Incoe Corporation

David M Reitan

Scott R Greb

Eric J Seres, Jr

A mold bushing for injecting plastic material into a mold cavity. The bushing member has a one-piece body member with a central passageway for a shut-off gate pin member and a separate and distinct passageway for the molten plastic material. In one embodiment, a tip member is positioned on the end of the body member and has a material discharge chamber. A gate or orifice opened and closed by the pin member is positioned either in the tip member or the mold. A wear bushing member can be positioned in the discharge chamber or the end of the body member 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 heater member or the like. In an alternate embodiment, the body member has an extension which partially fills the discharge chamber and the wear bushing is a cylindrical member positioned at the discharge end of the central passageway. In another alternate embodiment, an insert member is positioned on the lower end of the body member and held in place by a threaded sleeve member. The insert member has a first channel in alignment with the central passageway in the body member and a second channel in alignment with the molten plastic passageway. The first and second channels converge in an orifice whose opening is controlled by movement of the pin member.

Injection molding shut-off bushing with separate material flow path

A mold bushing for injecting plastic material into a mold cavity. The bushing member has a one-piece body member with a central passageway for a shut-off gate pin member and a separate and distinct passageway for the molten plastic material. A tip member is positioned on the end of the body member and has a material discharge chamber. A gate or orifice opened and closed by the pin member is positioned either in the tip member or the mold. A wear bushing member 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 heater member or the like. The wear bushing member can be indexed for proper positioning relative to the body member and the plastic flow passageway. The wear bushing member preferably has a body portion which partially fills the discharge chamber in the tip member. In an alternate embodiment, the body member has an extension which partially fills the discharge chamber and the wear bushing is a cylindrical member positioned at the discharge end of the central passageway.

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.

Injection mold bushing

A machine and method for injecting structural foam or other thermoplastic materials into one or more mold cavities. The machine comprises at least one mold-mounted shut-off bushing having a material delivery chamber formed between an outer body and a shank, with a shut-off pin slidably mounted in the shank, a heater being disposed between the pin and shank so as to heat the material passage as well as the shut-off pin tip. Closing of the shut-off bushings is independent of material pressures and is carried out from the space between a mold half and its platen by a cylinder operated cam rod.

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Union Lake, MI, United States of America

David M Reitan