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. 02, 1994
Filed:
Nov. 24, 1992
Masahiko Ando, Okazaki, JP;
Koji Noda, Anjo, JP;
Yoshihisa Yamamoto, Nishio, JP;
Masahiro Hayabuchi, Anjo, JP;
Kazumasa Tsukamoto, Toyota, JP;
Yasuo Hojo, Nagoya, JP;
Seitoku Kubo, Toyota, JP;
Yutaka Taga, Aichi, JP;
Hidehiro Oba, Aichi, JP;
Aisin AW Co., Ltd., both of, JP;
Toyota Jidosha Kabushiki Kaisha, both of, JP;
Abstract
A control system is provided for servo hydraulic pressure in a vehicular automatic transmission having planetary gear mechanisms. Shifting elements of the mechanisms can be connected to establish a different power flow in accordance with engagement or release of frictional engagement devices under the control of servo hydraulic pressure to achieve plural speed stages. The system comprises a servo pressure feed line for feeding, even in a non-running range, servo hydraulic pressure to at least one particular device out of plural frictional engagement devices which are caused to simultaneously engage in a reverse range of the transmission, a directional control valve disposed in the line to control feed or drain of the servo hydraulic pressure to or from said particular device through the line, and a solenoid valve for controlling the control valve to prevent the feed of the servo hydraulic pressure at vehicle speeds above a predetermined value.