Abstract:
An apparatus for manufacturing tyres for vehicle wheels wherein each tyre includes a carcass structure formed starting from at least one carcass ply laid on a forming support extended along a longitudinal axis. The apparatus includes at least one device for positioning at least one annular anchoring structure on at least one end edge of the carcass ply, the positioning device being circumferentially extended around the longitudinal axis of the forming support and axially movable with respect to the forming support between an operating position distal from the forming support and at least one operating position close to the forming support. The apparatus further includes a device for turning up the end edge of the carcass ply around the annular anchoring structure, the turning up device being circumferentially extended about the longitudinal axis of the forming support and axially movable for approaching/moving away to/from the forming support. The positioning device and the turning up device are radially expandable/contractible in a synchronous manner with respect to the longitudinal axis of the forming support and are settable in a plurality of different operating radial positions, each operating radial position being selected based on a respective radial dimension of the tyre to be manufactured.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This is a continuation of U.S. patent application Ser. No. 13/055,144, filed Apr. 13, 2011, which is a national stage entry under 35 U.S.C. §371 of international Application No. PCT/IB2008/001933, filed Jul. 23, 2008. All of the aforementioned applications are incorporated herein by reference in their entirety. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    Field of the Invention 
         [0003]    The present invention relates to an apparatus for manufacturing tyres for vehicle wheels. 
         [0004]    The invention also relates to a process for manufacturing a lot of tyres for vehicle wheels comprising at least two tyres of different radial dimensions. 
         [0005]    Description of the Related Art 
         [0006]    A tyre for vehicle wheel generally comprises a carcass structure comprising at least one carcass ply formed by reinforcing cords embedded in an elastomeric matrix. The carcass ply has end edges respectively engaged with annular anchoring structures. The latter are arranged in the tyre zones usually identified with the name of “beads” and normally consist each of an annular substantially circumferential insert on which at least one filling insert is applied, in a radially outer position thereof. Such annular anchoring structures are commonly identified as “bead cores” and have the task of keeping the tyre well fixed to the anchoring seat specifically provided in the wheel rim, thus preventing, in operation, the radially inner edge (also referred to an an “end edge” herein) of the tyre coining out from such seat. 
         [0007]    At the beads specific reinforcing structures may be provided having the function of improving the torque transmission to the tyre. 
         [0008]    In a radially outer position with respect to the carcass ply, a belt structure comprising one or more belt layers is associated, said belt layers being arranged radially one of top of the other and having textile or metal reinforcing cords with crossed orientation and/or substantially parallel to the direction of circumferential extension of the tyre. 
         [0009]    Between the carcass structure and the belt structure a layer of elastomeric material, known as “under-belt”, can be provided, said layer having the function of making the radially outer surface of the carcass structure as uniform as possible for the subsequent application of the belt structure. 
         [0010]    In a radially outer position with respect to the belt structure a tread band is applied, made from elastomeric material as well. 
         [0011]    Between the tread band and the belt structure a so-called “under-layer” of elastomeric material can be arranged, said layer having properties suitable to ensure a steady union of the tread band itself. 
         [0012]    On the side surfaces of the carcass structure respective sidewalls of elastomeric material are also applied, each one extending from one of the side edges of the tread band up to the respective annular anchoring structure to the beads. 
       SUMMARY OF THE INVENTION 
       [0013]    An apparatus for manufacturing the aforementioned carcass structure typically comprises a forming support extending along a longitudinal axis, wherein the above carcass ply is laid on a device for positioning the bead core on the end edge of the carcass ply and a device for turning up the end edge of the carcass ply about the bead core. 
         [0014]    The device for positioning the bead core essentially comprises a ring structure axially movable towards the forming support for positioning the bead core on the end edge of the carcass ply and away from the forming support for allowing the execution of the subsequent steps of the tyre bead forming process. 
         [0015]    WO 2008/001154 to the same Applicant shows an apparatus wherein the device for turning up the end edge of the carcass ply about the bead core essentially comprises an annularly continuous pressure element axially movable toward/away to/from the forming support. Such pressure element comprises a plurality of arms, each one carrying a respective turning up roller at a free end thereof. The turning up rollers are arranged one next to the other in a circumferential direction and coaxially with respect to the longitudinal axis of the forming support. The rollers are radially movable in a synchronous manner, thus obtaining the radial expansion/contraction of the above pressure element between a contracted position and an expanded position. The combination of the radial movement of the turning up rollers and of the movement of such rollers toward/away to/from the forming support, allows turning up the end edge of the carcass ply around the bead core for making the tyre bead. The turning up device is further provided with means for adjusting the contracted position of the pressure element based on the radial dimension of the tyre to be made. 
         [0016]    The Applicant has noted that a turning up device of the type schematically described above may be used for carrying out the step of turning up the end edge of the carcass ply in the manufacturing of tyres having different radial dimensions. 
         [0017]    However, the Applicant has noted that with a device of the type described above it is possible to carry out the aforementioned turning up step for tyres having at most two or three different and adjacent fittings; in other words, the device described above allows carrying out the turning up step for a number of tyres having radial dimensions that differ by two or three inches only. 
         [0018]    The Applicant has further noted that even using an apparatus of the type described in WO 2008/001154, the manufacturing of tyres of different radial dimensions would nevertheless continue to require the use of a bead core positioning device specifically designed based on the specific radial dimension of the tyre to be manufactured. The Applicant has further found that, if a step of pulling down the end edge of the carcass ply prior to the positioning of the bead core is provided and/or if a step of pulling down the filling insert of the bead core prior to the turning up of the end edge of the carcass ply about the bead core is provided, the manufacturing of tyres of different radial dimensions would require the use of respective devices specifically designed based on the specific radial dimension of the tyre to be manufactured. 
         [0019]    The Applicant has now found that it is possible to manufacture tyres of different radial dimensions using always the same apparatus, making all the devices that are involved in the execution of the various manufacturing steps of the carcass structure, and thus at least the device for positioning the bead cores and the device for turning up the end edge of the carcass ply, radially expandable/contractible with respect to the longitudinal axis of the forming support of the apparatus. 
         [0020]    The Applicant has further found that, if a step of pulling down the end edge of the carcass ply prior to the positioning of the bead core is provided and/or if a step of pulling down the filling insert of the bead core prior to the turning up of the end edge of the carcass ply about the bead core is provided, it is possible to make radially expandable/contractible with respect to the longitudinal axis of the forming support of the apparatus also the devices intended to carry out the above steps, thus also in these cases being able to manufacturing tyres of different radial dimensions with a same apparatus. 
         [0021]    The Applicant has thus found that providing an apparatus for manufacturing tyres wherein the bead core positioning device and the device for turning up the end edge of the carcass ply and, if provided, also the device for pulling down the end edge of the carcass ply and the device for pulling down the filling insert of the bead core, are expandable/contractible in radial direction it is possible to set such devices, and thus the apparatus composed thereby, in a plurality of different operating radial positions, each operating radial position being selected based on the radial dimension of the tyre to be manufactured. 
         [0022]    Throughout the present description and following claims, the terms “radial” and “axial” and the expressions “radially inner/outer” and “axially inner/outer” are used with reference to the radial direction and to the axial direction of the forming support. The terms “circumferential” and “circumferentially” instead, are used referring to the annular extension of the forming support. 
         [0023]    In a first aspect thereof, the present invention therefore relates to an apparatus for manufacturing tyres for vehicle wheels, the tyres comprising a carcass structure formed starting from at least one carcass ply laid on a forming support extended along a longitudinal axis, the apparatus comprising:
       at least one device for positioning at least one annular anchoring structure on at least one end edge of said at least one carcass ply, the positioning device being circumferentially extended around the longitudinal axis of the forming support and axially movable with respect to the forming support between an operating position distal from the forming support and at least one operating position close to the forming support;   at least one device for turning up the end edge of the carcass ply around the annular anchoring structure, the turning up device being circumferentially extended about the longitudinal axis of the forming support and axially movable for approaching/moving away to/from the forming support;
 
wherein the positioning device and the turning up device are radially expandable/contractible in a synchronous manner with respect to the longitudinal axis of the forming support and are settable in a plurality of different operating radial positions, each operating radial position being selected based on a respective radial dimension of the tyre to be manufactured.
       
 
         [0026]    Throughout the present description and in the following claims, the expression: radial dimension of the tyre, indicates the nominal fitting diameter of the rim whereon the tyre is intended to be fitted, such diameter generally being indicated in inches. 
         [0027]    In the present description and following claims, the expression “annular anchoring structure” and the term “bead core” shall often be used without distinction to indicate the same component of the tyre. 
         [0028]    Advantageously, an apparatus of the type described above may be used for manufacturing tyres having different radial dimensions; in fact, such apparatus is settable in a plurality of different operating configurations, each operating configuration being defined by a respective radial position of the devices for positioning the bead core and for turning up the end edge of the carcass ply, such radial position being properly selected based on the specific radial dimension of the tyre to be manufactured. 
         [0029]    Advantageously, the apparatus setup time and costs are thus drastically reduced when passing from the manufacturing of a tyre having a certain radial dimension to the manufacturing of a tyre having a different radial dimension. 
         [0030]    Moreover, advantageously, the apparatus of the present invention allows manufacturing tyres with at least four different and adjacent fittings. 
         [0031]    The apparatus of the present invention can comprise, individually or in a combination, at least one of the following preferred features. 
         [0032]    Preferably, the device for positioning the annular anchoring structure comprises a plurality of positioning members arranged adjacent to one another along a circumferential direction and coaxially to the longitudinal axis of the forming support, said positioning members being radially movable in a synchronous manner with respect to the longitudinal axis of the forming support between a maximum contraction position and a maximum expansion position. 
         [0033]    Advantageously, the synchronous movement in the radial direction of the aforementioned positioning members causes the radial expansion/contraction of the positioning device of the annular anchoring structure and allows setting up the aforementioned device to the radial position defined in the design stage based on the radial dimension of the tyre to be manufactured. 
         [0034]    Preferably, the apparatus of the present invention comprises a device for controlling the radial movement of said positioning members, such control device comprising a sliding guide with a spiral shape whose rotation around the longitudinal axis of the forming support can be controlled and a plurality of sliding runners extending radially with respect to said longitudinal axis, each of said positioning members being slidingly coupled to a respective sliding runner and to said sliding guide with a spiral shape so that a predetermined angular movement of the guide with a spiral shape causes a predetermined radial movement of each positioning member. 
         [0035]    Advantageously, the setup of the device for positioning the annular anchoring structure to the desired radial position is achieved by simply rotating the aforementioned sliding guide with a spiral shape by a predetermined angle. Such rotation in fact causes a predetermined radial movement of the positioning members. 
         [0036]    Preferably, the device for turning up the end edge of the carcass ply comprises a plurality of turning up members arranged adjacent to one another along a circumferential direction and coaxially to the longitudinal axis of the forming support, said turning up members being radially movable in a synchronous manner with respect to the longitudinal axis of the forming support between a maximum contraction position and a maximum expansion position. 
         [0037]    Advantageously, the synchronous movement in the radial direction of the above positioning members carries out the radial expansion/contraction of the device for turning up the end edge of the carcass ply and allows setting up the above device to the radial position defined in the design stage based on the radial dimension of the tyre to be manufactured. 
         [0038]    Preferably, the apparatus of the present invention comprises a device for controlling the radial movement of said turning up members, such control device comprising a sliding guide with a spiral shape whose rotation around the longitudinal axis of the forming support can be controlled and a plurality of sliding runners extending radially with respect to said longitudinal axis, each of said turning up members being slidingly coupled to a respective sliding runner and to said sliding guide with a spiral shape so that a predetermined angular movement of the guide with spiral movement causes a predetermined radial movement of each turning up member. 
         [0039]    Advantageously, the setup of the device for turning up the end edge of the carcass ply to the desired radial position is achieved by simply rotating the above sliding guide with a spiral shape by a predetermined angle. Such rotation in fact causes a predetermined radial movement of the turning up members. 
         [0040]    Preferably, each turning up member comprises a roller associated to a free end of a respective arm, each roller being coupled to the circumferentially consecutive roller by a compression spring. 
         [0041]    Advantageously, the above springs ensure the structural continuity in the circumferential direction of the device for turning up the end edge of the carcass ply. Such springs further ensure the desired concentricity of the assembly consisting of the above turning up members with respect to axis X-X of the forming support upon the variation of the radial position of the rollers during the turning up of the end edge of the carcass ply and the setup of the device for manufacturing tyres having different radial dimensions. 
         [0042]    Preferably, the device for positioning the annular anchoring structure and the device for turning up the end edge of the carcass ply are slidingly mounted on at least one sliding track extended along a direction parallel to the longitudinal axis of the forming support, the turning up device being associated to said at least one sliding track in an axially outer position to the positioning device with respect to the forming support and wherein the arms of the turning up members are axially sliding in radially inner position with respect to the positioning members. 
         [0043]    Advantageously, a configuration of the type described above allows containing the radial and axial dimension of the apparatus, with evident advantages in terms of space economy. 
         [0044]    In a preferred embodiment thereof, the apparatus of the present invention further comprises at least one device for pulling down the end edge of the carcass ply towards the longitudinal axis of the forming support, such pulling down device being circumferentially extended around the longitudinal axis of the forming support and axially movable between an operating position distal from the forming support and an operating position proximal to the forming support, the aforementioned pulling down device being radially expandable/contractible with respect to the longitudinal axis of the forming support synchronously to the positioning device and to the turning up device, the aforementioned pulling down device being further settable in a plurality of different operating radial positions, each operating radial position being selected based on a respective radial dimension of the tyre to be manufactured. 
         [0045]    Advantageously, such device can be used for manufacturing tyres of different radial dimensions. 
         [0046]    Preferably, the radial expansion/contraction of the device for pulling down the end edge of the carcass ply is actuated by the radial expansion/contraction of the positioning device. 
         [0047]    In a preferred embodiment thereof, the above pulling down device comprises a plurality of ply pulling down members arranged adjacent to one another along a circumferential direction and coaxially to the longitudinal axis of the forming support, said ply pulling down members comprising respective arms radially movable with respect to the longitudinal axis of the forming support between a maximum contraction position and a maximum expansion position. Advantageously, the synchronous movement in the radial direction of the arms of the aforementioned ply pulling down members causes the radial expansion/contraction of the device for turning up the end edge of the carcass ply and allows setting up the above device to the radial position defined in the design stage based on the radial dimension of the tyre to be manufactured. 
         [0048]    Preferably, each of the aforementioned ply pulling down members comprises at least two longitudinal finger plates arranged side by side and partially overlapped in a circumferential direction. More preferably, also the circumferentially adjacent finger plates of two circumferentially consecutive ply pulling down members are partially overlapped in the circumferential direction. Advantageously, the partial overlapping of the finger plates allows an even and effective turning up of the end edge of the carcass ply irrespective of the radial position of the pulling down members, and thus irrespective of the radial dimension of the tyre to be manufactured. Preferably, the device for positioning the annular anchoring structure is axially slidable in a radially outer position with respect to said finger plate and, for a predetermined radial position of the device for positioning the annular anchoring structure and the device for pulling down the end edge of the carcass ply, the finger plates are retained by the above positioning device in a radially contracted configuration when such positioning device is radially overlapped to the finger plates, the finger plates taking up a radially expanded configuration when such positioning device is axially moved with respect to the device for pulling down the end edge of the carcass ply so as not to be radially overlapped to the finger plates. 
         [0049]    Advantageously, in the passage from the radially expanded configuration to the radially contracted configuration, the finger plates causes the pulling down of the end edge of the carcass ply. More advantageously, for a predetermined radial position of the device for positioning the annular anchoring structure and the device for pulling down the end edge of the carcass ply, the radial expansion of the finger plates is actuated by the axial movement of the above pulling down device with respect to the device for positioning the annular anchoring structure, while the radial contraction of the finger plates is actuated by the axial movement of the device for positioning the annular anchoring structure with respect to the device for pulling down the end edge of the carcass ply. An advantageous process economy is thus obtained. 
         [0050]    The annular anchoring structure preferably comprises at least one substantially circumferential annular insert and at least one filling insert associated in a radially outer position with respect to the substantially circumferential annular insert, and in a preferred embodiment thereof, the apparatus of the present invention comprises at least one device for pulling down the filling insert end edge of the carcass ply. Preferably, the device for pulling down the filling insert comprises a plurality of filling insert pulling down members, each of such members being supported by a respective positioning member and being axially slidable with respect to said positioning member. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0051]    Further features and advantages of the present invention will appear more clearly from the following detailed description of some preferred embodiments of an apparatus and process according to the present invention, made with reference to the annexed drawings. In such drawings: 
           [0052]      FIG. 1  is a schematic side view of a portion of an apparatus for manufacturing tyres for vehicle wheels according to the present invention; 
           [0053]      FIG. 2  is an enlarged schematic side view of a portion of a bead core positioning device and of a ply pulling down device of the apparatus of  FIG. 1 ; 
           [0054]      FIG. 3  is a schematic perspective view of a portion of the ply pulling down device of the apparatus of  FIG. 1 ; 
           [0055]      FIG. 4  is a schematic front view of an element of the portion of  FIG. 3 ; 
           [0056]      FIG. 5  is an enlarged schematic side view of a portion of a turning up device of the apparatus of  FIG. 1 ; 
           [0057]      FIG. 6  is a schematic front view of a portion of the device of  FIG. 5 ; 
           [0058]      FIG. 7  is a schematic front view of a portion of the bead core positioning device of  FIG. 2  and of the turning up device of  FIG. 5 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0059]    In  FIG. 1 , reference numeral  100  globally indicates a portion of an exemplifying embodiment of an apparatus usable in a process for manufacturing a tyre for vehicle wheels, according to a preferred embodiment of the present invention. 
         [0060]    In particular, apparatus  100  is used in a step of building a carcass structure of the tyre for providing one or more-annular anchoring structures  10  (hereinafter also called bead cores and better shown in  FIG. 2 ) at that region of the carcass structure that will make the tyre bead. Such annular anchoring structures  10  are intended for keeping the tyre well fixed to the anchoring seat specifically provided in the vehicle tyre rim. 
         [0061]    The building of the carcass structure of the tyre comprises the initial step of arranging a carcass ply  2  on a substantially cylindrical forming support  50  so that the opposite end edges  2   a  of the carcass ply project cantilevered from the forming support  50 . Subsequently, each annular anchoring structure  10  is associated to each of the opposite end edges  2   a  of the carcass ply  2 . 
         [0062]    In the embodiment illustrated in the annexed figures, each annular anchoring structure  10  is associated to each end edge  2   a  of the carcass ply  2  at a respective side shoulder  51  of the forming support  50 . 
         [0063]    For simplicity of description, the description of apparatus  100  and of the process carried out thereby shall be made hereinafter with reference to only one of the opposite end edges  2   a  of the carcass ply  2  and to a side shoulder  51  of the forming support  50  (thus, with reference to only one of the opposite tyre beads). In fact, apparatus  100  is symmetrical in axial direction and the description made with reference to one end edge  2   a  and to one side  51  of the forming support  50  also applies with reference to the axially opposite end edge and side of the forming support  50 . 
         [0064]    The forming support  50  is rotatably mounted about an axis of rotation X-X in a totally conventional manner. The structure of the forming support  50  is not described in detail herein since it can be made in any convenient manner by a man skilled in the art. Likewise, the members for supporting and moving the forming support  50  shall not be described as they are totally conventional. 
         [0065]    As illustrated in  FIG. 2 , the annular reinforcing structure  10  comprises at least one substantially circumferential annular insert  11  and at least one filling insert  12  applied in radially outer position thereof. Apparatus  100  comprises a support frame  101  provided with support feet  102 . Opposite first pairs of axial sliding tracks  103   a  (only one track  103   a  being visible in  FIG. 1 ) and opposite second pairs of tracks  103   b  (only one track  103   b  being visible in  FIG. 1 ) parallel to tracks  103   a  are mounted on a base  101   a  of the support frame  101 . 
         [0066]    Apparatus  100  further comprises, at each of the axial ends thereof, a side upright  104  on which three longitudinal screws  105  are mounted arranged at 120° with respect to each other (only two of such screws being visible in  FIG. 1 ). 
         [0067]    Apparatus  100  comprises a device  110  slidable along a direction x parallel to the axis of rotation X-X of the forming support  50 , and thus in the two opposite ways of the direction indicated in  FIGS. 1 and 2  by arrow F, between a distal position with respect to the forming support  50  and a position close to the forming support  50 , so as to approach, or move away from, the forming support  50 . 
         [0068]    Device  110  is intended for supporting the annular anchoring structure  10  and bringing it in contact with the end edge  2   a  of the carcass ply  2 . In particular, device  110  acts on the substantially circumferential annular insert  11  of the annular anchoring structure  10  by supporting and pushing it against shoulder  51  of the forming support  50 . The annular anchoring structure  10  is thus positioned at the desired position on the end edge  2   a  of the carcass ply  2 . Hereinafter in the present description, device  110  shall also be defined as “bead core positioning device”. Device  110  comprises an annular element  115  mounted, by respective runners  116 , to the sliding tracks  103   a.    
         [0069]    In an alternative embodiment of apparatus  100  (not shown), instead of tracks  103   a  and of runners  116 , longitudinal guides extending from the side upright  104  parallel to the longitudinal screws  105  may be provided for allowing the axial sliding of device  110 . Preferably, three longitudinal guides are provided in this case, arranged at 120° with respect to each other, and thus one at each longitudinal screw  105 . The annular element  115  in this case is slidingly coupled to the aforementioned longitudinal guides by respective sliding bushes. 
         [0070]    A plurality of bead core positioning members  118  are mounted on the annular element  115  (one of these is shown in detail in  FIG. 2 ), the positioning members  118  being arranged adjacent to each other in a circumferential direction and coaxially to axis X-X of the forming support  50 . Each bead core positioning member  118  comprises a support portion  111  of the annular anchoring structure  10 , a portion  112  for pushing the annular anchoring structure  10 , arranged in a radially outer position to the support portion  111  and an arm  112   a  integral with respect to the thrust portion  112  and intended for allowing the coupling of the positioning member  118  to the annular element  115 . 
         [0071]    Preferably, the bead core positioning members are at least eight. More preferably, such members are sixteen or twenty-four. 
         [0072]    Arms  112   a  are radially and synchronously movable with respect to axis X-X of the forming support  50 , and thus in the two opposite ways of the direction indicated in  FIGS. 1 and 2  by arrow R. 
         [0073]    The radial synchronous movement of arms  112   a  allows the radial synchronous movement of the positioning members  118  and thus the radial expansion/contraction of the bead core positioning device  110  between a maximum contraction position and a maximum expansion position. Device  110  can thus take on a plurality of different operating setup configurations according to the radial dimension of the tyre to be manufactured, each of such configurations being defined by a corresponding radial operating position of the positioning members  118 . 
         [0074]    Details on the way the radial movement of arms  112   a , and thus the radial expansion/contraction of the bead core positioning device  110  is obtained, shall be given hereinafter in the present description. 
         [0075]    Apparatus  100  further comprises a device  120  for pulling down the end edge  2   a  of the carcass ply  2  towards the axis X-X of the forming support  50 . Such pulling down is required, in the embodiment shown in the annexed drawings, for allowing the bead core positioning device  110  to approach the forming support  50  for positioning the annular anchoring structure  10  at the desired position on the end edge  2   a  of the carcass ply  2 . Hereinafter in the present description, device  120  shall also be defined as “ply pulling down device”. 
         [0076]    As shown in  FIGS. 1 and 2 , device  120  is slidable parallel to axis X-X with respect to the bead core positioning device  110  in the two opposite ways of the direction indicated by arrow G. 
         [0077]    Device  120  comprises an annular element  125  slidingly mounted, by respective runners  126  ( FIG. 1 ), to the sliding tracks  103   b  mounted on the base  101 . If longitudinal guides parallel to longitudinal screws  105  are provided for the axial sliding of the bead core positioning device  110 , also tracks  103   b  and runners  126  (as well as tracks  103   a  and runners  116 ) may be omitted and the annular element  125  may be slidingly coupled to the above longitudinal guides by respective sliding bushes. 
         [0078]    The annular element  125  is further coupled, by respective lead nuts  127 , to the longitudinal screws  105 . Lead nuts  127 , once actuated in rotation, allow the sliding of the annular element  125  along a direction x parallel to the axis X-X of the forming support  50 . 
         [0079]    The annular element  125  is arranged in an axially external position to the annular element  115  of the bead core positioning device  110  with respect to the forming support  50 . Between the annular element  125  and the annular element  115  a pair of pneumatic cylinders  117   a ,  117   b  intended for controlling the relative axial sliding of the annular element  115  with respect to the annular element  125  are provided. 
         [0080]    A plurality of ply pulling down members  128  are mounted on the annular element  125  (one of these is shown in detail in  FIG. 2 ), the pulling down members  128  being arranged adjacent to each other in a circumferential direction and coaxially to the axis X-X of the forming support  50 . Such ply pulling down members  128  comprise respective arms  128   a  radially and synchronously movable with respect to the axis X-X of the forming support  50 , and thus in the two opposite ways of the direction indicated in  FIGS. 1 and 2  by arrow R′. 
         [0081]    The radial synchronous movement of arms  128   a  allows the radial synchronous movement of the ply pulling down members  128  and thus the radial expansion/contraction of the ply pulling down device  120  between a maximum contraction position and a maximum expansion position. Device  120  can thus take on a plurality of different operating setup configurations according to the radial dimension of the tyre to be manufactured, each of such configurations being defined by a corresponding radial operating position of the ply pulling down members  128 . 
         [0082]    As illustrated in  FIGS. 2-4 , each ply pulling down member  128  comprises, at a radially inner portion  128   b  of arms  128   a , a pair of holes  129 . Holes  129  house respective sliding guides  119  extending parallel to the axis X-X of the forming support  50  and integral to the thrust member  112  of a respective bead core positioning member  118  ( FIG. 2 ). 
         [0083]    Each ply pulling down member  128  therefore is slidable on the sliding guides  119  with respect to the bead core positioning member  118  and is radially supported by the respective bead core positioning member  118  to which it is associated, so that the radial movement of arm  128   a  of each ply pulling down member  128  is actuated by the radial movement of arm  112   a  of the respective bead core positioning member  118 . 
         [0084]    A central hole  129   a  is provided between holes  129 , the central hole  129   a  being suitable for housing a sliding guide (not visible in  FIG. 2 ) extending parallel to axis X-X of the forming support  50  between the sliding guides  119  and integral to the support member  111  of a respective bead core positioning member  118 , so as to allow, if desired, the relative axial sliding of the support portion  111  with respect to the thrust portion  112 . Preferably, a compression spring (not shown in  FIG. 2 ) is active between the head  119   a  of the sliding guide  119  and the radially inner portion  128   b  of arm  128   a  which in rest configuration, keeps the support portion  111  in the position shown in  FIG. 2 . 
         [0085]    As illustrated in  FIGS. 3 and 4 , each ply pulling down member  128  comprises a plurality of finger plates  121  (three in the annexed figures, respectively indicated with  121   a ,  121   b  and  121   c ), extending longitudinally at a radially inner surface of the radially inner portion  128   b  of arms  128   a  and partially overlapped in a circumferential direction. In particular, finger plate  121   c  of a ply pulling down member  128  is partially overlapped to finger plate  121   a  of the same member, whereas the central finger plate  121   b  of such member is partially overlapped to the aforementioned finger plates  121   a  and  121   c . In order to do so, finger plate  121   a  has an inclination angle ex greater than the inclination angle β of finger plate  121   c , so as to facilitate the overlapping of finger plate  121   c  on finger plate  121   a  ( FIG. 4 ). 
         [0086]      FIG. 3  also shows how the circumferentially outer finger plates  121  of two circumferentially consecutive ply pulling down members  128  are arranged in such a way as to also be partially overlapped in the circumferential direction. In particular, finger plate  121   c  of a ply pulling down member  128  is partially overlapped to finger plate  121   a  of the circumferentially consecutive ply pulling down member  128 . 
         [0087]    Finger plates  121  are preferably made of elastically bending material and are shaped so that, at rest, as a whole they take on an open corolla-like configuration, that is, a configuration expanded in a radial direction. When stressed in the radial direction, finger plates  121  on the other hand may take on, as a whole, a closed or radially contracted configuration. 
         [0088]    During the relative sliding of the ply pulling down device  120  with respect to the bead core positioning device  110 , finger plates  121  axially slide in the direction x in a position radially internal with respect to the bead core positioning members  118  ( FIG. 2 ). 
         [0089]    In the embodiment shown in the annexed figures, finger plates  121  are kept in the radially contracted configuration thereof by the bead core positioning members  118  of the bead core positioning device  110  when such device is radially overlapped to finger plates  121  ( FIG. 2 ). Finger plates  121  on the other hand, take on the radially expanded configuration when the finger plate pulling down device  120  is axially moved with respect to the bead core positioning device  110  in the direction x and so that the latter is not radially overlapped to finger plates  121 . 
         [0090]    The shape and the position of finger plates  121  is such that they remain partially overlapped in the circumferential direction when they are in the radially expanded configuration thereof. 
         [0091]    Apparatus  100  further comprises a device  130  for pulling down the filling insert  12 , mounted on the bead core positioning device  110  ( FIG. 2 ). 
         [0092]    In the specific embodiment illustrated in  FIG. 2 , device  130  comprises a plurality of filling insert pulling down members  138  each provided with a respective roller  131  (only one whereof is illustrated). Roller  131  is mounted on the top surface of the thrust member  112  of each bead core positioning member  118 . 
         [0093]    In this way, the radial movement of the bead core positioning members  118  causes a corresponding radial movement of rollers  131 , and thus the radial expansion/contraction of device  130 . The aforementioned device  130  can thus be used for pulling down the filling insert  12  of the annular anchoring structure  10  for different radial dimensions of the tyre to be manufactured. 
         [0094]    Rollers  131  are arranged one next to the other in a circumferential direction coaxially with respect to axis X-X of the forming support  50 . 
         [0095]    Each roller is elastically associated to the respective bead core positioning member  118 , as described in patent application PCT/IB2007/003500 to the same Applicant. In particular, each roller  131  is kept pressed, by a special compression spring  132 , against the radially outer surface of the thrust member  112  of the respective bead core positioning member  118 . 
         [0096]    The pulling down of the filling insert  12  on the end edge  2   a  of the carcass ply  2  takes place as a consequence of the rolling of rollers  131  on the radially outer surface of the radially outer annular portion of the respective bead core positioning member  118  and on the side surface  12   a  of the filling insert  12  of the annular anchoring structure  10 , starting from a radially inner annular portion of such side surface  12   a  to continue on a portion of the side surface  12   a  radially outermost with respect to the aforementioned radially inner annular portion. 
         [0097]    Apparatus  100  further comprises a device  140  suitable for turning up the end edge  2   a  of the carcass ply about the annular anchoring structure  10  in order to form a turned up end portion of the carcass ply  2  comprising the annular anchoring structure  10  therein. Hereinafter in the present description, device  140  shall also be defined as “turning up device”. 
         [0098]    Device  140  is slidable parallel to axis X-X with respect to the bead core positioning device  110  and to the ply pulling down device  120  in the two opposite ways of the direction indicated by arrow H in  FIGS. 1 and 5 . 
         [0099]    As shown in  FIG. 1 , device  140  comprises an annular element  145  mounted, by respective runners  146 , to the sliding tracks  103   a  and by respective lead nuts  147  to the longitudinal screws  105 . Lead nuts  147 , once actuated in rotation, allow the sliding of the annular element  145  along direction x parallel to the axis X-X of the forming support  50 . 
         [0100]    If longitudinal guides parallel to longitudinal screws  105  are provided in place of tracks  103   a ,  103   b  and of runners  116 ,  126  for the axial sliding of the bead core positioning device  110  and of the device  120  for pulling down the end edge  2   a  of the carcass ply  2 , the annular element  145  is slidingly coupled to the above longitudinal guides by respective sliding bushes. 
         [0101]    The annular element  145  is arranged in an axially external position to the annular element  125  of device  120  for pulling down the end edge of the carcass ply with respect to the forming support  50 . 
         [0102]    A plurality of turning up members  148  are mounted on the annular element  145  (one of these is shown in detail in  FIG. 5 ), the turning up members  148  being arranged adjacent to each other in a circumferential direction and coaxially to axis X-X of the forming support  50 . 
         [0103]    The number of turning up members  148  is equal to that of the positioning members  118 . 
         [0104]    Each turning up member  148  comprises a respective roller  141  supported by a respective arm  142 . The rollers are arranged adjacent to one another along a circumferential direction and coaxially to axis X-X of the forming support  50 . 
         [0105]    As shown in  FIG. 6 , each roller  141  is associated to the circumferentially consecutive roller  141  by the interposition of a respective compression spring  143 . 
         [0106]    Arms  142  are axially and radially movable in a synchronous manner with respect to the forming support  50  along a path that reproduces the profile of the annular anchoring structure  10  when the filling insert  12  is pull down on the carcass ply  2 . The synchronised radial movement of arms  142  causes the synchronised radial movement of the turning up members  148  and thus, the radial expansion/contraction of the turning up device  140 . 
         [0107]    The radial expansion of device  140 , along with the axial movement of the aforementioned device along the direction x, allows turning up the end edge  2   a  of the carcass ply  2  about the annular anchoring structure  10 , as is described for example in patent application WO2008/001154 to the same Applicant. 
         [0108]    The synchronous radial movement of the arms  142  of the turning up device  140  with respect to the axis X-X of the forming support  50 , and thus in the two opposite ways of the direction indicated in  FIGS. 1 and 2  by arrow “R”, further allows setting up the turning up device  140  to a plurality of different operating configurations according to the radial dimension of the tyre to be manufactured, each of such configurations being defined by a corresponding operating radial position of the arms  142  of the turning up members  148 . 
         [0109]    The radial movement of arms  112   a  of the bead core positioning members  118  takes place synchronously to that of arms  142  of the turning up members  148 . Such movement is obtained by respective control devices  200 ,  300  totally similar. 
         [0110]    Below is a detailed description of the control device  200  of the radial movement of arms  112   a  of the bead core positioning members  118 , referring to  FIGS. 2 and 7 . The control device  300  of the radial movement of arms  142  of the turning up members  148  is totally similar to device  200  and its components are identified in  FIGS. 3 and 7  with reference numbers corresponding to those related to device  200  and increased by 100. The reference numbers of the components of device  300  are shown hereinafter, and in  FIG. 7 , in brackets next to the reference numbers of the components of device  200 . 
         [0111]    Device  200  ( 300 ) comprises a bracket  201  ( 301 ) attached to the axially outer face of the annular element  115  ( 145 ) and intended for supporting a motor reduction unit  202  ( 302 ). 
         [0112]    A pulley  203  ( 303 ) is further mounted on bracket  201  ( 301 ), in axis with the motor reduction unit  202  ( 302 ). Motor reduction unit  202  ( 302 ) controls the rotation of pulley  203  ( 303 ) which, through a belt  204  ( 304 ), imparts a rotation to an annular member  205  ( 305 ) mounted on the axially outer face of the annular element  115  ( 145 ). A spiral guide  206  ( 306 ) shaped according to an Archimedes spiral is formed on the axially inner face of the annular member  205  ( 305 ) ( FIG. 7 ). 
         [0113]    Arm  112   a  ( 142 ) of each member  118  ( 148 ) is slidingly associated to guide  206  ( 306 ) by a respective pin  207  ( 307 ). It should be noted that for clarity reasons, only one arm  112   a  ( 142 ) is shown in  FIG. 7 . Arm  112   a  ( 142 ) of each member  118  ( 148 ) is further rigidly connected to a guide  208  ( 308 ) which is slidingly associated to a respective runner  209  ( 309 ) mounted on the annular element  115  ( 145 ) and arranged according to a radial direction. The rotation of the annular member  205  ( 305 ) by a predetermined angle along the circumferential direction indicated with T in  FIG. 7  therefore causes a corresponding shifting of each arm  112   a  ( 142 ) along the radial direction indicated with R (R″) in  FIG. 7 . The synchronous and centred movement of the bead core positioning members  118  and of the turning up members  148 , and thus the radial expansion/contraction of the bead core positioning device  110  and of the turning up device  140 , are thus obtained. 
         [0114]    In the light of the fact that, as said above, each ply pulling down member  128  and each member  138  for pulling down the filling insert  12  is constrained, in the radial direction, to a respective bead core positioning member  118 , the radial movement of the ply pulling down members  128  and of the members  138  for pulling down the filling insert  12  takes place integrally to the radial movement of the bead core positioning member  118 . 
         [0115]    From the above description it is clear that the possibility of the bead core positioning device  110 , of the ply pulling down device  120 , of the filling insert pulling down device  130  and of the turning up device  140 , of radially expanding/contracting with respect to the forming support  50  allows the use of apparatus  100  of the present invention for manufacturing a plurality of tyres having different radial dimension, in particular tyres with at least four different and adjacent fittings.