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:
Dec. 22, 1998
Filed:
Apr. 11, 1997
Ryoji Habuchi, Okazaki, JP;
Kojiro Kuramochi, Numazu, JP;
Masafumi Kinoshita, Toyota, JP;
Akiharu Abe, Toyota, JP;
Toyota Jidosha Kabushiki Kaisha, Toyota, JP;
Abstract
In a hydraulic control system for an automatic transmission of multiple clutch type for use in a motor vehicle, a shift valve which inverts the supply and cutoff of working oil for a hydraulic actuator serving to change-over gear shift stages is provided with a spool valvule and a clutch-oil-pressure supply port (as shown in FIG. 1). Even when a solenoid valve for controlling the shift valve has failed, a clutch oil pressure is supplied from the clutch-oil-pressure supply port so as to hold the switchover position of the spool valvule and to keep the gear shift stage already established. Thus, the hydraulic control system prevents an engine speed from rising or the motor vehicle from locking due to the failure of the solenoid valve.