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:
Jan. 19, 1988
Filed:
Dec. 05, 1985
Applicant:
Inventors:
Kentaro Nagano, Yokohama, JP;
Taichiro Kotani, Hatano, JP;
Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01C / ;
U.S. Cl.
CPC ...
29618 ; 156630 ; 338302 ;
Abstract
A resistance element causing less sliding noise for use in wound-type variable resistors and a method of making the same are disclosed. A resistance element obtained by winding a metallic resistance wire on a core is subjected to etching treatment. With this etching treatment, the metallic oxides, chlorides and sulfides considered acting as insulators, and organic molecules, adsorbed gases and other contamination forming the surface layer of the resistance wire are dissolved and removed. Furthermore, by immersing the etched resistance element in an ammonia solution, etc., the copper precipitated on the surface of the resistance wire is dissolved.