GB1194534A - Improvements in or relating to Moulding Rubber or Plastics Material - Google Patents

Abstract

1,194,534. Injection moulding. DUNLOP CO. Ltd. 12 July, 1967 [14 July, 1966], No. 31656/66. Heading B5A. A length of material, e.g. a corrugated rubber edging strip 11 for a conveyer belt, is injection moulded in a plurality of stages by a method comprising filling a plurality of moulds 10 in turn at an injection station so that the moulding material extends between and interconnects the moulds, the moulds being individually removed after passing through a curing zone and reapplied in position at the injection station. First embodiment (Fig. 1).-A strip of unvulcanized rubber from a reel 7 is supplied to an injection cylinder containing a feed screw (not shown) which injects the material through a head 5 into the last of a series of hinged-lid moulds 10 having interconnected cavities. As shown the last two moulds are held in a press 17 closed by oil-pressure cylinders 18. The remaining moulds are held in a curing press 19 closed by cylinders 20. The apparatus is also provided with a mould opening device (not shown), mould lowering table (24), mould cleaning station (26), return conveyer (25), mould closing station (27) and piston and cylinder assemblies (23) and (22) for mould removal and return respectively (see Fig. 2, not shown). The moulds are moved forward one at a time when the injection cylinder is moved by cylinders 16 into injection position. Second embodiment (Fig. 6).-In this case the moulds 1-4 move in a circular path instead of a straight line. An hydraulic ram 29 is operable to move a screw type injector 30 and a bolster 31 towards and away from the ends of three of the four moulds. The moulded strip 34 is guided by a pulley 37 on to a take-up drum 38. Curing is effected in a press (28), Fig. 5 (not shown) which also contains a bolster 35, Fig. 6, for restraining the moulds when under injection pressure. A mechanically operated mould indexing lever 36 is also provided.