Patent ID: 7252500

Claim:
In a check valve assembly for an injection molding apparatus having a rotatably and axially translatable feed-screw within a barrel bore for moving a plasticized polymeric material through the valve assembly towards an exit chamber of the apparatus, the check valve assembly characterized by; (A) a body member having a first forward valve seat surface and a first rearward valve seat surface, and (B) an axially slideable valve member movable from a valve-opened position, allowing plasticized material to move through the valve, to a valve-closed position prohibiting any material from entering the valve, the slidable member having, (1) a second forward valve seat surface which frictionally engages the first forward valve seat surface (2) a second rearward valve seat surface which sealingly and frictionally engages the first rearward valve seat surface, and (3) an outside diameter surface which sealingly and frictionally engages the inner surface of the barrel bore (C) the valve seats and the outside diameter surface constituting frictional wear surfaces (D) the improvement comprising a plurality of cylindrical recesses extending into at least part of the valve seats, said recesses filled with abrasion resistant disks securely attached therein, said disks effectively reducing frictional wear between relatively co-acting frictional wear surfaces and between the surfaces and the plasticized material as it is moved through the check valve assembly.