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:
May. 19, 1998
Filed:
Nov. 27, 1996
Kazutoshi Ogino, Anjo, JP;
Makita Corporation, Anjo, JP;
Abstract
To inform a user of wear on a carbon brush for a motor earlier than when the carbon brush is actually required to be replaced with a new brush. In a motor brush wear indicating device, a metal terminal is attached to a brush holder, being opposed to the inside of a holder shank of the brush holder, and an indicator is operated when the metal terminal contacts a brush spring. The metal terminal has a contact in the middle of a length of the brush holder. The indicator can be operated while the carbon brush is continuously pressed against a commutator by the brush spring. The metal terminal serves as a leaf spring. When the carbon brush is worn and shortened, the indicator is operated. Even after the indicator operates, the carbon brush is still pressed against the commutator by the brush spring. Therefore, the user can operate a motor-driven tool for some time before the carbon brush must be replaced with a new one.