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:
May. 14, 1991
Filed:
Dec. 07, 1988
Yasunobu Ito, Aichi, JP;
Kenji Suzuki, Aichi, JP;
Aisin AW Kabushiki Kaisha, , JP;
Abstract
A fail-safe control device for an electronically controlled automatic transmission mounted on a vehicle is provided with a sensor for sensing the number of revolutions input to the transmission and a sensor for sensing the number of revolutions output from the transmission or from a car speed sensor. The actual gear ratio of the transmission is calculated in accordance with the number of revolutions input to the transmission and the number of revolutions output from the transmission or from the car speed sensor each obtained from said sensors. The time taken for changing the actual gear ratio at the time of shift initiation to the fixed gear ratio after the shift is measured. A predetermined shift time which has been stored is compared with the thus-measured time for the purpose of detecting a failure of the transmission. As a result of this, a driver can take a measure such as performing an emergency control or the like, and furthermore, the failure can be displayed by a failure alarm device so that the driver can arrange for repair.