diaphragm valves, or the like.
[0102] FIGS. 6-8 show a transfer drum or a transfer wheel 200 for transferring the tire component 9, in particular a side wall, to the tire building drum 1. The general operation of a transfer wheel is described in WO 2021/107772 A1, which is incorporated herein by reference.
[0103] As shown in FIG. 6, the transfer wheel 200 defines a circumferential surface 201 extending about a transfer wheel axis S. The transfer wheel 200 comprises one or more pusher segments 202 and a plurality of retaining segments 204 distributed about the transfer wheel axis S in a first segment position B1 and a plurality of further segments positions B2-Bn along the circumferential surface 201. The retaining segments 204 are configured for retaining the tire component 9 to said circumferential surface 201, for example with suction or needles. Each pusher segment 202 is configured to separate the part of the tire component 9 supported thereon from the transfer wheel 200 when said part is to be transferred to the tire building drum 1. In this example, the transfer wheel 200 has two pusher segments 200, one at a first circumferential position on the transfer wheel 200 that is supposed to receive the leading end of the tire component 9 and one at a second circumferential position on the transfer wheel 200 that is supposed to receive the trailing end of the tire component 9.
[0104] FIGS. 7 and 8 shown one of the pusher segments 202 in more detail. Its operation is representative of the operation of both pusher segments 202. The pusher segment 202 comprises a segment body 220 that is configured to be flush with the circumferential surface 201 and a plurality of push-off members 203 in said segment body 220 arranged adjacent to each other in a lateral direction T parallel to the transfer wheel axis S. The plurality of push-off members 203 are movable relative to each other and the segment body 220 in a push-off direction W facing radially outward or in a radial direction R relative to the transfer wheel axis S. In particular, each push-off member 203 of the plurality of push-off members 203 is movable in the push-off direction between a flush position in which the respective push-off member 203 is flush with the circumferential surface 201 and a push-off position radially outside of said circumferential surface 201.
[0105] Preferably, the pusher segment 202 comprises at least ten push-off members 203. In this example, the pusher segment 202 has twenty-two push-off members 203.
[0106] The plurality of push-off members 203 define a shape of the circumferential surface 201 that is adaptable to a contour of the tire component 9 when transferring said tire component 9 to the tire building drum 1.
[0107] As best seen in FIG. 8, the plurality of push-off members 203 are pneumatically driven. In particular, the segment body 220 comprises a plurality of slots 221 for receiving the plurality of push-off members 203, wherein the segment body 220 further comprises a duct 222 for connecting the plurality of slots 221 to a source of compressed air or vacuum. The push-off members 203 are driven outwards with compressed air when it is time to separate the tire component 9 from the transfer wheel 200, for example when the pusher segment 202 is directly opposite to the cover 4 of the tire building drum 1. The push-off members 203 can be individually and/or independently moved inwards in a retraction direction V opposite to the push-off direction W against the pressure provided by the compressed air when the respective push-off members 203 to adapt to the cross section, contour or shape of the tire component 9. The pressure exerted by the compressed air is maintained throughout the transfer to maintain a pressure force on the tire component 9. The push-off members 203 can also be actively withdrawn or retracted in the retraction direction V by generating a partial vacuum in the slots 221, for example at the end of the transfer operation.
[0108] The pusher segments 200 as shown in FIG. 6 are exchangeable with any one of the retaining segments 204 in any one of the further segment positions B2-Bn. In particular, the transfer wheel 200 comprises a mounting body 210 which defines the plurality of segment positions B1-Bn, each with a connection to a source of compressed air or a partial vacuum. Each pusher segment 202 can be detached from mounting body 210 and reconnected to the mounting body 210 in any of the further segment positions B2-Bn. More in particular, each of the pusher segments 202 and the retaining segments 204 is provided with a universal connection 223, as shown in FIG. 8, which is mated with the connection at the mounting body 210 for connection to the source of compressed air or a partial vacuum. Because the connection is universal, the segments 202, 204 can be easily switched out or exchanged between segment positions B1-Bn, while maintaining the same functionality in the new segment position.
[0109] FIG. 9 shows an alternative transfer drum or transfer wheel 300 for transferring the tire component 9 to the tire building drum 1. The alternative transfer wheel 300 differs from the aforementioned transfer wheel 200 in that its pusher segment 302 holds a single push-off member 303 in the form of a bladder. The bladder can be inflated and/or deflated to closely match, follow or adapt to the contour of the tire component 9 across the width of the pusher segment 302.
[0110] A method for applying the tire component 9 to the aforementioned tire building drum 1, optionally with the use of one of the aforementioned transfer wheels 200, 300, will now be briefly elucidated with reference to FIGS. 1-10.
[0111] The method comprises the step of applying the tire component 9 around the tire building drum 1 at the location of the cover 4, 104, as shown in FIGS. 3 and 5, optionally with the use of the transfer wheel 200, 300, as shown in FIGS. 6 and 9. The pusher segment 202, 302 at the leading end of the tire component 9 may be supplied with compressed air such that the at least one push-off member 203, 303 moves towards the tire building drum 1 in the push-off direction W, while the at least one push-off member 203, 303 matches, follows or adapts to the contour of the tire component 9 between the transfer wheel 200, 300 and the tire building drum 1, as shown in FIGS. 8 and 9.
[0112] Once the leading end of the tire component 9 is transferred from the transfer wheel 200, 300 to the tire building drum 1, it can be retained to the cover 4 with the use of the plurality of retaining elements 5, 105. The operator may have previously closed or disabled the retaining elements 5, 105 which are not covered by the tire component 9 during the transfer, for example by manually turning the closure cap 63 from the open state, as shown in FIG. 4A, to the closed state, as shown in FIG. 4B. In this example, the tire component 9 is retained to the cover 4, 104 through suction.
[0113] Optionally, as shown in FIG. 10, the tire component 9 can be additionally clamped to or onto the tire building drum 1 with the use of a clip bar 400 during at least a part of the application of said tire component 9 around the tire building drum 1. The clip bar 400 can prevent that the tire component 9 separates from the tire building drum 1 during fast rotation of said tire building drum 1. The clip bar 400 can be used to clamp the tire component 9 at or near the same end that is retained by the retaining elements 5, 105. The clip bar 400 can be used prior to, during and/or after the retaining elements 5, 105 retain the tire component 9.
[0114] The above steps may be repeated to transfer the trailing end of the tire component 9 from the transfer wheel 200, 300 to the tire building drum 1, i.e. by operating the pusher segment 202 at said trailing end. In this example, there is no cover 4, 104 in the tire building drum 1 that is dedicated to retaining the trailing end of the tire component 9. The trailing end is immediately spliced or stitched to the leading end. Alternatively, a further cover (not shown) may be provided with retaining elements to retain the trailing end in a similar way to the leading end.
[0115] Note that the tire component 9 is retained to the cover 4, 104 prior to turning-up the plurality of the turn-up arms 3, as reflected by the arms-down position of the turn-up arms 3 in FIG. 3. In particular, the tire component 9 is wound around the tire building drum 1 until the leading end and the trailing end of said tire component 9 can be spliced or stitched. Then the cover 4, 104 can stop retaining the tire component 9, for example by terminating the suction, and the turn-up operation can be performed.
[0116] FIGS. 11 and 12 show an alternative method for applying a tire component 9 to the tire building drum 1 using an applicator 500 with at least one application member 501 for applying pressure on the tire component 9.
[0117] As shown in FIG. 11, the tire component 9 is supplied to the tire building drum 1 in a feeding direction or a supply direction F, in this example by a conveyor 509, e.g. a belt conveyor.
[0118] As shown in FIG. 12, the tire component 9, in this example a side wall, has a cross section perpendicular to the supply direction F that, in an unstressed or relaxed state, has a flat side 91 facing away from the tire building drum 1 and a non-flat side 92 facing towards the tire building drum 1. In this example, the non-flat side 92 is defined by a first tapering portion 93 and a second tapering portion 94 at opposite lateral ends of the cross section in the lateral direction T. In the context of side walls, the tapering portions 93, 94 are also known as wings or wing tips.
[0119] In this example, the applicator 500 comprises a first application member 501 and a second application member 502 which are positioned opposite to the tire building drum 1. The first application member 501 and the second application member 502 are configured so as to be aligned with the first tapering portion 91 and the second tapering portion 92, respectively, when the tire component 9 is first applied to the tire building drum 1. In other words, the application members 501, 502 are configured to press the tire component 9 onto the tire building drum 1 at the leading end of said tire component 9.
[0120] The application members 501, 502 may be shaped as fingers, blocks or convex pressing members to effectively press down onto the tire component 9 while reducing imprints. The application members 501, 502 are moved, preferably linearly, with at least a component in a pressing direction Z normal to the circumferential surface of the tire building drum 1 at the location of the suction openings 51, 52. The application members 501, 502 may be moved by any suitable actuators, such as pneumatic or hydraulic cylinders, linkages, gear racks, spindles, servo motors or the like.
[0121] The pressure exerted by the application members 501, 502 onto the tire component 9 cause it to deform into a deformed tire component 9 with a cross sectional shape as shown in dashed lines in FIG. 12. In particular, the previously flat side 91 is now non-flat and the previously non-flat side 92 has been deformed towards or into a more flat surface, in particular at the location of the respective suction openings 51, 52 in the tire building drum 1. The flattened or more flat contour of the tire component 9 can be retained more reliably with suction.
[0122] FIG. 13 shows an alternative tire building drum 601 according to a third exemplary embodiment of the invention, which differs from the tire building drum 1 as shown in FIG. 1 in that the cover 604 at the second drum half 612 is in a different position to the cover 4 at the first drum half 11. In particular, the cover 4 at the first drum half 11 is in a first splice position P1 for retaining the leading end of the first tire component 691 to the alternative tire building drum 601 to form a first splice S1 together with the trailing end of the same first tire component 691 at or near said first splice position P1. In contrast, the cover 604 at the second drum half 612 is in a second splice position P2 that is offset over an offset distance X in the circumferential direction C about the drum axis D for retaining the leading end of the second tire component 692 to the alternative tire building drum 601 to form a second splice S2 together with the trailing end of the same second tire component 692 at or near said second splice position P2. In this example, the tire components 691, 692 are both side walls.
[0123] The offset between the splices S1, S2 can reduce imbalance in the tire that is ultimately formed as a result of the splices.
[0124] It is to be understood that the above description is included to illustrate the operation of the preferred embodiments and is not meant to limit the scope of the invention. From the above discussion, many variations will be apparent to one skilled in the art that would yet be encompassed by the scope of the present invention.
