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:
Oct. 12, 2004
Filed:
Sep. 17, 2003
Mabuchi Motor Co., Ltd., Chiba, JP;
Abstract
The present invention provides a mechanical encoder device for use in a miniature motor, which encoder can provide, for each revolution of the motor, a plurality of pulses whose duty ratio does not change with time. A rotary contact portion is provided on a rotor shaft , and a pair of rotation-detecting brushes in sliding contact with the rotary contact portion are provided on a brush holder of an end cap . A plurality of rotary contact pieces are arranged on the outer circumferential surface of the rotary contact portion such that slits are formed therebetween. The paired rotation-detecting brushes are each formed of a resilient metal and each assume the shape of a cantilever plate or wire spring whose side surface portion is subjected to sliding contact. An inter-brush angle &agr; corresponding to an arcuate angle between contact points at which the paired rotation-detecting brushes abut the rotary contact portion is less than an arcuate angle &bgr; corresponding to a single rotary contact piece, whereby a plurality of pulses are generated while the rotor shaft rotates one revolution.