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:
Nov. 29, 1988
Filed:
Mar. 31, 1987
Koichi Yamamoto, Hiroshima, JP;
Fumiaki Baba, Higashihiroshima, JP;
Mazda Motor Corporation, , JP;
Abstract
A control system for automatic transmission employed in vehicle comprises a torque converter coupled with an engine, a power transmitting gear arrangement coupled with the torque converter, a speed change device for giving rise to speed change in the power transmitting gear arrangement, a valve arrangement for controlling an operation fluid to be supplied to and drained from the speed change device, a revolving speed sensor for detecting the revolving speed of an input or output portion of the power transmitting gear arrangement when the shifting-down to a low speed with which an engine brake effect is to be obtained from a high speed in the power transmitting gear arrangement is carried out, and a control device for selecting, as the low speed of a target of the shifting-down, a first low speed with which the engine brake effect can be obtained and a second low speed with which the engine brake effect can not be obtained alternatively in response to the revolving speed detected by the revolving speed sensor. The control device selects further the first low speed after the second low speed is selected for a predetermined period of time on the occasion of the shifting-down.