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. 05, 1991
Filed:
May. 10, 1991
John G Kubisch, Midland, MI (US);
Paul D Wilczynski, Bay City, MI (US);
General Motors Corporation, Detroit, MI (US);
Abstract
Vacuum countergravity casting apparatus and process employ a container having a peripheral wall defining an open bottom chamber that receives one or more molds or destructible patterns. A first inherently unstable mass of particulates (e.g., binderless sand) is disposed in the chamber about the molds/patterns and a second supportive mass of bonded particulates (e.g., resin-bonded sand) is disposed in the chamber about the molds/patterns beneath the first mass. The second supportive mass is strong enough to support the first mass and preferably the molds/patterns as well as castings ultimately formed as necessary during the casting operation in the event of intentional or unexpected interruption of a negative differential pressure established between the inside and outside of the container.