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:
Mar. 09, 2010
Filed:
Jan. 27, 2006
Kiyoharu Takagi, Okazaki, JP;
Kiyoharu Takagi, Okazaki, JP;
Aisin Seiki Kabushiki Kaisha, Kariya-Shi, Aichi-Ken, JP;
Abstract
There is provided a circuit configuration which does not require an additional fail-safe mechanism caused by the addition of a changeover valve in a hydraulic pressure control device for an automatic transmission having a function to directly supply a line pressure and hold (lock) an engaging pressure by combinations of electromagnetic valves and changeover valves. A changeover valveis disposed between an output portand a feedback portof a linear solenoid valveof the hydraulic pressure control device for an automatic transmission. The changeover valveoperates depending on at least an output pressure from the output port, and is switched between (1) a first state (control mode) in which a pressure Pc corresponding to an indicator current is outputted through the linear solenoid valveby bringing the output port into communication with the feedback port, and (2) a second state (lock mode) in which a line pressure PL is outputted through the linear solenoid valveby bringing the feedback portinto communication with a drain passage EX and discharging oil from the feedback port.