GB721217A - Improvements relating to injection moulding apparatus - Google Patents

Abstract

721,217. Injection-moulding. DUNLOP RUBBER CO., Ltd. Sept. 11, 1952 [Oct. 5, 1951], No. 23190/51. Class 87 (2). Injection-moulding apparatus comprises a bank of independent stationary presses, each press comprising at least two platens having means for attaching the parts of a mould to each pair of opposed platen faces, and an injector mounted on a carriage movable along the bank of presses, means being provided to hold the injector in charging relationship with the mould or moulds in each press and for holding the injector clear of the presses during movement' of the carriage. The drawings show two daylight presses 1 each having two platens 2 which carry mould halves 3 fed from opposite sides by two screw injectors 11 which with their actuating motors are pivotally supported on a carriage which slides along two parallel bars 5. The carriage comprises two plates 6 joined by an internally-threaded sleeve 7 engaged by a screw 8: when the screw is turned the carriage slides along the bars 5. Each injector with its actuating motor is carried by a triangular frame 10, 14, 15 pivoted at 6a on the plates 6. Each frame may be rocked about its pivot, to press its injector against the mould or to hold it away from the mould, by a doubleacting double-ended air cylinder 19 each piston rod 18 of which is connected by an eye 17 to a pin 16 joining members 14. Thermosetting material, e.g. heatvulcanizable rubber composition, in flexible strip form is fed from reels 13 mounted on the frames to openings 12 in the injectors. In operation, one mould is filled whilst the injectors are in the (horizontal) Fig. 2 position, then the injector motors are stop-. ped and the cylinder 19 is actuated to pivot the frames 10, 14, 15 upwardly, whereby the injectors are detached from the moulds, then the screw 8 is turned to slide the carriage along the bars 5 to the next press. Electric supply lines (not shown) are provided for a motor to move the carriage, to operate the electric motors of the injectors and to heat the rubber composition in the injectors. A time relay mechanism may effect correct automatic sequence. The presses may be hand-operated or electrically operated. In modifications (not illustrated) (1) the pneumatic cylinder for tilting the frames may be replaced by a crankshaft geared to a reversible electric motor. (2) Multi-daylight presses may be used. (3) The press platens and the injectors may be disposed vertically.