Manufacture of pneumatic tyres for vehicles

Plant for building pneumatic vehicle tyres comprising a carcass assembly with an inner layer, one or more carcass reinforcing layers and two side walls with bead wires and a breaker assembly with one or more reinforcing layers and a tread has at least four carcass building stations(4,5,6,7) each constructing a carcass layer on a drum(16). The stations(4,5,6,7) are separate from each other and the carcass drum(16) has controlled movement between them. Components are supplied to the carcass building drum(16) by a feeding unit which is itself fed by a conveyer. The plant also includes at least two separate breaker layer forming stations(8,10), one(10) for building a breaker layer on a drum(13) and the other(8) for constructing the tread layer. The drum(13) moves between the stations(8,10), each of which has a component feeding unit supplied by a conveyer. The apparatus(3) brings together the assemblies from the carcass(16) and breaker layer (13) building drums to produce a un vulcanised casing. At least one of the carcass(4,5,6,7) and/or breaker layer(8,10,11) building stations has two or more independently controllable feeding units supplying components to the corresponding drums(16,13) and at least one of these has a conveyer. In a claimed process employing the plant to produce carcass and/or breaker layer assemblies individual components are selectively fed to the building drum at each building station from one of two different feeding units.