| 摘要 |
By increasing the number of segments constituting the outer periphery of a tire building drum, sufficient roundness is ensured for the tire building drum in a wide diameter expansion/reduction range. The tire building drum (1) used for manufacture of an unvulcanized tire is expanded or reduced in diameter in at least a part of the outer periphery by displacing a plurality of extensible/contractible segments (10A and 10B) sequentially arranged in the drum peripheral direction. Furthermore, the tire building drum (1) is provided with a pair of segment displacing means which expand/contract the plurality of segments (10A and 10B), and the pair of segment displacing means are alternately connected to each of the segments (10A and 10B) in the drum peripheral direction. Each of the connected segments (10A and 10B) is displaced, respectively, by the pair of segment displacing means. |
