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:
Mar. 11, 1997
Filed:
Oct. 06, 1995
Jack A Erickson, Andover, MN (US);
John M Melberg, Andover, MN (US);
Robert L Kramer, Minneapolis, MN (US);
John M Hallis, Buffalo, MN (US);
Federal-Hoffman, Inc., Anoka, MN (US);
Abstract
A lead-free rim-fire primer mix which utilizes cupric azide, a highly sensitive chemical, as the primary explosive in lieu of lead styphnate. The cupric azide is mixed with carefully selected proportions of nitrocellulose, tetracene, fine particles of ground glass and a binder, typically gum tragacanth. When mixed in the proper proportions, this mix has the required sensitivity, stability, and non-hygroscopicity for regular commercial rim-fire ammunition. The tetracene is not required as a sensitizer, but is used as an ignition aid. The preferred range of percentages are 10-36% by weight of cupric azide, 5-10% by weight of tetracene, 15-30% by weight of nitrocellulose, 20-50% by weight of glass, and 1-2% by weight of a suitable gum.