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:
Oct. 01, 1991
Filed:
Aug. 08, 1990
Nobuyuki Kato, Toyota, JP;
Seitoku Kubo, Toyota, JP;
Katsumi Kouno, Toyota, JP;
Tetsuya Abe, Toyota, JP;
Hiroshi Itoh, Toyota, JP;
Kunio Morisawa, Toyota, JP;
Ryoji Habuchi, Aichi, JP;
Toyota Jidosha Kabushiki Kaisha, Toyota, JP;
Abstract
An apparatus for controlling a vehicle continuously variable transmission, including a directional control valve having a first spool movable between a shift-down and a shift-up position, a flow control valve including a second spool movable between a flow-restricting and a non-restricting position, and a first and a second solenoid-operated valve for applying an actuating pressure to the first and second spools. The directional and flow control valves and the solenoid-operated valves are adapted such that the first and second spools are moved toward the shift-up and flow restricting positions, respectively, when the actuating pressure is not applied to the spools, or when solenoid coils of the two solenoid-operated valves are both off. The directional control valve may have a shift-down chamber for receiving a pilot pressure to move the first spool to the shift-down position when a failure of one of the solenoid coils exists while the vehicle speed is lower than a predetermined limit.