Process and apparatus forr vulcazation and moulding of vehicle tyres

An apparatus for moulding and vulcanisation of tyres for vehicle wheels, comprising a vulcanisation press and a vulcanisation mould associated with said press, comprising:

• a pair of plates axially movable and designed to operate on a tyre bead and sidewalls;
• a plurality of circumferentially distributed mould sectors radially movable close to each other and designed to operate on a tread band of the tyre;
• a plurality of sector carriers, designed to support the mould sectors and movable together with the sectors;
• each mould sector comprising a plurality of surface ridges matching an outer surface of the tyre tread band to be obtained,
• the plates and sectors being mutually movable between an open condition at which they are spaced apart to enable loading of a tyre to be moulded and vulcanised, and a closed condition at which they define a moulding cavity having a geometric configuration matching an outer surface of the tyre to be obtained;
• wherein at least one first thrusting device is provided between each sector carrier and one of the plates to exert a radially outward thrust action on each mould sector or each sector carrier during the displacement of said mould sectors from the closed condition to the open condition at most until sector surface ridges are entirely pulled out of a vulcanized tyre.

A process for controlling a detachment of mould sectors from a vulcanised tyre in a vulcanization mould comprising a plurality of circumferentially distributed mould sectors comprising a plurality of surface ridges and a plurality of sector carriers, comprising:

• loading a green tyre into the vulcanization mould;
• vulcanising and moulding a green tyre;
• and
• opening the mould,
• wherein, during said opening of the mould:
• exerting a radially outward thrust action on each mould sector or on each sector carrier;
• and
• ending said radially outward thrust action when a radial distance not substantially greater than a maximum height of surface ridges is achieved between the vulcanised tyre and mould sectors.