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:
Sep. 12, 1989
Filed:
Aug. 30, 1988
Karl D Voss, Standish, MI (US);
James B Mercer, Saginaw, MI (US);
Gary F Ruff, Farmington Hills, MI (US);
General Motors Corporation, Detroit, MI (US);
Abstract
Apparatus for the vacuum-assisted, countergravity casting of thin-walled metal parts includes a plurality of expendable casting molds supported on a top side of a reusable drag slab. Each casting mold includes a mold cavity and a mold ingate passage extending from the mold cavity into registry with a respective underlying slab ingate passage that extends between the top side and a bottom side of the drag slab and that optionally includes a molten metal filter therein. When the bottom side of the drag slab is immersed in an underlying molten metal pool with the mold cavities evacuated, the molten metal is drawn upwardly through each slab ingate passage and the molten metal filter therein and then through each mold ingate passage registered therewith into each mold cavity. The molten metal filter in each slab ingate passage removes inclusion-forming impurities from the molten metal as it is drawn upwardly into each mold cavity. The presence of objectionable, non-metallic inclusions that can adversely affect part performance is thereby minimized in the thin-walled parts cast in the molds. The drag slab can be reused in the casting of successive sets of expendable casting molds.