Abstract: An injection mold bushing which is mounted on the mold and is adapted for sprueless molding. The construction comprises an inner shank and an outer body between which is mounted a heating element for independently controlling the heat at each gate. The material passage is straight and centrally located, minimizing the likelihood of material collecting and degrading in the passage, and making it simple to clear this passage if material build-up occurs. The location of the heater and insulating construction around the bushing insures that the mold will be uniformly cool relative to the material, minimizing distortion of the molded parts.

Abstract: Apparatus for coating one surface of a molded article that consists of a pair of hot relatively movable die members which when closed, form a cavity for molding the article in a desired configuration. A pin is selectively movable into and out of engagement with the surface of one of the die members. On retraction, the pin is also retracted through the opening in the injector nozzle allowing the injector to force material into the cavity to coat the outer surface of the article while the die members are closed. The barrel of the injector nozzle is cooled.

Abstract: An improved injection mold apparatus and method includes a gate interposed between a mold chamber or cavity and a runner passageway. The cross sectional opening of the gate is non-circular in shape and may comprise a plurality of foliations. The non-circular shape of gate opening enables the provision of sufficient area to insure adequate filling and compacting of molding material in a mold chamber within a reasonable time interval and also avoids difficult problems such as drooling, stringing, and/or freeze-off or blocking of material-supply passageways.