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. 07, 1990
Filed:
Jun. 07, 1989
Applicant:
Inventors:
Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01M / ; G01P / ;
U.S. Cl.
CPC ...
36442403 ; 36442405 ; 364565 ; 324161 ; 731181 ; 180233 ; 180249 ;
Abstract
A diagnostic system for detecting failure of rotational speed sensors incorporated in a central differential device of a four wheels drive vehicle for the purpose of controlling a lock-up clutch in the central differential device, wherein the rotational speed sensor for an output rotational member of the central differential device is checked, when the rotational speed detected thereby is lower than the rotational speed detected by the other rotational sensor, if the rotational speed detected thereby is continually zero over a period such as 10 seconds while the output of the other rotational speed sensor is above a certain low value.