IE40983B1 - Transfer molding apparatus - Google Patents

Abstract

1500816 Transfer moulding UNIROYAL AG 7 April 1975 [23 April 1974] 14097/75 Heading B5A Apparatus for moulding elastomeric stock comprises an injection unit having an injection chamber 36, an adaptor 34 defining a secondary chamber, valve means 38, 39 permitting unidirectional flow of stock from the injection to the secondary chamber, an apertured end plate 44 disposed at least in part in and movable axially relative to the secondary chamber, and means for moving the injection unit and a mould 80, 82, 84 relative to one another to reduce the axial extent of the secondary chamber and expel elastomeric stock through the end plate 44 and into the mould cavity. The valve means 38, 39 prevents backflow of elastomeric stock into the injection chamber 36 despite any pressure drop in the injection chamber during recharging thereof. A mould assembly 22 is moved towards the injection cylinder 28 initially by a toggle linkage array 20 and finally, to effect injection from chamber C into the mould, by means of a ram 70 in a housing 72 to which pressure fluid is admitted through an inlet 74. Plate 44 is made of heat resistant, flexible insulating material and formed with an array of apertures 58 having annular insets 60, e.g. of PTFE. Heating channels 43, 68 are provided in the adaptor 34 and a heating platen 66 respectively. An insulating sheet 64 is interposed between platen 66 and an end plate 62. [GB1500816A]