GB350810A - Machine for casting or moulding bodies from thermoplastic pulverous material - Google Patents

Abstract

350,810. Casting bobbins &c. in moulds charged through pressure nozzles. BUCHHOLZ, H., 32, Berlinerstrasse, Neuk÷lln, Berlin. Aug. 20, 1930, No. 24890. [Class 87 (ii).] In presses for handling thermoplastic material in which the material is heated in a press cylinder and then forced by a ram through a charging nozzle into a mould formed in two halves held in close abutment, the ram moves downwards in the cylinder until the material wedges, after which the ram and cylinder move as a unit to apply pressure to the upper mould section during the moulding operation, thereby maintaining the mould parts in close relationship without special locking means. The press cylinder 21 carries the nozzle 29 which fits into the water-cooled upper section 31 of the mould and is provided with an electric or other heater 26 at its central portion. The cylinder 21 and mould member 31 are connected to a metal beam 14 which can be raised by chains 16 and a pedal to separate the mould parts against the action of springs 19 which apply initial compression to the mould members. The ram 6 is lowered by the counterweighted handle 10 acting through rack- and-pinion gear to force material from the hopper 24 into the press cylinder 21. When the material jams, the continued movement of the handle moves the member 14 downwards and thus forces the shoulder on the nozzle 29 and the abutment members 63 against the mould member 31. The cooling fin 27 and metal beam 14 prevent the heat from softening the material in the hopper. In the particular machine illustrated, which is for the manufacture of small bobbins, the mould member 31 depresses cores 43 bodily against the action of springs 49. When the member 31 is raised again, the springs raise the core members clear of the lower mould members, in which position the moulded articles are ejected from them by a sliding bar 52 operated by a cam 60 rotated by th e hand-lever 59.