Patent · US Expired

Diagnostic system for rotational speed sensors in drive train of four wheels drive vehicle having central differential device

US4947325A · kind A · utility

14Cited by
5References
5Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJun 7, 1989
Grant dateAug 7, 1990
Priority date
Expiry dateJun 7, 2009

Classification

  • Technology area (CPC F)Mechanical Engineering; Lighting; Heating
  • CPC primaryF16H2061/1284
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

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.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.