A device for the shaping of a profiling in the barrel by a helicoidal guide camel-back an air tire blank

摘要

1,015,192. Moulding tyres. PIRELLI S.p.A. June 28, 1962 [July 7, 1961], No. 24821/62. Heading B5A. In forming an embossed pattern on a pneumatic tyre tread, the article is rigidly enclosed on all surfaces except the peripheral surface, which is then subjected to centripetal pressure from a plurality of rigid surfaces. Fig. 3 shows a mould comprising a lower annular section 8, an upper section 15 and a central section comprising a plurality of sectors 9, whose inner faces form the tread bond of a tyre 37. Each sector 9 is mounted on a support 10 provided with an inclined plate 12, which slides on a second inclined plate 13 attached to a supporting ring 14. A plate 7 moves relative to the ring 14, lifting section 8 and sectors 9, and as plate 7 rises sectors 9 move centrifugally. With the mould in this open position and upper section 15 withdrawn, the partly pre-shaped tyre 37 with a curing-bag 38 fitted is placed in the lower section 8 of the mould, and upper section 15 is lowered (see Fig. 3) to touch section 8. The force which lowers section 15 overcomes the hydraulic system supporting plate 7, and the mould descends, causing sectors 9 to move centripetally. At the same time fluid is admitted to curing-bag 38 so that when the mould is fully closed, the pressure within the tyre exceeds the centripetal pressure of sectors 9. The tread of the tyre being thus formed, the pressure within the curing-bag is increased and steam admitted to surround the mould (i.e. into container 2, Fig. 1, not shown). Fig. 2 (not shown) illustrates the mechanism used to lower the upper section 15 vertically. Fig. 5 (not shown) shows similar equipment to Fig. 3, but using a different form of curing-bag 54, which is applied to a tyre 55 with the mould open, by slowly withdrawing a cylinder 51 in response to fluid pressure in the bag 54. At the same time an upper section 47 is lowered as described above until a plate 48 contacts supports 42 of sectors 41. Further lowering depresses plate 39 so that the sectors move centripetally. A third embodiment (Fig. 6) has a cylindrical curing-bag 67. Starting with the mould, comprising a lower section 57, upper section (not shown) and sectors 58, open as shown, a tyre 72 is placed in position with a rigid cylindrical sleeve 71 resting on its upper bead. A disc 66 is lowered and fluid admitted to bag 67 which slides free of sleeve 7] to contact the tyre 72. The sleeve is removed, the upper section lowered, and the rest of the forming proceeds as above.