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:
Oct. 28, 1997
Filed:
May. 31, 1995
Nippon Soken, Inc., Nishio, JP;
Abstract
A hydraulic control system for an automatic transmission of an automotive vehicle is provided which has a fail-safe function of preventing unsafe operation of the automatic transmission if a failure occurs in any of solenoid valves which control engagement operations of frictional elements such as clutches and brakes of the transmission. The hydraulic control system includes a hydraulic pressure flow control unit which controls hydraulic pressure flow between at least one of the frictional elements and at least one of the solenoid valves to allow the hydraulic pressure to be supplied to a predetermined combination of the frictional elements to achieve the power transmission at one of given gear ratios. The hydraulic pressure flow control unit restricts the hydraulic pressure flow to an inoperative combination of the frictional elements which provides no power transmission. With these arrangements, the power transmission is established if any of the solenoid valves malfunctions to allow the vehicle to travel.