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:
Oct. 22, 2002
Filed:
Apr. 17, 2000
Robert E. Hildebrand, Webster, NY (US);
Xerox Corporation, Stamford, CT (US);
Abstract
In a method of plastic injection molding of plastic parts with a critical external dimensional accuracy, in particular plastic gears, the plastic molding material is first injected into the mold, and then gas is injected under pressure into the mold to reduce shrinkage of the plastic material away from the mold surface, forming a gas bubble in the plastic molding material in the mold. Then after cooling of that first injected plastic, a separate, secondary injection of more of the same plastic material under pressure into the gas bubble, in the mold (before removing the plastic part from the mold), provides increased strength and a uniform rotational moment of inertia of the gear.