Method and station for building a multilayer component for building a green tyre

Abstract

A method for building a multilayer component (7) for building a tyre (2) is implemented in a station (11), wherein a radially outer layer (7a) is arranged and subjected to a shaping to form a multilayer component being processed. Subsequently, a radially inner layer (7b) is arranged and subjected to a shaping executed within the multilayer component being processed until it is incorporated thereto. In the station (11), a building drum (13) has a building surface (14) and a profiler drum (17) comprises a profiler body (18) having a shaping surface (19). The shaping surface (19) has a convex axial profile corresponding to the axial profile of the multilayer component (7). The building surface (14) is openable and closable at an axial middle line zone (M) in order to generate an annular opening (16) adapted to allow the radial passage at least of the profiler body (18).

Description

[0001] "METHOD AND STATION FOR BUILDING A MULTILAYER COMPONENT FOR BUILDING A GREEN TYRE"

[0002] The present invention relates to a method and a station for building a multilayer component for building a green tyre.

[0003] The present invention further relates to a method for building a green tyre.

[0004] A tyre for vehicle wheels generally comprises a carcass structure comprising at least one carcass ply having respectively opposite end flaps engaged with respective annular anchoring structures, integrated in the areas usually identified by the name of "beads", having an inner diameter substantially corresponding to a so- called "fitting diameter" of the tyre on a respective mounting rim.

[0005] The carcass structure is associated with a belt structure which may comprise one or more belt layers, arranged in radial superposition with respect to each other and with respect to the carcass ply, having textile, metallic or hybrid reinforcement cords with crossed orientation and / or substantially parallel to the circumferential development direction of the tyre (at 0 degrees). A tread band is applied in a position radially outer to the belt structure, also made of elastomeric material like other semifinished products making up the tyre.

[0006] Respective sides of elastomeric material may further be applied in an axially outer position on the lateral surfaces of the carcass structure, each extending from one of the lateral edges of the tread band up at the respective annular anchoring structure to the beads. In "tubeless" tyres, an airtight coating layer, usually called "liner", covers the inner surfaces of the tyre. After the building of the green tyre, carried out by assembling respective components, a moulding and vulcanisation treatment is generally carried out in order to determine the structural stabilisation of the tyre through cross-linking of the elastomeric compositions, as well as to impart a desired tread pattern onto the same, where required, and any distinguishing or information graphic signs at the tyre sidewalls.

[0007] The carcass structure and the belt structure may be made separately of each other in respective work stations, to be mutually assembled at a later time.

[0008] More specifically, the manufacture of the carcass structure provides first that the carcass ply or plies are applied on a building drum, to form a so-called "carcass sleeve" substantially cylindrical. The annular anchoring structures to the beads are fitted or formed on the opposite end flaps of the carcass ply or plies, which are then looped back around the annular structures themselves so as to enclose them in a sort of loop.

[0009] A so-called "crown structure" is manufactured on a second drum or auxiliary drum in the shape of an outer sleeve comprising one or more belt layers applied in mutual radial superimposition, and optionally the tread band in a radially outer position to the belt layer(s). The crown structure is then picked up from the auxiliary drum to be coupled to the carcass sleeve. To this end, the crown structure is arranged coaxially around the carcass sleeve, after which the carcass ply or plies is / are shaped according to a toroidal configuration by mutual axial approach of the beads and concurrent introduction of fluid under pressure into the carcass sleeve, so as to cause a radial expansion of the carcass plies up to make them adhere against the inner surface of the crown structure.

[0010] The assembly of the carcass sleeve with the crown structure can be carried out on the same drum used for making the carcass sleeve, in which case it is called "single step building process" or "unistage process".

[0011] Building processes of the so-called "two-step" type are also known, in which a so-called "first-step drum" is first used for making the carcass sleeve, while the assembly between the carcass sleeve and the crown structure is carried out on a so- called "second-step drum" or "shaping drum", on which the carcass sleeve picked up from the first-step drum and then the crown structure picked up from the auxiliary drum are transferred.

[0012] "Tyre" means, unless otherwise specified, a green tyre and / or a moulded and vulcanised tyre.

[0013] The terms "radial" and "axial" and the expressions "radially inner / outer" and "axially inner / outer" are used referring to the radial direction and the axial direction of the tyre, i.e. to a direction perpendicular to the rotation axis of the tyre and a direction parallel to the rotation axis thereof, respectively. A radial plane of the tyre contains the rotation axis thereof.

[0014] The terms "circumferential" and "circumferentially" are instead used to refer to the annular development of the tyre, identifying with this expression the development assumed by the tyre along the rolling direction in operating conditions.

[0015] "Rotation axis" of a green tyre means the axis corresponding to the rotation axis of the vulcanised tyre when mounted in operating conditions on a respective mounting rim. The term "width" means an axial dimension of the tyre or a component thereof. The term "length" refers to a circumferential dimension of a tyre component.

[0016] The term "component" of the tyre means any portion of the tyre capable of performing its own function or part of it.

[0017] The term "multilayer component" of the tyre means a component of the tyre comprising a plurality of layers radially superimposed with respect to a rotation axis of the tyre, wherein said plurality of layers comprises at least one radially outer layer and one radially inner layer and wherein each layer comprises at least one elastomeric material matrix. Preferably, a multilayer component of the tyre may be a set comprising two or more belt layers and in particular it may be a belt structure or, more generally, a multilayer component may be a set comprising two or more layers intended to be part of the green tyre, each selectable for example from: liner, underliner, carcass ply(ies), belt layer(s), belt underlayer, tread band underlayer, tread band, etc.

[0018] The term "multilayer component being processed" means the multilayer component during the building thereof, optionally comprising an increasing number of layers starting from a radially outer layer and excluding the radially inner layer which completes the multilayer component.

[0019] The term "elastomeric material" is used to designate a composition comprising at least one elastomeric polymer and at least one reinforcement filler. Preferably, such composition further comprises additives such as, for example, a cross-linking agent and / or a plasticiser. Due to the presence of the cross- linking agent, such material may be cross-linked by heating, so as to form the final manufactured article.

[0020] The term "semifinished product" means a prefabricated product, i.e. a product manufactured before the production of the tyre and generally outside the building plant. The product is preferably prefabricated at full width, i.e. with its own pre-sized width so as to be equal to the width (measured in an axial direction of the tyre) of the layer of the component that the semifinished product is adapted to form. The semifinished product may be made of elastomeric material only, i.e. comprise only an elastomeric matrix, or it may be reinforced with at least one reinforcement cord made of textile and / or metallic and / or hybrid material.

[0021] The term "carcass sleeve" refers to the carcass structure in a substantially cylindrical shape comprising at least one carcass ply and a pair of annular anchoring structures. In other words, it is the carcass structure at the end of the building thereof into a cylindrical shape and before its shaping into a toroidal shape.

[0022] The term "belt structure" means a set of one or more belt layers, placed in the latter case in radial superimposition with respect to each other, having textile, metallic or hybrid reinforcement cords with crossed orientation and / o substantially parallel to the circumferential development direction of the tyre (at 0 degrees). Tyre for two-wheeled vehicles, in particular motorcycles, means a tyre whose curvature ratio is approximately between about 0.15 and about 0.45.

[0023] Curvature ratio in relation to a tyre (or a portion thereof or a drum) means the ratio of the distance of the radially outer point of the tread band (or of the outer surface of the portion or of the drum) from the line passing by the laterally opposite ends of the tread band itself (or of the outer surface itself of the portion thereof or of the drum), measured on a radial plane of the tyre (or of said portion thereof or of said drum) i.e. on a plane containing the rotation axis thereof (of the same portion thereof or of the drum), to the distance measured along the chord of the tyre (or of a portion thereof or of said drum) between said ends. The Applicant has observed that the building of a green tyre generally involves the building of a multilayer component by superimposed deposition of two or more layers starting from the radially inner layer towards the radially outer layer to form a multilayer cylindrical sleeve.

[0024] The Applicant has also observed that the subsequent shaping of the multilayer component which generally occurs in the building of a green tyre may cause the presence of high stresses. Furthermore, after being subjected to such shaping, the Applicant was able to verify that the multilayer components may exhibit imperfections such as folds and / or misalignment of the edges which are amplified when the nature of the shaping is substantially toroidal.

[0025] The Applicant has verified that these imperfections are due to the stresses that are generated at the interface between two radially adjacent layers due to the mutual adhesion between such layers and to the different expansion between the axially peripheral portions and the axially central portion of the multilayer component which generates differentiated narrowings and widenings in the material.

[0026] If at least one of the layers is reinforced with a series of reinforcement cords arranged parallel to each other or, if the reinforcement cords of one layer are arranged crossed with respect to the reinforcement cords of at least one radially adjacent layer, the Applicant has been able to note an increase of the critical issues listed above, a worsening of the folds, misalignments of the edges and, in addition, if present, a misalignment of the ends of the reinforcement cords.

[0027] The Applicant has verified that such further increase in critical issues is linked, when present, to the reinforcement cords which, during shaping, tend to rotate while remaining incorporated into the elastomeric matrix and that, if arranged crossed between the radially adjacent layers, those associated to a layer tend to rotate in directions opposite to those associated with a radially adjacent layer.

[0028] Finally, the Applicant has further observed that the superimposed building joints of the semifinished product which forms each layer of the multilayer component and any superimposed preparation joints create discontinuities which form points of concentration of the defects listed above.

[0029] The Applicant has also verified that the above emerges particularly clearly, but not exclusively, in the production of tyres with a high curvature ratio, as for example typically verified in tyres for two-wheeled vehicles. In other words, the Applicant has verified that the defects listed above, which affect the effective and constant reproducibility of the footprint area prefigured in the design step, are more relevant precisely in those tyres in which high reliability of the behaviour is required in order to achieve high driving safety.

[0030] With a view to trying to limit the imperfections detected following the shaping of a multilayer component, the Applicant has understood on the one hand the importance of the efforts linked to the interaction between the layers themselves and on the other hand the limited margin for improvement available in focusing attention on the interface between two radially adjacent layers to improve the interaction thereof.

[0031] The Applicant therefore perceived that a different approach to the building of the multilayer component was needed to decouple the layers during shaping.

[0032] The Applicant has finally found that starting from the radially outermost layer, it is possible in particular to shape each layer independently from the others so as to exclude any behaviour linked to the influence brought about by the presence of multiple layers, effectively cancelling out those imperfections due to their interaction.

[0033] According to a first aspect thereof, the present invention relates to a method for building a multilayer component for building a green tyre.

[0034] Preferably, provision is made for arranging a radially outer layer of said multilayer component.

[0035] Preferably, provision is made for to imposing, on said radially outer layer, a shaping adapted to attain a convex axial profile of said radially outer layer, thus obtaining a multilayer component being processed.

[0036] Preferably, provision is made for arranging a radially inner layer of said multilayer component.

[0037] Preferably, imposing, on said radially inner layer, a respective shaping thus obtaining a shaped radially inner layer.

[0038] Preferably, provision is made for incorporating said shaped radially inner layer with the multilayer component being processed, arranging it in a radially inner position with respect thereto, thus completing said multilayer component.

[0039] The Applicant believes that by decoupling the layers of a multilayer component during shaping and starting from the radially outer layer it is possible to avoid interferences due to mutual adhesions between the layers and, if present, to the rotation of the cords, cancelling folds and other imperfections.

[0040] According to a further aspect thereof, the present invention relates to a method for building a green tyre.

[0041] Preferably, provision is made for building a carcass sleeve.

[0042] Preferably, provision is made for building a belt structure by applying a method for building a multilayer component for building a green tyre wherein at least one layer of the multilayer component is a belt layer and said multilayer component is a belt structure.

[0043] Preferably, provision is made for toroidally shaping said carcass sleeve and assembling it to the belt structure, obtaining a tyre being processed.

[0044] Preferably, provision is made for building, on the tyre being processed, at least one additional component to complete the tyre.

[0045] Preferably, said at least one additional component comprises a tread band.

[0046] The Applicant believes that by decoupling the layers of a belt structure it is possible to avoid interferences due to mutual adhesions between the belt layers and, if present, to the rotation of the cords, cancelling folds and other imperfections. Furthermore, the belt layer thus created may be easily used in any method / process and plant for building tyres as it is adapted to be coupled to carcass sleeves irrespective of the building method thereof.

[0047] According to a further aspect thereof, the present invention relates to a station for building a multilayer component for building a green tyre.

[0048] Preferably, a building drum is provided, rotating around a rotation axis and having a radially outer cylindrical surface defining a building surface arranged around the rotation axis.

[0049] Preferably, a profiler drum is provided, arranged within the building drum and coaxial therewith.

[0050] Preferably, said profiler drum is radially expandable and contractable.

[0051] Preferably, said profiler drum comprises a profiler body having a radially outer surface defining a shaping surface arranged around the rotation axis.

[0052] Preferably, said shaping surface has a convex axial profile.

[0053] Preferably, said building surface is openable and closable at an axial middle line zone in order to generate an annular opening adapted to allow the radial passage at least of said profiler body. The Applicant believes that adopting a structurally independent building surface and shaping surface, wherein the first contains the second and opens to allow radial expansion thereof, allows the respective arrangement and shaping steps to be optimised and simplifies the arrangement and shaping of each layer independently of the others.

[0054] In at least one of the aforementioned aspects, the invention further comprises one or more of the following preferred features which are described below.

[0055] Preferably, arranging said radially outer layer and said radially inner layer comprises depositing a semifinished product on a cylindrical building surface that is coaxial with a rotation axis of the tyre.

[0056] The Applicant believes that deposition on a cylindrical surface represents the simplest and most inconvenience-free method among the possible building methods.

[0057] Preferably, before arranging said radially inner layer, provision is made for exerting a radial traction action towards the outside operating at a radially outer surface of the multilayer component being processed.

[0058] Preferably, provision is made for axially translating said multilayer component being processed, retained from the outside, moving it away from the building surface by maintaining it in stand-by during the arrangement of the radially inner layer. Preferably, provision is made for bringing back said multilayer component being processed, retained from the outside, in radial superimposition with respect to said building surface for incorporating said shaped radially inner layer with the multilayer component being processed.

[0059] The Applicant believes that retaining from the outside allows optimising the momentary transfer of the multilayer component being processed so as to favour the arrangement of the radially and internally adjacent layer.

[0060] Preferably, the shaping of the radially outer layer and of the radially inner layer comprises exerting a radial thrust action towards the outside by means of a shaping surface in radial expansion operating against a radially inner surface of the respective layer and having a convex axial profile.

[0061] The Applicant believes that carrying out the shaping by means of a surface operating against a radially inner surface of the respective layer allows the shape and dimensions of the layer to be controlled throughout the shaping while providing uniform support.

[0062] Preferably, provision is made for cancelling said radial thrust action when said radial traction action is exerted, at the end of the shaping of said radially outer layer so as to retain said multilayer component being processed from the outside.

[0063] The Applicant believes that retaining the multilayer component being processed from the outside simplifies the arrangement and shaping of each layer independently of the others.

[0064] Preferably, said radial thrust action is cancelled by radially contracting the shaping surface.

[0065] Preferably, provision is made for cancelling said radial traction action, at the end of the incorporating of said shaped radially inner layer with the multilayer component being processed with formation of the multilayer component, so as to release said multilayer component on said shaping surface and transfer said multilayer component in abutment on said shaping surface.

[0066] The Applicant believes that the transfer of the multilayer component associated with the shaping surface allows deformations to be avoided in the transition between different stations.

[0067] Preferably, provision is made for maintaining said radial traction action and cancelling said radial thrust action, at the end of the incorporating of said shaped radially inner layer with the multilayer component being processed with formation of the multilayer component, so as to retain, said multilayer component from the outside and transfer said multilayer component retained from the outside.

[0068] The Applicant believes that the transfer of the multilayer component retained from the outside allows the steps to be reduced and the structure of the plant to be simplified.

[0069] Preferably, the shaping of said radially outer layer and of said radially inner layer comprises:

[0070] - creating an annular opening centrally with respect to the building surface,

[0071] - radially expanding through said annular opening said shaping surface, structurally separate from said building surface.

[0072] The Applicant believes that providing a structurally independent building surface and shaping surface, wherein the first contains the second and opens to allow radial expansion of the second, allows the respective arrangement and shaping steps to be optimised and simplifies the arrangement and shaping of each layer independently of the others.

[0073] Preferably, the shaping of said radially inner layer is executed at least partly within the multilayer component being processed up to incorporating said shaped radially inner layer with the multilayer component being processed.

[0074] Preferably, before arranging said radially inner layer, provision is made for executing an intermediate sequence comprising arranging a radially intermediate layer, imposing, on said radially intermediate layer, a respective shaping thus obtaining a shaped radially intermediate layer, incorporating said shaped radially intermediate layer with the multilayer component being processed, arranging it in radially inner position with respect thereto. The Applicant believes that the number of layers of the multilayer component may be increased maintaining the approach of decoupling the layers during the shaping and of arranging them individually starting from the radially outer layer. Preferably, arranging said radially intermediate layer comprises depositing a semifinished product on said building surface.

[0075] Preferably, said intermediate sequence comprises, before arranging said radially intermediate layer, exerting a radial traction action towards the outside by operating at a radially outer surface of the multilayer component being processed.

[0076] Preferably, said intermediate sequence comprises axially translating said multilayer component being processed, retained from the outside, moving it away from the building surface, by maintaining it in stand-by during the arrangement of the radially intermediate layer.

[0077] Preferably, said intermediate sequence comprises bringing back said multilayer component being processed, retained from the outside, in radial superimposition with respect to said building surface for incorporating said shaped radially intermediate layer with the multilayer component being processed.

[0078] Preferably, the shaping of the radially intermediate layer comprises exerting a radial thrust action towards the outside by means of said shaping surface in radial expansion operating against a radially inner surface of the radially intermediate layer. Preferably, said intermediate sequence comprises cancelling said radial thrust action when said radial traction action is exerted, at the end of the incorporating of said shaped radially intermediate layer with the multilayer component being processed, so as to retain said multilayer component being processed from the outside.

[0079] Preferably, the shaping of said radially intermediate layer is executed at least partly within the multilayer component being processed up to incorporating said shaped radially intermediate layer with the multilayer component being processed.

[0080] Preferably, said multilayer component comprises two or more radially intermediate layers.

[0081] Preferably, provision is made for executing said intermediate sequence for each radially intermediate layer, before arranging said radially inner layer.

[0082] The Applicant believes that, irrespective of the number of layers, it is possible to repeat the actions relating to the arrangement and shaping so as to implement a versatile and accurate method.

[0083] Preferably, at least one layer of said multilayer component comprises a plurality of cords embedded in said elastomeric material matrix.

[0084] Preferably, said cords are arranged parallel to each other and form an angle with a circumferential direction of the respective layer.

[0085] Preferably, two layers of said multilayer component comprise a plurality of cords embedded in said elastomeric material matrix.

[0086] Preferably, the cords of one of said two layers are arranged crossed with the cords of the other layer.

[0087] The Applicant believes that the method is suitable for any type of layer, whether it is an elastomeric matrix layer or a layer reinforced for example with cords and intended to be associated with other reinforced layers.

[0088] Preferably, at least one layer of the multilayer component is a belt layer and said multilayer component is a belt structure.

[0089] The Applicant believes that the application to the belt structure makes the manufacturing of tyres of various shapes and curvature ratios particularly versatile.

[0090] Preferably, said convex axial profile corresponds to the axial profile of the multilayer component.

[0091] Preferably, said building drum comprises two groups of axially opposite building sectors, directed towards said axial middle line zone and circumferentially distributed around the axis.

[0092] Preferably, said building sectors are axially movable away from and close to the axial middle line zone in order to open and close said annular opening.

[0093] The Applicant believes that arranging a building drum with axially movable sectors allows a compact structure to be obtained, suitable for the arrangement and shaping using structurally distinct surfaces.

[0094] Preferably, said building drum comprises two half-drums relatively movable with respect to each other in an axial direction in order to mutually approach and move away from each other.

[0095] Preferably, each half-drum comprises a slide on which said building sectors are mounted.

[0096] The Applicant believes that using an openable structure of the building drum allows the station to be adapted to various modes of use, for example using the profiler drum as a transfer device for the multilayer component.

[0097] Preferably, said profiler drum is insertable within the building drum and extractable therefrom.

[0098] Preferably, a retention ring is provided comprising a support structure arranged circumferentially around the rotation axis, slidable parallel to the rotation axis and a plurality of grip elements mounted on the support structure and circumferentially distributed around the rotation axis.

[0099] The Applicant believes that the presence of a retention ring allows the multilayer component being processed and optionally the multilayer component to be retained from the outside so as to optimise the management thereof and optionally facilitate the arrangement and shaping of radially and internally adjacent layers.

[0100] Further features and advantages will become more apparent from the detailed description of a preferred but non-exclusive embodiment of a method and a station for building a multilayer component for building a green tyre, according to the present invention.

[0101] Such description is given hereinafter with reference to the accompanying drawings, provided only for illustrative and, therefore, non-limiting purposes, in which:

[0102] - Figures 1-13 schematically illustrate some elements of a station for building a multilayer component for building a green tyre at different moments of execution of a method for building a multilayer component for building a green tyre;

[0103] - Figure 14 schematically illustrates a layout of a plant for building a green tyre in a moment of execution of a method for building a green tyre;

[0104] - Figures 15-17 schematically illustrate some elements of a shaping station of the plant for building a green tyre at different moments of execution of a method for building a green tyre;

[0105] - Figure 18 schematically illustrates a layout of a plant for building a green tyre; - Figure 19 schematically shows a radial half-section of a tyre which may be manufactured according to the present invention.

[0106] With reference to Figure 18, reference numeral 1 generally indicates a plant for building green tyres.

[0107] Plant 1 is designed to manufacture tyres 2 (Figure 19) comprising at least one carcass ply 3 preferably internally coated with a layer of impermeable elastomeric material or so-called liner 4. Two annular anchoring structures 5 comprising each a so-called bead core 5a preferably bearing an elastomeric filler 5b in radially outer position are engaged to respective end flaps 3a of the carcass ply or plies 3. The annular anchoring structures 5 are integrated in the proximity of zones usually identified by the name of "beads" 6, at which the engagement between the tyre 2 with a respective mounting rim (not shown) usually occurs.

[0108] A crown structure comprises at least one belt structure 7 and a tread band 8 circumferentially superimposed on the belt structure 7. The crown structure is circumferentially arranged around the carcass ply(ies) 3.

[0109] The belt structure 7 comprises at least two layers: a radially outer belt layer 7a and a radially inner belt layer 7b. Optionally, one or more further radially intermediate belt layers may be provided between the radially outer belt layer 7a and the radially inner belt layer 7b.

[0110] The belt layers may comprise parallel textile and / or metallic and / or hybrid cords, arranged in an inclined orientation with respect to the circumferential development direction of the green tyre 2 and respectively crossed between belt layers adjacent to each other. The tyre 2 further comprises two sidewalls 9, extending each from the respective bead to a corresponding lateral edge of the tread band 8, applied in laterally opposite positions on the carcass ply(ies) 3.

[0111] The tyre 2 may also comprise further elements depending on the intended use.

[0112] Preferably, it is a tyre for motorcycles or other two-wheeled vehicles having a curvature ratio approximately between about 0.15 and about 0.45.

[0113] The plant 1 (Figure 18) comprises a station for building carcass structures 10 and a station for building belt structures 11.

[0114] The station for building carcass structures 10 is adapted to produce, for example according to known methods, a carcass sleeve 12 (Figures 15-17) having a substantially cylindrical shape. The carcass sleeve 12 includes said at least one carcass ply 3, preferably internally lined by liner 4, and having the respective end flaps 3a engaged, for example through looping back, to the respective annular anchoring structures 5. If necessary, the carcass sleeve 12 may also include sidewalls 9 or first portions of the same, extending each starting from a respective bead 6.

[0115] The station for building belt structures 11 is adapted to produce the belt structure 7 comprising at least the radially outer belt layer 7a and the radially inner belt layer 7b.

[0116] With reference to Figures 1-13, the station for building belt structures 11 comprises a building drum 13 rotating around a rotation axis "X" which, with reference to the tyre, corresponds to a rotation axis of the tyre itself. The building drum 13 is preferably radially expandable and contractable.

[0117] The building drum 13 has a radially outer cylindrical surface, not necessarily continuous, defining a building surface 14 arranged around the rotation axis "X".

[0118] The building drum 13 comprises two half-drums 15 which are movable relative to each other in an axial direction to mutually approach and move away from each other.

[0119] Preferably, each half-drum 15 comprises a slide 15a on which building sectors 15b are mounted circumferentially distributed around the "X" axis and directed towards an axial middle line zone "M" of the building drum 13. For simplicity of illustration, Figures 1-13 show a single building sector 15b for each halfdrum 15. The building sectors 15b are movable axially with respect to the respective slide 15a away from and close to the axial middle line zone "M" of the building drum 13. In the approached position of the two half-drums 15 and the building sectors 15b, the building sectors 15b define the building surface 14.

[0120] The axial distancing of the building sectors 15b from the axial middle line zone "M" of the building drum 13 creates an annular opening 16 (Figures 4-7 and 11-13) arranged centrally with respect to the building surface 14. The mutual distancing of the two half-drums 15, in particular of the two slides 15a, allows access to the area within the building drum 13.

[0121] The station for building belt structures 11 comprises a profiler drum 17. When the two half-drums 15 are moved away from each other, the profiler drum 17 may be inserted within the building drum 13 and mounted coaxial thereto, as shown for example in Figures 1-13, and may be extracted from the building drum 13 and moved away therefrom, as shown for example in Figure 14. Preferably, when mounted within the building drum 13, the profiler drum 17 is supported by the half-drums 15 for example by means of a mandrel / tailstock coupling.

[0122] The profiler drum 17 comprises a profiler body 18 having a radially outer surface, not necessarily continuous, defining a shaping surface 19 arranged around the rotation axis "X". The shaping surface 19 has a convex axial profile corresponding to the axial profile of the belt structure 7 so that the belt structure 7 has a toroidal shape. Belonging to two different drums, the shaping surface 19 is structurally distinct from the building surface 14.

[0123] Preferably, the profiler body 18 comprises profiling sectors 18a circumferentially distributed around a central shaft 20 of the profiler drum 17 and defining the shaping surface 19. For simplicity of illustration, Figures 1-13 show only one profiling sector 18a.

[0124] The profiler drum 17 is radially expandable and contractable between a first operating condition, in which the shaping surface 19 is in a radially contracted condition (for example illustrated in Figures 1 and 2), and a second operating condition, in which the shaping surface 19 is in a radially expanded condition (for example illustrated in Figures 3-7).

[0125] According to a possible embodiment, the sectors 18a of the profiler body 18 are movable, preferably simultaneously, from said first operating condition in which they are close to the central shaft 20, to the second operating condition in which said sectors are moved away from the central shaft. To this end, it may be contemplated that the sectors are carried by respective guiding members 21, preferably telescopically extendable, extending radially from the central shaft 20.

[0126] The profiler drum 17 comprises movement members 22 configured to implement the transition between the two aforementioned operating conditions. According to a possible embodiment, the movement members 22 comprise a screw-nut system 23 operationally interposed between the sectors 18a of the profiler body 18 and the central shaft 20. For example, the screw-nut system 23 comprises a plurality of pairs of control levers 24 associated with respective pairs of control nuts 25 operatively engaged on axially opposed threads 26a, 26b, respectively right-handed and left-handed, of a threaded bar 27 associated with the central shaft 20. According to this example, the rotation of the threaded bar 27 determines an opposing axial movement of the control nuts 25, which corresponds to a radial movement of the sectors 18a of the profiler body 18, towards the first or second operating condition depending on the direction of rotation of the threaded bar 27.

[0127] Preferably, the profiler drum 17, and in particular the shaping surface 19, in the second operating condition has a curvature ratio between about 0.15 and about 0.45, typically suitable for the production of tyres for motorcycles or other two-wheeled vehicles. However, if necessary, curvature ratios of values lower than those indicated above may be used, for example suitable for the production of car or truck tyres.

[0128] With reference to Figure 18, the plant 1 comprises a retention ring 28 associated with the station for building belt structures 11. The retention ring 28 comprises a support structure 29 arranged circumferentially around the rotation axis "X". The support structure 29 is preferably slidably mounted on one or more linear guides 30, to allow the translation of the support structure 29 parallel to the rotation axis "X".

[0129] With reference for example to Figure 1, a plurality of grip elements 31 circumferentially distributed around the rotation axis "X" are mounted on the support structure 29 (schematically represented).

[0130] For simplicity of illustration, Figures 1-13 show only one grip element 31.

[0131] Each of the grip elements 31 is preferably radially movable between a first position in which it is brought closer to the rotation axis "X" (for example illustrated in Figure 7) and a second position in which it is moved away from the rotation axis "X" (for example illustrated in Figure 1).

[0132] The movement of the grip elements 31 may be achieved mechanically (for example by means of a toothed ring nut, a cam system and / or arms) and / or hydraulically.

[0133] With reference to Figure 1, each grip element 31 comprises a body 32 having a retention surface 33 which faces towards the rotation axis "X" and which is associated with a vacuum retention system, for example a suction cup and / or aspirator system. The set of retention surfaces 33 of the grip elements 31 constitutes an overall retention surface of annular shape, not necessarily continuous.

[0134] With reference to Figure 1, the station for building belt structures 11 further comprises a dispensing station 35 suitable for dispensing semifinished products "S". Preferably, the dispensing station 35 comprises at least one conveyor belt 36 configured to transport a semifinished product "S" up to the building drum 13. The station for building belt structures 11 is designed to implement a method for building a multilayer component for building a green tyre according to the present invention. In other words, the station for building belt structures 11 is an example of a station for building a multilayer component 7 for building a tyre 2.

[0135] As defined above, a multilayer component comprises a plurality of layers radially superimposed with respect to a rotation axis of the tyre. The plurality of layers comprises at least one radially outer layer and one radially inner layer. Furthermore, each layer comprises at least one elastomeric material matrix.

[0136] Preferably, at least one layer of the plurality of layers comprises a plurality of cords embedded in the elastomeric material matrix. The cords may be arranged parallel to each other and form an angle with a circumferential direction of the respective layer (and of the tyre).

[0137] Preferably, the plurality of layers comprises two radially adjacent layers in which the cords of one of the two radially adjacent layers are arranged crossed with the cords of the other layer.

[0138] Preferably, the multilayer component is a belt structure 7 and one layer of the multilayer component is a belt layer. In this case, the following terms:

[0139] - "belt structure 7"

[0140] - "radially outer belt layer 7a"

[0141] - "radially inner belt layer 7b"

[0142] - "belt structure being processed 70" correspond, in the generalisation of the method according to the present invention, respectively to the following terms:

[0143] - "multilayer component 7" for building a tyre

[0144] - "radially outer layer 7a" of the multilayer component 7

[0145] - "radially inner layer 7b" of the multilayer component 7

[0146] - "multilayer component being processed 70" and are therefore indicated with their respective reference numerals.

[0147] In the event that at least one further radially intermediate belt layer is provided between the radially outer belt layer 7a and the radially inner belt layer 7b, the term "radially intermediate belt layer" corresponds to the term "radially intermediate layer" of the multilayer component 7.

[0148] According to the above, the method for building a multilayer component 7 for building a green tyre 2 comprises:

[0149] - arranging a radially outer layer 7a of the multilayer component 7 and imposing, on the radially outer layer 7a, a shaping adapted to attain a convex axial profile of the radially outer layer 7a, corresponding to an axial profile of the multilayer component 7, thus obtaining a multilayer component being processed 70,

[0150] - arranging a radially inner layer 7b of the multilayer component 7, imposing a respective shaping on the radially inner layer 7b obtaining a shaped radially inner layer 7b,

[0151] - incorporating the shaped radially inner layer 7b with the multilayer component being processed 70 by arranging it in a position radially internal thereto, thus completing said multilayer component 7.

[0152] The following description of the aforementioned method for building a multilayer component 7 for building a green tyre 2 according to the present invention is provided with reference to the building of the belt structure 7 according to the correspondence of the above terminology.

[0153] The building of the belt structure 7 involves arranging the radially outer belt layer 7a by depositing a semifinished product "S" around the building drum 13 and in particular around the cylindrical building surface 14. In this step, the building drum 13 has the two half-drums 15 and the respective building sectors 15b placed next to each other. The profiler drum 17 is arranged within the building drum 13 and in the first operating condition, in which the shaping surface 19 is in a radially contracted condition.

[0154] With reference to Figure 1, preferably the semifinished product "S" is advanced into the dispensing station 35 by means of the conveyor belt 36 until it reaches the building drum 13. The retention ring 28 is arranged axially staggered with respect to an axial middle line zone "M" of the building drum 13.

[0155] With reference to Figure 2, following the pointing of the semifinished product "S" on the building surface 14 and the rotation of the building drum 13 around the rotation axis "X", the semifinished product "S" is wrapped around the building drum 13 forming the radially outer belt layer 7a in the form of a cylindrical sleeve coaxial with the rotation axis "X". In particular, the semifinished product "S" is deposited centrally between the two half-drums 15 at the axial middle line zone "M" of the building drum 13.

[0156] The radial dimension of the building drum 13 may be set based on the type of tyre to be built. With reference to Figure 3, the profiler drum 17 is slightly expanded radially (arrow Fl) until the profiler body 18 approaches the radially outer belt layer 7a resting on the building surface 14.

[0157] With reference to Figures 4-6, the building of the belt structure 7 involves imposing on the radially outer belt layer 7a a shaping adapted to create a convex axial profile corresponding to the rounded axial profile of the belt layer 7 so that the latter has a toroidal shape. At the end of the shaping, a belt structure being processed 70 is obtained.

[0158] Preferably, the shaping of the radially outer belt layer 7a is carried out by exerting a radial outward thrust action operating against a radially inner surface of the layer itself.

[0159] In particular, with reference to Figure 4, the building sectors 15b of the two half-drums 15 are moved away from each other (arrows F2) starting to form the annular opening 16 arranged centrally on the building surface 14, corresponding to the axial middle line of the building drum 13. The profiler drum 17 is further expanded radially (arrow Fl).

[0160] At the same time, with reference to Figure 5, the profiler drum 17 is further expanded radially (arrow Fl) so that the profiler body 18 engages the radially outer belt layer 7a through the annular opening 16 and exerts a radial thrust action towards the outside (according to the same arrow Fl) operating against a radially inner surface of the radially outer belt layer 7a.

[0161] With reference to Figure 6, the shaping of the radially outer belt layer 7a is complete. The profiler drum 17 is therefore in the second operating condition, in which the shaping surface 19 is in a radially expanded condition. The building sectors 15b have moved further apart axially (arrow F2), widening the annular opening 16. The profiler body 18 has passed through the annular opening 16 and the radially outer belt layer 7a rests completely on the shaping surface 19, exhibiting a convex axial profile corresponding to the axial profile of the belt structure 7 and thus defining the belt structure being processed 70. The retention ring 28 arranged coaxially with the building drum 13 and the profiler drum 17 is positioned centrally around the belt structure being processed 70 (arrow F3) at the axial middle line "M" of the building drum 13.

[0162] With reference to Figures 7-8, it is contemplated to exert a radial traction action towards the outside operating at a radially outer surface of the belt structure being processed 70 and cancel the radial thrust action so as to retain the belt structure being processed 70 from the outside.

[0163] With particular reference to Figure 7, the grip elements 31 are moved towards the rotation axis "X" (arrow F4) so that each retention surface 33 comes into contact with the radially outer surface of the belt structure being processed 70. With reference to Figure 8, the retention system is activated for example by vacuum, so as to exert a radial traction action towards the outside (arrows F5) operating at the radially outer surface of the belt structure being processed 70, which is thus retained by the retention ring 28. The profiler drum 17 is contracted radially (arrow F6) to cancel the radial thrust action. The profiler body 18 is completely retracted into the area within the building drum 13. The building sectors 15b of the two half-drums 15 of the building drum 13 approach each other in the axial direction (arrows F7), closing the annular opening 16 and reconstituting the building surface 14.

[0164] With reference to Figure 9, it is preferably contemplated to axially translate (arrow F8) the retention ring 28 and therefore the belt structure being processed 70, retained from the outside, moving it away from the building surface 14 and from the axial middle line zone "M" of the building drum 13. The grip elements 31 may be moved slightly away from the rotation axis "X". The retention ring 28 which retains the belt structure being processed 70 from the outside remains decentralised with respect to the building surface 14 and the axial middle line zone "M" during the subsequent arrangement of a radially and internally adjacent layer which, in the described example in which the belt structure 7 comprises two layers, corresponds to the radially inner belt layer 7b. In particular, the belt structure being processed 70 retained by the retention ring 28 is axially moved away from the building surface 14 and put in stand-by at least until the shaping of the radially and internally adjacent layer begins.

[0165] Again with reference to Figure 9, the building of the belt structure 7 involves arranging the radially inner belt layer 7b by placing a semifinished product "S" around the building drum 13 while the belt structure being processed 70 is put in stand-by retained by the retention ring 28 in a position axially away from the building surface 14. Preferably, the semifinished product "S" is advanced into the dispensing station 35 by means of the conveyor belt 36 until it reaches the building drum 13.

[0166] With reference to Figure 10, following the pointing of the semifinished product "S" on the building surface 14 and the rotation of the building drum 13 around the rotation axis "X", the semifinished product "S" is wrapped around the building drum 13 forming the radially inner belt layer 7b in the form of a cylindrical sleeve coaxial with the rotation axis "X". The semifinished product "S" is deposited centrally between the two half-drums 15 at the axial middle line zone "M" of the building drum 13.

[0167] The radial dimension of the building drum 13 may be set based on the type of tyre to be built.

[0168] The profiler drum 17 is arranged within the building drum 13 in the first operating condition, in which the shaping surface 19 is in a radially contracted condition.

[0169] With reference to Figures 11-12, the building of the belt structure 7 involves imposing a respective shaping on the radially inner belt layer 7b, obtaining a shaped radially inner belt layer 7b and incorporating the shaped radially inner belt layer 7b with the belt structure being processed 70, placing it in a position radially internal thereto, thus completing the belt structure 7.

[0170] The belt structure being processed 70, retained from the outside by the retention ring 28, may be brought back to the axial middle line zone "M" of the building drum 13, in radial superimposition with respect to the building surface 14, to incorporate the shaped radially inner belt layer with the belt structure being processed 70. Preferably, the belt structure being processed 70, retained from the outside by the retention ring 28, may be brought back to the axial middle line zone "M" of the building drum 13, in radial superimposition with respect to the building surface 14 for at least part of the temporally subsequent shaping which, in the example described corresponds to that of the radially inner belt layer 7b.

[0171] Preferably, the shaping of the radially inner belt layer 7b is carried out by exerting a radial outward thrust action operating against a radially inner surface of the layer itself.

[0172] What has been described with reference to Figures 4-6 and to the radially outer belt layer 7a is repeated for the radially inner belt layer 7b. With particular reference to figure 11, preferably before the radial expansion of the profiler drum 17 and the radially inner belt layer 7b, the retention ring 28 translates axially (arrow F3) returning to the axial middle line zone "M" of the building drum 13 and centrally around the building surface 14 and the radially inner belt layer 7b. The grip elements 31, if previously moved slightly away from the rotation axis "X", are moved again towards the rotation axis "X". The building sectors 15b of the two half-drums 15 are axially moved away from each other (arrows F2) starting to form the annular opening 16 arranged centrally on the building surface 14, corresponding to the axial middle line "M" of the building drum 13. At the same time, the profiler drum 17 is expanded radially (arrow Fl) so that the profiler body 18 engages the radially inner belt layer 7b through the annular opening 16. The radial expansion of the profiler drum 17 (arrow Fl) continues until it completely crosses the annular opening 16 so as to exert a radial thrust action towards the outside against a radially inner surface of the radially inner belt layer 7b. Preferably, the radial expansion of the profiler drum 17 takes place inside the belt structure being processed 70 so that, at the end of the radial expansion, the radially inner belt layer 7b which rests completely on the shaping surface 19 is shaped and incorporated with the belt structure being processed 70 as illustrated in Figure 12, forming the belt structure 7.

[0173] With reference to Figure 13, at the end of the incorporating of the shaped radially inner belt layer 7b with the belt structure being processed 70, preferably at the end of the shaping of the radially inner belt layer 7b with formation of the belt structure 7, the retention for example by vacuum is deactivated, thus cancelling the radial traction action, releasing the belt structure 7 on the profiler drum 17.

[0174] The grip elements 31 are moved towards the second position in which they are moved away from the rotation axis "X" (arrow Fll).

[0175] The half-drums 15 are moved away from each other axially (arrows F12) and are positioned at a relative distance such as to allow complete access to the area within the building drum 13 so that the profiler drum 17 is picked up to continue building the tyre. The belt structure 7 is then transferred in abutment on the shaping surface 19 of the profiler drum 17 (Figure 14).

[0176] Alternatively, according to a possible example not illustrated, at the end of the incorporating of the shaped radially inner belt layer 7b with the belt structure being processed 70, preferably at the end of the shaping of the radially inner belt layer 7b with formation of the belt structure 7, the retention for example by vacuum is kept active, thus maintaining the radial traction action while the radial thrust action is cancelled, so as to retain the belt structure 7 from the outside and transfer it retained from the outside by means of the retention ring 28. The belt structure 7 may further comprise a radially intermediate belt layer. In this case, before arranging the radially inner belt layer 7b, it is contemplated to execute an intermediate sequence comprising arranging the radially intermediate belt layer, imposing a respective shaping on the radially intermediate belt layer, obtaining a shaped radially intermediate belt layer, incorporating the shaped radially intermediate belt layer with the belt structure being processed 70, placing it in a position radially internal thereto. The actions described with reference to Figures 9-12 also apply to the radially intermediate belt layer. The intermediate sequence ends by exerting a radial traction action towards the outside operating at a radially outer surface of the belt structure being processed 70 and cancelling the radial thrust action exerted by the profiler drum 17 so as to retain from the outside the belt structure being processed 70, and translate it axially as described above with reference to Figures 8 and 9.

[0177] If the belt structure includes two or more radially intermediate belt layers, it is contemplated to execute the intermediate sequence for each radially intermediate belt layer, before arranging the radially inner belt layer 7b.

[0178] The plant 1 further comprises a shaping station 37 adapted to receive the carcass sleeve 12 and the belt structure 7 and to shape the carcass sleeve 12 according to a toroidal configuration by coupling it to the belt structure 7.

[0179] With reference to Figure 18, reference numeral 38 indicates carcass loading devices, for example a carcass manipulator having jaws operating on an outer surface of the carcass sleeve 12 and movable between the station for building carcass structures 10 and the shaping station 37. Reference numeral 39 indicates devices for loading belt structures comprising, for example a grip ring 40, for example with sectors operating in a vacuum using suction cups and / or suction systems, movable in and out of the shaping station 37 preferably on axes parallel and perpendicular to a central axis "Y" of the shaping station 37.

[0180] Reference numeral 41 indicates a belt structure transfer device operating between the station for building belt structures 11 and the belt structure loading devices 39, preferably the grip ring 40. The belt structure transfer device 41 may be implemented using a robot 42 adapted to hold and transfer the profiler drum 17 around which a belt structure 7 is arranged.

[0181] Preferably, the shaping station 37 comprises engagement devices 43 of the carcass sleeve 12 and shaping devices 44, upon the action of which the carcass sleeve 12 is shaped according to a toroidal configuration.

[0182] The engagement devices 43 include for example a first flange element 43a and a second flange element 43b, coaxially facing each other and having respective circumferential engagement seats 45a, 45b, whereby they can be operationally engaged each at one of the annular anchoring structures 5 respectively carried by the axially opposite ends of the carcass sleeve 12.

[0183] The shaping devices 44 may for example comprise a fluiddynamic circuit (not shown) to introduce pressurised air or other inflating operating fluid between the flange elements 43a, 43b, within the carcass sleeve 12 and preferably a profiler drum 46 substantially similar to the profiler drum 17, therefore in Figures 15-17 the same elements have been indicated with the same reference numerals. The radially outer surface, not necessarily continuous, of the profiler body 18 of the profiler drum 46, has a shape suitable for the profile to be imposed on the carcass sleeve 12 and therefore on the tyre 2.

[0184] The plant 1 is designed to implement a method for building a green tyre comprising:

[0185] - building the carcass sleeve 12 in the station for building carcass structures 10, for example according to known methods,

[0186] - building the belt structure 7 in the station for building belt structures 11 by applying the method for building a multilayer component for building a green tyre according to the present invention.

[0187] With reference to Figure 15, the carcass sleeve 12 is transferred to the shaping station 37 by means of the carcass loading devices 38. Furthermore, the carcass sleeve 12 is arranged coaxial to the central axis "Y" and retained by the engagement devices 43.

[0188] The belt structure 7 is transferred from the profiler drum 17 to the grip ring 40 and carried together with the grip ring 40 into the shaping station 37, in a position coaxial to the central axis "Y" and axially distant from the carcass 12. The profiler drum 46, if not already present, is inserted in a cantilever way into the shaping station 37. The profiler drum 17 is brought back to the station for building belt structures 11.

[0189] With reference to Figure 16, the shaping station 37 is closed axially and the grip ring 40 is arranged around the carcass sleeve 12.

[0190] With reference to Figure 17, the shaping devices 44 cause the expansion and toroidal shaping of the carcass sleeve 12 which is thus assembled to the belt structure 7, obtaining a tyre being processed 50.

[0191] Subsequently, a tread band 8 and preferably further additional components are built on the tyre being processed 50 to complete the green tyre 2, for example the sidewalls 9.

Claims

CLAIMS1. Method for building a multilayer component (7) for building a green tyre (2), comprising:- arranging a radially outer layer (7a) of said multilayer component (7) and imposing, on said radially outer layer (7a), a shaping adapted to attain a convex axial profile of said radially outer layer (7a), thus obtaining a multilayer component being processed (70),- arranging a radially inner layer (7b) of said multilayer component (7), imposing, on said radially inner layer (7b), a respective shaping thus obtaining a shaped radially inner layer (7b), incorporating said shaped radially inner layer (7b) with the multilayer component being processed (70), arranging it in a radially inner position with respect thereto, thus completing said multilayer component (7).

2. Method for building a multilayer component (7) for building a green tyre (2) according to claim 1, wherein arranging said radially outer layer (7a) and said radially inner layer (7b) comprises depositing a semifinished product (S) on a cylindrical building surface (14) that is coaxial with a rotation axis (X) of the tyre (2).

3. Method for building a multilayer component (7) for building a green tyre (2) according to claim 2, comprising, before arranging said radially inner layer (7b), exerting a radial traction action towards the outside operating at a radially outer surface of the multilayer component being processed (70), axially translating said multilayer component being processed (70), retained fromthe outside, moving it away from the building surface (14) by maintaining it in stand-by during the arrangement of the radially inner layer (7b), and bringing back said multilayer component being processed (70), retained from the outside, in radial superimposition with respect to said building surface (14) for incorporating said shaped radially inner layer (7b) with the multilayer component being processed (70).

4. Method for building a multilayer component (7) for building a green tyre (2) according to one or more of the preceding claims, wherein the shaping of the radially outer layer (7a) and of the radially inner layer (7b) comprises exerting a radial thrust action towards the outside by means of a shaping surface (19) in radial expansion operating against a radially inner surface of the respective layer and having a convex axial profile.

5. Method for building a multilayer component (7) for building a green tyre (2) according to claim 4, when dependent on claim 3, comprising cancelling said radial thrust action when said radial traction action is exerted, at the end of the shaping of said radially outer layer (7a) so as to retain said multilayer component being processed (70) from the outside.

6. Method for building a multilayer component (7) for building a green tyre (2) according to claim 5, wherein said radial thrust action is cancelled by radially contracting the shaping surface (19).

7. Method for building a multilayer component (7) for building agreen tyre (2) according to claim 4, when dependent on claim 3, comprising cancelling said radial traction action, at the end of the incorporating of said shaped radially inner layer (7b) with the multilayer component being processed (70) with formation of the multilayer component (7), so as to release said multilayer component (7) on said shaping surface (19) and transfer said multilayer component (7) in abutment on said shaping surface (19).

8. Method for building a multilayer component (7) for building a green tyre (2) according to claim 4, when dependent on claim 3, comprising maintaining said radial traction action and cancelling said radial thrust action, at the end of the incorporating of said shaped radially inner layer (7b) with the multilayer component being processed (70) with formation of the multilayer component (7), so as to retain said multilayer component (7) from the outside and transfer said multilayer component (7) retained from the outside.

9. Method for building a multilayer component (7) for building a green tyre (2) according to one of the claims from 4 to 6, when dependent on claim 2 or 3, wherein the shaping of said radially outer layer (7a) and of said radially inner layer (7b) comprises:- creating an annular opening (16) centrally with respect to the building surface (14),- radially expanding through said annular opening (16) said shaping surface (19), structurally separate from said building surface (14).

10. Method for building a multilayer component (7) for building a green tyre (2) according to one or more of the preceding claims, wherein the shaping of said radially inner layer (7b) is executed at least partly within the multilayer component being processed (70) up to incorporating said shaped radially inner layer (7b) with the multilayer component being processed (70).

11. Method for building a multilayer component (7) for building a green tyre (2) according to claim 1, comprising, before arranging said radially inner layer (7b), executing an intermediate sequence comprising arranging a radially intermediate layer, imposing, on said radially intermediate layer, a respective shaping thus obtaining a shaped radially intermediate layer, incorporating said shaped radially intermediate layer with the multilayer component being processed (70), arranging it in radially inner position with respect thereto.

12. Method for building a multilayer component (7) for building a green tyre (2) according to claim 11, when dependent on claim 2, wherein arranging said radially intermediate layer comprises depositing a semifinished product (S) on said building surface (14).

13. Method for building a multilayer component (7) for building a green tyre (2) according to claim 12, wherein said intermediate sequence comprises, before arranging said radially intermediate layer, exerting a radial traction action towards the outside by operating at a radially outer surface of the multilayer component being processed (70), axially translating said multilayercomponent being processed (70), retained from outside, moving it away from the building surface (14), by maintaining it in stand-by during the arrangement of the radially intermediate layer, and bringing back said multilayer component being processed (70), retained from outside, in radial superimposition with respect to said building surface (14) for incorporating said shaped radially intermediate layer with the multilayer component being processed (70).

14. Method for building a multilayer component (7) for building a green tyre (2) according to claim 4 and one or more of the claims from 11 to 13, wherein the shaping of the radially intermediate layer comprises exerting a radial thrust action towards the outside by means of said shaping surface (19) in radial expansion operating against a radially inner surface of the radially intermediate layer.

15. Method for building a multilayer component (7) for building a green tyre (2) according to claim 14, when dependent on claim 13, wherein said intermediate sequence comprises cancelling said radial thrust action when said radial traction action is exerted, at the end of the incorporating of said shaped radially intermediate layer with the multilayer component being processed (70), so as to retain said multilayer component being processed (70) from the outside.

16. Method for building a multilayer component (7) for building a green tyre (2) according to claim 15, wherein said radial thrust action is cancelled by radially contracting the shaping surface(19).

17. Method for building a multilayer component (7) for building a green tyre (2) according to one of the claims from 11 to 16, wherein the shaping of said radially intermediate layer is executed at least partly within the multilayer component being processed (70) up to incorporating said shaped radially intermediate layer with the multilayer component being processed (70).

18. Method for building a multilayer component (7) for building a green tyre (2) according to one or more of the claims from 11 to 17, wherein said multilayer component (7) comprises two or more radially intermediate layers and wherein said method comprises executing said intermediate sequence for each radially intermediate layer, before arranging said radially inner layer (7b).

19. Method for building a multilayer component (7) for building a green tyre (2) according to one or more of the preceding claims, wherein at least one layer of said multilayer component comprises a plurality of cords embedded in said elastomeric material matrix.

20. Method for building a multilayer component (7) for building a green tyre (2) according to claim 19, wherein said cords are arranged parallel to each other and form an angle with a circumferential direction of the respective layer.

21. Method for building a multilayer component (7) for building a green tyre (2) according to claim 20, wherein two layers of said multilayer component comprise a plurality of cords embedded in said elastomeric material matrix and wherein the cords of one of said two layers are arranged crossed with the cords of the other layer.

22. Method for building a multilayer component (7) for building a green tyre (2) according to one or more of the preceding claims, wherein at least one layer of the multilayer component (7) is a belt layer (7a, 7b) and said multilayer component is a belt structure (7).

23. Method for building a green tyre (2) comprising : building a carcass sleeve (12), building a belt structure (7) by applying a method according to claim 22, toroidally shaping said carcass sleeve (12) and assembling it to the belt structure (7), obtaining a tyre being processed (50), building, on the tyre being processed (50), at least one additional component to complete the tyre (2), wherein said at least one additional component comprises a tread band (8).

24. Station (11) for building a multilayer component (7) for building a green tyre (2) comprising:- a building drum (13) rotating around a rotation axis (X) and having a radially outer cylindrical surface defining a building surface (14) arranged around the rotation axis (X),- a profiler drum (17) arranged within the building drum (13) and coaxial therewith, wherein said profiler drum (17) is expandable and contractable radially and comprises a profiler body (18) having a radially outer surface defining a shaping surface (19) arranged around the rotation axis (X), said shaping surface (19) having a convex axial profile, wherein said building surface (14) is openable and closable at an axial middle line zone (M) in order to generate an annular opening (16) adapted to allow the radial passage at least of said profiler body (18).

25. Station (11) for building a multilayer component (7) for building a green tyre (2) according to claim 24, wherein said building drum (13) comprises two groups of axially opposite building sectors (15b), directed towards said axial middle line zone (M) and circumferentially distributed around the axis (X), and wherein said building sectors (15b) are axially movable away from and close to the axial middle line zone (M) in order to open and close said annular opening (16).

26. Station (11) for building a multilayer component (7) for building a green tyre (2) according to claim 25, wherein said building drum (13) comprises two half-drums (15) relatively movable with respect to each other in an axial direction in order to mutually approach and move away from each other and wherein each half-drum (15) comprises a slide (15a) on which said building sectors (15b) are mounted.

27. Station (11) for building a multilayer component (7) for building a green tyre (2) according to claim 26, wherein said profiler drum (17) is insertable within the building drum (13) and extractable therefrom.

28. Station (11) for building a multilayer component (7) for building a green tyre (2) according to one of the claims from 24 to 27, comprising a retention ring (28) comprising a support structure (29) arranged circumferentially around the rotation axis (X), slidable parallel to the rotation axis (X) and a plurality of grip elements (31) mounted on the support structure (29) and circumferentially distributed around the rotation axis (X).

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