Mold clamping device for injection molding machine

Claim 1

A mold clamping device for injection molding machines having a pair of closable mold halves, comprising: A. an open interior mold clamping ram; B. a quick feed ram operatively movably inserted through said mold clamping ram; C. a pair of opposed threaded half nuts hydraulically movably mounted in said mold clamping ram and extendable into or retractable from the open interior thereof; D. a screw thread on the periphery of said quick feed ram of mating configuration with those of said half nuts; E. a movable plate and a fixed plate, said mold halves being disposed between said movable and fixed plates; F. an outwardly extending peripheral flange on said quick feed ram; G. a connecting ring attached to said movable plate including an inwardly extending rim spaced from said movable plate and forming a gap therebetween, said flange being movable in said gap a distance nearly equal to the tooth thickness of the respective screw threads and in a direction whereby the respective screw threads are brought into perfect engagement by inward pressure applied to said half nuts and a component force on the slanting surfaces of the respective screw threads in contact with one another; H. said quick feed ram, upon mold closing, being moved with respect to said mold clamping ram and the threads of said half nuts and of said quick feed ram interengaging and interconnecting said mold clamping and said quick feeding rams, thereby directly pressing said quick feed ram in the direction of a mold by said mold clamping ram.