US 4,412,806 AGranted

Parison ejector for an injection molding apparatus

AssigneeBroadway Companies, Inc.

InventorsWilliam R. Gaiser, James Niepoky

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Abstract

A parison ejector is used in combination with an injection molding apparatus of the type for molding parisons having an injector portion including a plurality of mold cavities communicating with a source of molten plastic material, an ejector portion for engaging the injector portion which includes a movable platen, a plurality of cores shaped and positioned to matingly engage the mold cavities, and an ejector frame which is carried by the movable platen and supports the cores. The parison ejector includes a hydraulic ram which actuates an ejector carriage which carries a pair of jaws pivotally mounted on the carriage and having mating ends which meet to form bearing surfaces which receive cams mounted in the ejector frame. The ends of the jaws form a portion of the mold and the parison is partly formed within it. Reciprocal movement of the ejector carriage with respect to the ejector frame causes the bearing race to move relative to the stationary cam thereby forcing the jaws apart so that the molded parison is removed from the end of the core. The cores preferably are hollow and include a helical pathway for a coolant to flow therethrough.

Claims26

Dependent claims

In an injection molding machine of the type having an injector portion including a mold cavity module having a plurality of mold cavities communicating with a source of molten plastic material, an improved ejector portion comprising:

a platen mounted to said machine for reciprocating movement toward and away from said mold cavity module;
a frame mounted to said platen and extending toward said mold cavity module;
a plurality of cores mounted to said frame and extending toward said mold cavity module, said cores positioned to enter and withdraw from said mold cavities upon said reciprocating movement of said platen;
carriage plate means slidably mounted to said frame for movement toward and away from said platen and including a plurality of bores through which pass said cores;
a plurality of pairs of opposing jaws pivotally mounted to said carriage plate means, each of said pairs enclosing one of said cores and forming complementary portions of a parison mold;
said pairs of jaws including mating longitudinal edges defining opposing bearing surfaces having a converging portion proximate said carriage plate means;
cam means mounted to said frame and positioned between said opposing bearing surfaces;
and
means for reciprocating said carriage plate means relative to said frame and cores such that movement of said carriage plate means away from said platen in an ejection sequence causes said jaws to move relative to said cores thereby removing molded parisons therefrom and causes said bearing surfaces to slidably engage said cam means whereby said cam means forces said pairs of jaws apart upon encountering said converging portions thereof so that said jaws release molded parisons from said mold portions thereof.

6 more elements

For use with an injection molding machine for forming parisons of the type having an injector portion including a mold cavity module having a plurality of mold cavities communicating with a source of molten plastic material and an ejector portion for engaging said injector portion including a movable platen, a parison ejector apparatus comprising:

a frame having a rear portion adapted to be mounted to a platen and having a plurality of cores mounted thereto and an upper plate having a plurality of openings through which said cores extend and adapted to abut a mold cavity module when an associated ejector portion engages an associated injector portion;
carriage plate means slidably mounted to said frame for reciprocal movement between said upper plate and said rear portion, said carriage plate including a plurality of transverse bores through which pass said cores;
pairs of opposing jaws enclosing each of said cores, each of said jaws pivotally mounted to said carriage plate means and formning a complementary portion of a parison mold;
said pairs of opposing jaws including mating longitudinal edges defining opposing bearing surfaces having converging portions proximate said carriage plate means;
cam means mounted in said upper plate and extending between said opposing bearing surfaces;
and
means for reciprocating said carriage plate means relative to said frame and said cores such that movement of said carriage plate means toward said upper plate in an ejection sequence causes said jaws to move along said cores thereby removing molded parisons therefrom and causes said bearing surfaces to slidably engage said cam means whereby said cam means forces said jaws to pivot away from each other upon encountering said converging portions such that a parison formed on said core may be urged off of said core and out of said complementary portions.

4 more elements

Dependencies are inferred from the claim text.