Valving means for injection molding apparatus

Claim 1

In an injection molding apparatus having a housing manifold having means located therein for receiving a quantity of molten material, said molten material being transported from said receiving means through designated passages within said manifold, and means for heating said molten material during operation of said molding apparatus, a supply reservoir of molten material having pressure means connected thereto and being directly connected to said receiving means located within said housing manifold, a cavity member having a plurality of receptive ports located therein, the improvement comprising: a plurality of valving means positioned within said housing manifold and connected to said passages within said manifold, and having means for heating said material during operation of said apparatus; a fluid pressure source joined to each of said valving means, each of said valving means having a substantially cylindrically shaped body having a first and second chamber located therein, an elongated rod member having first and second opposing end portions and adapted to move within said first and second chamber, said first chamber having at one end an entrance port connected to one of said designated passages within said housing manifold, and at the other end an exit port which aligns with and connects to one of said receptive ports within said cavity member, said elongated rod member having a piston attached at said second opposing end, said piston adapted for moving within said second chamber, said second chamber being joined at one end to a first pressure port and at the other end to a second pressure port, said first and second pressure ports being attached to said fluid pressure source, thereby causing said piston to move within said second chamber when pressure is altered on said first and second pressure ports by said pressure source.