The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 15, 1994
Filed:
Aug. 26, 1992
David G Hlavaty, Allen Park, MI (US);
Suresh D Shah, Rochester Hills, MI (US);
David E Compeau, Oxford, MI (US);
General Motors Corporation, Detroit, MI (US);
Abstract
A gas injector having a retractable nozzle with linear gas feed passage therethrough for a gas assist plastics injection molding machine. The injector interfaces with the injection molding tool and has a nozzle with a tip that, in a forward position, protrudes through a port therein leading into the tool cavity or a runner system leading into the cavity for gas injection during molding. The nozzle tip is connected by a nozzle body to a base that is operatively mounted in an actuator housing. The base is connected to an in-line gas routing extension of the nozzle that projects through the outer cover of the housing. The extension is coaxial with an internal spring that seats on the base and holds the nozzle tip in a gas injection position resisting the force of plastics injection pressure. The base connected nozzle is retracted by combined flux fields of an electromagnet and a permanent magnet mounted within the housing while compressively loading the spring enhancing gas release from the cavity tool separation and subsequent ejection of molded part. The electromagnet is then deenergized since the permanent magnet has a sufficient magnetic force field to, hold the base and the attached nozzle in the retracted position. For return to the gas injection position, the electromagnet is again energized but with the current supplied thereto reversed so flux field of the electromagnet is reversed to negate flux field of the permanent magnet allowing the spring to return the nozzle to the forward position.