| 摘要 |
727,815. Tyre moulds. DUNLOP RUBBER CO., Ltd. July 20, 1953 [Aug. 12, 1952], No. 20235/52. Class 87 (2) To facilitate the removal of the completed tyre from a tyre mould the tread-forming face is formed of four arcuate segments 5, having moulding surfaces 7 detachably secured to them, the segments being radially movable by the engagement and disengagement of lugs 17 in inclined slots 14 formed in housings 11 attached to segments 5. Dove-tailed keys 8 attached to segments 5 slide in slots 9 in mould part 2 to constrain the segments to move in a radial direction and bolt 10 limits the outward movement. In operation, an assembled' unvulcanized car tyre cover and air bag are placed in the mould part 2 with segments 5 in their outer-most position, the top part 1 is then lowered and, guided by chamfered parts 12b and 15, lugs 17 engage the slots 14 thus forcing the segments 5 radially inwards with a cam action. The parts 1 and 2 may be attached to a press which secures the mould during vulcanization, the segments 5 being thus moved automatically outwards on separation of the parts to permit easy removal of the tyre. |
