Process for building tyres for vehicle wheels

A process for building tyres for mounting on vehicle wheels in a carcass structure building line, each tyre comprising a carcass structure having at least one carcass ply and a pair of anchoring annular structures, comprising the steps of:

• a) transferring a forming drum to a support rings associating work station;
• a1) transferring a pair of support rings from a support rings temporary storage, where a plurality of pairs of support rings are stored, to the support rings associating work station;
• a2) associating the pair of support rings with the forming drum in the support rings associating work station;
• b) building at least one structural component of the carcass structure of a tyre being processed on the forming drum provided with said pair of support rings in a work station of the carcass structure building line;
• b1) transferring, with a first transfer device comprising a first robot arm, the forming drum associated with the pair of support rings from the work station of the carcass structure building line to a support rings removing work station;
• c) removing the pair of support rings from the forming drum in the support rings removing work station;
• d) transferring, with a second transfer device comprising a second robot arm, the pair of support rings dissociated from the forming drum from the support rings removing work station to the support rings temporary storage;
• e) building at least one further structural component of the carcass structure of the tyre being processed on the forming drum without the pair of support rings in a further work station of the carcass structure building line;
• f) transferring the forming drum without the pair of support rings from the further work station of the carcass structure building line to a shaping and assembly work station;
• building a crown structure in at least one crown structure building line comprising a plurality of work stations, said crown structure comprising at least one belt structure;
• and
• toroidally shaping said carcass structure and assembling said carcass structure to said crown structure in said shaping and assembling work station to obtain a shaped green tyre,
• wherein the transferring in a1) is carried out with said second transfer device or further transfer device comprising a robot arm,
• wherein the process comprises removing the built shaped green tyre from the forming drum, which is unprovided with the pair of support rings, and transferring the forming drum from which the built shaped green tyre has been removed, without the built shaped green tyre, to the support rings associating work station, wherein it is associated with any pair of support rings from the plurality of the pairs of support rings, and
• wherein the process is repeated and the carcass structure building line selectively transfers the forming drum, associated with any pair of support rings from the plurality of pairs of support rings, from said support rings associating work station to a forming drums temporary storage, and transfers directly the forming drum, associated with any pair of support rings from the plurality of pairs of support rings, to start a new building cycle without the forming drum entering the forming drums temporary storage.