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:
Apr. 01, 2003
Filed:
Jun. 12, 2000
Takashi Sano, Shizuoka, JP;
Jatco LTD, Fuji, JP;
Abstract
An automatic transmission has a frictionally engaging element, such as a low-and-reverse brake or the like, that is hydraulically actuated for assuming a certain gear position. A hydraulic control system for the transmission comprises a first hydraulic section which produces a line pressure; a solenoid which produces a solenoid pressure; a decompression control valve which receives the line pressure to produce an output pressure while using both the solenoid pressure and the output pressure as signal pressures; a switching valve interposed between the decompression control valve and the frictionally engaging element. The switching valve has a first position wherein the output pressure is fed to the frictionally engaging element and a second position wherein the line pressure is fed to the frictionally engaging element. The hydraulic control system further comprises a second hydraulic section that keeps the switching valve at the first position when a signal pressure applied thereto is lower than a predetermined switching pressure and turns the switching valve to the second position when the signal pressure becomes higher than the predetermined switching pressure.