Stitcher, Tire Manufacturing Apparatus Comprising the Stitcher, and Stitching Method for Tire Constituent Members

Abstract

The present invention relates to a tire building apparatus and a method for stitching tire components, the tire building apparatus comprising a tire building drum and a stitcher, the tire building drum having beadlock segments retractable to a retracted position relative to a remainder of the tire building drum, the stitcher having a disk-shaped stitching body having a first surface for pressing the tire components during stitching and a second surface opposite the first surface, the second surface being concave, and the stitcher is positionable relative to the tire building drum such that the concave second surface fits at least partially in a transition between the beadlock segments in a retracted position and the remainder of the tire building drum.

Description

Technical Field

[0001] The present invention relates to a stitcher, a tire manufacturing apparatus including the stitcher, and a method for stitching tire components.

Background Art

[0002] International Publication No. 2018 / 111091 discloses a tire manufacturing drum including two drum halves, particularly a tire manufacturing apparatus including a crown drum for single-stage tire manufacturing. Each drum half includes a crown up-segment, a turn-up portion, and a bead lock portion located axially between the crown up-segment and the turn-up portion. The bead lock portion includes a plurality of bead lock members distributed circumferentially about a central axis and movable radially between a release position and a bead lock position.

Summary of the Invention

[0003] A drawback of known tire manufacturing apparatuses is that in some cases, particularly between the bead and the drum, it is necessary to form the sidewall by folding the sidewall around the radially inner side of the bead. Since it is difficult to form a skirt in which the sidewall is uniformly folded back radially inside the bead, it is particularly difficult to fold the sidewall radially inside the bead. It is impossible to do this manually. However, the available space between the bead and the bead lock portion in the release position is only a few millimeters, which is insufficient to accommodate a conventional stitch roller. Therefore, it is necessary to move the drum half at least partially axially so that the sidewall can be folded around the bead. Alternatively, it is necessary to fold the sidewall around the bead on a first drum with a small diameter and then transfer the tire component to a forming drum as in the case of conventional two-stage tire manufacturing.

[0004] An object of the present invention is to provide a stitcher with an improved method for forming a sidewall, a tire manufacturing apparatus including the stitcher, and a method for stitching tire components.

[0005] According to a first aspect, the present invention provides a tire manufacturing apparatus including a tire manufacturing drum and a stitcher for stitching tire components, wherein the tire manufacturing drum includes a bead lock segment that can be retracted to a retracted position relative to the remaining portion of the tire manufacturing drum, and the stitcher includes a disc-shaped stitching body having a first surface for pressing the tire component during stitching and a second surface on the opposite side of the first surface, the second surface being concave, and the stitcher is relatively positionable with respect to the tire manufacturing drum such that the concave second surface at least partially fits into a transition portion between the bead lock segment in the retracted position and the remaining portion of the tire manufacturing drum.

[0006] Due to the concave second surface, the stitcher according to the first aspect of the present invention can move so as to approach the periphery of the tire manufacturing drum without colliding, particularly at the transition portion or the transition end portion, whereby the stitcher can reach a relatively small space between the retracted bead lock segment and the radially inner side of the bead.

[0007] Preferably, the disc-shaped stitching body is concentric with the stitching axis, and the first surface defines a pressing surface disposed on an inclined portion that is inclined away from the second surface at a relief angle in a radial direction away from the stitching axis. More preferably, the relief angle is in the range of 0 degrees to 15 degrees, and most preferably in the range of 2 degrees to 10 degrees. With this relief angle, the stitcher can be scooped up immediately below the radially inner side of the bead with the stitching axis inclined with respect to the vertical plane, whereby at least a part of the pressing surface can be inclined toward the horizontal plane or within the horizontal plane. In this way, while the stitcher is disposed obliquely with respect to the tire manufacturing drum, the pressing surface can effectively bend and press the tip portion of the tire component around the radially inner side of the bead.

[0008] According to a second aspect, the present invention provides a method of stitching a tire component using the tire manufacturing apparatus according to the first aspect of the present invention, the method comprising: positioning the stitcher relative to the tire manufacturing drum such that the concave second surface at least partially fits into a transition portion between the bead lock segment in the retracted position and the remaining portion of the tire manufacturing drum.

[0009] This method relates to the practical application of the aforementioned tire manufacturing apparatus and thus, although not repeated below, has the same technical advantages.

[0010] Preferably, the disc-shaped stitching body is concentric with the stitching axis, and the first surface defines a pressing surface disposed in an inclined portion that is inclined away from the second surface at a relief angle in a radial direction away from the stitching axis, and the method comprises: positioning the stitcher relative to the tire manufacturing drum such that the stitching axis is inclined with respect to a vertical plane, thereby inclining at least a part of the pressing surface toward or within a horizontal plane.

[0011] In the horizontal or substantially horizontal direction, the pressing surface can effectively bend and press from within the bead to the tip of the tire component.

[0012] According to a third aspect, the present invention provides a stitcher for stitching a tire component, the stitcher defining a first stitching axis and comprising a first stitching member that is concentric with the first stitching axis and rotatable about the first stitching axis for stitching the tire component along a first portion of a stitching path. The stitcher further comprises a second operating member and a positioning member for relatively moving the second operating member to an operating position where the second operating member projects partially beyond the first stitching member in a radial direction perpendicular to the first stitching axis with respect to the first stitching axis. The positioning member is rotatable about the first stitching axis and is arranged such that rotation of the positioning member is driven by eddy currents generated between the positioning member and the first stitching member.

[0013] The second operating member can be sized or optimized to fit into a space where the first stitching member cannot fit. More specifically, the second operating member can fit into a relatively small space between the bead lock member and the radially inner surface of the bead. The force generated by the eddy currents can be used to pull along the positioning member when the first stitching member rotates. Thus, no separate driving means for driving the positioning member is necessary.

[0014] In one embodiment, the second operating member is a second stitching member for stitching the tire component along a second portion of the stitching path. The second stitching member fits into a relatively small space between the bead lock member and the radially inner surface of the bead and can stitch and / or bend the sidewall along the radially inner surface of the bead.

[0015] Preferably, the stitcher defines a second stitching axis, and the second stitching member is concentric with the second stitching axis and rotatable about the second stitching axis. Thus, the second stitching member can stitch and / or bend the side wall with minimal friction while the drum on which the side wall and bead are supported is rotating.

[0016] In a further embodiment, the rotation of the positioning member about the first stitching axis is arranged to be driven by the rotation of the first stitching member. Thus, no separate driving means for driving the positioning member is required.

[0017] In a further embodiment, the positioning member is rotatable between a standby position in which the second operating member is spaced apart from the tire component member during stitching and a stitching position. Thus, the second operating member can switch, move and / or rotate between each position according to the stitching operation to be performed.

[0018] In a further embodiment, the stitcher includes a first limiter and a second limiter for restricting the rotation of the positioning member between the standby position and the operating position. As a result, the second operating member can move between the two positions. In particular, it is possible to prevent the positioning member from moving beyond the two positions where the second operating member may potentially interfere with the operation of the first stitching member.

[0019] In a further embodiment, the first limiter and the second limiter that limit the rotation of the positioning member to a range of less than 180 degrees are provided. As a result, the positioning member can move between two positions spaced less than 180 degrees apart.

[0020] In a further embodiment, the positioning member is configured to rotate in the same direction about the first stitching axis, similar to the first stitching member. Therefore, the rotation direction of the first stitching member can be used to control the rotation direction of the positioning member.

[0021] In another embodiment, the positioning member includes a plurality of magnets. By rotating the first stitching member through the magnetic field generated by the plurality of magnets provided on the positioning member, the aforementioned eddy currents can be generated.

[0022] More preferably, the positioning member includes a disc-shaped body concentric with the first stitching axis, and the plurality of magnets are distributed in the circumferential direction on the disc-shaped body about the first stitching axis. In this way, eddy currents can be evenly generated throughout the disc-shaped body.

[0023] In a further embodiment, the plurality of magnets have alternating polarities. The alternating polarities increase the eddy currents that can be generated.

[0024] In a further embodiment, the first stitching member includes a ferromagnetic material or a paramagnetic material. Due to the magnetic interaction between the magnet and the ferromagnetic material, sufficient eddy currents can be generated to pull along the positioning member.

[0025] In a further embodiment, the first stitching member includes aluminum. Aluminum itself is not a strong magnetic material. However, when moved in the magnetic field of a plurality of magnets, it can act as a paramagnetic material capable of generating sufficient eddy currents to pull along the positioning member.

[0026] In a further embodiment, the first stitching member has a first surface for attaching the stitcher to a robotic manipulator, and the second operating member is disposed on a second surface of the first stitching member that is opposite the first surface. Thus, the second operating member can be disposed on the side of the first stitching member where there are no other components, and thereby can be moved as close as possible to the periphery of the tire manufacturing drum without colliding with the tire manufacturing drum.

[0027] In a further embodiment, the first stitching member defines a cavity, and the positioning member is at least partially received within the cavity. Thus, the positioning member does not increase the thickness or overall size of the stitcher. As a result, the stitcher can approach the circumferential surface of the tire manufacturing drum without colliding.

[0028] In a further embodiment, the first stitching axis and the second stitching axis are parallel or substantially parallel to each other. Thus, the stitching member can be rotated about the parallel stitching axes and operate in the same or substantially the same direction.

[0029] According to a fourth aspect, the present invention provides a tire manufacturing apparatus comprising the stitcher according to any one of the embodiments of the third aspect of the present invention and a tire manufacturing drum.

[0030] Since the tire manufacturing apparatus includes the aforementioned stitcher, the same technical advantages are achieved, which will not be repeated hereinafter.

[0031] Preferably, the tire manufacturing drum is rotatable about a drum axis in a first rotational direction and a second rotational direction opposite to the first rotational direction, and the rotation of the first stitching member about the first stitching axis is arranged to be driven by the rotation of the tire manufacturing drum. The positioning member is rotatable about the first stitching axis in a third rotational direction and a fourth rotational direction opposite to the third rotational direction, and the rotation of the positioning member about the first stitching axis is arranged to be driven by the rotation of the first stitching member. The change in the rotation of the tire manufacturing drum from the first rotational direction to the second rotational direction controls the rotational direction in which the positioning member rotates. Accordingly, the rotational direction of the tire manufacturing drum can indirectly control the rotation of the positioning member and thus the position of the second operating member. In particular, the rotation of the tire manufacturing drum can be reversed to move the secondary operating member to a stitching position where it can be operated. Conveniently, the stitcher does not require dedicated control means or drive means for moving the second operating member.

[0032] According to a fifth aspect, the present invention provides a method of stitching a tire component using a stitcher according to any one of the embodiments of the third aspect of the present invention, the method comprising: stitching a tire component along the first portion of the stitching path using the first stitching member; moving the second operating member to the operating position relative to the first stitching axis using the positioning member.

[0033] This method relates to the practical implementation of the stitcher described above and thus, although not repeated below, has the same technical advantages.

[0034] In one embodiment, the second operating member is a second stitching member, and the method further comprises stitching a tire component along the second portion of the stitching path using the second stitching member.

[0035] In a further embodiment of the method, the rotation of the positioning member about the first stitching axis is driven by the rotation of the first stitching member.

[0036] In a further embodiment, the rotation of the positioning member is restricted between a standby position and the operating position.

[0037] In a further embodiment, the rotation of the positioning member is restricted to a range of less than 180 degrees between the standby position and the operating position.

[0038] In a further embodiment, the positioning member rotates in the same direction as the first stitching member about the first stitching axis.

[0039] In a further embodiment, the rotation of the positioning member is driven by eddy currents generated between the positioning member and the first stitching member.

[0040] According to a sixth aspect, the present invention provides a stitcher for stitching a tire component, the stitcher comprising a hub rotatable about a stitching axis, and a plurality of stitching segments connected to the hub and arranged around the hub and extending radially away from the hub, the stitching segments being elastically deformable relative to the hub.

[0041] The stitching segments can provide a segmented periphery that can effectively adapt to the shape of the tire component to be stitched.

[0042] Preferably, among the plurality of the stitching segments, at least two directly adjacent stitching segments are coupled to each other in the circumferential direction centered on the stitching axis. Since the stitching segments influence each other's deflection to some extent, the shape of the stitcher is deformed more gently, that is, without causing a sharp step between the stitching segments.

[0043] The various aspects and features described and shown in this specification can be applied individually as much as possible. These individual aspects, particularly the aspects and features described in the appended dependent claims, can be the subject of a divisional patent application.

Brief Description of the Drawings

[0044] The present invention is elucidated based on exemplary embodiments shown in the appended schematic drawings.

Figure 1

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Figure 4

Figure 5

Figure 6

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BEST MODE FOR CARRYING OUT THE INVENTION

[0045] FIGS. 1 to 3 show a tire manufacturing apparatus 1 for manufacturing a green tire or an unvulcanized tire 9 according to a first exemplary embodiment of the present invention.

[0046] The tire manufacturing apparatus 1 includes a tire manufacturing drum 2 for molding a green tire 9. The green tire 9 is formed by molding one or more plies 91, particularly a body ply or a breaker ply, around a bead 92 to form a tire carcass. The bead 92 is an annular or substantially annular member and has a radially inner surface 93 that defines an inner diameter B of the bead. The green tire 9 further includes a sidewall 94 that is applied to the carcass by being at least partially bent around the radially inner surface 93 of the bead 92 in this example. In particular, an inner end or inner tip 95 of the sidewall 94 is bent around the radially inner surface 93 of the bead 92.

[0047] The tire manufacturing drum 2 is rotatable about a drum axis D extending in the axial direction A, and the tire manufacturing drum 2 includes a first drum half 3, a second drum half 4, and a central portion 5 in the axial direction A between the drum halves 3 and 4.

[0048] Each drum half 3, 4 is provided with bead lock portions 31, 41 for holding the bead 92. The bead lock portions 31, 41 are provided with a plurality of bead lock segments 32, 42 that are expandable and contractible in the radial direction R perpendicular to the drum axis D, and engage and hold the bead 92 at the inner diameter B of the bead. The plurality of bead lock segments 32 can be retracted or contracted to a flush or retracted position with respect to the other parts of the tire manufacturing drum 2 so as to provide sufficient space for fitting one or more plies 91 and the bead 92 into the tire manufacturing drum 2 and folding the sidewall 94 around the inner side 93 in the radial direction of the bead 92.

[0049] Each drum half 3, 4 further includes turn-up portions 35, 45 for folding a portion of one or more plies 91 located outside the central portion 5 around the bead 92 onto a portion of one or more plies 91 in the central portion 5. In particular, the turn-up portions 35, 45 include turn-up arms (not shown).

[0050] The central portion 5 is provided with a plurality of crown segments 51 that are expandable in the radial direction to crown up a portion of one or more plies 91 in the central portion 5 into a toroidal shape or a substantially toroidal shape.

[0051] As shown in FIG. 1, the tire manufacturing apparatus 1 further includes stitchers 6 and further stitchers 6' respectively provided on the first side and the second side of the central portion 5 for stitching the sidewalls 94 to the crowned portions of one or more plies 91 in the central portion 5. Each stitcher 6, 6' is attached to a robot manipulator 100 that controls the orientation of each stitcher 6, 6' as a whole with respect to the tire manufacturing drum 1. The tire manufacturing drum 1 is rotated about the drum axis D, causing relative movement between one or more plies 91 and the sidewalls 94 supported thereon and the stitchers 6, 6'. The stitchers 6, 6' have the same or similar structures except that they are mirror-symmetrical with respect to the central portion 5 and / or operate in a mirror-symmetrical manner. The stitchers 6, 6' are moved on the opposite side of the central portion 5 along their respective stitching paths P. In particular, as shown in FIGS. 1 and 2, the stitchers 6, 6' are moved along a first portion P1 of the stitching path P, and as shown in FIG. 3, along a second portion P2 of the stitching path P. Hereinafter, only the stitcher 6 shown on the side of the second drum half 4 will be described in more detail. However, this description also applies mutatis mutandis to the further stitcher 6'.

[0052] As best seen in FIG. 4, the stitcher 6 includes a first stitching shaft portion 60 that defines a first stitching axis S1. The stitcher 6 includes a first stitching member 61 attached concentrically to the first stitching shaft portion 60. In other words, the first stitching member 61 is concentric with the first stitching axis S1. The first stitching member 61 is rotatable about the first stitching shaft portion 60 and / or the first stitching axis S1 for stitching the sidewall 94. A bearing 65 is provided to facilitate rotation of the first stitching member 61 about the first stitching shaft portion 60. Alternatively, the first stitching shaft portion 60 may be fixed to the first stitching member 61, in which case the first stitching shaft portion 60 can rotate relative to the manipulator 100.

[0053] The first stitching member 61 includes a stitching body having a first surface M that defines a stitching surface 62 for pressing against the side wall 94. The stitching body is preferably disc-shaped, wheel-shaped, or roller-shaped. The stitching surface 62 is rounded or convex in the vicinity of the circumferential end or contour of the first stitching member 61 in order to press both the radial direction R perpendicular to the first stitching axis S1 and the direction oblique to the radial direction R. The stitching body further has a mounting head 64 for attaching the first stitching member 61 to the first stitching shaft portion 60 on the first surface M.

[0054] The stitching body of the first stitching member 61 may contain a ferromagnetic material or a paramagnetic material such as aluminum.

[0055] The first stitching member 6 further has a second surface N facing away from the first surface M. On the second surface N, the first stitching member 61 includes a cavity 63. The first stitching shaft portion 60 extends through the first stitching member 61 into the cavity 63.

[0056] The stitcher 6 includes a second operating member 71. In this example, the second operating member 71 is a second stitching member 71 concentrically attached to the second stitching shaft portion 70 defined by the stitcher 6. In other words, the second stitching member 71 is concentric with the second stitching axis S2. The second stitching member 71 also includes a disc-shaped, wheel-shaped, or roller-shaped stitching body, similar to the first stitching member 61. However, the stitching body of the second stitching member 71 is considerably smaller than the stitching body of the first stitching member 61, preferably at least 2 to 3 times smaller. The second stitching member 71 is rotatable about the second stitching shaft portion 70 and / or the second stitching axis S2 in order to stitch the side wall 94 along the radially inner surface 93 of the bead 92. The second stitching member 71 is located on the second surface N side of the first stitching member 61.

[0057] Alternatively, the second operating member 71 may have a function different from stitching, for example, functions such as cutting, brushing, pulling, tagging, or detecting. The second operating member 71 may be, for example, a brush or a sensor.

[0058] The following description is for the second stitching member 71, but the same features can also be applied mutatis mutandis to the other second operating members described above.

[0059] As shown in FIG. 4, the stitcher 6 further includes a positioning member 8 for relatively moving the second stitching axis S2 with respect to the first stitching axis S2 to a stitching position or an operating position where the second stitching member 71 projects radially R beyond the first stitching member 61. In particular, the second stitching member 71 projects beyond the circumferential end and / or contour of the first stitching member 61 at the stitching position. Therefore, the second stitching member 71 can reach a relatively small gap between the radially inner surface 93 of the bead 92 and the bead lock segments 32, 42 of the tire manufacturing drum 2.

[0060] As best seen in FIG. 6, the second stitching member 71 at the stitching position is located at a position slightly offset from the center with respect to the drum axis D. In particular, the second stitching member 71 is offset with respect to the drum axis D such that the second stitching axis S2 does not intersect the drum axis D. Thereby, only a part of the circumference of the second stitching member 71 that rotates toward and / or within the small gap between the radially inner surface 93 of the bead 92 and the bead lock segments 32, 42 of the tire manufacturing drum 2 contacts the bead 92, while a part of the circumference of the second stitching member 71 that rotates away from and / or out of the small gap is free from and / or does not contact the bead 92. Thereby, it is possible to avoid a force that could potentially interfere with each other from acting between the bead 92 and the second stitching member 71.

[0061] The positioning member 8 is rotatable about the first stitching shaft portion 60 and / or the first stitching shaft S1. The positioning member 8 may be directly attached to the first stitching shaft portion 60 using a bearing 85, for example as shown in FIG. 4, or alternatively, may be rotatably supported about the first stitching shaft S1 by an edge or guide of a suitable shape provided in the cavity 63 of the first stitching member 61.

[0062] In another embodiment (not shown), another positioning member may be provided to linearly displace the second stitching member 71, for example in the radial direction R, between a standby position where the second stitching member 71 is completely located inside the circumference of the first stitching member 61 and a stitching position where it protrudes at least partially beyond the circumference of the first stitching member 61.

[0063] The second stitching shaft portion 70 is coupled, connected, or supported by the positioning member 8 at a position spaced from the first stitching shaft portion 60. In other words, the first stitching shaft S1 and the second stitching shaft S2 are spaced apart from each other. At this spaced position, the second stitching member 71, which is much smaller than the first stitching member 61, can be considered as a member having a relationship of a planet and a satellite with respect to the first stitching member 61, and it appears to move along an orbit defined almost by the end of the first stitching member 61. The positioning member 8 is configured to hold the second stitching shaft portion 70 in a direction parallel or substantially parallel to the first stitching shaft portion 60. In other words, the first stitching shaft S1 and the second stitching shaft S2 are parallel or substantially parallel to each other.

[0064] As best seen in FIGS. 5 and 6, the positioning member 8 is disc-shaped or has a disc-shaped body 80. In particular, the positioning member 8 includes a plurality of magnets 81 evenly and / or circumferentially distributed on the disc-shaped body 80 about the first stitching shaft S1. In this embodiment, the plurality of magnets 81 have alternating polarities.

[0065] The positioning member 8 further includes a first limiter 85 and / or a second limiter 86 for limiting the rotation of the positioning member 8 about the first stitching shaft portion 60 and / or the first stitching shaft S1 to less than 180 degrees, preferably less than 100 degrees. In this exemplary embodiment, the first limiter 85 and the second limiter 86 are defined or formed by the ends of the angular grooves that interact with the pins of the first stitching member 61. Alternatively, the limiters 85, 86 may be provided on one of the first stitching member 61, the first stitching shaft portion 60, the positioning member 8 and / or the second stitching member 71, and may be formed by appropriately arranged obstacles that interact with the other one of the first stitching member 61, the first stitching shaft portion 60, the positioning member 8 and the second stitching member 71.

[0066] Next, a method of stitching the side wall 94 using the above-described stitcher 6 will be briefly described with reference to FIGS. 1 to 6.

[0067] Figures 1 and 5 show the situation at the start of the first stitching operation where the second stitching member 71 is spaced from the side wall 94, does not interact with the side wall 94, and / or does not press on the side wall 94. The manipulator 100 positions the first stitching member 61 at the starting position of the first part P1 of the stitching path P in such an arrangement that it can press and / or stitch the radially outer portion of the side wall 94 against one or more plies 91 therebelow. Figure 2 shows the situation after the manipulator 100 has further moved the first stitching member 61 along the end of the first part P1 of the stitching path P. The second stitching member 71 remains held in the standby position. Figures 3 and 6 show the situation at the start of the second stitching operation where the second stitching member 71 is moved relative to the first stitching shaft portion 60 and / or the first stitching axis S1 from the standby position to the stitching position. As best seen in Figure 3, the stitcher 6 can be moved by the manipulator 100 such that the second stitching member 71 follows, presses against, and folds the side wall 94 around the radially inner surface 93 of the bead 92 without colliding with the underlying bead lock segments 32, 42.

[0068] In this exemplary embodiment, the positioning member 8 is not directly driven or controlled by dedicated driving means. Instead, the rotation of the first stitching member 61 is transmitted to the positioning member 8. In particular, the positioning member 8 is configured to rotate in the same direction about the first stitching axis S1, similar to the first stitching member 61. In other words, the positioning member 8 is configured to passively follow the rotation of the first stitching member 61. In this example, the transmission of rotation is achieved by generating eddy currents when the first stitching member 61 rotates relative to the plurality of magnets 81 of the positioning member 8. The positioning member 8 is rotatable freely. Thus, it comes to be pulled by the first stitching member 61. In this way, the positioning member 8 can be driven by the rotation of the first stitching member 61 within the range defined by the limiters 85, 86, and move the second stitching member 71 from the standby position shown in FIG. 5 to the stitching position shown in FIG. 6.

[0069] Alternatively, the rotation of the first stitching member 61 can be transmitted to the positioning member 8 via other transmission means, particularly mechanical transmission means. For example, mechanical friction may be provided between the first stitching shaft portion 60 and the positioning member 8. In another example, the centrifugal force generated by the rotation of the first stitching member 61 can be utilized to operate a centrifugal clutch or coupling.

[0070] Similarly, the first stitching member 61 is not directly driven or controlled by dedicated driving means. Instead, when the first stitching member 61 comes into contact with the tire manufacturing drum 2 or one or more plies 91 and / or sidewalls 94 supported by the tire manufacturing drum 2, the rotation of the tire manufacturing drum 2 is transmitted to the first stitching member 61. In other words, the first stitching member 61 is configured to be passively driven by the tire manufacturing drum 2. In particular, the rotation direction of the tire manufacturing drum 2 determines the rotation direction of the first stitching member 61. And since the positioning member 8 is passively follower the rotation of the first stitching member 61, it can be said that the tire manufacturing drum 2 indirectly drives and / or controls the rotation of the positioning member 8 about the first stitching shaft portion 60 and / or the first stitching axis S1.

[0071] Utilizing this principle, the positioning member 8 can be moved between the standby position in FIG. 5 and the stitching position in FIG. 6. In particular, as shown in FIG. 5, when the tire manufacturing drum 2 is rotated in the first rotation direction R1 about the drum axis D, the first stitching member 61 of the stitcher 6 rotates in the third rotation direction R3, whereby the positioning member 8 rotates in the same third rotation direction R3, and the second stitching member 71 is moved away from the stitching position to the standby position. Also, when moving the second stitching member 71 to the stitching position, as shown in FIG. 6, the rotation direction of the tire manufacturing drum 2 is reversed to the second rotation direction R2 opposite to the first rotation direction R1, whereby the rotation direction of the first stitching member 61 is reversed to the fourth rotation direction R4 opposite to the third rotation direction R3. Thereby, the positioning member 8 moves in the same fourth rotation direction R4, and the second stitching member 71 is moved to the stitching position.

[0072] The short moment of stopping and reversing the rotation direction of the tire manufacturing drum 2 terminates the first stitching operation of the first stitching member 61 along the first part P1 of the stitching path P, and if necessary, relocates the stitcher 6 to a convenient position for the second stitching operation including folding back the sidewall 94 around the radially inner surface 93 of the bead 92, and can be conveniently used.

[0073] It will be apparent to those skilled in the art that the first stitching member 61 and / or the second stitching member 71 can be directly and / or individually driven by suitable driving means such as a servo motor. Additionally or alternatively, other means for transmitting rotation between the first stitching member 61 and the positioning member 8, such as mechanical transmission means like gears, may be provided.

[0074] FIG. 7 shows an alternative tire manufacturing apparatus 101 that is different from the aforementioned tire manufacturing apparatus 1 in that the stitcher 106 includes a disc-shaped stitching body 160 having a first surface 161 and a second surface 162 opposite to the first surface 161. The second surface 162 is concave. Due to the concave surface, the stitcher 106 can approach the peripheral surface of the tire manufacturing drum 2 without collision.

[0075] The disc-shaped stitching body 161 is concentric about the stitching axis S. The first surface 161 defines a pressing surface 163 that is inclined or disposed as an inclined surface away from the second surface 162 at a relief angle H in the radial direction R away from the stitching axis S. The relief angle H is within the range of 0 degrees to 15 degrees, preferably within the range of 1 degree to 15 degrees, more preferably within the range of 2 degrees to 10 degrees, still more preferably within the range of 4 degrees to 6 degrees, and most preferably about 5 degrees.

[0076] As shown in FIG. 7, the bead lock segment 42 is retracted to a retracted position with respect to the remaining portion of the tire manufacturing drum 2. The recess of the bead lock segment 42 defines a transition portion T or a transition end portion between the retracted bead lock segment 42 and the remaining portion of the tire manufacturing drum 2. The stitcher 106 can be positioned with respect to the tire manufacturing drum 2 such that the concave second surface 162 at least partially fits over the transition portion T, for example using the manipulator 100 shown in FIGS. 1-4. In other words, the transition portion T is at least partially received within the cavity defined by the second surface 162. More specifically, the stitcher 106 is arranged with respect to the tire manufacturing drum 2 such that the stitching axis S makes an angle oblique to the vertical plane. In this orientation, the stitcher 106 can pass under or scoop under the radially inner surface 93 of the bead 92 to reach the limited space between the radially inner surface 93 and the concave bead lock segment 42. Also, the oblique orientation of the stitcher 106 causes at least a portion of the pressing surface 163 to be inclined with respect to or within the horizontal plane in order to reliably press against the inner tip portion 95 of the sidewall 94.

[0077] The stitcher 106 of the alternative tire manufacturing apparatus 101 may be arranged or offset to a position slightly off-center with respect to the drum axis D, similar to the second stitching member 71 of FIG. 6, such that at its stitching position, its stitching axis S does not intersect the drum axis D. In this way, a portion of its circumference remains in contact with the bead 92 while other portions remain free from and / or do not contact the bead 92.

[0078] Figures 8 to 11 show a further alternative tire manufacturing apparatus 201 according to a third embodiment of the present invention. The alternative tire manufacturing apparatus 201 is different from the tire manufacturing apparatuses 1, 101 described above in that it includes an alternative stitcher 206 having an alternative stitching body 260. The alternative stitching body 260 is rotatable about a stitching axis S. As best seen in FIGS. 9 and 10, the alternative stitching body 260 includes a hub 261 and a plurality of stitching segments 262 distributed circumferentially about the stitching axis S. The stitching segments are connected to the hub 261 and extend from the hub 261 in the radial direction of the stitcher direction P2. The stitching segment 262 is elastically deformable with respect to the hub 261 in the axial stitcher direction A2. In other words, the end of each stitching segment 262 is elastically movable back and forth in the axial stitcher direction A2. The alternative stitching body 260 is flat or substantially flat and / or disc-shaped. The hub 261 has a relatively low height in the axial stitcher direction A2 compared to the stitching body 60 described above. Therefore, the alternative stitching body 60 can be more easily interposed between the bead 92 and the bead lock segments 32, 42. In this exemplary embodiment, each of the stitching segments 262 includes a pressing portion 265 at its respective end for pressing the side wall 94 against the radially inner surface 93 of the bead 92. The pressing portion 265 bulges from the stitching segment 262 in the axial stitcher direction A2.

[0079] Optionally, as best shown in FIG. 11, the stitching segments 262 are interconnected in the circumferential direction of the stitcher about the stitching axis S. For the interconnection, the displacement of the axial stitcher direction A2 of one end of the stitching segment affects the displacement of the adjacent and / or proximate stitching segments 262. In other words, when one of the stitching segments 262 is displaced in the axial stitcher direction A2, the adjacent and / or proximate stitching segments are also displaced. Each stitching segment 262 includes a first profile portion 263 and a second profile portion 264 complementary to the first profile portion 263. Preferably, the alternative stitching body 260 is manufactured by 3D printing.

[0080] It should be understood that the above description is included to explain the operation of the preferred embodiment and is not intended to limit the scope of the invention. From the above discussion, many variations that would be encompassed within the scope of the invention will be apparent to those skilled in the art.

Description of Reference Numerals

[0081] 1: Tire manufacturing apparatus 2: Tire manufacturing drum 3: First drum half 31: Bead lock portion 32: Bead lock segment 35: Turnup portion 4: Second drum half 41: Bead lock portion 42: Bead lock segment 45: Turnup portion 5: Central portion 51: Crown segment 6: Stitcher 6’: Further stitcher 60: First stitching axis portion 61: First stitching member 62: Stitching surface 63: Cavity 64: Mounting head 65: First bearing 70: Second stitching shaft portion 71: Second stitching member 8: Positioning member 80: Disk-shaped body 81: Magnet 85: Second bearing 9: Green tire 91: Ply 92: Bead 93: Radial inner surface 94: Side wall 95: Inner tip 100: Robot manipulator 101: Alternative tire manufacturing apparatus 106: Alternative stitcher 160: Disk-shaped stitching body 161: First surface 162: Second surface 163: Pressing surface 201: Further alternative tire manufacturing apparatus 206: Alternative stitcher 260: Stitching body 261: Hub 262: Stitching segment 263: First profile portion 264: Second profile portion 265: Pressing portion A: Axial direction C: Circumferential direction D: Drum axis H: Relief angle M: First surface N: Second surface P: Stitching path P1: First part of the stitching path P2: Second part of the stitching path R: Radial direction R1: First rotation direction R2: Second rotation direction R3: Third rotation direction R4: Fourth rotation direction S: Stitching axis S1: First stitching axis S2: Second stitching axis T: Transition part

Claims

1. A tire manufacturing apparatus comprising a tire manufacturing drum and a stitcher for stitching tire components, The tire manufacturing drum includes bead lock segments, and the bead lock segments are retractable to a retracted position relative to the remaining portion of the tire manufacturing drum formed by portions of the tire manufacturing drum other than the bead lock segments, The stitcher includes a disc-shaped stitching body having a first surface for pressing the tire component during stitching and a second surface on the opposite side of the first surface, The second surface is concave, and the stitcher is relatively positionable with respect to the tire manufacturing drum such that the concave second surface at least partially fits into a transition portion between the bead lock segment in the retracted position and the remaining portion of the tire manufacturing drum.

2. The disc-shaped stitching body is concentric with a stitching axis, and the first surface defines a pressing surface disposed on an inclined portion that is inclined away from the second surface at a relief angle in a radial direction away from the stitching axis. The tire manufacturing apparatus according to claim 1.

3. The tire manufacturing apparatus according to claim 2, wherein the relief angle is in a range of 1 degree to 15 degrees.

4. The tire manufacturing apparatus according to claim 2, wherein the relief angle is in a range of 2 degrees to 10 degrees.

5. A method of stitching a tire component using the tire manufacturing apparatus according to claim 1, The method includes a step of relatively positioning the stitcher with respect to the tire manufacturing drum such that the concave second surface at least partially fits into the transition portion between the bead lock segment in the retracted position and the remaining portion of the tire manufacturing drum.

6. The disc-shaped stitching body is concentric with the stitching axis, and the first surface defines a pressing surface disposed in an inclined portion that is inclined away from the second surface at a relief angle in a radial direction away from the stitching axis. The method is as follows: The method according to claim 5, further comprising positioning the stitcher relative to the tire manufacturing drum such that the stitching axis is inclined with respect to a vertical plane, thereby inclining at least a part of the pressing surface with respect to a horizontal plane or making it lie in a horizontal plane.

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