| 摘要 |
A forming drum comprises circumferentially consecutive sectors (24) that are radially movable between a contracted condition and an expanded condition in which the sectors (24) are radially moved away from a geometric axis (X-X) in order to define a radially external abutment surface ("S"). Each sector (24) has circumferentially opposite coupling portions (36a, 36b), each comprising circumferential projections (37) alternated with circumferential cavities (39). The projections (37) of each sector (24) are slidably engaged in the respective cavities (39) of circumferentially adjacent sectors. From at least one of the projections (37), at least one support wing (42) is extended having a first side (42a) and a second side (42b) that are respectively opposite. The first side (42a) coincides with a portion of the abutment surface ("S") and the second side (42b) at least partially overlaps one of the projections (37) belonging to an adjacent sector (24). A process for building tyres employing the aforesaid drum is also described. |
