Patent Publication Number: US-2017368776-A1

Title: Process and apparatus for looping anchoring annular structures in a process for building tyres for vehicle wheels

Description:
The present invention relates to a process and an apparatus for looping anchoring annular structures, in particular in a process for building tyres for vehicle wheels. 
     The process and the drum of the invention are preferably used in building tyres for automobiles, more particularly in building the carcass structures of such tyres. 
     Hereinbelow, with the term “loop” it is intended to indicate an annular element comprising one or more threadlike reinforcement elements that are substantially parallel to each other, such as textile or metallic cords, possibly incorporated in, or covered with, a layer of elastomeric material, such annular element being obtained by cutting to size a belt-like element and mutually joining a head portion and an end portion of such belt-like element. 
     With the term “elastomeric material” it is intended to indicate a composition comprising at least one elastomeric polymer and at least one reinforcement filler. Preferably, such composition also comprises additives such as a cross-linking agent and/or a plasticiser agent. Due to the presence of the cross-linking agent, such material can be cross-linked by means of heating, so as to form the final manufactured product. 
     The terms “radial” and “axial” and the expressions “radially inner/outer” and “axially inner/outer” are used with reference to the radial direction and the axial direction of a tyre or of a drum used for the looping of the anchoring annular structures of tyres. The terms “circumferential” and “circumferentially” are instead used with reference to the annular extension of the aforesaid tyre/drum. 
     With the term configuration of an element, it is intended the spatial orientation or arrangement of such element. 
     A tyre for vehicle wheels generally comprises a carcass structure comprising at least one carcass ply formed by reinforcement cords incorporated in a matrix of elastomeric material. The carcass ply has end flaps respectively engaged with anchoring annular structures. The latter are situated in the zones of the tyre normally identified with the name “beads” and are normally each formed by a substantially circumferential annular insert on which at least one filler insert is applied, in radially outer position. The annular inserts are commonly identified as “bead cores” and have the task of maintaining the tyre firmly fixed to the anchoring seat suitably provided in the wheel rim, thus preventing, during operation, the exit of the radially inner end flap of the tyre from such seat. 
     At the beads specific reinforcement structures of the anchoring annular structures can be provided, termed “loops”, having the function of improving the transmission of torque to the tyre. The region of the beads is in fact particularly active in the transmission of torque from the rim to the tyre during acceleration and braking, and hence in the presence of suitable reinforcement structures in such zone, it ensures that the transmission of the torque occurs with maximum possible reactivity. 
     In radially outer position with respect to the carcass structure, a crown structure is associated comprising a belt structure and, in radially outer position with respect to the belt structure, a tread band made of elastomeric material. 
     The belt structure comprises one or more belt layers situated in radial superimposition with respect to each other and having textile or metallic reinforcement cords with cross orientation and/or substantially parallel to the circumferential extension direction of the tyre. 
     Respective sidewalls made of elastomeric material are applied on the lateral surfaces of the carcass structure, each extended from one of the lateral edges of the tread band up to the respective anchoring annular structure to the beads. 
     WO 2010/116253, on behalf of the Applicant, provides for the use of two service drums and describes a looping process in which, while on one service drum the deposit of the loop is carried out, on the other service drum the positioning of the anchoring annular structure in radially outer position with respect to the loop is carried out, as well as the turning up of the loop around the anchoring annular structure in order to form the reinforced anchoring annular structure, and also the unloading of the latter. In a further step of the process, the service drums are moved integrally in rotation around the pivoting axis, exchanging position. 
     The Applicant has observed that by arranging a service drum that is at least partly radially expandable/contractible, as described in WO 2010/116253, it is possible to sequentially loop anchoring annular structures of different size, suitable for tyres having different fitting diameters, consequently increasing the production flexibility. 
     The Applicant has however observed that the implementation of a process of the type described in WO 2010/116253 obliges sequentially carrying out the positioning of the anchoring annular structure on the service drum, the turning up and the unloading of the reinforced anchoring annular structure and that, due to such sequence of operations, the productivity of the apparatus described in WO 2010/116253 is rather limited. 
     The Applicant has perceived the need to automatically manage a looping apparatus, increasing the productivity thereof in particular in order to be adapted to the increasingly high levels of productivity of the tyre building plants. 
     In this perspective, the Applicant has perceived that it can be advantageous to optimise the simultaneous/sequential nature of the actions of a looping process by also exploiting the transfer steps of the looping drums. 
     The Applicant has therefore found that it is possible to considerable improve the cycle time of the entire building plant and simplify the plant itself by selecting the simultaneous or sequential actions of the looping process and exploiting a transfer action of a looping drum, such as a turning up action. 
     The present invention, in a first aspect thereof, therefore relates to a process for looping anchoring annular structures in a process for building tyres for vehicle wheels. 
     Preferably provision is made for an action a) of depositing a loop on an annular portion of a radially outer surface of a radially expandable/contractible looping drum, at a loop deposit station. 
     Preferably provision is made for an action b) of loading an anchoring annular structure on the looping drum in radially outer position with respect to said loop, at a loading station configured for loading the anchoring annular structure on the looping drum. 
     Preferably provision is made for an action c) of turning up each of the opposite end flaps of said loop on said anchoring annular structure so as to form a looped anchoring annular structure. 
     Preferably provision is made for an action d) of unloading, from the looping drum, the looped anchoring annular structure, at an unloading station configured for unloading the looped anchoring annular structure from the looping drum. 
     Preferably provision is made for an action e) of transferring a looping drum between the loop deposit station, the loading station and the unloading station. 
     Preferably said actions a) to e) define a looping cycle. 
     Preferably at least the actions a), b) and d) are at least partly carried out simultaneously with each other respectively on at least three different looping drums. 
     Preferably the action c) is at least partially carried out during the transfer of the looping drum from the loading station to the unloading station. 
     The present invention, in a second aspect thereof, relates to an apparatus for looping anchoring annular structures of a tyre for vehicle wheels. 
     Preferably provision is made for at least three looping drums, wherein each looping drum has a longitudinal axis thereof and is radially expandable/contractible with respect to said longitudinal axis. 
     Preferably provision is made for a loop deposit station comprising at least one device for feeding the loop towards the looping drum. 
     Preferably provision is made for a loading station configured for loading the anchoring annular structures on the looping drum comprising loading equipment. 
     Preferably provision is made for an unloading station configured for unloading the looped anchoring annular structures from the looping drum comprising unloading equipment. 
     Preferably said loop deposit station, loading station and unloading station are angularly offset from each other. 
     Preferably provision is made for a turret transfer apparatus on which said looping drums are supported in positions that are angularly offset with respect to each other. 
     Preferably said turret transfer apparatus is configured for transferring said looping drums between the loop deposit station, the loading station and the unloading station rotating around a transfer axis. 
     Preferably each looping drum is configured for at least partially turning up said loop around said anchoring structure during its transfer from said loading station to said unloading station. 
     The Applicant deems that by selecting the actions of depositing the loop, loading the anchoring annular structure and unloading the looped anchoring annular structure to be simultaneous, and by exploiting the transfer between the loading station and the unloading station in order to achieve the turning-up action, the cycle time of the entire building plant considerably decreases and the plant itself is simplified. 
     The present invention, in at least one of the aforesaid aspects, can have at least one of the following preferred characteristics, taken separately or in combination with the others. 
     Preferably, said loop deposit station, loading station and unloading station are angularly offset from each other. In this manner, the structure of the apparatus is optimised together with the transfer actions. 
     Preferably said looping drums are supported by a turret transfer apparatus in positions angularly offset with respect to each other. In this manner, the presence of multiple looping drums is optimised. 
     Preferably the transfer of the looping drum between the loop deposit station, the loading station and the unloading station is obtained by rotating said turret apparatus around a substantially vertical transfer axis. 
     Preferably said looping drums are supported by said turret transfer apparatus and transferred between the loop deposit station, the loading station and the unloading station with substantially horizontal longitudinal axis. In this manner the transfer of the drums as well as the actions operated thereon in the various stations are simplified. 
     Preferably said anchoring annular structures are supplied in a supply configuration by means of a supply device. 
     Preferably loading an anchoring annular structure on the looping drum comprises picking up said anchoring annular structure from the supply device by means of a first pick-up device. 
     Preferably loading an anchoring annular structure on the looping drum comprises centring said anchoring annular structure on a load handling device before loading it on the looping drum. In this manner the looping drum is simplified, assigning the centring action to a different device. 
     Preferably, in order to be loaded on a looping drum, said anchoring annular structure is picked up from the supply device by means of said first pick-up device, arranged and centred on said load handling device, transferred to a loader and fit on the looping drum. 
     Preferably said loader transfers said anchoring annular structure on the looping drum with a movement coaxial with the longitudinal axis X-X- of the looping drum itself. 
     Preferably provision is made for moving away said looped anchoring annular structures in a moving-away configuration, wherein said looped anchoring annular structures are moved away by means of a moving-away device. 
     Preferably unloading a looped anchoring annular structure from the looping drum comprises picking up said looped anchoring annular structure by means of a second pick-up device. 
     Preferably unloading a looped anchoring annular structure from the looping drum comprises transferring said looped anchoring annular structure onto an unloader with a movement coaxial with the longitudinal axis X-X- of the looping drum itself. 
     Preferably in order to be unloaded from the looping drum, said looped anchoring annular structure is transferred from the looping drum on said unloader, transferred onto an unload handling device, picked up from the second pick-up device and arranged on a moving-away device. 
     Preferably the action c) is carried out due to a radial expansion/contraction of the looping drum. In this manner, the actuation thereof is simplified, in the course of the transfer of the looping drum. 
     Preferably said looping drums are supported on said turret transfer apparatus in positions angularly offset with respect to each other, in accordance with said loop deposit station, loading station and unloading station. In this manner the arrangement of the apparatus and the operation thereof are optimised. 
     Preferably said transfer axis is substantially vertical. 
     Preferably said angular offset is equal to about 120°. 
     Preferably said loading equipment comprises a load handling device configured for centring said anchoring annular structure before fitting it on the looping drum. In this manner, the structure of the looping drum is simplified, assigning the centring action to the load handling device. 
     Preferably said loading equipment comprises a loader configured for transferring said anchoring annular structure on the looping drum with a movement coaxial with the longitudinal axis X-X- of the looping drum itself. 
     Preferably said loading equipment comprises a first pick-up device configured for picking up said anchoring annular structure from a supply device. 
     Preferably said first pick-up device is movable between said supply device and said load handling device. 
     Preferably said unloading equipment comprises an unloader configured for receiving said looped anchoring annular structure and transferring it to an unload handling device. 
     Preferably said unloader is configured for receiving said looped anchoring annular structure according to a movement coaxial with the longitudinal axis X-X- of the looping drum itself. 
     Preferably said unloading equipment comprises a second pick-up device configured for picking up said looped anchoring annular structure from said unload handling device in order to automate the process as much as possible. 
     Preferably said second pick-up device is movable between said unload handling device and a moving-away device. 
     Further characteristics and advantages will be clearer from the detailed description of a preferred but not exclusive embodiment of a process and an apparatus for looping anchoring annular structures in accordance with the present invention. 
    
    
     
       Such description will be set forth hereinbelow with reference to the enclosed drawings, provided only as a non-limiting example, in which: 
         FIG. 1  is a schematic longitudinal section view of an anchoring annular structure; 
         FIG. 2  is a schematic longitudinal section view of a looped anchoring annular structure; 
         FIG. 3  is a schematic plan view of an apparatus for looping anchoring annular structures of a tyre for vehicle wheels according to the present invention; 
         FIG. 4  is a schematic longitudinal section view of a looping drum. 
     
    
    
     With reference to  FIG. 3 , reference number  1  overall indicates an apparatus for looping anchoring annular structures of a tyre for vehicle wheels, hereinbelow indicated in brief as apparatus  1 . 
     The looping is a process actuated on anchoring annular structures  100  in order to obtain respective looped anchoring annular structures  200 . The latter are used in building tyre carcass structures. In particular, they are positioned at the beads of the tyre and are intended to maintain the tyre fixed to the anchorage seat suitably provided in the wheel rim of the vehicle. 
     One embodiment of an anchoring annular structure  100  intended to be looped is illustrated in  FIG. 1  and comprises a substantially circumferential annular insert  110 , also termed bead core, and a filler insert  120 . The filler insert  120  is associated with the annular insert  110  in radially outer position with respect to the latter. A-A indicates an extension axis of the anchoring annular structure  100  defining an axis of symmetry of the bead core and of the filler insert. 
     One embodiment of a looped anchoring annular structure  200  is illustrated in  FIG. 2  and comprises the anchoring annular structure  100  and a loop  210 . A central portion of the loop  210  is coupled to the radially inner surface of the anchoring annular structure  100 . Opposite flaps  220   a ,  220   b  of the loop  210  are turned-up around the anchoring annular structure  100  in a manner so as to completely enclose the latter. Preferably, the end portions of the end flaps  220   a ,  220   b  of the loop  210  are offset in radial direction by a distance R (termed “scaling”) which can be comprised between about 4 mm and about 10 mm. Also in the case of the looped anchoring annular structure  200  with A-A, the extension axis has been indicated. 
     With reference to  FIG. 3 , the apparatus  1  comprises at least three looping drums  2 . Each looping drum  2  has a longitudinal axis X-X thereof around which the looping drum is concentrically extended. 
     Each looping drum  2  is radially expandable/contractible with respect to the longitudinal axis X-X in a manner so as to turn up the loop  210  around the anchoring annular structure  100 . 
     One embodiment of a looping drum  2  is illustrated in  FIG. 4  during the looping of an anchoring annular structure  100 . 
     The looping drum  2  comprises an intermediate annular portion  3  and, in a position axially adjacent to the opposite axial ends of the intermediate annular portion  3 , a pair of lateral annular portions  4 . 
     The intermediate annular portion  3  and/or the lateral annular portions  4  are radially expandable/contractible. In particular the lateral annular portions  4  are independently radially expandable/contractible with respect to the intermediate annular portion  3 . 
     Preferably, the intermediate annular portion  3  can comprise a plurality of identical, circumferentially adjacent intermediate angular sectors  5 . 
     Preferably, each of the lateral annular portions  4  can comprise a plurality of identical, circumferentially adjacent lateral angular sectors  6   a ,  6   b . The lateral angular sectors  6   a ,  6   b  of each lateral annular portion  4  are arranged mirrored with respect to a centreline plane M of the looping drum  2 . 
     The looping drum  2  also comprises, in radially inner position with respect to the intermediate angular sectors  5  and to the lateral angular sectors  6   a ,  6   b , a hub  7  extended coaxially with the longitudinal axis X-X. The hub  7  is adapted to be projectingly fixed on a turret transfer apparatus  8  of the apparatus  1 , as will be described hereinbelow in the present invention. 
     The hub  7  can be made in sleeve form, at whose interior, and coaxially with the longitudinal axis X-X, a worm screw  9  is provided having two opposite axial portions, e.g. a first axial right-hand portion  9   a  and, on the opposite side with respect to the centreline plane M of the looping drum  2 , a second left-hand axial portion  9   b.    
     The screw  9  is supported inside the hub  7  by means of a pair of rolling bearings, not illustrated. Such screw  9  can be rotated by a suitable motor group, also not illustrated. 
     Each axial portion  9   a ,  9   b  of the screw  9  is arranged in radially inner position with respect to respective lateral angular sectors  6   a ,  6   b.    
     With reference to the specific embodiment of the looping drum  2 , in radially inner position with respect to each pair of lateral angular sectors  6   a ,  6   b , a support body  10  is provided. Such support body  10  comprises two support body portions  10   a ,  10   b  arranged symmetrically on axially opposite sides with respect to the centreline plane M of the looping drum  2 . Each support body portion  10   a    10   b  is arranged in radially inner position with respect to a lateral angular sector  6   a ,  6   b  of one of the lateral annular portions  4 . 
     The intermediate annular portion  3  and/or the lateral annular portions  4  are expandable/contractible with respect to the hub  7 . In particular the intermediate angular sectors  5  and/or the lateral angular sectors  6   a ,  6   b  can be subjected to a synchronous radial movement with respect to the hub  7 . 
     Each lateral annular portion  4  can be axially movable with respect to the hub  7 . In particular the lateral angular sectors  6   a ,  6   b  of each lateral annular portion  4  can be subjected to a synchronous and opposite radial movement with respect to the hub  7  and with respect to the intermediate annular portion  3 . 
     Each lateral annular portion  4  is configured and arranged with respect to the hub  7  in a manner so as to exert a thrust stress on the respective flap  220   a ,  220   b  of the loop  210  following the synchronous radial movement and the synchronous axial movement of the respective lateral angular sectors  6   a ,  6   b  with respect to the hub  7 . 
     The synchronous radial movement of the lateral angular sectors  6  with respect to the hub  7  can be achieved by means of a screw-nut screw coupling. For example, a respective lever  11   a  and  11   b  is pivoted on each support body portion  10   a  and  10   b . Each lever  11   a  and  11   b  is further pivoted to a nut screw  12   a ,  12   b  coupled to a respective axial portion  9   a ,  9   b  of the screw  9 . 
     Due to the screw-nut/screw coupling, a rotation of the screw  9  produces a synchronous axial movement of the nut screws  12   a ,  12   b  in opposite directions and consequently a synchronous radial movement of the support body  10  defining a radial expansion or a radial contraction of the lateral annular portions  6   a ,  6   b  as a function of the rotation sense of the screw  9 . 
     The synchronous and opposite axial movement of the lateral annular portions  4 , and in particular of the respective lateral angular sectors  6   a ,  6   b , can be obtained by means of pneumatic, elastic elements or the like, not illustrated, interposed between the support body  10  and each lateral angular sector  6   a ,  6   b.    
     The synchronous radial movement of the intermediate angular sectors  5  can be obtained by means of pneumatic, elastic elements or the like, not illustrated, interposed between the support body  10  and each intermediate angular sector  5 . 
     The operation of a looping drum  2  as described above can be the following. 
     Initially, the looping drum  2  is situated in a configuration of maximum radial contraction and is radially expanded until an operative diameter is reached, selected as a function of a fitting diameter of a tyre to be built. Such radial expansion is attained due to the simultaneous and synchronous radial movement of the intermediate angular sectors  5  and of the lateral angular sectors  6   a ,  6   b . This occurs for example following a rotation of the screw  9  which generates a synchronous axial, mutual approaching movement of the nut screws  12   a  and  12   b  and, due to the consequent movement of the levers  11   a  and  11   b , a synchronous radial movement in radially outer direction of the support bodies  10   a ,  10   b  and hence of the lateral angular sectors  6   a ,  6   b  associated therewith and of the intermediate angular sectors  5 . 
     For the deposition of the loop  210 , the looping drum  2  can be rotated around the longitudinal axis X-X by decoupling the screw  9  from the drum in order to prevent further radial expansions or contractions of the drum itself. At the end of the deposition of the loop  210 , the end flaps  220   a    220   b  of the loop are respectively positioned on at least part of each respective lateral angular sector  6  and an intermediate portion of the loop  210  is positioned on each intermediate angular sector  5 . Preferably, the position of the loop  5  is asymmetric with respect to the centreline plane M of the looping drum  2 . 
     Subsequently, the anchoring annular structure  100  is positioned in radially outer position with respect to the loop  210 . 
     The turning up of the end flaps  220   a ,  220   b  of the loop  210  can be obtained due to the radial expansion of only the lateral annular portions  4  and the simultaneous axial movement of the lateral angular sectors  6   a ,  6   b . The radial expansion of the lateral annular portions  4  is obtained due to the synchronous movement of only the lateral angular sectors  6   a ,  6   b , for example as previously described. Preferably the radial movement of the intermediate angular sectors  5  is prevented. 
     The simultaneous synchronous axial movement of the lateral angular sectors  6   a ,  6   b  is obtained progressively as the lateral angular sectors  6   a ,  6   b  are moved radially outward, due to an axial thrust exerted for example by elastic or pneumatic elements or the like, until the anchoring annular structure  100  is completely enclosed by the loop  210 . A looped anchoring annular structure  200  is thus obtained. 
     By reversing the rotation sense of the screw  9 , the lateral annular portions  4  are contracted. 
     With reference to  FIG. 3 , the looping apparatus  1  comprises the turret transfer apparatus  8  centrally arranged with respect to a plurality of stations comprising at least one loop deposit station  13 , a loading station  14  configured for loading the anchoring annular structures  100  on the looping drum  2  and an unloading station  15  configured for unloading the looped anchoring annular structures  200  from the looping drum  2 . 
     The loop deposit station  13 , the loading station  14  and the unloading station  15  are angularly offset from each other. 
     The turret transfer apparatus  8  is configured for supporting the looping drums  2  in positions angularly offset with respect to each other, in accordance with the aforesaid stations. In accordance with the illustrated embodiment, the angular offset α between the positions of said looping drums  2  is equal to about 120°. 
     The turret transfer apparatus  8  is configured for transferring the looping drums  2  between the loop deposit station  13 , the loading station  14  and the unloading station  15  rotating around a substantially vertical transfer axis Y. In particular the looping drums  2  are supported by the turret transfer apparatus with substantially horizontal longitudinal axis X-X and transferred between the loop deposit station  13 , the loading station  14  and the unloading station  15 . 
     The turret transfer apparatus  8  comprises a rotary table  16  managed for example by a brushless motor integrated with a precision wheel  17 . The wheel has a central hole  18  suitable for receiving and carrying the pneumatic and electrical connections to the looping drums  2 . 
     The rotary table  16  supports each looping drum  2  by means of a respective drum-carrier turret  19  comprising, for example, a first gear motor  20  for the rotation of the looping drum  2 , a second gear motor  21  for the radial expansion of the sectors of the looping drum  2 , a coupling group  22  that ensures the locking of the head of the loop during winding on the looping drum  2 . 
     In accordance with one possible embodiment, the looping cycle is of oscillating type. In other words, a looping drum  2  associated with the turret transfer apparatus  8  is transferred from the loop deposit station  13  to the loading station  14  with a first rotation preferably of 120° of the turret transfer apparatus  8 . Subsequently, the looping drum  2  is transferred from the loading station  14  to the unloading station  15  with a second rotation preferably of about 120° of the turret transfer apparatus  8 . Subsequently, the looping drum  2  returns into the loop deposit station  13  with a rotation of the turret transfer apparatus  8  of 240° in opposite sense with respect to the first and second rotation. 
     Alternatively, the looping cycle is continuous, i.e. attained by means of rotations that are always concordant with each other. 
     The loop deposit station  13  comprises at least one device for feeding the loop  23  configured for feeding the loop  210  towards the looping drum  2 . The loop feeding device  23  comprises at least one reel, preferably two reels  24  of continuous elongated material which, once cut, defines the loop  210 . The loop feeding device  23  also comprises a cutting and deposit group  25  configured for supporting and centring the loop  210  before the feed, positioning it on the looping drum  2 . 
     In the loop deposit station  13 , after the coupling group  22  has locked the head of the loop, the looping drum  2  is rotated around the longitudinal axis X-X in order to lay the loop  210  flat on the radially outer surface of the lateral angular sectors  6  and of the intermediate angular sectors  5 . 
     The loading station  14  comprises loading equipment  26  configured for loading the anchoring annular structures  100  on the looping drum  2 . 
     One embodiment of loading equipment  26 , illustrated in  FIG. 3 , comprises a load handling device  27  configured for centring the anchoring annular structure  100  before the same is loaded on the looping drum  2 . In particular the load handling device  27  is configured for receiving the anchoring annular structure  100  and bringing it into a loading configuration, i.e. with the extension axis A-A parallel to a longitudinal axis X-X of a looping drum at the loading station. 
     The load handling device  27  can comprise sensors adapted for verifying the correct diameter of the picked-up anchoring annular structure and a plurality of pick-up fingers that are radially movable with respect to the extension axis A-A in a synchronous and self-centring manner, in order to retain the anchoring annular structure at radially inner portions. 
     The load handling device  27  is preferably multi-fitting and does not require a manual set-up upon size change. 
     The loading equipment  26  also comprises a supply station, comprising a supply device  28  and a first pick-up device  29  configured for picking up the anchoring annular structure  100  from the supply device  28  and arranging it on the load handling device  27 . 
     The supply device  28  allows supplying the anchoring annular structures  100  arranged in a preferred but not exclusive supply configuration, wherein the extension axis A-A is vertically arranged. 
     The first pick-up device  29  can comprise magnetic devices pneumatically driven in order to grasp one anchoring annular structure at a time. 
     The load handling device  27 , once the anchoring annular structure  100  has been received from the first pick-up device  29  and after having carried out a centring thereof, transfers such structure to a loader  30 , also multi-fitting, which in turn transfers it onto the looping drum  2  with a movement coaxial with the longitudinal axis X-X- thereof. 
     The load handling device  27  can be configured for rotating the anchoring annular structures  100  from the supply configuration to the loading configuration. In particular the load handling device  27  can be configured for rotating 90° each anchoring annular structure  100 . 
     The unloading station  15  comprises unloading equipment  31  configured for unloading the looped anchoring annular structures  200  from the looping drum  2  arranged in the unloading station  15 . 
     In particular the unloading station  15  can be substantially mirrored with respect to the loading station  14 . 
     One embodiment of unloading equipment  31 , illustrated in  FIG. 3 , comprises an unloader  35  configured for receiving the looped anchoring annular structure  200  with the extension axis A-A parallel to a longitudinal axis X-X of the looping drum and an unload handling device  32 , which can be structurally similar to the load handling device  27 . 
     The unloading equipment  31  also comprises a moving-away station, defined for example by a moving-away device  33  and a second pick-up device  34  configured for picking up the looped anchoring annular structure  200  from the unload handling device  32  and arranging it on the moving-away device  33 . 
     The second pick-up device  34  can be structurally and functionally similar to the first pick-up device  29 . 
     The second pick-up device  34  is movable between the unload handling device  32  and a deposition position in proximity to the moving-away device  33 . 
     The unload handling device  32  can be configured for rotating each looped anchoring annular structure  200  from an unloading configuration to a moving-away configuration, different with respect to the unloading configuration. In particular the unload handling device  32  can be configured for rotating 90° each looped anchoring annular structure  200 . 
     The second pick-up device  34  can comprise magnetic devices pneumatically driven in order to grasp one anchoring annular structure at a time. 
     In an apparatus as described above, it is possible to actuate a process for looping anchoring annular structures according to the present invention. The looping process is part of a process for building tyres for vehicle wheels. 
     With reference to the apparatus  1 , a looping cycle of the looping process provides for depositing the loop  210  on an annular portion  3 ,  4  of the outer annular surface of a looping drum  2 , at the loop deposit station  13 . 
     At least partly simultaneously with the deposit of the loop in the loop deposit station  13 , the looping cycle provides, at the loading station  14 , for loading an anchoring annular structure  100  on a looping drum  2  different from that arranged in the loop deposit station  13 , in radially outer position with respect to a loop  210  already deposited. 
     At least partly simultaneously with the depositing of the loop in the loop deposit station  13  and with the loading of the anchoring annular structure  100  in the loading station  14 , the looping cycle provides, at the unloading station  15 , for unloading a looped anchoring annular structure  200  from a looping drum  2  different from those respectively arranged in the loop deposit station  13  and in the loading station  14 . 
     The looping cycle also provides for transferring each looping drum between the loop deposit station  13 , the loading station  14  and the unloading station  15 . 
     The looping cycle also provides for turning up each of the opposite end flaps  220   a    220   b  of the loop  210  on the anchoring annular structure  100  so as to form a looped anchoring annular structure  200 . Such action is at least partially carried out during the transfer of a looping drum  2  from the loading station  14  to the unloading station  15 . 
     With reference to the apparatus  1  and considering a looping drum  2  arranged in the loop deposit station  13 , one proceeds to deposit the loop  210 , for example as described above. In particular, the coupling group  22  locks the head of the loop provided by the loop feeding device  23 . The looping drum  2  is rotated around the longitudinal axis X-X until the  210  loop is completely deposited. 
     The turret transfer apparatus  8  completes a rotation of 120° and transfers the looping drum  2  from the loop deposit station  13  to the loading station  14 . 
     Meanwhile, the anchoring annular structures  100  are supplied in the supply configuration by means of the supply device  28  in order to be loaded on the looping drum  2 , arranged in the loading station  14 . 
     In order to be loaded on the looping drum  2  arranged in the loading station  14 , an anchoring annular structure  100  is picked up from the supply device by means of the first pick-up device  29 , centred on the load handling device  27 , transferred by the latter to the loader  30  and fit on the looping drum  2  in radially outer position with respect to the already-laid loop  210 . 
     The turret transfer apparatus  8  then completes a further rotation of 120° and transfers the looping drum  2  from the loading station  14  to the unloading station  15 . During such transfer, the looping drum  2  is driven, for example as previously described with reference to the operation of the looping drum illustrated in  FIG. 4 . In particular during the transfer of the looping drum from the loading station  14  to the unloading station  15 , each of the opposite end flaps  220   a    220   b  of the loop  210  is turned up on the anchoring annular structure  100  due to a radial expansion/contraction of the looping drum  2 . 
     When the drum has reached the unloading station  15 , in order to unload the looped anchoring annular structure  20 , the latter is transferred from the looping drum  2  onto the unloader  35 , then from the unloader  35  to the unload handling device  32 , and then picked up by the second pick-up device  34 , arranged on the moving-away device  33 .