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:
Aug. 22, 1989
Filed:
Dec. 07, 1988
Nobuyuki Kato, Toyota, JP;
Koujiro Kuramochi, Okazaki, JP;
Shinya Nakamura, Owariasahi, JP;
Yasuo Houjo, Nagoya, JP;
Toyota Jidosha Kabushiki Kaisha, Aichi, JP;
Abstract
The hydraulic pressure for operating the two wheel drive/four wheel drive switchover clutch in the part-time type four wheel drive device or the central differential lock-up clutch in the full-time type four wheel drive device is produced by a combination of a pressure regulation valve and two switchover valves to be selectable among several substantially different pressure levels so that the four wheel drive device can be quickly switched over between the complete four wheel operation and the complete two wheel operation, including one or more intermediate half clutched incomplete four wheel operation.