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:
Sep. 17, 1996
Filed:
Nov. 18, 1994
Naoki Hakamada, Okazaki, JP;
Mitsuo Inagaki, Okazaki, JP;
Yoriaki Ando, Nagoya, JP;
Kunihiro Kubo, Nishio, JP;
Nippon Soken, Inc., Nishio, JP;
Abstract
A hydraulic control system for an automatic transmission of automotive vehicles is provided. The hydraulic control system includes a pressure source, a plurality of solenoid valves, and a plurality of directional control valves. Each solenoid valve selectively supplies and release hydraulic pressure to and from one of frictional element of a power train of the automatic transmission according to a given schedule of transmission operation for establishing a given gear ratio. The directional control valves are interposed between the frictional elements of the power train and the solenoid valves, respectively. Each of the directional control valves is responsive to input of the hydraulic pressure supplied from the pressure source through a preselected hydraulic line to assume first and second valve positions, the first valve position being to allow the hydraulic pressure to be directed to one of the frictional elements, the second valve position being to release the hydraulic pressure acting on one of the frictional element. Additionally, the hydraulic pressure to activate the frictional elements is reduced in pressure level temporarily upon supply thereto for absorbing mechanical shock caused by engagement of the frictional elements.