| 摘要 |
To form a tyre carcass (2), a body ply (20) is wound about a drum (1), which has two half-drums (5) movable axially in opposite directions along the longitudinal axis (3), to and from a centre plane (4) of the drum (1), and having respective turn-up bladders (8; 34), on each of which is laid a respective annular lateral portion (23) of the body ply (20); each annular lateral portion (23) being turned up about a respective bead bundle (7) and onto a sidewall (24) of a toroidal-shaped annular central portion (22) of the body ply (20) by inflating the relative turn-up bladder (8; 34) and controlling distension of a given annular portion (12; 38) of the turn-up bladder (8; 34) so that, when inflation is completed, the annular portion (12; 38) assumes a given final position, in which an intermediate portion of the turn-up bladder (8; 34) rolls outwards along the relative sidewall (24) of the annular central portion (22) of the body ply (20). |
