Method and apparatus for moulding and curing tyres for vehicle wheels

A method of moulding and curing tyres for vehicle wheels, comprising the steps of:

• disposing a tyre being processed on a toroidal support, wherein an outer surface of the toroidal support substantially mates with an inner surface of the tyre;
• enclosing the tyre and the toroidal support inside a moulding cavity defined in a vulcanization mould, the moulding cavity having walls, wherein a shape of the moulding cavity walls matches an outer surface of the tyre when vulcanization is completed;
• pressing the outer surface of the tyre against the moulding cavity walls;
• and
• administering heat to the tyre to cause molecular crosslinking of the tyre;
• wherein the pressing step comprises the steps of:
• compressing side portions of the tyre between the moulding cavity walls and the outer surface of the toroidal support, concurrently with the enclosing step, wherein the side portions extend from inner circumferential edges of the tyre to transition regions between sidewalls, located at respective side portions, and a tread band disposed at a radially-outer portion of the tyre, delimited between the side portions;
• and
• expanding a radially-outer portion of the tyre to bring the radially-outer portion of the tyre against the walls of the moulding cavity, said radially-outer portion being delimited between the side portions,
• wherein said expanding step includes a step of admitting a fluid under pressure, and, before the expanding step, admitting a working fluid between the outer surface of the toroidal support and the inner surface of the tyre while the mould is closed, wherein the working fluid is under a lower pressure than that of the fluid under pressure admitted during the expanding step.