Injection molding machine and method
AssigneeIncoe Corporation
InventorDavid M. Reitan
Life of this patent
Estimating the term…
Abstract
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.
Claims12
A shut-off bushing for an injection molding machine comprising an elongated hollow outer body having a central axis, a shank within and fixed to said body, the facing surfaces of the body and shank forming an axially uninterrupted material passage, a relatively narrow delivery orifice formed in one end of said body by radially inwardly extending portions thereof and leading from said material passage, said one end of the body being immovable with respect to the remainder of the body, a shut-off pin slidably mounted in said shank and movable into closed position with respect to said orifice, said pin being at all times in non-obstructing relation with said material passage, heating means disposed inwardly of said material passage and in thermally conductive relation with said shank and said pin, and actuating means connected to said pin for moving said pin to its closed position independently of the pressure in said material passage and at said orifice.
A shut-off bushing for an injection molding machine comprising an elongated hollow outer body having a central axis, a shank within and fixed to said body, facing surfaces on the body and shank forming an axially uninterrupted material passage, a relatively narrow delivery orifice formed in one end of said body by radially inwardly extending portions thereof and leading from said material passage, a shut-off pin slidably mounted in said shank and movable into closed position with respect to said orifice, said pin being at all times in non-obstructing relation with said material passage, heating means disposed inwardly of said material passage and in thermally conductive relation with said shank, said heating means comprising a coil in contact with said pin and the interior surface of said shank, and actuating means connected to said pin for moving said pin to its closed position independently of the pressure in said material passage and said orifice.
An injection molding machine comprising two platens, a mold element carried by each of said platens, said mold elements forming at least one cavity, at least one shut-off bushing supported on one of said mold elements, said shut-off bushing having an orifice communicating with said cavity, actuating means for said shut-off bushing disposed between said one mold element and its platen, there being a plurality of shut-off bushings supported on said one mold element and a manifold supported between said shut-off bushings and the platent for said one mold element, said manifold having a platen for receiving material and passages leading from said port to said shut-off bushings, said actuating means being for said plurality of shut-off bushings and being disposed between said manifold and said one mold element, each said shut-off bushing having a slidably mounted pin moved by said actuating means to close said orifice, said actuating means comprising a cam rod slidably mounted for movement transversely to the extent of said pins, and a reciprocable motor moving said cam rod.
Dependencies are inferred from the claim text.