Apparatus for moulding plastic articles

Abstract

The specification discloses a method of making an aperture-defining frame member, particularly a window-frame, comprising a rigid frame-shaped reinforcement made of e.g. a solid metal section embedded in synthetic resinous material. The method comprises placing the reinforcement in a mould cavity having the shape of the required frame member and locating the reinforcement in the cavity solely by engaging complementary interfitting formations on the reinforcement and on pin-like projections which extend from the cavity walls, e.g., recesses on the reinforcement engaging the ends of the projections. The longitudinal axes of all the projections are parallel to a predetermined plane and the engagement of the end of each projection with the complementary recess of the reinforcement prevents movement of the latter at least in first directions perpendicular to the plane. The projections are located around the reinforcement to prevent movement of the reinforcement in second directions parallel to the plane. The mould cavity is filled with synthetic resinous material to embed the reinforcement therein while the reinforcement is located in the cavity by the projections, and the cavity is subsequently opened and the projections withdrawn from the completed frame member which is then removed from the cavity.

I claim: 
     
       1. Apparatus for making an aperture-defining frame member .[.comprising.]. .Iadd.including .Iaddend.a rigid frame-shaped reinforcement embedded in synthetic resinous material, the apparatus comprising mould parts which define a mould cavity having the shape of the required frame member, the mould parts including a fixed inner member, outer members movable towards and away from the inner member in first directions parallel to a fixed plane .Iadd.containing said inner member .Iaddend.and a closing member movable towards and away from .Iadd.said .Iaddend.inner and outer members in second directions perpendicular to said plane, a plurality of pin like projections for locating the reinforcement in the cavity, means for mounting respective pairs of said projections on said inner and outer members around said cavity to prevent movement of the reinforcement in the cavity at least in directions parallel to said plane and so that the longitudinal axis of each projection is parallel to said plane and to one of said first directions; and positively operable means .Iadd.engaging respective projections mounted on said inner member .Iaddend.for projecting into and withdrawing from the mould cavity those respective projections mounted on the inner member. 
     
     
       2. Apparatus according to claim 1 wherein the longitudinal axes of all the projections lie in said plane. 
     
     
       3. Apparatus according to claim 1 wherein the respective projections mounted on the outer members are fixed in position relative thereto so as to be withdrawn from the frame member as the outer members are moved away from the inner member.