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:
Feb. 10, 1987
Filed:
Nov. 27, 1985
Applicant:
Inventors:
Assignee:
General Motors Corporation, Detroit, MI (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B22D / ;
U.S. Cl.
CPC ...
164255 ; 164306 ; 164340 ; 164361 ; 164365 ;
Abstract
Apparatus for the countergravity, shell-mold casting process comprising a gas-permeable shell mold sealed in the mouth of a vacuum chamber and a hollow, expendable, gas-permeable, thermally degradable, core disposed with the molding cavity for engulfment and retention by the metal being cast. The core defines a central evacuation cavity and an unobstructed vent for exhausting the evacuation cavity into the vacuum chamber such that the pressure in the evacuation cavity is substantially equal to that in the vacuum chamber during casting.