A green tyre (2) for bicycles is built, comprising at least one carcass ply (4) having axially opposite end flaps (4a) engaged with respective bead cores (5) and a tread band (6) applied in a radially outer position around said at least one carcass ply (4). The green tyre (2) removed from the building drum, is profiled so as to translate the tread band (6) in a radially outer direction with respect to the bead cores (5), so as to impart a cross-sectional convex profile to the tyre (2) in a radially outer direction. The profiled tyre is engaged by means of a transfer member (31) while the tyre itself is mechanically restrained so as to maintain at least partly said cross-sectional convex profile in the radially outer direction.

In a process for building tyres for vehicle wheels, a carcass sleeve is arranged on a shaping drum including two half-drums and two supports. Each support is operatively associated with one of the half-drums and carries a plurality of turning-up levers having free ends positioned close to the respective half-drum. Two annular anchoring structures are disposed around the carcass sleeve and each of the two supports is locked to the respective half-drum by interposing only stiff mechanical elements in mutual contact between the support and the half-drum. The carcass sleeve is shaped in a toroidal conformation, by setting a threaded shaft in rotation and moving the half-drums close to each other. Subsequently, each of the two supports is unlocked from the respective half-drum and the threaded shaft is set in rotation to move each support close to the respective half-drum and lift up the free ends of the turning-up levers until the end flaps of the carcass sleeve are turned up around the annular anchoring structures.

A plant for building tyres, includes: a shaping work station configured for receiving a carcass sleeve; at least one radially expandable/contractible toroidal forming drum engageable in the shaping work station; at least one work station configured for building at least one component of a crown structure on a radially external surface of a tyre being processed, defined starting from the carcass sleeve that is shaped and coupled to the forming drum; transfer devices configured for moving said forming drum along a closed-loop completion path and arranging it in proximity to the work station in order to obtain a green tyre, the closed-loop completion path being extended from an initial work station to a final work station coinciding with the shaping work station; and a pick-up device configured for picking up said green tyre decoupled from the respective forming drum.

A plant for building tyres, includes: a shaping work station configured for receiving a carcass sleeve; at least one radially expandable/contractible toroidal forming drum engageable in the shaping work station; at least one work station configured for building at least one component of a crown structure on a radially external surface of a tyre being processed, defined starting from the carcass sleeve that is shaped and coupled to the forming drum; transfer devices configured for moving said forming drum along a closed-loop completion path and arranging it in proximity to the work station in order to obtain a green tyre, the closed-loop completion path being extended from an initial work station to a final work station coinciding with the shaping work station; and a pick-up device configured for picking up said green tyre decoupled from the respective forming drum.

A carcass sleeve is situated in a radially external position with respect to a toroidal forming drum, arranged in a first radially contracted operative condition. The carcass sleeve is shaped according to a toroidal configuration while the forming drum is positioned inside the carcass sleeve. During shaping of the carcass sleeve, the forming drum is radially expanded up to a second radially expanded operative condition. Upon completed shaping, the carcass sleeve is coupled to the forming drum in the second operative condition. The forming drum, coupled to the shaped carcass sleeve, is arranged in proximity to at least one device for building at least one belt layer at a radially external position relative to the shaped carcass sleeve.

A carcass sleeve is situated in a radially external position with respect to a toroidal forming drum, arranged in a first radially contracted operative condition. The carcass sleeve is shaped according to a toroidal configuration while the forming drum is positioned inside the carcass sleeve. During shaping of the carcass sleeve, the forming drum is radially expanded up to a second radially expanded operative condition. Upon completed shaping, the carcass sleeve is coupled to the forming drum in the second operative condition. The forming drum, coupled to the shaped carcass sleeve, is arranged in proximity to at least one device for building at least one belt layer at a radially external position relative to the shaped carcass sleeve.

A process for building tyres employing a forming drum having circumferentially consecutive sectors that are radially movable between a contracted condition and an expanded condition in which the sectors are radially moved away from a geometric axis in order to define a radially external abutment surface. Each sector has circumferentially opposite coupling portions each having circumferential projections alternated with circumferential cavities. The projections of each sector are slidably engaged in the respective cavities of circumferentially adjacent sectors. From at least one of the projections, at least one support wing is extended having a first side and a second side that are respectively opposite. The first side coincides with a portion of the abutment surface and the second side at least partially overlaps one of the projections belonging to an adjacent sector.

A process for building tyres employing a forming drum having circumferentially consecutive sectors that are radially movable between a contracted condition and an expanded condition in which the sectors are radially moved away from a geometric axis in order to define a radially external abutment surface. Each sector has circumferentially opposite coupling portions each having circumferential projections alternated with circumferential cavities. The projections of each sector are slidably engaged in the respective cavities of circumferentially adjacent sectors. From at least one of the projections, at least one support wing is extended having a first side and a second side that are respectively opposite. The first side coincides with a portion of the abutment surface and the second side at least partially overlaps one of the projections belonging to an adjacent sector.

A method of manufacturing a pneumatic tire including forming a green case by cylindrically winding a tire component member which includes at least one layer of a carcass ply. The green tire is shaped by expanding the green case into a toroidal shape with the supply of a fluid into the green case so that the green case adheres to a tread ring arranged radially outside the green case. The green tire is subjected to vulcanization molding within a mold die. During the shaping of the green tire, the fluid is supplied in accordance with a pressure profile which changes in a stepwise manner. The pressure profile is set such that a former stage pressure which allows the green case to expand to 35% to 40% of a full expansion amount is set lower than a final stage pressure in a final stage.

A method of manufacturing a pneumatic tire including forming a green case by cylindrically winding a tire component member which includes at least one layer of a carcass ply. The green tire is shaped by expanding the green case into a toroidal shape with the supply of a fluid into the green case so that the green case adheres to a tread ring arranged radially outside the green case. The green tire is subjected to vulcanization molding within a mold die. During the shaping of the green tire, the fluid is supplied in accordance with a pressure profile which changes in a stepwise manner. The pressure profile is set such that a former stage pressure which allows the green case to expand to 35% to 40% of a full expansion amount is set lower than a final stage pressure in a final stage.