INJECTION MOLDING SHUT-OFF BUSHING WITH SEPARATE MATERIAL FLOW PATH

摘要

A mold bushing (10) having a one-piece body member (30) with a central passageway (60) for a shut-off gate pin member (50) and a separate and distinct passageway for injecting molten plastic material into a mold cavity (16). A tip member (32) is positioned on the end of the body member and has a material discharge chamber (38). A gate or orifice (56) opened and closed by the pin member is positioned either in the tip member or the mold (12). A wear bushing (34) is positioned in the discharge chamber or the end of the body member and acts to support the end of the pin member and prevent the flow of plastic material into the central passageway. The body member is heated by an annular cast member (42). The wear bushing member can be indexed for proper positioning relative to the body member and the plastic flow passageway.