Apparatus for manufacturing tyres for vehicle wheels

Abstract

Building the carcass structure of tyres for vehicle wheels includes associating, at each end edge of a carcass ply, at least one respective annular reinforcement structure formed by depositing along a circumferential direction a plurality of reinforcement elements having a first length. Such elements are cut to size from a reinforced continuous band-like element fed to a cutting group arranged at a first operative position adapted to allow a barycentric grip of the reinforcement elements. The cutting group can translate along a feeding direction of the band-like element to a second operative position for cutting to size a plurality of second reinforcement elements having a second length different from the first length. The second operative position is defined on the basis of the second length, so as to have a barycentric grip of the second reinforcement elements too.

Claims

1. An apparatus for building at least one reinforcement structure on a tyre component formed on a forming support, comprising: a feeder to feed a reinforced continuous band-like element along a feeding direction; a cutting group of the reinforced continuous band-like element translatable along the feeding direction to form at least one first reinforcement element and at least one second reinforcement element having a first cutting length and at least one second cutting length that is different from said first cutting length, respectively; at least one moving and depositing device for moving said at least one first reinforcement element and at least one second reinforcement element close to the forming support and depositing said at least one first reinforcement element and at least one second reinforcement element on respective deposition areas defined on respective tyre components, and the at least one moving and depositing device comprises: at least one gripping member of said at least one first reinforcement element and said at least one second reinforcement element, said at least one gripping member movable between the cutting group and a transfer position and at least one positioning member which is movable between said transfer position and a deposition position defined at the forming support and comprises a support member attachable at a barycentric position of the at least one first reinforcement element and the at least one second reinforcement element; and a controller configured to control the translation of said cutting group along said feeding direction between a first operative position defined on a basis of said first cutting length and a second operative position defined on a basis of said at least one second cutting length so that a barycentric grip condition of the at least one first reinforcement element and the at least one second reinforcement element by the gripping member is maintained.

2. The apparatus according to claim 1, wherein the cutting group is mounted on a support frame through an interposition of a sliding rail extending along said feeding direction.

3. The apparatus according to claim 1, comprising two positioning members arranged on opposite sides with respect to a middle plane of said apparatus.

4. The apparatus according to claim 1, wherein said forming support is substantially cylindrical.

5. The apparatus according to claim 1, wherein the apparatus is for manufacturing tyres for vehicle wheels.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further features and advantages of the present invention will appear more clearly from the following detailed description of some preferred embodiments of an apparatus and process according to the present invention, made with reference to the annexed drawings. In such drawings:

(2) FIG. 1 is a simplified schematic plan view of an apparatus for manufacturing tyres for vehicle wheels according to the present invention, in an operative configuration thereof;

(3) FIG. 2a is a simplified schematic plan view of a cutting group of the apparatus of FIG. 1 in a first working position thereof;

(4) FIG. 2b is a simplified schematic plan view of the cutting group of the apparatus of FIG. 1 in a second working position thereof;

(5) FIG. 3 is a simplified schematic plan view of a gripping member of the apparatus of FIG. 1 in a gripping position of reinforcement elements having different cutting lengths;

(6) FIG. 4 is a simplified schematic plan view of the gripping member and of a positioning member of the apparatus of FIG. 1 in a transfer position of reinforcement elements having a different cutting lengths from the gripping member to the positioning member;

(7) FIG. 5 is a simplified schematic plan view of the positioning member of the apparatus of FIG. 1 in a deposition position of reinforcement elements having a different cutting lengths on a forming support.

(8) In FIG. 1, reference numeral 100 globally indicates an exemplary embodiment of an apparatus for manufacturing tyres for vehicle wheels according to the present invention.

(9) Preferably, apparatus 100 may be used in a process for manufacturing different batches of tyres.

(10) More preferably, apparatus 100 allows associating respective reinforcement structures to specific tyre components.

DETAILED DESCRIPTION OF THE INVENTION

(11) In the specific embodiment illustrated herein, apparatus 100 is used for building carcass structures. Such building in particular comprises forming a first annular reinforcement structure 1a, 1b at each end edge 2a, 2b of a first carcass ply 2 deposited on a forming support 150 for manufacturing a first batch of tyres, and forming an annular reinforcement structure 1a, 1b at each end edge 2a, 2b of a second carcass ply 2 deposited on the forming support 150, for manufacturing a second batch of tyres differing from the tyres of the first batch at least by the width of the reinforcement structure and/or the deposition angle of the reinforcement element on the end edge of the carcass ply. Preferably, the forming support 150 is cylindrical.

(12) The above end edges 2a, 2b are defined at axial end zones of the carcass ply 2, 2 configured to define the bead region of the tyres.

(13) Throughout the present description, reference shall first be made to the building of the reinforcement structures 1a, 1b on a first carcass ply 2 for manufacturing the first batch of tyres.

(14) Each reinforcement structure 1a, 1b extends in a circumferential direction on the respective end edge 2a, 2b of the carcass ply 2 and is defined by a predetermined number of reinforcement elements 5a, 5b, having the same length L1 and width W, deposited one after the other on respective deposition areas defined on the opposite end edges 2a, 2b of the carcass ply 2.

(15) In particular, FIG. 1 shows a reinforcement structure in being formed through deposition of the reinforcement elements 5a at the end edge 2a of the carcass ply 2 and a reinforcement structure 1b being formed through deposition of the reinforcement elements 5b at the opposite end edge 2b of the carcass ply 2.

(16) Apparatus 100 comprises a support frame 101 whereto, in operation, the forming support 150 is moved close and on which the various members or devices needed for forming the reinforcement structures 1a, 1b are mounted.

(17) In order to allow the subsequent deposition in circumferential direction of the reinforcement elements 5a, 5b, the forming support 150 is periodically controlled in rotation about the axis of rotation X-X thereof by an angle corresponding to a predetermined circumferential step.

(18) The reinforcement elements 5a, 5b are preferably obtained by operations of cutting to size at least one reinforced continuous band-like element 4 extending along a direction of longitudinal extension, indicated with letter G in FIG. 1, and fed close to the forming support 150 through a proper feeding device 20.

(19) The reinforced continuous band-like element 4 has a defined and constant width W, preferably comprised between 1 and 100 mm, more preferably between 30 and 70 mm.

(20) The reinforced continuous band-like element 4 is fed along the direction G of longitudinal extension thereof by the feeding device 20 with a predetermined advancing step, such step defining a predetermined cutting length L1 of the reinforced continuous band-like element 4, which corresponds to a predetermined width of the reinforcement elements 5a, 5b when they are deposited on the forming support 150.

(21) The expressions direction of longitudinal extension and feeding direction shall be used without distinction to refer to the same direction indicated with letter G in FIG. 1.

(22) Apparatus 100 comprises a cutting group 30 configured to carry out the sequential operations of cutting to size the reinforced continuous band-like element 4 for obtaining the reinforcing elements 5a, 5b in a sequence.

(23) The cutting group 30 acts on the continuous reinforced band-like element 4, with a predetermined cutting frequency, along a cutting direction defining, on the lying plane of the reinforced continuous band-like element 4, a predetermined cutting angle with the direction G of longitudinal extension of the reinforced continuous band-like element 4.

(24) In the preferred embodiments of the present invention, the cutting angle is set to a value greater than zero, preferably comprised between about 15 and about 90 more preferably between about 20 and about 50, even more preferably between about 22 and about 45.

(25) If the cutting angle is equal to 90, length L1 of the reinforcement elements 5a, 5b deposited on the forming support 150 corresponds to width W of the reinforced continuous band-like element 4. If the cutting angle is smaller than 90, length L1 of the reinforcement elements 5a, 5b is equal to width. W of the reinforced continuous band-like element 4 divided by the sine of angle .

(26) The cutting group 30 is pivoted to frame 101 about a respective axis of rotation and can rotate as a whole around such axis for allowing the cutting of the reinforced continuous band-like element 4 with different angles .

(27) As shown in FIGS. 1 and 2a, the cutting group 30 is mounted on a pair of sliding rails 31 associated with support frame 101 and extending parallel to the feeding direction G of the reinforced continuous band-like element 4. In this way, the cutting group 30 can translate along the feeding direction G of the reinforced continuous band-like element 4 for positioning at operative positions different from that shown in FIG. 1, thus allowing the cut of reinforcement elements having lengths different from that of the reinforcement elements 5a, 5b.

(28) As shall appear more clearly throughout the present description, the different operative positions of the cutting group 30 are defined on the basis Of the desired cutting length of the reinforcement elements.

(29) In order to control the translation of the cutting group 30 (indicated with double arrow A in FIG. 1) along the feeding direction G, apparatus 100 comprises a proper control device 35 associated with the cutting group 30.

(30) Downstream of the cutting group 30, i.e. between the cutting group 30 and the forming support 150, a moving and depositing device of the reinforcement elements 5a, 5b is provided.

(31) The moving and depositing device in particular comprises a gripping member 40 of the reinforcement elements 5a, 5b.

(32) The gripping member 40 comprises a pair of arms 41a, 41b configured to alternately pick the reinforcement element 5a, 5b just made up to move it towards the respective end edge 2a, 2b of the carcass ply 2 deposited on the forming support 150.

(33) Arms 41a, 41b are fixedly connected to one another and angularly spaced by a predetermined angle, preferably equal to 90.

(34) Each arm 41a, 41b comprises, at a free end thereof, a clamp 42a, 42b for gripping the reinforcement element 5a, 5b to be cut.

(35) Each clamp 42a, 42b is slidingly mounted on the respective arm 41a, 42b so as to carry out a linear sliding movement with respect to arms 41a, 41b along the respective longitudinal directions. Such movement allows the release of the reinforcement element 5a, 5b just cut from the cutting group 30 for the subsequent movement thereof towards the forming support 150.

(36) The grip of the reinforcement elements 5a, 5b by clamps 42a, 42b takes place at barycentre B of the above reinforcement elements (i.e. at a barycentric position), as schematically shown in FIGS. 2a and 3.

(37) The gripping member 40 is pivoted to frame 101 around a respective axis of rotation Y.sub.1 defined at a plane M of apparatus 100, such plane M corresponding to the equatorial plane of the tyre being formed on the forming support 150.

(38) The gripping member 40 can rotate about axis Y.sub.1 in both directions of rotation with an alternating movement, so as to move in an alternating sequence the reinforcement elements 5a towards the end edge 2a of the carcass ply 2 and the reinforcement elements 5b towards the end edge 2b of the carcass ply 2.

(39) The moving and depositing device further comprises, between the gripping member 40 and the forming support 150, a pair of positioning members 50a, 50b, each configured for picking a respective reinforcement element 5a, 5b up from a respective arm 41a, 41b of the gripping member 40 at a respective transfer position after such arm has made a predetermined angular movement (preferably equal to 90) starting from the cutting group 30.

(40) The positioning members 50a, 50b (which are absolutely identical to one another) are preferably arranged symmetrically on the opposite sides with respect to plane M of apparatus 100 and are moved synchronously with arms 41a, 41b. Each reinforcement element 5a, 5b can thus be transferred by a respective arm 41a, 41b of the gripping member 40 to a respective positioning member 50a, 50b, which then deposits the reinforcement element 5a, 5b on a respective end edge 2a, 2b of the carcass ply 2 deposited on the forming support 150.

(41) Each positioning member 50a, 50b comprises a respective articulated arm in turn comprising a first arm 51a, 51b having a free end pivoted on frame 101 at a pivoting axis Y.sub.2, and a second arm 52a, 52b having a free end pivoted at a pivoting axis Y.sub.3 on a free end of the respective first arm 51a, 52a opposite the one where the respective first arm 51a, 52a is pivoted to frame 101.

(42) Each second arm 52a, 52b comprises, at a free end thereof opposite the one were the second arm 52a, 52b is pivoted to the first arm 51a, 51b, a respective support member 53a, 53b configured to pick the respective reinforcement element 5a, 5b up from the respective arm 41a, 41b of the gripping member 40 at the above transfer position for moving it to the respective end edge 2a, 2b of the carcass ply 2 deposited on the forming support 150.

(43) The transfer of the reinforcement element 5a, 5b from arm 41a, 41b of the gripping member 40 to the support member 53a, 53b of the positioning member 50a, 50b takes place so that the reinforcement element 5a, 5b is subsequently held by the respective support member 53a, 53b at barycentre B thereof, i.e. at a barycentric position.

(44) Each support member 53a, 53b is provided with a device for holding the reinforcement element 5a, 5b by suction or suction cup or electromagnet (according to whether the reinforcement cords inside the reinforcement elements are textile or metal), configured to prevent the reinforcement element 5a, 5b from falling down during the movement towards the forming support 150.

(45) Each support member 53a, 53b is movable parallel to the pivoting axes Y.sub.2 and Y.sub.3 for allowing the deposition of the reinforcement elements 5a, 5b on the end edges 2a, 2b of the carcass ply 2 deposited on the forming support 150.

(46) In a preferred embodiment of apparatus 100 of the present invention, such as that illustrated herein, the support members 53a, 53b, after having deposited the reinforcement elements 5a, 5b on the respective end edges 2a, 2b of the carcass ply 2, press such reinforcement elements 5a, 5b against the forming support 150 so as to deform them consistently with the geometry of the forming support 150, thus achieving the complete laying of the reinforcement elements 5a, 5b on the above end edges 2a, 2b.

(47) In an alternative embodiment of apparatus 100 of the present invention, not shown, a pair of respective pressing members configured to press on the reinforcement elements 5a, 5b after they have been deposited by the support members 53a, 53b on the above end edges 2a, 2b are provided downstream of the positioning members 50a, 50b, i.e. between the positioning members 50a, 50b and the forming support 150.

(48) Irrespective of the specific embodiment of apparatus 100 being used, the reinforcement elements 5a, 5b are each time deposited on the end edges 2a, 2b at respective deposition areas defined in circumferentially symmetrical positions with respect to a vertical radial plane of the forming support 150, that is so that barycentre B of the reinforcement element 5a, 5b deposited is on said radial plane, as shown in FIG. 5.

(49) Apparatus 100 may further comprise a pair of idle rollers (not shown in the figures) movable perpendicularly to the rotation axis X-X of the forming support 150. Such rollers are coated with a deformable material and are arranged at opposite sides with respect to plane H of apparatus 100, each one in the proximity of a respective positioning member 50a, 50b.

(50) The above rollers are configured to be activated when the respective reinforcement structure 1a, 1b has been completed at each end edge 2a, 2b of the carcass ply 2 for improving the compaction and adhesion of said reinforcement structure 1a, 1b on the carcass ply 2.

(51) With reference to FIG. 1, a preferred embodiment of the process carried out by apparatus 100 described above shall now be described, aimed to the manufacture of a first batch of tyres wherein the reinforcement structures 1a, 1b comprise reinforcement elements 5a, 5b having a predetermined first length L1.

(52) Before starting the above process, a carcass ply 2 is deposited on the forming support 150 and the forming support 150 is moved close to frame 101. Apparatus 100 is then set up on the basis of the features of the tyres to be made.

(53) The setup of apparatus 100 comprises, among the other things, the positioning of the cutting group 30 at the desired cutting angle with respect to the feeding direction G of the reinforced continuous band-like element 4. The above setup further comprises the positioning of the cutting group 30 in an operative position defined along the feeding direction of the reinforced continuous band-like element 4 on the basis of the desired cutting length L1.

(54) As described above, in the above process the reinforcement elements 5a, 5b are cut in a sequence from the reinforced continuous band-like element 4 and they are alternately deposited each on a respective end edge 2a, 2b of the carcass ply 2. In particular, the deposition of a reinforcement element 5a on an end edge 2a takes place immediately after a reinforcement element 5b has been deposited on the other end edge 2b and vice versa, so as to make a reinforcement structure In on the end edge 2a while another reinforcement structure 1b is made on the end edge 2b.

(55) At the regime state, thus, there is a situation wherein at least one reinforcement element. 5a has already been deposited on the end edge 2a and at least one reinforcement element 5b has already been deposited on the other end edge 2b. Such situation is shown in FIG. 1.

(56) Starting from such situation, the reinforced continuous band-like element 4 is moved along said feeding direction G by a predetermined advancing step. During advancing of the reinforced continuous band-like element 4, gripping member 40 is made to rotate so as to bring arm 41a at the cutting group 30. In this position, arm 41a is activated to pick a free end of the reinforced continuous band-like element 4 up.

(57) Simultaneously with the rotation of the gripping member 40, a synchronous rotation of the positioning member 50a takes place.

(58) Afterwards, the reinforced continuous band-like element 4 is cut to obtain the reinforcement element 5a.

(59) FIG. 1 shows an operative configuration of the apparatus and process of the present invention wherein the reinforcement element 5b just cut has been picked up by clamp 42b of arm 41b of the gripping member 40 and the latter has been moved by about 90 to bring clamp 42b to a transfer position of the reinforcement element 5b to the positioning member 50b which meanwhile has been moved towards the gripping member 40. At the same period of time, arm 41a of the gripping member 40 has been brought at the cutting group 30 for picking up the reinforcement element 5a which is about to be cut from the reinforced continuous band-like element 4.

(60) After the reinforcement element 5b has been transferred from the gripping member 40 to the positioning member 50b, the latter is made to rotate about the pivoting axis Y.sub.2 to bring the above reinforcement element 5b at the end edge 2b of the carcass ply 2. During such rotation, the reinforcement element 5b is held at the barycentric position on the support member 53b of the positioning member 50b by the holding device described above.

(61) Meanwhile, the forming support 150 is made to rotate about axis X-X by a predetermined angle corresponding to a movement in the circumferential direction by a length equal to (if the circumferentially consecutive reinforcement elements 5a, 1b must be deposited in contact with each other and without overlapping) or greater than (if the reinforcement elements 5a, 5b must be deposited leaving a free space between two circumferentially consecutive reinforcement elements) the advancing step of the reinforced continuous band-like element 4.

(62) Once the support member 53b is at a radially outer position with respect to the forming support 150, the support member 53b is moved towards the forming support 150 (and thus in a direction perpendicular to the rotation axis X-X of the forming support 150) up to positioning the reinforcement element. 5b on a respective deposition area defined on the end edge 2b of the carcass ply 2.

(63) Subsequently, the support member 53b exerts a predetermined thrust action against the forming support 150, so as to obtain the complete laying of the reinforcement element 5b on the end edge 2b of the carcass ply 2.

(64) As an alternative, said thrust action may be carried out by a pressing member separate from the support member 53b.

(65) The process described above is repeated cyclically through the positioning members 50a and 50b, each time depositing a new reinforcement element 5a, 5b on the respective end edge 2a, 2b of the carcass ply 2, up to completing the reinforcement structures 1a, 1b on both end edges 2a, 2b of the carcass ply 2.

(66) Afterwards, if the idle rollers described above are provided, each one of such idle rollers is brought in contact with the respective reinforcement structure 1a, 1b just formed. The rotation of the forming support 150 is then controlled for at least one full revolution. The action of the rollers during such rotation produces the compaction of the reinforcement structures 1a, 1b on the respective end edges 2a, 2b of the carcass ply 2.

(67) According to the present invention, a process totally similar to that described above may be carried out by the same apparatus 100 for manufacturing a second batch of tyres differing from the tyres of the first batch in that the reinforcement structures 1a, 1b of the tyres of the second batch comprise reinforcement elements 15a, 15b having a cutting length L2 different from the cutting length of the reinforcement elements 5a, 5b of the tyres of the first batch.

(68) Throughout the present description, particular reference is made to the case where length L2 is lower than length L1, as shown in FIG. 2b.

(69) In this case, a carcass ply 2 is deposited on the forming support 150 and the process described above is repeated.

(70) In particular, in order to proceed with the cutting of the reinforcement elements 15a, 15b to the desired length L2, the cutting group 30 is first translated along the feeding direction G of the reinforced continuous band-like element 4 towards barycentre B of the reinforcement elements 5a, 5b previously cut (i.e. in the direction indicated by arrow T in FIG. 2a). In particular, the cutting group 30 is moved from a first operative position taken for cutting the reinforcement elements 5a, 5b having length L1 to a new operative position which is far from the first operative position by a distance P whose longitudinal extension along the feeding direction G is a function of the difference between length L1 and length L2 (FIGS. 2a and 2b).

(71) More in particular, said extension is equal to half the difference between length L1 and length L2.

(72) Of course, if length L2 is greater than length L1, the movement of the cutting group 30 takes place in a direction opposite to that indicated with letter T in FIG. 2 (i.e. away from barycentre of the reinforcement elements 5a, 5b previously cut) and the extent of distance P is equal to half the difference between length L2 and length L1.

(73) In this way, it is ensured that the pickup of the reinforcement elements 15a, 15b by clamps 42a, 42b of the gripping member 40 and the transfer of the same to the support members 53a, 53b of the positioning members 50a, 50b always takes place at a barycentric position, as described above with reference to the reinforcement elements 5a, 5b (FIG. 4).

(74) Accordingly, it is ensured that the deposition of the reinforcement elements 15a, 15b on the end edges 2a, 2b of the carcass ply 2 each time takes place at circumferentially symmetrical positions with respect to the vertical radial plane of the forming support 150, as described above with reference to the reinforcement elements 5a, 5b (FIG. 5).

(75) In other words, as shown in FIGS. 3-5, during all the process steps of the present invention the spatial position of barycentre B of the reinforcement elements 15a, 15b always matches that of barycentre B of the reinforcement elements 5a, 5b.

(76) In this way, it is possible to ensure the accurate and repeatable deposition of the reinforcement elements 5a, 5b, 15a, 15b on the end edges 2a, 2b of the carcass plies 2, 2 upon the variation of the cutting length of the reinforcement elements.

(77) Of course, a man skilled in the art can make further modifications and variants to the invention described above in order to satisfy specific and contingent application requirements, these variants and modifications in any case being within the scope of protection as defined by the following claims.