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:
Sep. 28, 1993
Filed:
Dec. 02, 1991
Tsunefumi Niiyama, Saitama, JP;
Honda Giken Kogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
A hydraulic relief valve according to the invention comprises; a housing having a clutch port communicating with a hydraulic chamber of a given hydraulic clutch and a drain port communicating with a drain, a spool inserted in the housing and being movable between an operational position at which the clutch port is isolated from the drain port and a relief position at which the clutch port communicates with the drain port, and biasing means to push the spool toward the operational position. The housing further includes an up-shift port communicating with a hydraulic chamber of an up-shift clutch which is engaged when the speed range is shifted up from the given speed range and a down shift port communicating with a hydraulic chamber of a down-shift clutch which is engaged when the speed range is shifted down from the give speed range. The hydraulic pressure in the chamber of the up-shift clutch is supplied into said housing through the up-shift port to push the spool toward the relief position when the speed range is shifted up. The hydraulic pressure in the chamber of the down-shift clutch is supplied into the housing through the down-shift port to push the spool toward the relief position when the speed range is shifted down.