METHOD AND PLANT FOR BUILDING TYRES FOR VEHICLE WHEELS

Abstract

A plant for building tyres for vehicle wheels includes a gripping ring arranged in a fixed reference position. A first stage building line defines a closed first-stage path for the movement of a plurality of building drums and an open first-stage path for building and moving carcass sleeves being processed. A second stage building line defines a closed second-stage path for the movement of a plurality of auxiliary drums and an open second-stage path for building and moving a plurality of outer sleeves being processed. The open second-stage path and the open first-stage path terminate at the gripping ring configured for carrying out a radially outer contrast function during the shaping of a first carcass sleeve being processed and the assembly thereof with a first outer sleeve being processed.

Claims

1.-22. (canceled)

23. A method for building tyres for vehicle wheels, comprising: moving a plurality of building drums along a closed first-stage path, moving a plurality of carcass sleeves being processed along an open first-stage path, wherein along a first stage operating section in common between said closed first-stage path and said open first-stage path each carcass sleeve being processed of said plurality of carcass sleeves being processed is built on a respective building drum of said plurality of building drums, said open first-stage path ending at a gripping ring arranged in a fixed reference position, moving a plurality of auxiliary drums along a closed second-stage path, moving a plurality of outer sleeves being processed along an open second-stage path, wherein along a second stage operating section in common between said closed second-stage path and said open second-stage path each outer sleeve being processed of said plurality of outer sleeves being processed is built and moved on a respective auxiliary drum of said plurality of auxiliary drums, said open second-stage path ending at said gripping ring, at the end of the second stage operating section, separating from the respective auxiliary drum a first outer sleeve being processed of said plurality of outer sleeves being processed and holding said first outer sleeve being processed by said gripping ring, at the end of the open first-stage path, arranging a first carcass sleeve being processed of said plurality of carcass sleeves being processed in a coaxial and radially inner position with respect to the first outer sleeve being processed held by said gripping ring, and shaping, inside the gripping ring, said first carcass sleeve being processed, assembling said first carcass sleeve being processed with said first outer sleeve being processed to obtain a first green tyre being processed.

24. The method for building tyres for vehicle wheels according to claim 23, wherein said gripping ring performs a radially outer contrast function during the shaping of the first carcass sleeve being processed.

25. The method for building tyres for vehicle wheels according to claim 24, comprising: monitoring a force exerted on the gripping ring by the first carcass sleeve being processed and the first outer sleeve being processed during the shaping of the first carcass sleeve being processed.

26. The method for building tyres for vehicle wheels according to claim 25, wherein said open first-stage path comprises a final section arranged inside a shaping machine and ending at said gripping ring, and said first carcass sleeve being processed is moved axially along said final section associated with a shaping drum until said first carcass sleeve being processed is arranged in a coaxial and radially inner position with respect to the first outer sleeve being processed held by said gripping ring.

27. The method for building tyres for vehicle wheels according to claim 26, comprising: removing said shaping drum carrying said first green tyre being processed from said gripping ring by moving said shaping drum along a finishing path, and performing a rolling action of said first green tyre being processed associated with said shaping drum in a rolling station arranged along said finishing path.

28. The method for building tyres for vehicle wheels according to claim 27, comprising: arranging again said first green tyre being processed at said gripping ring, after said rolling action, said finishing path being a closed path starting and ending at said gripping ring.

29. The method for building tyres for vehicle wheels according to claim 28, comprising: separating said first green tyre being processed from the shaping drum at the end of the finishing path and holding said first green tyre being processed by said gripping ring.

30. The method for building tyres for vehicle wheels according to claim 29, comprising: performing a quality check of said first green tyre being processed by said gripping ring.

31. The method for building tyres for vehicle wheels according to claim 30, wherein said finishing path is arranged inside said shaping machine.

32. The method for building tyres for vehicle wheels according to claim 31, comprising: removing said first green tyre being processed from said shaping machine and from said gripping ring, at the end of the finishing path.

33. The method for building tyres for vehicle wheels according to claim 32, wherein the separating said first outer sleeve being processed from the respective auxiliary drum is performed by said gripping ring, said second stage operating section ending at said gripping ring.

34. The method for building tyres for vehicle wheels according to claim 33, wherein the separating said first outer sleeve being processed from the respective auxiliary drum comprises: axially moving the auxiliary drum carrying the first outer sleeve being processed and inserting the auxiliary drum in the gripping ring at a first access of the gripping ring itself until reaching a position radially inside the gripping ring, and holding said first outer sleeve being processed by said gripping ring while the auxiliary drum is axially withdrawn from the first outer sleeve being processed.

35. The method for building tyres for vehicle wheels according to claim 34, wherein the arranging said first carcass sleeve being processed in a coaxial and radially inner position with respect to the first outer sleeve being processed comprises: axially moving said first carcass sleeve being processed and inserting said first carcass sleeve being processed into the gripping ring at a second access of the gripping ring axially opposite to said first access.

36. The method for building tyres for vehicle wheels according to claim 35, comprising: building, by depositing semi-finished products, a first part of components of a carcass sleeve being processed along a first portion of said first stage operating section, said first part of components comprising at least one carcass ply, and building, by spiraling a continuous elongated element, a second part of components of the carcass sleeve being processed along a second portion of said first stage operating section, said second part of components comprising at least one between i) anti-abrasive inserts and ii) at least a portion of sidewalls.

37. The method for building tyres for vehicle wheels according to claim 36, comprising: performing a bead building action in a position arranged between said first portion and said second portion of the first stage operating section, wherein said bead building action comprises engaging axially opposite ends of the carcass sleeve being processed to respective annular anchoring structures.

38. The method for building tyres for vehicle wheels according to claim 37, comprising: building, by depositing semi-finished products, a first part of components of an outer sleeve being processed along a first portion of the second stage operating section, said first part of components comprising at least one belt layer, and building, by spiraling a continuous elongated element, a second part of components of the outer sleeve being processed along a second portion of the second stage operating section, said second part of components comprising at least one tread band.

39. The method for building tyres for vehicle wheels according to claim 38, wherein along said first stage operating section in common between said closed first-stage path and said open first-stage path, each carcass sleeve being processed of said plurality of carcass sleeves being processed is moved on a respective building drum of said plurality of building drums.

40. A plant for building tyres for vehicle wheels, comprising: a first stage building line defining a closed first-stage path for moving a plurality of building drums and an open first-stage path for building and moving carcass sleeves being processed, wherein said closed first-stage path and said open first-stage path have a first stage operating section in common for building and moving each carcass sleeve being processed of said plurality of carcass sleeves being processed associated with a respective building drum of said plurality of building drums and wherein said first stage building line comprises a plurality of first stage work stations arranged along a portion of the first stage operating section, a second stage building line defining a closed second-stage path for moving a plurality of auxiliary drums and an open second-stage path for building and moving a plurality of outer sleeves being processed, wherein said closed second-stage path and said open second-stage path have a second stage operating section in common for building and moving each outer sleeve being processed of said plurality of outer sleeves being processed associated with a respective auxiliary drum of said plurality of auxiliary drums and wherein said second stage building line comprises a plurality of second stage work stations arranged along a portion of the second stage operating section, and a gripping ring arranged in a fixed reference position, wherein said open second-stage path and said open first-stage path end at said gripping ring configured for the assembly of said first carcass sleeve being processed with a first outer sleeve being processed.

41. The plant for building tyres for vehicle wheels according to claim 40, wherein at least one first stage work station, comprising a semi-finished product dispensing device, is arranged along a first portion of said first stage operating section for building a first part of components of a carcass sleeve being processed, said first part of components comprising at least one carcass ply, and at least another one first stage work station, comprising a device for dispensing a continuous elongated element, is arranged along a second portion of said first stage operating section for building a second part of components of a carcass sleeve being processed, said second part of components comprising at least one between i) anti-abrasive inserts and ii) at least a portion of sidewalls.

42. The plant for building tyres for vehicle wheels according to claim 41, wherein said first stage building line comprises a work station configured for building beads arranged between said first portion and said second portion of said first stage operating section.

43. The plant for building tyres for vehicle wheels according to claim 42, wherein: at least one second stage work station, comprising a semi-finished product dispensing device, is arranged along a first portion of said second stage operating section for building a first part of components of the outer sleeve being processed, said first part of components comprising at least one belt layer, and at least another one second stage work station, comprising a device for dispensing a continuous elongated element, is arranged along a second portion of said second stage operating section for building a second part of components of the outer sleeve being processed, said second part of components comprising at least one tread band.

44. The plant for building tyres for vehicle wheels according to claim 42, wherein said gripping ring is configured for performing a radially outer contrast function during the building of a first carcass sleeve being processed.

Description

[0134] Such description will be set forth hereinbelow with reference to the enclosed drawings, provided only as a non-limiting example, in which:

[0135] FIG. 1 and FIG. 2 schematically illustrate a top view of a plant for producing tyres;

[0136] FIGS. 3-9 illustrate a side view of a portion of the plant of FIG. 1 or 2 in different configurations corresponding to several actions of a method for building tyres;

[0137] FIG. 10 illustrates a radial half-section of a tyre that can be attained by the method and the plant according to the invention.

[0138] With reference to FIG. 10, a tyre 1 has a middle line plane A perpendicular to the rotation axis R of the same (it is specified that in FIG. 2 the position of the rotation axis R with respect to the section of the tyre 1 is shown only as a schematic example). The middle line plane A divides the tyre 1 into a first axial half 2a and a second axial half. For illustration simplicity, FIG. 10 shows only the first axial half 2a of the tyre 1, the other half being substantially mirrored (except for the tread design which might not be symmetric with respect to the aforesaid middle line plane A).

[0139] The tyre 1 essentially comprises a carcass structure 3 having one or two carcass plies 4a, 4b. An airtight elastomeric material layer or so-called liner 5 is applied inside the carcass ply/plies 4a, 4b.

[0140] Two annular anchoring structures 6 (of which only that of the axial half 2a is shown in FIG. 10) are engaged, in axially opposite positions (with respect to the middle line plane A), with respective axial ends of the carcass ply/plies 4a, 4b. The two annular anchoring structures 6 each comprise a so-called bead core 6a carrying an elastomeric filler 6b in radially outer position. The two annular anchoring structures 6 are integrated in proximity to zones normally identified with the name “beads” 7 (of which only that of the axial half 2a is shown in FIG. 10), at which the engagement between the tyre 1 and a respective mounting rim usually occurs. A belt structure 8 comprising belt layers 8a, 8b is circumferentially applied around the carcass ply/plies 4a, 4b, and a tread band 9 is circumferentially superimposed on the belt structure 8. The belt structure 8 can comprise a further layer (not illustrated) so-called at zero degrees in radially outer position with respect to the aforesaid layers 8a, 8b. The belt structure 8 can also be associated with so-called “under-belt inserts” 10, each situated between the carcass ply/plies 4a, 4b and one of the axially opposite terminal edges of the belt structure 8. Two sidewalls 11, each extended from the corresponding bead 7 to a corresponding lateral edge of the tread band 9, are applied in axially opposite positions (with respect to the middle line plane A) on the carcass ply/plies 4a, 4b. The set of the portion of each sidewall 11 close to the respective lateral edge of the tread band 9 and of each portion of the tread band 9 close to the respective sidewall 11 is known as shoulder 12 of the tyre.

[0141] With reference to FIGS. 1-9, reference number 100 indicates a plant for building tyres, hereinbelow more simply indicated as plant 100.

[0142] The plant 100 comprises a first stage building line 200 for building carcass sleeves, a second stage building line 300 for building outer sleeves and a gripping ring 400 arranged in a fixed reference position within the plant 100.

[0143] Preferably the plant 100 comprises a shaping machine 500 which, in turn, preferably comprises the gripping ring 400 arranged in fixed position within the shaping machine 500.

[0144] Preferably the plant 100 comprises a rolling station 600. Still more preferably the shaping machine 500 comprises the rolling station 600.

[0145] In addition, the plant 100 comprises a vulcanisation line 700 arranged in a proximal or remote position with respect to the first stage building line 200 and to the second stage building line 300.

[0146] The first stage building line 200 defines a closed first-stage path 201 for moving a plurality of building drums 202 and an open first-stage path 203 for building and moving carcass sleeves being processed 204. Except for possible size changes, the building drums 202 are continuously moved along the closed first-stage path 201, providing support to respective carcass sleeves being processed 204.

[0147] The closed first-stage path 201 starts and finishes at a same position.

[0148] The open first-stage path 203 starts in the position in which, on a respective building drum 202, a first component of a carcass sleeve being processed 204 is built, or a first part thereof is built, and terminates at the gripping ring 400.

[0149] In a normal operating condition of the plant, N building drums 202 (simultaneously for N>1) are moved along the closed first-stage path 201 and N carcass sleeves being processed 204 (simultaneously for N>1) are moved along the open first-stage path 203. N is an integer greater than or equal to 1, preferably greater than or equal to 5 and still more preferably equal to 6. Preferably, the building drums 202 are substantially cylindrical.

[0150] The closed first-stage path 201 and the open first-stage path 203 have a first stage operating section 205 in common. Along the first stage operating section 205, each carcass sleeve being processed 204 is built and more preferably moved, associated with a respective building drum 202. In other words, the first stage operating section 205 starts in the position in which, on a respective building drum 202, a first component of a carcass sleeve being processed 204 is built, or a first part thereof is built, and terminates in the position in which the carcass sleeve being processed 204 is separated from the respective building drum 202 or at the gripping ring 400 where the carcass sleeve being processed is shaped and assembled to a respective outer sleeve being processed.

[0151] The first stage building line 200 comprises one or more transfer devices for moving the building drums 202 along the closed first-stage path 201 and/or the carcass sleeves being processed 204 along the open first-stage path 203.

[0152] A transfer device can for example comprise one or more from among: [0153] a non-anthropomorphic Cartesian handling device, preferably with at least four, more preferably five degrees of freedom, configured for gripping one building drum 202 at a time and/or one carcass sleeve being processed 204 at a time and moving it preferably along three Cartesian axes and in rotation around at least one, preferably two, of said Cartesian axes, [0154] an anthropomorphic robot preferably with a robotic arm with at least 6 movement axes, configured for gripping and moving one building drum 202 at a time and/or one carcass sleeve being processed 204 at a time, [0155] a shuttle that is movable for example on guides, preferably rectilinear, configured for gripping one building drum 202 at a time and/or one carcass sleeve being processed 204 at a time and moving it preferably along a single axis, [0156] at least one support, possibly translating and/or rotating, configured for receiving and possibly moving one building drum 202 at a time, preferably with rotation axis vertically oriented, and/or one carcass sleeve being processed 204 at a time.

[0157] One or more transfer devices, preferably one or more anthropomorphic robots and/or one or more shuttles, can be configured for imparting a building motion to the building drum 202. The building motion is for example a rotary motion of the building drum 202 around the axis thereof and/or an axial translation motion.

[0158] For building the carcass sleeve being processed 204, the first stage building line 200 comprises a plurality of first stage work stations arranged along the first stage operating section 205. The first stage work stations are operatively connected to each other by means of at least one part of the transfer devices.

[0159] Each first stage work station is configured for building a component of a carcass sleeve, or at least one part thereof, on a respective building drum 202.

[0160] The first stage building line 200 can for example comprise the following first stage work stations, listed according to an operating sequence with which the carcass sleeve being processed 204 can be built: [0161] a work station 206a configured for the application of the liner (optional); [0162] a work station 206b configured for the application of the under-liner (optional); [0163] a work station 206c configured for the application of a carcass ply, said carcass ply able to comprise under-belt inserts associated therewith; [0164] a work station 206d configured for the application of metallic and/or textile reinforcements (optional); [0165] a work station 206e configured for the application of sidewall inserts; [0166] a work station 206f configured for building the beads; [0167] a work station 206g configured for the application of anti-abrasive inserts (optional); [0168] a work station 206h configured for the application of at least one portion of the sidewalls, corresponding to at least the radially inner portion of the sidewalls of the tyre.

[0169] Other different stations can be provided in addition or in substitution, for example a work station can be present that is configured for building a self-sealing layer, or the work stations configured for the application of the liner and of the under-liner can be substituted by a work station configured for the application of the so-called complex or liner-complex, comprising liner, under-liner and anti-abrasive insert.

[0170] In addition to the work station 206c configured for the application of a carcass ply and to the work station 206f configured for building the beads, at least one of the first stage work stations listed above as optional may possibly be provided. Each first stage work station can be repeated one or more times. For example, two work stations 206c can be provided, as illustrated in FIG. 1, each configured for the application of a carcass ply.

[0171] The first stage work stations can be arranged according to a spatial sequence equal to or different from the operating sequence with which the carcass sleeve being processed 204 is built.

[0172] A first part of components of the carcass sleeve being processed 204 comprises at least one carcass ply and preferably also one or more from among liner, under-liner, metallic and/or textile reinforcements, under-belt inserts, sidewall inserts, self-sealing layer, anti-abrasive insert.

[0173] Preferably the first part of components of the carcass sleeve being processed 204 comprises the so-called “braced” components, i.e. made of elastomeric material reinforced with cords made of textile and/or metallic and/or hybrid material.

[0174] The first part of components is built along a first portion 205a of the first stage operating section 205. In other words, at least work station/stations 206c configured for the application of a carcass ply is/are arranged along the first portion 205a of the first stage operating section 205. Preferably all the first stage work stations—provided that, according to the operating sequence with which the carcass sleeve being processed 204 is built, they precede work station 206f configured for building the beads—are arranged along the first portion 205a of the first stage operating section 205.

[0175] Such work stations 206a, 206b, 206c, 206d and 206e are preferably sequentially arranged between two ends of the first portion 205a of the first stage operating section 205.

[0176] Preferably, the first portion 205a of the first stage operating section 205 is substantially rectilinear.

[0177] Each building drum 202 can be moved between the work stations of the first portion 205a of the first stage operating section 205 in a sequence equal to or different from the spatial sequence of such work stations.

[0178] Along the first portion 205a of the first stage operating section 205, the building of the first part of components of the carcass sleeve being processed 204 is preferably carried out with the building drum 202 associated with a pair of axially opposite support rings (not shown).

[0179] The first stage work stations arranged along the first portion 205a of the first stage operating section 205 are arranged to form, on each building drum 202, the first part of components of the carcass sleeve being processed 204, according to predefined manufacturing instructions. In particular each building drum 202 is preferably moved between the first stage work stations arranged along the first portion 205a of the first stage operating section 205 according to a sequence defined by the reference specifications that can be programmed/configured for each carcass sleeve being processed.

[0180] The first stage building line 200 comprises at least one transfer device 207, e.g. a shuttle, dedicated to the first portion 205a of the first stage operating section 205 in order to move each building drum 202, preferably associated with the pair of support rings, between one or more of the work stations of the first portion 205a. Preferably the transfer device 207 is configured for supporting each building drum 202 and for imparting a building motion (rotary motion and/or axial translation motion) thereto.

[0181] Preferably the transfer device 207 is configured for moving one of the N building drums 202 at a time along the first portion 205a of the first stage operating section 205.

[0182] The transfer device 207 is for example attained by means of a shuttle capable of being moved—moved by a suitable motor —preferably along guides 208 (preferably rectilinear) in two opposite travel directions, and of imparting a building motion (rotary motion and/or axial translation motion) to the building drum 202.

[0183] Preferably first stage work station/stations arranged along the first portion 205a of the first stage operating section 205 comprises/comprise a semi-finished product dispensing device 209. First stage work station/stations arranged along the first portion 205a of the first stage operating section 205 is/are arranged to form the first part of components of the carcass sleeve being processed 204 by depositing semi-finished products.

[0184] Such semi-finished products are preferably made of elastomeric material reinforced with cords made of textile and/or metallic and/or hybrid material. Such cords are preferably arranged parallel to each other and oriented with a certain angle with respect to the longitudinal extension of the semi-finished product.

[0185] Preferably the first stage building line 200 comprises a transfer device 210 operatively interposed between the first portion 205a of the first stage operating section 205 and the work station 206f configured for building the beads. The work station 206f configured for building the beads is arranged between the first portion 205a and a second portion 205b of the first stage operating section 205.

[0186] Preferably the transfer device 210 is configured for transferring sequentially, one at a time, the N building drums 202 exiting from the first portion 205a of the first stage operating section 205 to the work station 206f. In addition, such transfer device is preferably configured for separating each building drum 202 from the pair of support rings.

[0187] The transfer device 210 can comprise a rotating support configured for cooperating with the transfer device 207 in order to separate each building drum 202 from the pair of support rings. In addition the transfer device 210 can comprise a translating support and/or an anthropomorphic robot for transferring each building drum 202 from the rotating support to the work station 206f.

[0188] In the work station 206f and along the second portion 205b of the first stage operating section 205, the building drum 202 is separated from the pair of support rings.

[0189] The work station 206f configured for building the beads is adapted to sequentially carry out, on one of the N building drums at a time, the engagement of axially opposite ends of the carcass structure being processed with respective annular anchoring structures.

[0190] Preferably the first stage building line 200 comprises a transfer device 211 operatively interposed between the work station 206f configured for building the beads and the second portion 205b of the first stage operating section 205. The transfer device 211 is configured for transferring sequentially, one at a time, the N building drums 202 exiting from the work station 206f to the second portion 205b of the first stage operating section 205. The transfer device 211 can comprise an anthropomorphic robot or a Cartesian handling device and/or a possibly translating support.

[0191] A second part of components of the carcass sleeve being processed 204 comprises at least one from between anti-abrasive inserts and at least one portion of sidewalls, in such case at least the radially inner portion of sidewalls of the tyre. Preferably the second part of components of the carcass sleeve being processed 204 comprises the non-“braced” components, i.e. only made of elastomeric material.

[0192] The second part of components is built along the second portion 205b of the first stage operating section 205. In other words, at least one between the work station 206g configured for the application of anti-abrasive inserts and the work station 206h configured for the application of at least one portion of the sidewalls is arranged along the second portion 205b of the first stage operating section 205. Preferably all the work stations 206g-206h—which according to the operating sequence with which the carcass sleeve being processed 204 is built, follow the work station 206f configured for building the beads—are arranged along the second portion 205b of the first stage operating section 205.

[0193] The N building drums which progressively exit from the work station 206f are moved along the second portion 205b of the first stage operating section 205.

[0194] Each building drum 202 can be moved between the work stations of the second portion 205b of the first stage operating section 205 in a sequence equal to or different from the spatial sequence of such work stations.

[0195] The first stage work stations arranged along the second portion 205b of the first stage operating section 205 are arranged to form, on each building drum 202, the second part of components of the carcass sleeve being processed 204, according to predefined manufacturing instructions. In particular each building drum 202 is preferably moved between the first stage work stations arranged along the second portion 205b of the first stage operating section 205 according to a sequence defined by the reference specifications that can be programmed/configured for each carcass sleeve being processed.

[0196] Preferably first stage work station/stations arranged along the second portion 205b of the first stage operating section 205 comprises/comprise a device for dispensing a continuous elongated element 212, preferably an extruder. First stage work station/stations arranged along the second portion 205b of the first stage operating section 205 is/are arranged to form the second part of components of the carcass sleeve being processed 204 by spiraling. Preferably, at least one first stage work station arranged along the second portion 205b of the first stage operating section 205 is provided with two or more devices for dispensing a continuous elongated element 212 so as to allow selecting the type of continuous elongated element to be dispensed, depending on the predefined manufacturing instructions for the carcass sleeve being processed.

[0197] The continuous elongated element 212, in the example illustrated in FIG. 1, is only made of elastomeric material.

[0198] Preferably the first stage building line 200 comprises a plurality of transfer devices 213a, 213b and 213c for moving the N building drums 202 between the work stations of the second portion 205b of the first stage operating section 205 and 214a, 214b and 214c dedicated to the final part of the second portion 205b and of the first stage operating section 205.

[0199] One or more transfer devices 213a, 213b are configured both for moving the building drums 202 along the second portion 205b of the first stage operating section 205, and for supporting them during the spiraling of the continuous elongated element thereon and for imparting a building motion (rotary motion and axial translation motion) to the building drums 202. In particular two transfer devices 213a, 213b are provided for, respectively associated with the work station 206g configured for the application of anti-abrasive inserts and with the work station 206h configured for the application of at least one portion of the sidewalls.

[0200] For example, each transfer device 213a, 213b, is made by means of an anthropomorphic robot, preferably with a robotic arm with at least 6 movement axes.

[0201] One or more transfer devices 214a, 214b and 214c are used only in the movement of the building drums 202 along the final part of the second portion 205b of the first stage operating section 205. Preferably, such transfer devices comprise a translating support 214a and/or a Cartesian handling device 214b and/or a fixed or rotating support 214c.

[0202] According to one possible embodiment, illustrated in the figures, the first stage operating section 205 terminates outside the shaping machine 500, for example at the transfer device 214c made by means of a rotating support which supports the building drum 202 while the carcass sleeve being processed 204 is separated therefrom and moved away along the open first-stage path 203 by means of a transfer device 215, for example a Cartesian handling device.

[0203] A transfer device 216, for example a shuttle or a translating support, closes the closed first-stage path 201, bringing back to an initial position the building drum 202, uncoupled from the carcass sleeve being processed. Before again starting a production cycle, the building drum 202 is newly associated with the corresponding support rings.

[0204] The open first-stage path 203 comprises a final section 203a arranged within the shaping machine 500 and ending at the gripping ring 400.

[0205] The second stage building line 300 defines a closed second-stage path 301 for moving a plurality of auxiliary drums 302 and an open second-stage path 303 for building and moving outer sleeves being processed 304. Except for possible size changes, the auxiliary drums 302 are continuously moved along the closed second-stage path 301, providing support to respective outer sleeves being processed 304.

[0206] The closed second-stage path 301 starts and finishes at a same position.

[0207] The open second-stage path 303 starts in the position in which, on a respective auxiliary drum 302, a first component of an outer sleeve being processed 304 is built, or a first part thereof is built, and terminates at the gripping ring 400.

[0208] In a normal operating condition of the plant, M auxiliary drums 302 (simultaneously for M>1) are moved along the closed second-stage path 301 and M outer sleeves being processed 304 (simultaneously for M>1) are moved along the open second-stage path 303.

[0209] M is an integer greater than or equal to 1, preferably greater than or equal to 5 and still more preferably equal to 6. In a preferred embodiment, considered in the following description, N=M>1.

[0210] Preferably, the auxiliary drums 302 have a geometry variable from cylindrical to slightly convex.

[0211] The closed second-stage path 301 and the open second-stage path 303 have a second stage operating section 305 in common. Along the second stage operating section 305, each outer sleeve being processed 304 is built and moved, associated with a respective auxiliary drum 302. In other words, the second stage operating section 305 starts in the position in which, on a respective auxiliary drum 302, a first component of an outer sleeve being processed 304 is built, or a first part thereof is built, and terminates in the position in which the outer sleeve being processed 304 is separated from the respective auxiliary drum 302 or at the gripping ring 400 where the outer sleeve being processed is assembled with a respective carcass sleeve being processed.

[0212] The second stage building line 300 comprises one or more transfer devices for moving the auxiliary drums 302 along the closed second-stage path 301 and/or the outer sleeves being processed 304 along the open second-stage path 303.

[0213] A transfer device can for example comprise one or more from among: [0214] a non-anthropomorphic Cartesian handling device, preferably with at least four, more preferably five degrees of freedom, configured for gripping one auxiliary drum 302 at a time and/or one outer sleeve being processed 304 at a time and moving it preferably along three Cartesian axes and in rotation around at least one, preferably two of said Cartesian axes, or [0215] an anthropomorphic robot preferably with a robotic arm with at least 6 movement axes, configured for gripping and moving one auxiliary drum 302 at a time and/or one outer sleeve being processed 304 at a time, [0216] a shuttle that is movable for example on guides, preferably rectilinear, configured for gripping one auxiliary drum 302 at a time and/or one outer sleeve being processed 304 at a time and preferably moving it along a single axis, [0217] a support, possibly translating and/or rotating, configured for receiving and possibly moving one auxiliary drum 302 at a time, preferably with vertically oriented rotation axis, and/or one outer sleeve being processed 304 at a time.

[0218] One or more transfer devices, preferably one or more anthropomorphic robots and/or one or more shuttles, can be configured for imparting a building motion to the auxiliary drum 302. The building motion is for example a rotary motion of the auxiliary drum 302 around the axis thereof and/or an axial translation motion.

[0219] For building the outer sleeve being processed 304, the second stage building line 300 comprises a plurality of second stage work stations arranged along the second stage operating section 305. The second stage work stations are operatively connected to each other by means of at least one part of the transfer devices.

[0220] Each second stage work station is configured for building a component of an outer sleeve, or at least one part thereof, on a respective auxiliary drum 302.

[0221] The second stage building line 300 can for example comprise the following second stage work stations, listed according to an operating sequence with which the outer sleeve being processed 304 can be built: [0222] a work station 306a configured for the application of under-belt inserts (optional); [0223] a work station 306b configured for the application of a belt layer; [0224] a work station 306c configured for the application of a reinforcement layer (belt layer at 0 degrees—optional); [0225] a work station 306d configured for the application of an underlayer (optional); [0226] a work station 306e configured for the application of a tread band; [0227] a work station 306f configured for the application of at least one portion of sidewalls, corresponding to at least the radially outer portion of the sidewalls of the tyre.

[0228] In addition to the work station 306b configured for the application of a belt layer and to the work station 306e configured for the application of tread band, at least one of the second stage work stations listed above as optional may possibly be provided. Each second stage work station can be repeated one or more times. For example, two work stations 306b can be provided, as illustrated in FIG. 1, each configured for the application of a belt layer.

[0229] The second stage work stations can be arranged according to a spatial sequence equal to or different from the operating sequence with which the outer sleeve being processed 304 can be built.

[0230] A first part of components of the outer sleeve being processed 304 comprises at least one belt layer, preferably two and preferably also a reinforcement layer (belt layer at 0 degrees).

[0231] Preferably the first part of components of the outer sleeve being processed 304 comprises the so-called “braced” components, i.e. made of elastomeric material reinforced with cords made of textile and/or metallic and/or hybrid material.

[0232] The first part of components is built along a first portion 305a of the second stage operating section 305. In other words, at least work station/stations 6b configured for the application of a belt layer is/are arranged along the first portion 305a of the second stage operating section 305. Preferably all the second stage work stations—provided that, according to the operating sequence with which the outer sleeve being processed 304 can be built, they precede the work station 306d configured for the application of an underlayer or the work station 306e configured for the application of the tread band—are arranged along the first portion 305a of the second stage operating section 305.

[0233] Such work stations 306a,306b and 306c are preferably arranged sequentially between two ends of the first portion 305a of the second stage operating section 305.

[0234] Preferably, the first portion 305a of the second stage operating section 305 is substantially rectilinear.

[0235] Each auxiliary drum 302 can be moved between the work stations of the first portion 305a of the second stage operating section 305 in a sequence equal to or different from the spatial sequence of such work stations.

[0236] The second stage work stations arranged along the first portion 305a of the second stage operating section 305 are arranged to form, on each auxiliary drum 302, the first part of components of the outer sleeve being processed 304, according to predefined manufacturing instructions. In particular each auxiliary drum 302 is preferably moved between the second stage work stations arranged along the first portion 305a of the second stage operating section 305 according to a sequence defined by the reference specifications that can be programmed/configured for each outer sleeve being processed.

[0237] The second stage building line 300 comprises at least one transfer device 307, e.g. a shuttle, dedicated to the first portion 305a of the second stage operating section 305 in order to move each auxiliary drum 302 between one or more of the work stations of the first portion 305a. Preferably the transfer device 307 is configured for supporting each auxiliary drum 302 and for imparting a building motion thereto (rotary motion and/or axial translation motion).

[0238] Preferably the transfer device 307 is configured for moving one of the M auxiliary drums 302 at a time along the first portion 305a of the second stage operating section 305.

[0239] The transfer device 307 is for example attained by means of a shuttle capable of being moved—moved by a suitable motor, along suitable guides 308 (preferably rectilinear) in two opposite travel directions, and of imparting a building motion (rotary motion and/or axial translation motion) to the auxiliary drum 302.

[0240] Preferably second stage work station/stations arranged along the first portion 305a of the second stage operating section 305 comprises/comprise a semi-finished product dispensing device 309. Second stage work station/stations arranged along the first portion 305a of the second stage operating section 305 is/are arranged to form the first part of components of the outer sleeve being processed 304 by depositing semi-finished products. The only exception is the work station 306c configured for the application of a reinforcement layer (belt layer at 0 degrees) which generally operates by spiraling a rubber-covered cord or more preferably a rubber-covered “strip-like element” comprising multiple rubber-covered cords, in substance a continuous elongated element “braced” with at least two cords.

[0241] The aforesaid semi-finished products are preferably made of elastomeric material reinforced with cords made of textile and/or metallic and/or hybrid material. Such cords are preferably arranged parallel to each other and oriented with a certain angle with respect to the longitudinal extension of the semi-finished product.

[0242] Preferably the second stage building line 300 comprises a transfer device 310a, 310b and 310c, operatively interposed between the first portion 305a of the second stage operating section 305 and a second portion 305b of the second stage operating section 305.

[0243] Preferably the transfer device 310a, 310b and 310c, is configured for transferring sequentially, one at a time, the M auxiliary drums 302 exiting from the first portion 305a of the second stage operating section 305 to the second portion 305b of the second stage operating section 305.

[0244] The transfer device 310a, 310b and 310c can comprise a rotating support 310a configured for cooperating with the transfer device 307, a Cartesian handling device 310b and/or a translating support 310c.

[0245] A second part of components of the outer sleeve being processed 304 comprises at least the tread band, preferably also at least one portion of sidewalls, in such case at least the radially outer portion of sidewalls of the tyre, and/or an underlayer. Preferably the second part of components of the outer sleeve being processed 304 comprises the non-“braced” components, i.e. only made of elastomeric material.

[0246] The second part of components is built along the second portion 305b of the second stage operating section 305. In other words, at least the work station 306e configured for the application of the tread band and preferably also the work station 306d configured for the application of an underlayer and/or the work station 306f configured for the application of at least one portion of sidewalls is arranged along the second portion 305b of the second stage operating section 305.

[0247] The M building drums which progressively exit from the first portion 305a of the second stage operating section 305 are moved along the second portion 305b of the second stage operating section 305.

[0248] Each auxiliary drum 302 can be moved between the work stations of the second portion 305b of the second stage operating section 305 in a sequence equal to or different from the spatial sequence of such work stations.

[0249] The second stage work stations arranged along the second portion 305b of the second stage operating section 305 are arranged to form, on each auxiliary drum 302, the second part of components of the outer sleeve being processed 304, according to predefined manufacturing instructions. In particular each auxiliary drum 302 is preferably moved between the second stage work stations arranged along the second portion 305b of the second stage operating section 305 according to a sequence defined by the reference specifications that can be programmed/configured for each outer sleeve being processed.

[0250] Preferably second stage work station/stations arranged along the second portion 305b of the second stage operating section 305 comprises/comprise a device for dispensing a continuous elongated element 312, preferably an extruder. Second stage work station/stations arranged along the second portion 305b of the second stage operating section 305 is/are arranged to form the second part of components of the outer sleeve being processed 304 by spiraling. Preferably, at least one second stage work station arranged along the second portion 305b of the second stage operating section 305 is provided with two or more devices for dispensing a continuous elongated element 312 so as to allow selecting the type of continuous elongated element to be dispensed, depending on the predefined manufacturing instructions for the outer sleeve being processed.

[0251] Preferably, the continuous elongated element 312 is only made of elastomeric material.

[0252] More preferably, in the case of co-extrusion, there can be at least two types of material forming the continuous elongated element 312.

[0253] Preferably the second stage building line 300 comprises a plurality of transfer devices 313a, 313b and 313c, in order to move the M building drums 302 between the work stations of the second portion 305b of the second stage operating section 305 and 314a, 314b, dedicated to the final part of the second portion 305b and of the second stage operating section 205.

[0254] One or more transfer devices 313a, 313b and 313c are configured both for moving the auxiliary drums 302 along the second portion 305b of the second stage operating section 305, and for supporting them during the spiraling of the continuous elongated element thereon and for imparting a building motion (rotary motion and axial translation motion) to the auxiliary drums 302. In particular three transfer devices 313a, 313b and 313c are provided, respectively associated with the work station 306d configured for the application of an underlayer, with the work station 306e configured for the application of the tread band and with the work station 306f configured for the application of at least one portion of sidewalls.

[0255] For example, each transfer device 313a, 313b is attained by means of an anthropomorphic robot, preferably with a robotic arm with at least 6 movement axes.

[0256] One or more transfer devices 310b, 314a, 314b are only used in the movement of the auxiliary drums 302 along the second portion 305b of the second stage operating section 305, and/or in the final part of said second stage operating section 305.

[0257] Preferably, such transfer devices 310b, 314a, 314b comprise a translating support 314a and/or a fixed or rotating support 314b and/or a Cartesian handling device, e.g. the Cartesian handling device 310b.

[0258] According to a possible embodiment, illustrated in the figures, the second stage operating section 305 terminates at the gripping ring 400.

[0259] A transfer device, for example the Cartesian handling device 310b and/or the rotating support 310a, closes the closed second-stage path 301, bringing back to an initial position the auxiliary drum 302, uncoupled from the outer sleeve being processed 304.

[0260] The shaping machine 500 comprises a mandrel 501 arranged coaxial with the gripping ring 400 along a shaping axis 502.

[0261] Preferably the shaping machine 500 comprises a rectilinear guide 503 parallel to the shaping axis 502 and the mandrel 501 is axially movable along this in approaching the gripping ring 400 and in being removed from the gripping ring 400. Preferably the gripping ring 400 is arranged at one end of the rectilinear guide 503.

[0262] The gripping ring 400 is adapted to receive a first outer sleeve being processed 304a. A shaping drum 504 of the mandrel 501 is adapted to receive a first carcass sleeve being processed 204a.

[0263] In accordance with a possible embodiment, the mandrel 501 is stably associated with the shaping drum 504 and receives the first carcass sleeve being processed 204a uncoupled from the respective building drum 202. In other words the shaping drum 504 is structurally separated from the building drum 202. In this case, the first stage operating section 205 terminates outside the shaping machine 500.

[0264] Alternatively, the mandrel 501 is configured for receiving a building drum 202 associated with the first carcass sleeve being processed 204a. In this case the building drum 202 is attained as a “single-stage” drum and is adapted to operate as a shaping drum 504 in the shaping machine 500. In this case the first stage operating section 205 continues within the shaping machine 500.

[0265] Reference number 505 indicates a handling device for unloading the green tyre from the shaping machine 500.

[0266] The rolling station 600 for example comprises one or more rolling rollers 601.

[0267] The operation of the plant 100 implements a method for building tyres for vehicle wheels in accordance with the following description.

[0268] The aforesaid method provides for moving N building drums 202 along the closed first-stage path 201 and for moving N carcass sleeves being processed 204 along the open first-stage path 203 which terminates at the gripping ring 400.

[0269] Along the first stage operating section 205, each carcass sleeve being processed 204 is built and moved on a respective building drum 202, starting from the position in which a first component of the carcass sleeve being processed 204 is built, or a first part thereof is built, on the respective building drum 202.

[0270] The first part of components of the carcass sleeve being processed 204 is built by depositing semi-finished products along the first portion 205a of the first stage operating section 205.

[0271] In a position arranged between the first portion 205a and a second portion 205b of the first stage operating section 205, a bead building action is executed by engaging axially opposite ends of a carcass sleeve being processed 204 with respective annular anchoring structures.

[0272] Subsequently the second part of components of the carcass sleeve being processed 204 is built by spiraling a continuous elongated element along the second portion 205b of the first stage operating section 205.

[0273] The aforesaid method also provides for moving M auxiliary drums 302 along the closed second-stage path 301 and for moving M outer sleeves being processed 304 along the open second-stage path 303 which terminates at the gripping ring 400.

[0274] Along the second stage operating section 305, each outer sleeve being processed 304 is built and moved on a respective auxiliary drum 302, starting from the position in which a first component of the outer sleeve being processed 304 is built, or a first part thereof is built, on the respective auxiliary drum 302.

[0275] The first part of components of the outer sleeve being processed 304 is built by depositing semi-finished products along the first portion 305a of the second stage operating section 305.

[0276] Subsequently the second part of components of an outer sleeve being processed 304 is built by spiraling a continuous elongated element along the second portion 305b of the second stage operating section 305.

[0277] At the end of the second stage operating section 305, a first outer sleeve being processed 304a of the M outer sleeves being processed 304 is separated from the respective auxiliary drum 302 and at the end of the open second-stage path 303, the first outer sleeve being processed 304a is held by the gripping ring 400.

[0278] Preferably the first outer sleeve being processed 304a is separated from the respective auxiliary drum 302 by means of the gripping ring 400 so that the second stage operating section 305 terminates at the gripping ring 400. In this case, in order to separate the first outer sleeve being processed 304a from the respective auxiliary drum 302, provision is made for axially moving the auxiliary drum 302 carrying the first outer sleeve being processed 304a and inserting it in the gripping ring 400 at a first access 400a of the gripping ring itself until reaching a radially inner position with respect to the gripping ring 400.

[0279] Subsequently provision is made for holding the first outer sleeve being processed 304a by means of the gripping ring 400 while the auxiliary drum 302 is radially contacted and subsequently axially withdrawn from the first outer sleeve being processed 304a. During the withdrawal, the auxiliary drum 302 free of the first outer sleeve being processed 304a is moved axially according to a sense that is opposite with respect to that with which it was inserted.

[0280] At the end of the open first-stage path 203, a first carcass sleeve being processed 204a of the N carcass sleeves being processed 204 is arranged in a coaxial and radially inner position with respect to the first outer sleeve being processed held by said gripping ring 400.

[0281] In accordance with one possible embodiment, the first carcass sleeve being processed 204a is separated from the respective building drum 202 outside of the shaping machine 500 and fit on the shaping drum 504. In this case, the first stage operating section 205 terminates in the position in which the first carcass sleeve being processed 204a is separated from the respective building drum 202. The final section 203a of the open first-stage path 203, ending at the gripping ring 400, is arranged within the shaping machine 500. The first carcass sleeve is moved axially along the final section 203a associated with the shaping drum 504 until it is arranged in a coaxial and radially inner position with respect to the first outer sleeve being processed 304a held by the gripping ring 400.

[0282] In accordance with a different embodiment, in which the building drum 202 is a “single-stage” drum, the first carcass sleeve being processed 204a is inserted in the shaping machine 500 with the respective building drum which thus performs the shaping drum 504 functions. In this case the first stage operating section 205 terminates at the gripping ring 400. The final section 203a of the open first-stage path 203, ending at the gripping ring 400, is arranged within the shaping machine 500. The first carcass sleeve is moved axially along the final section 203a associated with the shaping drum (building drum 202) until it is arranged in a coaxial and radially inner position with respect to the first outer sleeve being processed 304a held by the gripping ring 400.

[0283] In order to arrange the first carcass sleeve being processed 204a in a coaxial and radially inner position with respect to the first outer sleeve being processed 304a, provision is made for axially moving the first carcass sleeve being processed 204a and inserting it in the gripping ring 400 at a second access 400b of the gripping ring itself that is axially opposite with respect to the first access 400a. In particular the first carcass sleeve being processed 204a is moved axially associated with the shaping drum 504 until it is inserted in the gripping ring 400 at the second access 400b.

[0284] The aforesaid method also provides for shaping, within the gripping ring 400, the first carcass sleeve being processed 204a assembling it with the first outer sleeve being processed 304a. Following the insertion of the first carcass sleeve being processed 204a in a coaxial and radially inner position with respect to the first outer sleeve being processed 304a, the gripping ring 1 is adapted to carry out radially outer contrast function during the shaping of the carcass sleeve. In other words, the gripping ring 1 opposes the radial expansion of the first carcass sleeve in its coupling with the first outer sleeve held by the gripping ring itself.

[0285] In this manner, a first green tyre being processed 506 is obtained.

[0286] Preferably provision is made for monitoring the force exerted on the gripping ring 400 by first carcass sleeve being processed 204a and by the first outer sleeve being processed 304a during the shaping of the first carcass sleeve being processed 204a.

[0287] At the end of the shaping, the shaping drum 504 carrying the first green tyre being processed 506 is removed from the gripping ring 400 by moving it along a finishing path 509. On the first green tyre being processed 506 associated with the shaping drum 504, a rolling action in the rolling station 600 is executed, arranged along the finishing path 507.

[0288] The finishing path 507 is arranged inside the shaping machine 500.

[0289] At the end of the rolling, the first green tyre being processed 506 is again arranged at the gripping ring 400. A closed finishing path 507, that starts and ends at the gripping ring 400, thus follows.

[0290] The gripping ring 400 externally grips the first green tyre being processed 506 and holds it while the shaping drum 504 is again moved away. In this manner, the first green tyre being processed 506 is separated from the shaping drum 504 at the end of the finishing path 507. Preferably provision is made for performing a quality check of the first green tyre being processed 506 by means of the gripping ring 400, preferably while the gripping ring 400 grips the first green tyre being processed 506.

[0291] Finally, the first green tyre being processed 506 is removed from the shaping machine 500 and from said gripping ring 400 at the end of the finishing path 507.