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:
Dec. 08, 1987
Filed:
Feb. 18, 1986
Applicant:
Inventors:
Assignee:
George Fischer Ltd., Schaffhausen, CH;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B22D / ;
U.S. Cl.
CPC ...
164 661 ; 164119 ; 164154 ; 164259 ; 164306 ;
Abstract
A casting furnace is fed an inert gas under pressure through a feed line with the pressure being regulated by a melt level control device. When the pressure is reduced, the inert gas is exhausted from the casting furnace by an exhaust line, the feed line having a check valve to prevent gas which is contaminated by magnesium from entering the feed line. An oxidizing gas, preferably pressurized air, is periodically fed into the exhaust line by an oxidizing gas line for cleaning the drain line and the pressure-controlling aperture therein by oxidizing the magnesium.