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. 20, 2001
Filed:
May. 03, 1999
Hitachi, Ltd., Tokyo, JP;
Abstract
A hydraulic control apparatus for an automatic transmission, which is improved in accurately controlling a variation in torque generated when a shift lever is turned from an N range into a D range or R range by perfectly electronically controlling a hydraulic control system. The hydraulic control apparatus has a pressure governing means for governing a hydraulic pressure, which has been generated by a hydraulic pressure generating means of an automatic transmission and is to be supplied from a spool valve to a clutch, by an actuator, thereby suppressing a variation in output torque of the automatic transmission. The hydraulic pressure governed by the actuator is introduced into the spool valve again, and it is supplied to a forward clutch and a reverse clutch through a hydraulic line switching means for switching hydraulic lines communicated to the forward clutch and the reverse clutch from each other.