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:
Feb. 02, 1999
Filed:
Jan. 08, 1997
Denso Corporation, Kariya, JP;
Abstract
To provide a hydraulic controller for automatic transmission use which commonalizes a lockup control valve and a friction engagement element control valve, thereby simplifying a hydraulic circuit, reducing the number of parts, and achieving low cost, a lockup solenoid to control engagement or release of a lockup clutch, a first friction engagement element to engage an friction engagement element only in a portion or entirety of a shifting stage to prohibit lockup, and a manual shift lever to determine whether a vehicle exists in a lockup prohibition condition are provided. A switching valve selectively switches the lockup solenoid to either communicate with the lockup clutch or communicate with the foregoing first friction engagement element. The manual shift valve is disposed in a path extending from the switching valve to the first friction engagement element.