Method and apparatus for forming a tyre for a vehicle wheel

Abstract

The carcass sleeve (16) is picked up from the forming drum (17) and engaged on the shaping drum (20), then it is toroidally shaped to be coupled with the outer sleeve (18). Removing the carcass sleeve (16) from the forming drum (17) comprises the following steps: arranging the forming drum (17) carrying the carcass sleeve (16) in a coaxial and axially central position between two clamping members (23) which are mutually side by side and coaxial with respect to the alignment axis (X-X); clamping each of the beads (7) of the carcass sleeve (16) by means of a plurality of coupling elements (28) carried by each of the clamping members (23) and circumferentially distributed around the alignment axis (X-X); retracting the forming drum (17) to disengage it from the carcass sleeve (16) held by the coupling elements (28).

Description

Technical Field

[0001] This invention relates to a method and apparatus for forming wheels and tires.

[0002] In particular, the present invention can be conveniently used to improve the connection between the tire carcass sleeve and the outer sleeve during tire molding. Background Technology

[0003] Tires used for wheels typically include a carcass structure comprising at least one carcass ply having opposing end flaps that engage with corresponding anchoring ring structures integrated in an area commonly referred to as a “bead”, the inner diameter of which substantially corresponds to the tire’s so-called “mounting diameter” on the corresponding mounting rim.

[0004] The carcass structure is associated with a belt structure, which may include one or more belt layers radially stacked relative to each other and relative to the carcass plies, having woven or metal reinforcing cords oriented in a cross-directional and / or substantially parallel to the tire's circumferential extension direction (0 degrees). A tread belt, also made of an elastomeric material, is applied at a radially outer position relative to the belt structure.

[0005] Corresponding sidewalls made of elastomeric material are also applied to the axially outer positions of the lateral surfaces of the tire carcass structure, each sidewall extending from one of the lateral edges of the tread band to the corresponding anchoring annular structure at the bead. In tubeless tires, an impermeable coating (often called a "liner") covers the inner surface of the tire.

[0006] The forming of a raw tire is basically defined as the manufacture and / or assembly of one or more carcass plies, anchoring ring structures and / or other components of the carcass structure on a forming drum to form a so-called "carcass sleeve" having a basic cylindrical shape.

[0007] The carcass sleeve is then shaped according to the supertoroidal configuration in order to be coupled to the so-called “outer sleeve”, which was previously obtained by manufacturing and / or assembling the belt layer, tread belt and / or other components together.

[0008] Also known is a molding method of the “single-step” type, in which the shaping action of the carcass sleeve is performed by two axially opposite halves that are axially close to the molding drum for the purpose of assembly with the outer sleeve, so that the assembly can be completed without removing the carcass sleeve from the molding drum.

[0009] Other forming methods, known as the "two-step" type, require the use of a so-called shaping drum for connecting the body sleeve to the outer sleeve. In these methods, the body sleeve, formed on the forming drum, needs to be transferred to the shaping drum for processing and assembly together with the outer sleeve.

[0010] After the raw tire is formed by the assembly of the corresponding components, it is usually molded and vulcanized to determine the structural stability of the tire through crosslinked elastomer compositions, and, if necessary, to emboss the desired tread design and possible unique graphic markings on the tire sidewall.

[0011] The terms "axial" and "axial inside / outer" are used with reference to the axial direction of the axis of rotation of the tire, carcass sleeve, or outer sleeve, and the forming or shaping drum used during molding. The terms "radial" and "axial" and "radial inside / outer" are used with reference to the radial direction (i.e., the direction perpendicular to the corresponding axis of rotation) of the tire, carcass sleeve, or outer sleeve, and the forming or shaping drum used during molding. The radial plane of the tire, carcass sleeve, or outer sleeve, and the forming or shaping drum encompasses its corresponding axis of rotation.

[0012] US 5,861,079 describes an apparatus for forming a tire, including a transfer ring or belt ring for a tire carcass sleeve, the transfer ring or belt ring having circumferentially spaced and radially movable clamping elements for contacting the tire carcass or belt.

[0013] WO2008007398, under the same applicant, describes a method for molding a tire on a toroidal support having an external shaping surface that conforms to the internal shape of the finished tire. Prior to tire vulcanization, the tire's bead is molded, with each bead closed between the toroidal support and an annular restraining portion axially opposite to the toroidal support itself. The restraining portion keeps the tire's bead closed during transfer of the tire bead and the toroidal support together within the vulcanization mold and during vulcanization.

[0014] WO2008007400, under the same applicant, describes a method in which a raw tire is removed from a forming drum and transferred to a molding and pre-curing station, wherein each bead is closed between two limiting surfaces for molding and pre-curing. The bead remains closed between the limiting surfaces during the transfer of the tire within the curing mold and during the curing process.

[0015] The applicant has observed that, in the two-step molding method, the quality of the final product in terms of geometric and structural accuracy, quality balance, and result repeatability may be lower than expected. In this case, the applicant believes that, in the two-step molding method, a key aspect of the final product quality is the need to remove the jig sleeve from the molding drum and attach it to the settling drum for assembly.

[0016] Specifically, the applicant has observed that when the forming drum is removed from the tire carcass sleeve, the tire carcass sleeve tends to deform due to gravity and / or internal tension present in the tire components, altering the geometry previously set during forming on the forming drum.

[0017] When the carcass sleeve is engaged with the shaping drum, these deformations can be partially corrected, but the initial shape of the carcass sleeve is not always restored in a sufficiently precise manner. Therefore, the connection between the carcass sleeve and the outer sleeve may occur suboptimally, and / or deformations or twists may exist that could affect the final product.

[0018] However, the applicant has recognized that by properly supporting the carcass sleeve during the removal of the forming drum and the connection with the sizing drum, undesirable structural distortions can be adequately counteracted, resulting in significant quality improvements.

[0019] More specifically, it has been found that by engaging and retaining the carcass sleeve at the bead during the process of removing it from the forming drum and transferring it to the setting drum, the centering of the carcass sleeve can be improved, effectively preventing its undesirable structural distortion. Summary of the Invention

[0020] Therefore, in a first aspect, the present invention relates to a method for forming wheel tires.

[0021] Preferably, a carcass sleeve is formed on the forming drum, the carcass sleeve including at least one carcass ply having end flaps that engage with a corresponding annular reinforcement structure incorporated in the corresponding bead.

[0022] Preferably, the tire sleeve is picked up from the forming drum.

[0023] Preferably, the tire sleeve is attached to the shaping drum.

[0024] Preferably, the tire sleeve carried by the shaping drum is subjected to super-toroidal shaping in order to connect it to an outer sleeve including a belt structure.

[0025] Preferably, picking up the tire carcass sleeve involves arranging the forming drum that carries the tire carcass sleeve in a coaxial and axially centered position between two clamping members that are side by side and coaxial with respect to the alignment axis.

[0026] Preferably, picking up the tire carcass sleeve includes clamping each of the tire beads of the tire carcass sleeve by a plurality of connecting elements carried by each of the clamping members and distributed circumferentially around the alignment axis.

[0027] Preferably, the pickup of the tire carcass sleeve includes shrinking the molded drum to disengage it from the tire carcass sleeve held by the coupling element.

[0028] According to another aspect, the present invention relates to an apparatus for shaping wheel tires.

[0029] Preferably, a forming drum, a setting drum, and a conveyor are provided, the conveyor being configured to pick up the tire sleeve from the forming drum and arrange it on the setting drum.

[0030] Preferably, the conveyor includes two clamping members that are side by side and coaxial with respect to the alignment axis.

[0031] Preferably, each clamping member includes an annular support.

[0032] Preferably, each clamping member includes a plurality of connecting elements supported by an annular support and circumferentially distributed around the alignment axis.

[0033] Preferably, each connecting element has a support post that slidably engages with the annular support of the corresponding clamping member.

[0034] Preferably, each connecting element has a clamping protrusion that extends axially from the support post toward another clamping member.

[0035] The applicant argues that the retention effect applied to the tire bead allows for the fixed positioning of the bead to a mutual position, even after the forming drum has shrunk and no further mechanical support is applied to the carcass sleeve. The positioning stability of the bead prevents deformation and twisting due to internal tension or component weight, and positions the carcass sleeve under optimal conditions for subsequent engagement with the forming drum.

[0036] It also maintains the ease of introduction and removal of the forming drum and the sizing drum relative to the tire carcass sleeve itself, both for the purpose of transferring the tire carcass sleeve to the sizing drum and for removing the sizing drum that carries the tire carcass sleeve for subsequent assembly with the outer sleeve.

[0037] In one of the foregoing aspects, the present invention may further include one or more of the following preferred features.

[0038] Preferably, prior to shrinking the molding drum, the action of holding the tire sleeve is actuated by the retention action distributed on its radial outer surface.

[0039] The retention effect on the radial outer surface helps to retain the bead by the connecting element, thereby helping to effectively maintain the shape of the carcass sleeve without the need for a forming drum. Undesirable twisting of the carcass sleeve is effectively prevented, for example, due to internal tension in the components of the carcass sleeve itself and / or due to weight.

[0040] Preferably, the action of holding the tire carcass sleeve is maintained during at least a portion of the action of engaging the tire carcass sleeve onto the shaping drum.

[0041] Preferably, the retaining sleeve includes a plurality of retaining elements placed against the radial outer surface of the retaining sleeve.

[0042] Preferably, the retaining sleeve includes securing the radial outer surface to the retaining element by an attraction force toward the retaining element itself.

[0043] Preferably, clamping each bead includes a connecting element that radially translates each clamping member toward the alignment axis to position the clamping protrusion of the connecting element itself at a diameter smaller than the inner diameter of the bead.

[0044] Preferably, clamping each bead includes axially translating a connecting element toward the tire carcass sleeve to position the clamping protrusion of each connecting element in a position radially aligned with the corresponding bead.

[0045] Preferably, clamping each bead includes radially translating the coupling element away from the alignment axis so that the clamping protrusion of each coupling element abuts against the radial inner edge of the corresponding bead.

[0046] Preferably, clamping each bead includes a connecting element that radially translates each clamping member toward the alignment axis to position the clamping protrusion of the connecting element itself in alignment with the undercut axis defined along the axial outer circumferential edge of the respective bead.

[0047] Preferably, clamping each bead includes an axially translatable connecting element toward the tire carcass sleeve to position the clamping protrusion of each connecting element in an engagement relationship with the undercut.

[0048] Preferably, after the shrinking of the forming drum, the forming drum is axially withdrawn relative to the clamping member.

[0049] Preferably, the action of engaging the carcass sleeve onto the shaping drum includes axially inserting the shaping drum into a coaxially centered position within the carcass sleeve held by the clamping member.

[0050] Preferably, the action of engaging the tire sleeve onto the shaping drum includes radially expanding the annular shoulder carried by each of the two axially opposite halves of the shaping drum from a contracted state to an expanded state, wherein in the contracted state the maximum diameter of the annular shoulder is less than the inner diameter of the tire bead, and in the expanded state the maximum diameter is greater than the inner diameter of the tire bead.

[0051] Preferably, the action of engaging the carcass sleeve onto the shaping drum includes moving the annular shoulders axially away from each other in the expanded state so that each of them is carried on the axial inner wall of one of the bead segments.

[0052] Preferably, the action of engaging the tire carcass sleeve onto the shaping drum includes radially expanding the annular clamping element carried by each of the two axially opposite halves of the shaping drum from a contracted state to an expanded state. In the contracted state, the maximum diameter of the annular clamping element is smaller than the inner diameter of the tire bead. In the expanded state, each annular clamping element operates against the radial inner edge of one of the tire beads with a radial thrust relationship.

[0053] Preferably, the action of maintaining the tire sleeve is maintained at least until the action of axially distancing the annular shoulders from each other in the expanded state is completed.

[0054] Preferably, the connecting element is disengaged from the tire bead before the radially expanding annular clamping element.

[0055] Preferably, disengaging the coupling element from the bead includes axially translating the coupling element away from the tire carcass sleeve to position each clamping protrusion at an axially external position relative to the corresponding bead.

[0056] Preferably, disengaging the connecting element from the tire bead involves radially translating the connecting element away from the alignment axis to position the clamping protrusion according to a minimum diameter greater than the maximum diameter presented by the tire carcass sleeve.

[0057] Preferably, disengaging the coupling element from the bead further includes radially translating the coupling element toward the alignment axis so as to space each clamping protrusion from the radially inner surface of the corresponding bead before axially translating the coupling element away from the carcass sleeve.

[0058] Preferably, each clamping member further includes at least one actuator carried by an annular support and operated on one or more of the coupling elements to move them radially between a contracted state and an expanded state relative to the alignment axis.

[0059] Preferably, the actuator includes a first cylinder that operates on a support column and an additional cylinder that operates by means of a contrast bracket rigidly supported by an annular support.

[0060] Preferably, the first cylinder and the auxiliary cylinder are mechanically connected in series to selectively position the connecting element in a contracted state, an expanded state, or an intermediate state between the contracted and expanded states.

[0061] Preferably, when the connecting element is in the intermediate state, the first cylinder and the auxiliary cylinder are each in the corresponding limit stop state.

[0062] Preferably, the radial positioning of the connecting element in the intermediate state is mechanically determined by the limiting stops in the first cylinder and the auxiliary cylinder.

[0063] In this way, the connecting elements can be positioned more precisely in the middle.

[0064] Preferably, the conveyor further includes at least one axial movement device for axially moving the connecting elements of the clamping members, bringing them closer together and moving them apart.

[0065] Preferably, the axial movement device operates on the annular support of the clamping member.

[0066] Preferably, the axial movement device includes at least one actuator carried by a central support ring arranged axially between the clamping members.

[0067] Preferably, a radially outer retaining element is also provided, which is distributed according to the substantially cylindrical action area between the clamping members, and can be activated to retain the radially outer surface of the tire carcass sleeve.

[0068] Preferably, the retaining element includes a suction cup that can be activated by the suction circuit.

[0069] Preferably, the retaining element is supported by an arm that extends axially from the annular support of each clamping member toward the other clamping member.

[0070] Preferably, each of the retaining elements is radially movable toward and away from the alignment axis.

[0071] Preferably, each of the retaining elements engages with the corresponding arm via a radial movement actuator.

[0072] Preferably, the shaping drum comprises two halves that are axially movable relative to each other.

[0073] Preferably, each half-piece includes a radially expandable annular shoulder.

[0074] Preferably, each half-piece includes a radially expandable annular clamping element arranged in an axially external position relative to the annular shoulder.

[0075] Preferably, the annular shoulder of each half has an axial thrust surface that is axially opposed to the other half of the shaping drum.

[0076] Preferably, the annular shoulder of each half-piece includes a plurality of circumferentially distributed and radially movable abutment sectors.

[0077] Preferably, the annular clamping element of each half comprises a plurality of circumferentially distributed and radially movable elements.

[0078] Preferably, the annular clamping element of each half-piece further includes an elastomeric ring, which is assembled around the expansion sector and has a radially external thrust surface. Attached Figure Description

[0079] Further features and advantages will become clearer from the detailed description of preferred, but not unique, embodiments of the method and apparatus for forming wheel tires according to the present invention. This description will be set forth below with reference to the accompanying drawings, which are provided by way of non-limiting example only, wherein:

[0080] Figure 1 A side view of the device according to the invention is schematically shown, which is integrated into a facility for forming tires;

[0081] Figure 2 A perspective view of a forming drum that carries the tire carcass sleeve is shown, the forming drum being arranged in an axially aligned relationship with the conveyor.

[0082] Figure 3 Shown in a discontinuous perspective view Figure 2 The specific structure of the conveyor;

[0083] Figure 4 A partial diameter cross-sectional view of a forming drum that carries the tire carcass sleeve is shown. The forming drum is coaxially inserted into the conveyor and located at the axial center of the conveyor.

[0084] Figure 5 It shows Figure 4 The subsequent operating steps involve bringing the connecting element radially closer to the alignment axis;

[0085] Figure 6 It shows Figure 5 The subsequent operating steps involve the connecting element being radially close to the tire bead of the tire carcass sleeve;

[0086] Figure 7 It shows Figure 6 The subsequent operating steps involve holding the element against the radial outer surface of the tire carcass sleeve while simultaneously moving the connecting element radially away to engage the tire bead;

[0087] Figure 8 An operating procedure is shown in which the forming drum radially contracts so as to be removed by transfer, while the element is held against the radial outer surface of the tire carcass sleeve during operation, and the connecting element holds the tire bead.

[0088] Figure 9 An operating procedure is shown in which a shaping drum arranged in a radially contracted state is coaxially inserted into an axially centered position in a tire carcass sleeve, which is held by a retaining element and a connecting element.

[0089] Figure 10An operating step is shown in which the axially inner annular shoulder of the shaping drum is radially expanded;

[0090] Figure 11 An operating procedure is shown in which the axially opposite half of the shaping drum is axially moved apart so that the annular shoulder abuts against the axial inner wall of the bead.

[0091] Figure 12 An operating procedure is shown in which the connecting element detaches from the bead and is held by the annular shoulder;

[0092] Figure 13 An operating procedure is shown in which the connecting element is positioned to move radially away from the alignment axis, while the annular clamping element expands against the radial inner edge of the tire bead and retains the element detached from the outer surface of the tire carcass sleeve.

[0093] Figure 14 An embodiment variation of the device is shown in an operational step in which the connecting element is radially approached toward the alignment axis;

[0094] Figure 15 A variation of an embodiment of the device is shown during engagement of the tire bead by the connecting element when the retaining element abuts against the tire carcass sleeve;

[0095] Figure 16 A variant embodiment of the device is shown, in which the shaping drum is inserted into a tire carcass sleeve held by retaining elements and connecting elements;

[0096] Figure 17 A variant embodiment is shown that abuts the annular clamping element activated by the bead and the annular shoulder of the shaping drum;

[0097] Figure 18 A variation of the embodiment is shown in which the connecting element is removed from the bead and the retaining element is removed from the radial outer surface of the carcass sleeve;

[0098] Figure 19 A radial cross-sectional view of a tire for a wheel, which is available according to the present invention, is shown schematically. Detailed Implementation

[0099] Specific reference Figure 1 Reference numeral 1 generally indicates an apparatus for forming a tire according to the invention, which can be used to actuate the forming method.

[0100] An example of a tire typically available through device 1 is... Figure 19The tire 2 is indicated by the symbol 2, and the entire tire is indicated by the symbol 2. The tire 2 includes a carcass structure 3 having at least one carcass ply 4. An impermeable elastomeric material, or so-called liner 5, may be applied to the inside of one or more carcass ply 4. Two anchoring ring structures 6 engage with corresponding end flaps 4a of one or more carcass ply 4, each anchoring ring structure 6 including a so-called bead core 6a, which carries elastomeric filler 6b in a radially outer position. The anchoring ring structures 6 are integrated near an area generally identified by the term "bead" 7, in which engagement typically occurs between the tire 2 and the corresponding mounting rim.

[0101] A belt structure 8, comprising one or more belt layers 8a, 8b, extends circumferentially around the carcass structure 3, and a tread belt 9 is circumferentially superimposed on the belt structure 8.

[0102] The belt structure 8 can be associated with so-called "belt under-inserts" 10, each insert being located between one or more carcass ply 4 and one of the axially opposite terminal edges of the belt structure 8.

[0103] Two sidewalls 11 are applied at laterally opposite positions to one or more carcass plies 4. Each sidewall has a radially inner triangular rubber 11a connected to a corresponding bead 7 and a radially outer terminal portion 11b possibly connected to an axially outer triangular rubber 12 carried by the tread belt 9 at its axially outer end 9a.

[0104] Equipment 1 is integrated into a facility arranged for tire forming, in which tire carcass production line 13, outer sleeve production line 14, and assembly station 15 can be seen, such as Figure 1 As shown by the dashed line.

[0105] In the tire carcass production line 13, at least a portion of the liner 5, bead 7, one or more carcass ply 4, and preferably sidewall 11 are manufactured and / or assembled to obtain a substantially cylindrical carcass sleeve 16 on at least one forming drum 17, which moves through multiple workstations according to a pre-established path, which are not shown and not described in detail, as they can be obtained in any convenient manner.

[0106] At least a portion of the belt layers 8a, 8b, tread belt 9, and preferably sidewall 11 are manufactured and / or assembled with each other in the outer sleeve production line 14 to obtain a substantially cylindrical outer sleeve 18 on at least one auxiliary drum 19, which moves through a plurality of additional workstations according to a pre-established path, which are not shown and are not described in detail because they can be obtained in any convenient manner.

[0107] The molding drum 17 and the auxiliary drum 19 follow paths in the tire body production line 13 and the outer sleeve production line 14, respectively, converging toward the assembly station 15.

[0108] Operating in assembly station 15 is at least one shaping drum 20 adapted to receive the carcass sleeve 16 previously removed from forming drum 17, and a transfer ring 21 operatively coupled to auxiliary drum 19 and shaping drum 20. Transfer ring 21 is adapted to pick up an outer sleeve 18 from auxiliary drum 19 to hold it in an axially centered position relative to the shaping drum 20 coaxially inserted within the outer sleeve 18, while the outer sleeve 18 is held by the transfer ring itself. Shaping drum 20 has two halves 20a that are axially movable to approach and move apart from each other. After the halves 20a of shaping drum 20 are axially approached, the carcass sleeve 16, initially obtained according to the substantially cylindrical shape of forming drum 17, takes on a substantially toroidal shape. Thus, mutual assembly is achieved between the carcass sleeve 16 and the outer sleeve 18, which is pre-positioned in an axially centered position around shaping drum 20. The resulting green tire 2 is suitable for subsequent molding and vulcanization.

[0109] The transfer of the tire body sleeve 16 from the forming drum 17 to the shaping drum 20 is achieved by means of... Figure 1 and 2 The conveyor represented by 22 in the middle is used.

[0110] Conveyor 22 includes two clamping members 23 that are side by side and coaxial with respect to their respective aligned axes XX.

[0111] Preferably, the clamping members 23 are slidably guided relative to the central support ring 24 and axially interposed between them in the axial centerline plane M. At least one axial movement device 25, operatively carried by the central support ring 24, can be activated for axially moving the clamping members 23 toward and away from each other. The axial movement device 25 may, for example, include at least one rotary actuator that drives two racks, each carried by a drive rod 26, which project axially from each of the clamping members 23 toward the central support ring 24.

[0112] Each of the clamping members 23 includes an annular support 27, preferably in the form of a disc, which carries a plurality of connecting elements 28 distributed circumferentially around the alignment axis XX. Each connecting element 28 has a support post 28a that slidably engages with the annular support 27 of the corresponding clamping member 23, for example by a guide block 29 fixed to the same annular support 27.

[0113] At the radially inner end of each of the support columns 28a, which are part of the clamping members 23, a clamping protrusion 30 is arranged, which protrudes axially toward the other clamping member 23. The clamping protrusion 30 has an abutment surface 31, which is arranged to act against the bead 7 of the tire body sleeve 16.

[0114] In one embodiment, the abutment surface 31 faces outwards and is adapted to act against the radial inner edge of the corresponding bead 7.

[0115] exist Figures 14 to 18 In one possible embodiment variation shown, the abutment surface 31 faces axially inward, i.e., toward the axial centerline plane M, and is adapted to abut against an undercut S defined along the axial outer circumferential edge of the corresponding bead 7. The undercut S faces radially toward the axis XX, and the abutment surface 31 may be shaped opposite to it.

[0116] At least one actuator, carried by the annular support 27, operates on at least one of the connecting elements 28 to move radially relative to the alignment axis XX between a contracted state and an expanded state. In the illustrated example, an actuator is provided for each of the connecting elements 28, but it is also possible for a single actuator to drive the simultaneous movement of multiple connecting elements 28 belonging to the same clamping member 23.

[0117] In the illustrated embodiment, each actuator includes a first cylinder 32 with hydrodynamic actuation, whose drive post acts on an attachment bracket 33 projecting axially from a support post 28a. The first cylinder 32 may be directly fixed to a guide block 29, or slidably guided relative to the guide block 29, and integrated with an auxiliary cylinder 34, which operates with its post abutting against an opposing bracket 35 projecting axially from the guide block 29.

[0118] In other words, the first cylinder 32 and the auxiliary cylinder 34 are mechanically connected in series to drive the connecting element 28 to move between a contracted state and an expanded state. The selective activation of the first cylinder 32 and the auxiliary cylinder 34 determines the selective positioning of the corresponding connecting element 28 in the expanded state, the contracted state, and the intermediate state between the contracted and expanded states.

[0119] Preferably, when the connecting element 28 is in the intermediate state, the first cylinder 32 and the auxiliary cylinder 34 are each in their respective limiting stop states. In other words, the radial positioning of the connecting element 28 in the intermediate state is mechanically determined by the limiting stops in the first cylinder 32 and the auxiliary cylinder 34.

[0120] Preferably, the connecting element 28 has radial self-centering movement.

[0121] The conveyor 22 may also include radially outer retaining elements 36, which are distributed according to a generally cylindrical working area between the clamping members 23 and can be selectively activated to retain the radially outer surface of the tire sleeve 16.

[0122] The retaining element 36 may include, for example, a suction cup that can be pneumatically activated via a suction circuit not shown.

[0123] In the illustrated example, retaining elements 36 are carried by corresponding arms 37, which extend axially and projectingly relative to the annular support 27 of each clamping member 23. More specifically, each arm 37 is specified to extend from one of the guide blocks 29 fixed to the annular support 27 of the corresponding clamping member 23. In the illustrated example, each arm 37 carries three retaining elements 36 that are axially spaced apart from each other. Each arm 37 carried by one of the clamping members 23 is arranged between two arms of the arm 37 carried by the other clamping member 23. In other words, the arms 37 belonging to the two clamping members 23 follow each other circumferentially in an alternating sequence.

[0124] It can be specified that each of the retaining elements 36 engages with the corresponding arm 37 via a radial movement actuator 36a. The activation of the radial movement actuator 36a determines the movement of the retaining element 36 between an operating state and an idle state. In the operating state, the retaining element 36 moves radially closer to the alignment axis XX to operate on the outer surface of the tire carcass sleeve 16. In the idle state, the retaining element 36 moves radially away from the alignment axis XX and is spaced apart from the tire carcass sleeve 16.

[0125] The conveyor 22 is adapted to interact with the forming drum 17 to pick up the carcass sleeve 16 previously formed on the forming drum 17. For this purpose, the forming drum 17 carrying the carcass sleeve 16 is arranged in an axially aligned relationship with the conveyor 22, and the conveyor 22 is provided with a connecting element 28 and a retaining element 36 in a radially expanded state, such as... Figure 1 and 2 As shown. In the illustrated example, the forming drum 17 is supported by a robotic arm 38, and the conveyor 22 is supported by a mobile arm 39.

[0126] As the conveyor 22 and / or forming drum 17 moves, the forming drum 17 is positioned coaxially and axially centered between the clamping members 23, such as Figure 4 As shown. In the absence of interference between the components of the carcass sleeve 16 and the conveyor 22, the positioning of the connecting element 28 in the expanded state and the positioning of the retaining element 36 in the idle state allow for easy axial insertion of the forming drum 17. In fact, in the expanded state, the clamping protrusion 30, like the retaining element 36, is preferably positioned tangent to an ideal circumference whose minimum diameter is greater than the maximum diameter of the carcass sleeve 16.

[0127] During positioning, the actuator of clamping member 23 is activated to position the connecting element 28. Figure 5 The illustrated radial contraction state. Figures 2 to 13 In the example shown, the combined activation of the first cylinder 32 and the auxiliary cylinder 34 preferably involves a self-centering method to radially translate the connecting element 28 of each clamping member 23 toward the alignment axis XX, positioning the clamping protrusion 30 so that the corresponding abutment surface 31 is circumferentially distributed according to a diameter smaller than the inner diameter of the bead 7.

[0128] By means of the axial moving device 25, the connecting element 28 is axially and preferably symmetrically translated toward the tire carcass sleeve 16 to position the clamping protrusion 30 of each connecting element 28 so that its abutment surface 31 is radially aligned with the corresponding tire bead 7, such as Figure 6 As illustrated. In this case, the clamping protrusion 30 of each clamping member 23 is traversed by a radial plane that also intersects with the corresponding bead 7.

[0129] The new activation of the actuator determines a radial translation of the coupling element 28 away from the alignment axis XX. Therefore, the clamping protrusion 30 of each coupling element 28 abuts its abutting surface 31 against the radial inner edge of the corresponding bead 7, as... Figure 7 As illustrated, this ensures that the bead 7 is effectively kept coaxial with the alignment axis XX.

[0130] exist Figures 2 to 13 In the example shown, this translation can be achieved by enabling only the additional cylinder 34.

[0131] exist Figures 14 to 16 In the variant embodiment, the operational sequence is alternatively specified such that, prior to the activation of the axial movement device 25, for example, the activation of only the actuator of the first cylinder 32 causes the connecting element 28 to enter a radially contracted state, with the corresponding abutment surface 31 facing axially in an axially aligned relationship with the undercut S defined along the axially outer circumferential edge of the corresponding bead 7. Figure 14 exemplified.

[0132] With the aid of the axial moving device 25, the connecting element 28 is axially translated toward the tire carcass sleeve 16, positioning the clamping protrusion 30 of each connecting element 28 in an engaging relationship with the undercut S, such as Figure 15 As illustrated, the abutment surface 31 of each connecting element 28 has a geometry substantially complementary to the undercut S, acting on the undercut S so that the bead 7 is effectively kept coaxial with the alignment axis XX.

[0133] While gripping the tire bead 7 as described above, for example before, during, or after its execution, the retaining element 36 can be activated. For this purpose, as... Figure 7 and Figure 15As illustrated, the action of the radial movement actuator 36a determines that the retaining element 36 is close to the radial outer surface of the tire carcass sleeve 16, while the activation of the aforementioned suction circuit determines the fixation of the radial outer surface through the attraction towards the retaining element itself. The tire carcass sleeve 16 is thus subjected to a retaining force 36 distributed on its radial outer surface.

[0134] After the retaining elements 36 have been activated, these retaining elements are preferably radially constrained to the connecting element 28. This constraint prevents relative movement between the outer surface of the carcass sleeve 16 and the bead 7, which could result in undesirable deformation, particularly during the removal of the forming drum 17 as described below.

[0135] Then, the forming drum 17 can shrink radially, as... Figure 8 As illustrated, this allows for axial withdrawal relative to the clamping member 23 and thus removal from the carcass sleeve 16, while the carcass sleeve 16 remains securely held at the bead 7 and its radial outer surface, thus preventing significant deformation.

[0136] The tire sleeve 16 is then adapted to be engaged on the shaping drum 20.

[0137] As in Figures 9 to 13 and Figures 16 to 18 As can be seen from the image, each of the halves 20a of the shaping drum 20 preferably has an annular shoulder 40 and a radially expandable annular clamping element 41, the clamping element 41 preferably being arranged in a self-centering manner at an axially external position relative to the annular shoulder 40.

[0138] Each half 20a has an annular shoulder 40 comprising a plurality of abutment sectors 42 circumferentially distributed and preferably self-centering radially movable between a contracted and expanded state. In the contracted state, the abutment sectors 42 impart a maximum diameter to the annular shoulder 40 smaller than the inner diameter of the bead 7, thus not impeding the axial insertion of the carcass sleeve 16 into the shaping drum 20. In the expanded state, the abutment sectors 42 impart a maximum diameter to the annular shoulder 40 larger than the inner diameter of the bead 7, and define an axial thrust surface 40a axially opposed to the other half of the shaping drum 20 for each half 20a.

[0139] Each annular clamping element 41 of half-piece 20a further includes multiple circumferentially distributed expansion sectors 43. In the elastically expanded state, an elastomer ring 44 is assembled around the expansion sector 43. This elastomer ring 44 has a radial thrust surface 44a facing the radially inner edge of the corresponding bead 7. The expansion sector 43 is radially movable between a contracted state and an expanded state. When the expansion sector 43 is in the contracted state, the maximum diameter of the annular clamping element 41 detectable outside the elastomer ring 44 is smaller than the inner diameter of the bead 7, thus not hindering the axial insertion of the carcass sleeve 16 onto the shaping drum 20. When the expansion sector 43 is in the expanded state, the radial surface 44a of the elastomer ring 44 acts on the radially inner edge of the corresponding bead 7 to apply a mechanical thrust, and preferably, also provides an airtight seal for subsequent steps of shaping the carcass sleeve 16.

[0140] The engagement between the tire carcass sleeve 16 and the shaping drum 20 is specified such that the shaping drum 20 is axially inserted into the coaxial center position of the tire carcass sleeve itself, while the tire carcass sleeve is held by the clamping member 23 and the holding element 36 of the conveyor 22, as follows. Figure 9 and Figure 16 As illustrated, insertion can be performed by axial movement of the conveyor 22 relative to the shaping drum 20, and vice versa.

[0141] like Figure 10 As shown, the annular shoulder 40, carried by each of the two halves 20a, expands from a contracted state to an expanded state, preferably in a self-centering manner via a self-centering kinematic mechanism (not shown). As the half-piece 20a moves axially away, the annular shoulder 40 substantially moves away, and preferably moves away symmetrically relative to each other, to approach the corresponding bead 7, until each annular shoulder causes its axial thrust surface 40a to act against the axial inner wall of the bead itself, as... Figure 11 As illustrated, the axial translation of the annular shoulder 40 preferably occurs symmetrically to prevent irregular axial movement of the tire sleeve 16.

[0142] The retaining element 36, which has so far been engaged on the radial outer surface of the tire carcass sleeve 16, can now be deactivated and moved away from the sleeve itself, or remain engaged until the subsequent expansion of the annular clamping element 41 is complete.

[0143] Preferably, the retaining element 36 is disengaged by radially translating the retaining element 36 away from the alignment axis XX in order to position them according to the outer diameter which is greater than the maximum diameter presented by the tire sleeve 16.

[0144] like Figure 12As shown, the expansion of the annular clamping element 41 can occur before the connecting element 28 disengages from the bead 7. More specifically, this disengagement can be actuated by axially translating the connecting element 28 away from the carcass sleeve 16 to position each clamping protrusion 30 in an axially external position relative to the corresponding bead 7. Subsequently, the connecting element 28 is translated away from the alignment axis XX to reposition the clamping protrusion 30 in the expanded state.

[0145] exist Figures 2 to 13 In the illustrated embodiment, the axial removal of the connecting element 28 preferably precedes the radial translation of the connecting element 28 toward the alignment axis XX, so as to space each clamping protrusion 30 from the radially inner surface of the corresponding bead 7, such as... Figure 12 As shown by the dashed line. Figures 14 to 18 In the illustrated embodiment variant, the disengagement of the bead 7 can also occur alternatively after the annular clamping element 41 expands, without requiring the connecting elements 28 to be radially brought closer together before they are axially separated from each other.

[0146] like Figure 13 , Figure 17 and Figure 18 As illustrated, when the expansion state is reached, the annular clamping elements 41 each abut against the radial inner edge of the corresponding bead 7 with a radial thrust relationship.

[0147] The tire sleeve 16 engages correctly with the shaping drum 20 at this point, so that the shaping drum 20 can be axially withdrawn from the conveyor 22 without mechanical interference.

[0148] The shaping drum 20 carrying the carcass sleeve 16 will then engage with the transfer ring 21 in the assembly station 15 to shape the actuated carcass sleeve 16 in a known manner according to the supertoroidal configuration for connection with the outer sleeve 18.

Claims

1. A method for forming a wheel or tire, comprising the following steps: A carcass sleeve (16) is formed on a forming drum (17), the carcass sleeve comprising at least one carcass ply having end flaps that engage with a corresponding annular reinforcement structure incorporated in a corresponding bead (7); Pick up the tire sleeve (16) from the forming drum (17); The tire sleeve (16) is attached to the shaping drum (20); The tire carcass sleeve (16) carried by the shaping drum (20) is shaped to the toroidal surface to connect the tire carcass sleeve to the outer sleeve (18) including the belt structure. The process of picking up the tire sleeve (16) includes: The forming drum (17) carrying the carcass sleeve (16) is arranged in a coaxial and axially centered position between two clamping members (23) that are side by side and coaxial with respect to the alignment axis (XX); wherein each clamping member (23) includes: Annular support (27); a plurality of connecting elements (28) supported by the annular support (27) and circumferentially distributed around the alignment axis (XX); wherein each connecting element (28) has a support post (28a) slidably engaged with the annular support (27) of a corresponding clamping member (23), and a clamping protrusion (30) axially projecting from the support post (28a) toward another clamping member (23); Each of the bead (7) of the tire body sleeve (16) is clamped by the plurality of connecting elements (28) carried by each of the clamping members (23); The molding drum (17) is contracted to disengage the molding drum (17) from the tire sleeve (16) held by the connecting element (28).

2. The method according to claim 1, wherein, Before the molding drum (17) is contracted, the action of holding the tire sleeve (16) is performed by the retention action distributed on the radial outer surface of the tire sleeve.

3. The method according to claim 2, wherein, The action of holding the tire sleeve (16) is maintained during at least a portion of the action of engaging the tire sleeve (16) onto the shaping drum (20).

4. The method according to claim 2, wherein, The tire carcass sleeve (16) includes: Multiple retaining elements (36) are placed against the radial outer surface of the tire carcass sleeve (16); The radial outer surface is fixed to the retaining element (36) by an attraction toward the retaining element (36) itself.

5. The method according to any one of the preceding claims, wherein, Clamping each tire bead (7) includes: The connecting element (28) of each clamping member (23) is radially translated toward the alignment axis (XX) to position the clamping protrusion (30) of the connecting element itself at a diameter smaller than the inner diameter of the bead (7); The connecting element (28) is axially translated toward the tire sleeve (16) to position the clamping protrusion (30) of each connecting element (28) in a position radially aligned with the corresponding tire bead (7); The connecting element (28) is radially translated away from the alignment axis (XX) so that the clamping protrusion (30) of each connecting element (28) abuts against the radial inner edge of the corresponding bead (7).

6. The method according to any one of claims 1 to 4, wherein, Clamping each tire bead (7) includes: The connecting element (28) of each clamping member (23) is radially translated toward the alignment axis (XX) to position the clamping protrusion (30) of the connecting element (28) itself in alignment with the undercut (S) axially defined along the axial outer circumferential edge of the corresponding bead (7); The connecting element (28) is axially translated toward the tire sleeve (16) to position the clamping protrusion (30) of each connecting element (28) in an engaging relationship with the undercut.

7. The method according to any one of claims 1-4, wherein, After the action of retracting the forming drum (17), the forming drum (17) is axially withdrawn relative to the clamping member (23).

8. The method according to claim 1, wherein, The action of attaching the tire sleeve (16) to the shaping drum (20) includes: The shaping drum (20) is axially inserted into the coaxially centered position of the tire sleeve (16) held by the clamping member (23); The annular shoulder (40) carried by each of the two axially opposite halves (20a) of the shaping drum (20) is radially expanded from a contracted state to an expanded state, wherein in the contracted state the maximum diameter of the annular shoulder (40) is smaller than the inner diameter of the bead (7), and in the expanded state the maximum diameter is larger than the inner diameter of the bead (7); In the expanded state, the annular shoulders (40) are moved axially away from each other so that each annular shoulder abuts against the axial inner wall of one of the bead (7); The annular clamping element (41) carried by each of the two axially opposite halves (20a) of the shaping drum (20) is radially expanded from a contracted state to an expanded state. In the contracted state, the maximum diameter of the annular clamping element (41) is smaller than the inner diameter of the bead (7). In the expanded state, each annular clamping element (41) operates against the radial inner edge of one of the beads (7) with a radial thrust relationship.

9. The method according to claim 8, wherein, Before the molding drum (17) is contracted, the action of holding the tire body sleeve (16) is performed by a retaining action distributed on the radial outer surface of the tire body sleeve, wherein the action of holding the tire body sleeve (16) is maintained at least until the action of moving the annular shoulder (40) axially away from each other in the expanded state is completed.

10. The method according to claim 8 or 9, wherein, Before radially expanding the annular clamping element (41), the connecting element (28) is disengaged from the bead (7).

11. The method of claim 10, wherein disengaging the connecting element (28) from the bead (7) comprises: The connecting element (28) is axially translated away from the carcass sleeve (16) to position each clamping protrusion (30) at an axially external position on the corresponding bead (7); The connecting element (28) is radially translated away from the alignment axis (XX) to position the clamping protrusion (30) according to the minimum diameter which is greater than the maximum diameter of the tire sleeve (16).

12. The method according to claim 11, wherein, Disconnecting the connecting element (28) from the bead (7) also includes radially translating the connecting element (28) toward the alignment axis (XX) before axially moving the connecting element (28) away from the carcass sleeve (16) to space each clamping protrusion (30) from the radially inner surface of the corresponding bead (7).

13. An apparatus for forming wheel tires, comprising: Molding drum (17); Shaping drum (20); A conveyor (22) is configured to pick up a tire sleeve (16) from the forming drum (17) and place the tire sleeve on the shaping drum (20); in, The conveyor (22) includes: Two clamping members (23) are arranged side by side and coaxial with respect to the alignment axis (XX), wherein each clamping member (23) includes: Annular support (27); Multiple connecting elements (28) are supported by the annular support (27) and circumferentially distributed around the alignment axis (XX); Each connecting element (28) has a support post (28a) that slidably engages with the annular support (27) of the corresponding clamping member (23), and a clamping protrusion (30) that extends axially from the support post (28a) toward the other clamping member (23).

14. The device according to claim 13, wherein, Each clamping member (23) also includes at least one actuator carried by the annular support (27) and operated on one or more of the connecting elements (28) to move the connecting element radially between a contracted state and an expanded state relative to the alignment axis (XX).

15. The device according to claim 14, wherein, The actuator includes a first cylinder (32) that acts on the support column (28a) and an additional cylinder (34) that operates on an opposing support (35) rigidly supported by the annular support (27).

16. The device according to claim 15, wherein, The first cylinder (32) and the auxiliary cylinder (34) are mechanically connected in series to selectively position the connecting element (28) in a contracted state, an expanded state, and an intermediate state between the contracted state and the expanded state.

17. The device according to claim 16, wherein, When the connecting element (28) is in the intermediate state, the first cylinder (32) and the auxiliary cylinder (34) are each in the corresponding limit stop state.

18. The device according to claim 16, wherein, The radial positioning of the connecting element (28) in the intermediate state is mechanically determined by the limiting stop in the first cylinder (32) and the auxiliary cylinder (34).

19. The device according to claim 13, wherein, The conveyor (22) further includes at least one axial moving device (25) for axially translating the connecting element (28) of the clamping member (23) so that the clamping members move closer to each other and away from each other.

20. The device according to claim 19, wherein, The axial moving device (25) operates on the annular support of the clamping member (23).

21. The device according to claim 19 or 20, wherein, The axial movement device (25) includes at least one actuator supported by a central support ring (24) axially arranged between the clamping members (23).

22. The device according to claim 13, wherein, The device also includes radially external retaining elements (36) distributed in a substantially cylindrical area between the clamping members (23) and capable of being activated to retain the radially outer surface of the tire sleeve (16).

23. The device according to claim 22, wherein, The retaining element (36) includes a suction cup that can be activated by at least one suction circuit.

24. The device according to claim 22 or 23, wherein, The retaining element (36) is carried by an arm (37) that extends axially from the annular support (27) of each clamping member (23) toward the other clamping member (23).

25. The device according to claim 22 or 23, wherein, Each retaining element (36) can move radially toward and away from the alignment axis (XX).

26. The device according to claim 24, wherein, Each of the retaining elements (36) engages with the corresponding arm (37) via a radial movement actuator (36a).

27. The device according to claim 13, wherein, The shaping drum (20) includes: Two axially movable halves (20a) relative to each other, wherein each half comprises: A radially expandable annular shoulder (40); A radially expandable annular clamping element (41) is arranged in an axially external position relative to the annular shoulder (40).

28. The device according to claim 27, wherein, Each half of the ring shoulder (40) has an axial thrust surface (40a) that is axially opposed to the other half of the shaping drum (20).

29. The device according to claim 27 or 28, wherein, The annular shoulder (40) of each half-piece includes a plurality of circumferentially distributed and radially movable abutment sectors (42).

30. The device according to claim 27 or 28, wherein, The annular clamping element (41) of each half-piece includes a plurality of circumferentially distributed and radially movable expansion sectors (43).

31. The device according to claim 30, wherein, Each half-piece of the annular clamping element (41) further includes an elastomeric ring (44) assembled around the expansion sector (43) and having a radially external thrust surface.

Images