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:
May. 09, 1989
Filed:
Sep. 29, 1982
Aisin Warner Kabushiki Kaisha, Aichi, JP;
Abstract
A hydraulic control system for a four-wheel drive torque transfer mechanism for a vehicle, including an automatic transmission, a transfer mechanism having gear positions of a two-wheel drive direct-coupling mode H.sub.2, a four-wheel drive direct-coupling mode H.sub.4 and a reduced-speed four-wheel drive mode L.sub.4, and a hydraulic control circuit for controlling the transmission and the transfer mechanism. The transfer mechanism includes a reduction gear mechanism, a first output shaft, a second output shaft rotationally connectible to the first output shaft through a link mechanism, a four-wheel drive clutch for releasably coupling the first and second output shafts, a direct-coupling clutch for releasably coupling an input shaft of the reduction gear mechanism with the first output shaft, and a reduction brake for setting the reducing gear mechanism in a gear train of the reduced-speed mode. The hydraulic control circuit includes an inhibitor valve which is supplied with governor pressure and which selectively applies pressurized fluid to one of the servomotors of the direct-coupling clutch and reduction brake while draining the other servomotor, the inhibitor valve feeding pressurized fluid continuedly to the servomotor of the direct-coupling clutch if manual shift of the transfer mechanism selects the mode L.sub.4 when the governor pressure is higher than a predetermined level, and instead feeding pressurized fluid to the servomotor of the reduction brake and draining the servomotor of the direct-coupling clutch when the governor pressure drops below the predetermined level.