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:
Aug. 04, 1992
Filed:
Apr. 05, 1990
Applicant:
Inventor:
Isao Shibuya, Matsudo, JP;
Assignee:
Mabuchi Motor Co., Ltd., Chiba, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H02K / ; H01R / ; H01R / ; H01R / ;
U.S. Cl.
CPC ...
310251 ; 310252 ;
Abstract
A carbon brush used for a miniature motor, which has a permanent magnet field and is caused to rotate through current commutation via a commutator, formed by bonding graphite powder and used for making sliding contact with the commutator for current commutation, in which the carbon brush is a metal-plated graphite brush formed by pressure-forming and sintering the graphite powder after covering particles of the graphite powder with a metallic layer; the graphite powder used for the metal-plated graphite brush being purified to reduce the ash content of the graphite powder to 0.05 wt. %, and the method of making the same.