Patent Application
20240399691
The invention relates to a stitcher, a tire building machine comprising said stitcher and a method for stitching a tire component.
WO 2018/111091 A2 discloses a tire building machine having a tire building drum, in particular a crown drum for single stage tire building, comprising two drum halves. Each drum half comprises a crown-up section, a turn-up section and a bead-lock section that is located in the axial direction between the crown-up section and the turn-up section. The bead-lock section comprises a plurality of bead-lock members distributed circumferentially about a central axis and movable in the radial direction between a release position and a bead-lock position.
A disadvantage of the known tire building machine is that in some cases a side wall needs to be applied by folding said side wall around the radially inner side of the bead, in particular between the bead and the drum. The folding of the sidewall around the radial inner side of the bead is particularly difficult because the sidewall forms a skirt along the bead that is hard to fold consistently around the radial inner side of the bead. This cannot be done manually. However, the available space between the bead and the bead-lock members in the release position is only a few millimeters and insufficient to accommodate a conventional stitching roller. Hence, the drum halves need to be at least partially moved away in the axial direction to allow folding of a side wall around the bead. Alternatively, the side wall has to be folded around the bead on a first drum with a smaller diameter, after which the tire components have to be transferred to a shaping drum, as is the case in conventional two stage tire building.
It is an object of the present invention to provide a stitcher, a tire building machine comprising said stitcher and a method for stitching a tire component, with an improved approach to applying the side wall.
According to a first aspect, the invention provides a tire building machine comprising a tire building drum and a stitcher for stitching a tire component, wherein the tire building drum comprises bead-lock segments which are retractable into a recessed position relative to the rest of the tire building drum, wherein the stitcher comprises a disc-shaped stitching body having a first side for pressing on the tire component during stitching and a second side opposite to the first side, wherein the second side is concave, wherein the stitcher is positionable relative to the tire building drum such that the concave second side fits at least partially over a transition between the bead-lock segments in the recessed position and the rest of the tire building drum.
Because of the concave second side, the stitcher according to the first aspect of the invention can be moved closer to the circumference of the tire building drum without colliding, in particular at said transition or transition edge, so that the stitcher can reach into the relatively small space between the retracted bead-lock segments and the radially inner side of the bead.
Preferably, the disc-shaped stitching body is concentric about a stitching axis, wherein the first side defines a pressing surface that is arranged at a slope that is inclined away from the second side at a clearance angle in a radial direction away from the stitching axis. More preferably, the clearance angle is in a range of zero to fifteen degrees, and most preferably in a range of two to ten degrees. Because of the clearance angle, the stitcher can be scooped underneath the radially inner side of the bead with the stitching axis at an oblique angle to a vertical plane, thereby tilting at least a part of the pressing surface towards or into a horizontal plane. The pressing surface can thus effectively fold and press the tip of the tire component around the radially inner side of the bead while the stitcher is arranged at an oblique angle to the tire building drum.
According to a second aspect, the invention provides a method for stitching a tire component with the use of a tire building machine according to the first aspect of the invention, wherein the method comprises the step of:
The method relates to the practical implementation of the aforementioned tire building machine and thus has the same technical advantages, which will not be repeated hereafter.
Preferably, the disc-shaped stitching body is concentric about a stitching axis, wherein the first side defines a pressing surface that is arranged at a slope that is inclined away from the second side at a clearance angle in a radial direction away from the stitching axis, wherein the method comprises the step of:
In said horizontal or substantially horizontal orientation, the pressing surface can effective fold and press onto the tip of the tire component from within the bead.
According to a third aspect, the invention provides a stitcher for stitching a tire component, wherein the stitcher defines a primary stitching axis and comprises a primary stitching member concentric to and rotatable about said primary stitching axis for stitching the tire component along a first part of a stitching path, wherein the stitcher further comprises a secondary operational member and a positioning member for moving the secondary operational member relative to the primary stitching axis into an active position in which the secondary operational member partially projects beyond the primary stitching member in a radial direction perpendicular to the primary stitching axis, wherein the positioning member is rotatable about the primary stitching axis, wherein the rotation of the positioning member is arranged to be driven by Eddy current generated between said positioning member and the primary stitching member.
The secondary operational member can be dimensioned or optimized to fit into a space into which the primary stitching member can not fit. More in particular, the secondary operational member can fit in the relatively small space between the bead-lock members and the radial inner side of the bead. The forces generated by Eddy current can be used to pull along the positioning member as the primary stitching member rotates. Therefore, no separate drive means is necessary to drive the positioning member.
In one embodiment the secondary operational member is a secondary stitching member for stitching the tire component along a second part of the stitching path. The secondary stitching member can fit in the relatively small space between the bead-lock members and the radial inner side of the bead to stitch and/or fold the sidewall along the radial inner side of the bead.
Preferably, the stitcher defines a secondary stitching axis, wherein the secondary stitching member is concentric to and rotatable about said secondary stitching axis. The secondary stitching member can thus stitch and/or fold the sidewall while the drum with the sidewall and bead supported thereon are being rotated, with a minimal amount of friction.
In a further embodiment the rotation of the positioning member about the primary stitching axis is arranged to be driven by the rotation of the primary stitching member. Therefore, no separate drive means is necessary to drive the positioning member.
In a further embodiment the positioning member is rotatable between a standby position in which the secondary operational member is spaced apart from the tire component during stitching and the stitching position. Hence, the secondary operational member can be switched, moved and/or rotated between said positions depending on the stitching operation that is being performed.
In a further embodiment the stitcher comprises a first limiter and a second limiter for limiting the rotation of the positioning member between the standby position and the active position. Consequently, the secondary operational member can be moved between said two positions. In particular, it can be prevented that the positioning member is moved beyond said two positions where the secondary operational member can potentially interfere with the operation of the primary stitching member.
In a further embodiment comprises the first limiter and the second limiter limit the rotation of the positioning member to a range of less than one-hundred-and-eighty degrees. Consequently, the positioning member can be moved between two positions that are spaced apart over one-hundred- and -eighty degrees or less.
In a further embodiment the positioning member is configured for rotating in the same direction about the primary stitching axis as the primary stitching member. Hence, the direction of rotation of the primary stitching member can be used to control the direction of rotation of the positioning member.
In another embodiment, the positioning member is provided with a plurality of magnets. The rotation of the primary stitching member through the magnetic fields generated by the plurality of magnets on the positioning member can cause the aforementioned Eddy current.
More preferably, the positioning member comprises a disc-shaped body concentric to the primary stitching axis, wherein the plurality of magnets are distributed circumferentially over the disc-shaped body about said primary stitching axis. The Eddy current can thus be equally generated across the entire disc-shaped body.
In a further embodiment the plurality of magnets have alternating polarities. The alternating polarities increase the Eddy current that can be generated.
In a further embodiment the primary stitching member comprises ferromagnetic or paramagnetic material. The magnetic interaction between the magnets and the ferromagnetic material can generate sufficient Eddy current to pull along the positioning member.
In a further embodiment the primary stitching member comprises aluminum. Aluminum in itself is not a very strong magnetic material. However, when moved through the magnetic fields of the plurality of magnets, it can act as a paramagnetic material that can generate sufficient Eddy current to pull along the positioning member.
In a further embodiment the primary stitching member has a first side for mounting the stitcher to a robotic manipulator, wherein the secondary operational member is located at a second side of primary stitching member facing away from the first side. The secondary operational member can thus be located at a side of the primary stitching member that is otherwise free of components, such that it can be moved as close as possible to the circumference of the tire building drum without colliding with said tire building drum.
In a further embodiment the primary stitching member defines a cavity, wherein the positioning member is at least partially accommodated within said cavity. Hence, the positioning member does not add to the thickness or overall size of the stitcher. Consequently, the stitcher can be moved closer to the circumference of the tire building drum without colliding.
In a further embodiment the primary stitching axis and the secondary stitching axis are parallel or substantially parallel to each other. The stitching members can thus be rotated about parallel stitching axis, operating in the same or substantially the same orientation.
According to a fourth aspect, the invention provides a tire building machine comprising the stitcher according to any one of the embodiments of the third aspect of the invention and a tire building drum.
The tire building machine includes the aforementioned stitcher and thus has the same technical advantages, which will not be repeated hereafter.
Preferably, the tire building drum is rotatable about a drum axis in a first rotation direction and a second rotation direction, opposite to the first rotation direction, wherein the rotation of the primary stitching member about the primary stitching axis is arranged to be driven by the rotation of the tire building drum, wherein the positioning member is rotatable about the primary stitching axis in a third rotation direction and a fourth rotation direction opposite to the third rotation direction, wherein the rotation of the positioning member about the primary stitching axis is arranged to be driven by the rotation of the primary stitching member and wherein a change in rotation of the tire building drum from the first rotation direction to the second rotation direction controls the rotation direction in which the positioning member is rotated. Hence, the rotation direction of the tire building drum can indirectly control the rotation of the positioning member, and thus the position of the secondary operational member. In particular, the rotation of the tire building drum can be reversed to move the secondary operational member into an operative stitching position. Conveniently, no dedicated control or drive means are required at the stitcher to move the secondary operational member.
According to a fifth aspect, the invention provides a method for stitching a tire component with the use of a stitcher according to any one of the embodiments of the third aspect of the invention, wherein the method comprises the steps of:
The method relates to the practical implementation of the aforementioned stitcher and thus has the same technical advantages, which will not be repeated hereafter.
In one embodiment the secondary operational member is a secondary stitching member, wherein the method further comprises the step of:
In a further embodiment of the method the rotation of the positioning member about the primary stitching axis is driven by the rotation of the primary stitching member.
In a further embodiment the rotation of the positioning member is limited between a standby position and the active position.
In a further embodiment the rotation of the positioning member is limited between the standby position and the active position to a range of less than one-hundred- and -eighty degrees.
In a further embodiment the positioning member is rotated in the same direction about the primary stitching axis as the primary stitching member.
In a further embodiment the rotation of the positioning member is driven by Eddy current generated between said positioning member and the primary stitching member.
According to a sixth aspect, the invention provides stitcher for stitching a tire component, wherein the stitcher comprises a hub that is rotatable about a stitcher axis and a plurality of stitching segments connected to, distributed around and extending radially away from the hub, wherein the stitching segments are resiliently flexible with respect to said hub.
The stitching segments can provide a segmented circumference which can effectively adapt to the shape of the tire component to be stitched.
Preferably, at least two directly adjacent stitching segments of the plurality of stitching segments are mutually coupled in a circumferential direction about the stitcher axis. By having the stitching segments influence each other's flexing to some extent, the shape of the stitcher is deformed more gradually, i.e. without abrupt steps between the stitching segments.
The various aspects and features described and shown in the specification can be applied, individually, wherever possible. These individual aspects, in particular the aspects and features described in the attached dependent claims, can be made subject of divisional patent applications.
The invention will be elucidated on the basis of an exemplary embodiment shown in the attached schematic drawings, in which:
The tire building machine 1 comprises a tire building drum 2 for forming the green tire 9. The green tire 9 is formed by shaping one or more plies 91, in particular body plies or breaker plies, around a bead 92 into a tire carcass. The bead 92 is an annular or substantially annular element that has a radially inner side 93 that defines an inner bead radius B. The green tire 9 is further provided with a side wall 94 that, in this example, is applied to the carcass by folding it, at least partially, around the radially inner side 93 of the bead 92. In particular, the inner edge or inner tip 95 of the side wall 94 is folded around the radially inner side 93 of the bead 92.
The tire building drum 2 is rotatable about a drum axis D extending in an axial direction A. The tire building drum 2 comprises a first drum half 3, a second drum half 4 and a center section 5 in the axial direction A between said drum halves 3, 4.
Each drum half 3, 4 comprises a bead-lock section 31, 41 for retaining the bead 92. The bead-lock section 31, 41 is provided with a plurality of bead-lock segments 32, 42 which are expandable in a radial direction R perpendicular to the drum axis D to engage and retain the bead 92 at the inner bead radius B. The plurality of bead-lock segments 32 are retractable or contractable in to a flush or recessed position relative to the rest of the tire building drum 2 to allow fitting of the one or more plies 91 and the beads 92 onto the tire building drum 2 and to provide sufficient space for folding of the side wall 94 around the radially inner side 93 of said beads 92.
Each drum half 3, 4 further comprises a turn-up section 35, 45 for folding up the parts of the one or more plies 91 located outside of the center section 5 around the bead 92 onto the parts of the one or more plies 91 at said center section 5. In particular, the turn-up sections 35, 45 are provided with turn-up arms (not shown).
The center section 5 comprises a plurality of crown segments 51 which are expandable in the radial direction to crown-up the parts of the one or more plies 91 at the center section 5 into a toroidal or substantially toroidal shape.
As shown in
As best seen in
The primary stitching member 61 comprises a stitching body that has a first side 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 near the circumferential edge or contour of the primary stitching member 61 for pressing both in a radial direction R perpendicular to the primary stitching axis S1 and a direction oblique to said radial direction R. The stitching body further has a mounting head 64 at the first side M for mounting the primary stitching member 61 onto the primary stitching shaft 60.
The stitching body of the primary stitching member 61 may comprise ferromagnetic or paramagnetic material, such as aluminum.
The primary stitching member 6 further has a second side N facing away from the first side M. At the second side N, the primary stitching member 61 is provided with a cavity 63. The primary stitching shaft 60 extends through the primary stitching member 61 into the cavity 63.
The stitcher 6 is provided with a secondary operational member 71. In this example, the secondary operational member 71 is a secondary stitching member 71 that is concentrically mounted to a secondary stitching axis 70 defined by the stitcher 6. In other words, the secondary stitching member 71 is concentric to the secondary stitching axis S2. The secondary stitching member 71, like the primary stitching member 61, also comprises a disc-shaped, wheel-shaped or roller-shaped stitching body. However, the stitching body of the secondary stitching member 71 is a lot smaller than the stitching body of the primary stitching member 61, preferably at least a factor two or three smaller. The secondary stitching member 71 is rotatable about the secondary stitching shaft 70 and/or the secondary stitching axis S2 for stitching side wall 94 along the radially inner side 93 of the bead 92. The secondary stitching member 71 is located at the second side N of primary stitching member 61.
Alternatively, the secondary operational member 71 may have a function different from stitching, for example cutting, brushing, pulling, tagging or detecting. The secondary operational member 71 may for example be a brush or a sensor.
The description hereafter is directed to the secondary stitching member 71, but the same features can be applied mutatis mutandis to the alternative secondary operational members described above.
The stitcher 6 further comprises a positioning member 8 for moving the secondary stitching axis S2 relative to the primary stitching axis S2 into a stitch position or an active position, as shown in
As best seen in
The positioning member 8 is rotatable about the primary stitching shaft 60 and/or the primary stitching axis S1. The positioning member 8 may be mounted directly onto the primary stitching shaft 60, for example with bearings 85 as shown in
In another embodiment (not shown), an alternative positioning member may be provided which displaces the secondary stitching member 71 linearly, for example in the radial direction R to move said secondary stitching member 71 between a standby position fully inside the circumference of the primary stitching member 61 and a stitching position at least partially projecting beyond the circumference of said primary stitching member 61.
The secondary stitching shaft 70 is coupled to, connected to or carried by the positioning member 8 in a position spaced apart from the primary stitching shaft 60. In other words, the primary stitching axis S1 and the secondary stitching axis S2 are spaced apart from each other. In said spaced apart position, the secondary stitching member 71, which is a lot smaller than the primary stitching member 61, can be considered as a planetary satellite member to the primary stitching member 61, almost as if it is travelling along an orbit defined by the edge of the primary stitching member 61. The positioning member 8 is configured for holding the secondary stitching shaft 70 in an orientation parallel or substantially parallel to the primary stitching shaft 60. In other words, the primary stitching axis S1 and the secondary stitching axis S2 are parallel or substantially parallel to each other.
As best seen in
The positioning member 8 is further provided with a first limiter 85 and/or a second limiter 86 for limiting the rotation of the positioning member 8 about the primary stitching shaft 60 and/or the primary stitching axis S1 to a range of less than one-hundred-and-eighty degrees, preferably less than one-hundred degrees. In this exemplary embodiment, the first limiter 85 and the second limiter 86 are defined or formed by the terminal ends of an angular slot that interacts with a pin of the primary stitching member 61. Alternatively, the limiters 85, 86 may be formed by any suitably placed obstacle provided on one of the primary stitching member 61, the primary stitching shaft 60, the positioning member 8 and/or the secondary stitching member 71 and interacting with another one of the primary stitching member 61, the primary stitching shaft 60, the positioning member 8 and the secondary stitching member 71.
A method for stitching the side wall 94 with the use of the aforementioned stitcher 6 will now be briefly elucidated with reference to
In this exemplary embodiment, the positioning member 8 is not directly driven or controlled by any dedicated drive means. Instead, the rotation of the primary stitching member 61 is transferred onto the positioning member 8. In particular, the positioning member 8 is configured for rotating in the same direction about the primary stitching axis S1 as the primary stitching member 61. In other words, the positioning member 8 is configured to passively follow the rotation of the primary stitching member 61. In this example, the transfer of rotation is achieved by generating Eddy current as the primary stitching member 61 is rotated relative to the plurality of magnets 81 of the positioning member 8. The positioning member 8 is freely rotatable. Hence, it will tend to be pulled along by the primary stitching member 61. As such, the positioning member 8 can be driven by the rotation of the primary stitching member 61, within the range defined by the limiters 85, 86, to move the secondary stitching member 71 from the standby position, as shown in
Alternatively, the rotation of the primary stitching member 61 can be transferred onto the positioning member 8 via other transmission means, in particular a mechanical transmission. For example, a mechanical friction may be provided between the primary stitching shaft 60 and the positioning member 8. In another example, the centrifugal forces generated by the rotation of the primary stitching member 61 can be used to activate a centrifugal clutch or coupling.
Similarly, the primary stitching member 61 is not directly driven or controlled by any dedicated drive means. Instead, the rotation of the tire building drum 2 is transferred onto the primary stitching member 61 when the primary stitching member 61 is brought into contact with the tire building drum 2 or the one or more plies 91 and/or the side wall 94 supported on said tire building drum 2. In other words, the primary stitching member 61 is configured to be passively driven by the tire building drum 2. In particular, the direction of rotation of the tire building drum 2 determines the direction of rotation of the primary stitching member 61. And because the positioning member 8 passively follows the rotation of the primary stitching member 61, it can be said that the tire building drum 2 indirectly drives and/or controls the rotation of the positioning member 8 about the primary stitching shaft 60 and/or the primary stitching axis S1.
This principle can be used to move the positioning member 8 between the standby position of
The brief moment of stopping and reversing the rotation direction of the tire building drum 2 can conveniently be used to terminate the primary stitching operation of the primary stitching member 61 along the first part P1 of the stitching path P and reposition the stitcher 6, if necessary, to be optimally positioned for the secondary stitching operation which involves folding the side wall 94 around the radially inner side 93 of the bead 92.
It will be apparent to one skilled in the art that the primary stitching member 61 and/or the secondary stitching member 71 can be driven directly and/or individually by a suitable drive means, such as a servo motor. Additionally or alternatively, other means of transferring rotation between the primary stitching member 61 and the positioning member 8 may be provided, for example mechanical transfer means such as gears or the like.
The disc-shaped stitching body 161 is concentric about a stitching axis S. The first side 161 defines a pressing surface 163 that is arranged at a slope or an inclination that is inclined away from the second side 162 at a clearance angle H in a radial direction R away from the stitching axis S. The clearance angle H is in a range of zero to fifteen degrees, preferably in a range of one to fifteen degrees, more preferably in a range of two to ten degrees, more preferably in a range of four to six degrees and most preferably approximately five degrees.
As shown in
The stitcher 106 of the alternative tire building machine 101, in its stitch position, may be located or offset slightly off center with respect to the drum axis D, in a similar way to the secondary stitching member 71 in
Optionally, as is best shown in
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.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2029249 | Sep 2021 | NL | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/NL2022/050491 | 8/29/2022 | WO |
