GB1371821A - Tyre mould apparatus - Google Patents

Abstract

1371821 Moulding tyres GOODYEAR TIRE & RUBBER CO 15 May 1972 [1 June 1971 14 March 1972] 22746/72 Heading B5A A tyre mould comprises an upper part 18 movable coaxially relative a lower part 14, tread mould segments 22 movable radially and in axially fixed relation to the part 14 which has cam means for moving the segments radially outwardly, and a ring 93 associated with the part 18 for moving the segments radially inwardly when that part is lowered. The part 14 is located on a platen 12, and the lower surface of each segment carries a T-block 50 which slides in a T-slot 52 in the platen. A cam follower 62 is attached to each block and engages a cam ramp 69, Fig. 3, of a cam ring 32 which is rotated about the mould axis by a fluid operated cylinder 76. Rotation of the ring in one direction forces the segments outwardly whereas rotation in the opposite direction allows the segments to be moved inwardly by the ring 93. The ring forms part of a bolster 90 from which depends a platen 16 attached to the part 18, relative movement between the parts 90 and 18 being provided by a number of spring sets 130 and bolts 140. The cam means of Figs. 5-6 includes a cam ring 160 rotated about the lower platen by a cam plate 164 integral with a part-cylindrical plate 170 having a cam slot 172. A stud 174 on the ring 93<SP>1</SP> engages the slot when the ring descends, causing rotation of the plate 164 and permitting a spring-loaded pawl 180 on the plate to pass into a next adjacent notch 188 of the ring 160. Rotation of the latter is prevented by each cam follower 62 engaging a face 190 of a notch. Upward movement of the bolster and ring 93<SP>1</SP> effects clockwise movement of the cam ring whereby the tread segments are moved outwardly. Subsequent downward bolster movement causes inward movement of the segments. In the embodiment of Fig. 8, not shown, the cam ring (200) and cam drive plate (202) are integral, the latter having an upwardly extending slotted plate engaged by a stud (208) on the bolster ring (93<SP>11</SP>); upward bolster movement effects outward radial movement of the tread segments. In an alternative construction, Fig. 11, the slide blocks 257 have portions 263 of limited radial width to permit easier withdrawal of the segments from their T-slots. The upper platen 237 is vertically driven by an hydraulic cylinder and includes a bearer ring 277, preferably of a metal dissimilar from that of the segments 243 and of the closing ring 279. Relative movement of the upper platen relative to the bolster 271 is limited by bolts 291.