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:
Apr. 25, 2000
Filed:
May. 27, 1997
Applicant:
Inventors:
Assignee:
Denso Corporation, Kariya, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01P / ;
U.S. Cl.
CPC ...
7351439 ; 324174 ;
Abstract
A detector detects a rotational speed of a rotating object. The detector includes a closed magnetic circuit having a magnet therein, and detects the rotational speed according to a magnetic flux alteration in the closed magnetic circuit. The detector comprises a cylindrical rotor switch, which rotates together with the rotating object, and a fixed sensor device having a magnet, an electromagnetic coil and claws constituting a magnetic switch. At least two magnetic switches are provided in the closed magnetic circuit in order to increase the flux alteration in the circuit and thereby to enhance a detection accuracy.