| 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 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 sequentially arranged in the drum peripheral direction. Furthermore, the tire building drum is provided with a pair of segment displacing means which expand/contract the plurality of segments, and the pair of segment displacing means are alternately connected to each of the segments in the drum peripheral direction. Each of the connected segments is displaced, respectively, by the pair of segment displacing means. |
