GB1004325A - Cutter device for plastics, such as foamed polystyrene - Google Patents

Abstract

1,004,325. Heated-filament cutting of plastics. ADAM OPEL A.G. July 2, 1964 [July 20, 1963], No. 27339/64. Heading B5A. A plastics-cutting device, particularly for use on foamed polystyrene, comprises an electricallyheatable incandescent filament 19 Fig. 3, which in a retracted position lies below a table 12 and within a tube 20, and wherein on raising the tube to engage a coupling member 55 between jaws 111, 112, Fig. 5, of a holding device 16 (Fig. 1, not shown) and then retracting the tube, the filament is left exposed in its operative position. The filament 19 is tensioned by compression of a spring 57, Fig. 3, between a plug 52 and filament clamp 58 when tube 20 is lowered. The tube 20 is operated via a connection 46 to an endless chain 21 driven by means of a hand wheel 18 (Fig. 2, not shown) provided with a braking system. The electrical circuit comprises, at the lower end of the filament, a wire 59 which passes around fixed sheaves 51, 61 and a weighted pulley 62 and which tensions the filament in its retracted position, and at the upper end a contactor 113, Fig. 5, held by a spring 121 against the top of member 55 when the latter is between jaws 111, 112. To retract the filament, tube 20 is raised and an electromagnet 82 is actuated to raise wedges 92, 93 (Fig. 4, not shown) which force jaws 111, 112 apart against the action of springs 109, 110 respectively. Limit switches prevent heating of the filament unless the tube 20 is fully retracted and operation of magnet 82 unless the tube is fully raised.