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. 29, 1981
Filed:
Aug. 28, 1978
Applicant:
Inventors:
Lewis V McCarty, Cleveland Heights, OH (US);
John W Pugh, Gates Mills, OH (US);
Assignee:
General Electric Company, Schenectady, NY (US);
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
B21F / ; B21F / ;
U.S. Cl.
CPC ...
29 2514 ; 29 2518 ; 29424 ; 140 715 ;
Abstract
An electric lamp filament of tungsten is disclosed that has been coiled and heat-treated to at least 1600.degree. C. on a wire mandrel containing molybdenum but which is essentially free of molybdenum contamination. A barrier layer of tungsten or tantalum is provided on said mandrel to preclude the molybdenum contamination and the coated mandrel can thereafter be dissolved from the uncontaminated tungsten filament coil in an acid mixture.