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:
Jan. 15, 1991
Filed:
Oct. 31, 1988
Kazuhiko Sugano, Yokohama, JP;
Nissan Motor Co., Ltd., Yokohama, JP;
Abstract
In order to increase a torque transmission capacity of a lock-up clutch without any increase in the internal pressure of a torque converter, a lock-up clutch release circuit and a lock-up clutch engagement circuit share a primary relief valve, and the lock-up release circuit is further provided with a secondary relief valve disposed between a lock-up control valve and the torque converter. Thus, when the lock-up clutch engagement circuit is opened, the primary relief valve works to prevent the pressure of hydraulic fluid from increasing above a first predetermined value, whereas, when the lock-up clutch release circuit is opened, the secondary relief valve causes a drop in the hydraulic pressure and prevents the hydraulic pressure from increasing above a second predetermined value. The first predetermined value is higher than the second predtermined value.