Injection molding apparatus for making parts having complex geometric shapes

摘要

An apparatus for making parts having complex geometric shapes by injection molding apparatus. The apparatus avoids the formation of a parting line in the molded object. The apparatus includes an injector plate, an ejector plate and a floating plate. The injector plate has at least one mold cavity for making a part and a passageway to allow molten plastic to enter the mold cavity. The ejector plate has at least one mold cavity corresponding to the mold cavity in the injector plate. The floating plate has at least one projection. The plates are adapted to fit together when the mold is closed so that the floating plate is between the injector and ejector plates and the projection fits centrally between the cavities of the injector and ejector plates. A mechanism moves the injector plate, ejector plate and floating plate with respect to one another. Another mechanism provides a motion for forwardly jack-screwing the projection when a molded part is still in a deformable state while restraining the base of the part from movement to substantially remove the parting line from the molded part.