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. 23, 1994
Filed:
Jul. 23, 1993
Tokyo Parts Industrial Co., Ltd., Isesaki, JP;
Abstract
A dc vibrator motor has a generally cylindrically-shaped magnetically conductive case, a ring-shaped permanent field magnet, and an armature rotor including a shaft. The field magnet has at least four and at most eight alternate north and south pole sections arranged at an even angular pitch coaxially with the shaft. The armature rotor has at least three armature poles having an angular interval of 60.degree. between adjacent poles and at most six armature poles having an angular interval of 30.degree. between any pair of adjacent poles and at least six and at most twelve commutator segments arranged at an even angular pitch coaxially with the shaft. A pair of commutator brushes have an angular interval of at least 45.degree. and at most 90.degree. . Since all of the armature poles are situated within an angular range of 180.degree. about the shaft, the center of mass of the rotor is radially off the shaft, thereby causing vibrations.