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. 04, 1984
Filed:
Aug. 18, 1981
Alfons Loffler, Friedrichshafen, DE;
Zahnradfabrik Friedrichshafen, AG., Friedrichshafen, DE;
Abstract
A hydraulic control device for the pressurization of a clutch or the like for a transmission operable under load comprises a spool-type valve displaceable in one direction to pressurize the clutch and in the opposite direction to vent the same. The valve spool operates with a damping piston which receives the clutch pressure buildup and acts against a control piston which, in turn, is displaced by an operative valve. According to the invention, the pressure head is maintained substantially constant by providing a sleeve or bushing within the damping piston chamber which bears against the spool by a spring and which can be biased by a spring between the damping piston and the sleeve.