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:
Apr. 04, 1978
Filed:
Jan. 17, 1977
Robert H Schaefer, Westfield, IN (US);
Ted M McQuinn, Carmel, IN (US);
General Motors Corporation, Detroit, MI (US);
Abstract
A multiratio powershift transmission having fluid operated drive devices including a forward clutch with an apply chamber supplied with fluid apply pressure to engage the clutch for forward drives and exhausted to disengage the clutch for reverse drive. The apply chamber is in a housing rotating at input speed during forward and reverse drive. In forward drive, a dump valve mounted on the rotating housing is biased closed by a spring, static fluid apply pressure, and centrifugal pressure head, in the rated input speed range. At a higher speed, centrifugal force on the dump valve element opens the dump valve to exhaust the apply chamber and disengage forward drive. In reverse drive, the dump valve is biased closed only by the spring which at idle speed closes the dump valve, and at a low speed used in reverse drive, centrifugal force opens the dump valve to flush the dump valve during reverse drive.