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:
Jan. 09, 1996
Filed:
Aug. 26, 1994
Martin R Dadel, Plainfield, IN (US);
Charles F Long, Pittsboro, IN (US);
General Motors Corporation, Detroit, MI (US);
Abstract
The present invention is directed to a retarder control system for protection against transmission overspeed. The system operates in conjunction with a rotatable input member and an output member that is rotatable relative to the input member. A torque transfer device is operatively connected between the relatively rotatable input and output members. Specifically, a piston assembly is operated by an input control chamber that selectively receives pressurized hydraulic fluid which effects translation of the piston assembly to actuate the torque transfer device and thereby effect a driving connection between the relatively rotatable input and output members. The present system is adapted to control a hydrodynamic retarder assembly having a work cavity to receive hydraulic fluid. The retarder input valve assembly is supported from one of the relatively rotatable members selectively to deliver pressurized hydraulic fluid from the input control chamber to the retarder cavity. In order to achieve overspeed protection the retarder input valve opens in response to a predetermined angular velocity of the relatively rotatable member on which the retarder input valve assembly is supported. In a variation of the retarder control system explained above, a dump valve assembly is provided which opens selectively to release pressurized hydraulic fluid from the work cavity of said retarder in response to the pressure of the hydraulic fluid within said retarder work cavity.