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:
May. 05, 2009
Filed:
Sep. 02, 2005
Charles F. Long, Pittsboro, IN (US);
Mark A. Rader, Avon, IN (US);
Bradley L. Mccafferty, Zionsville, IN (US);
Charles F. Long, Pittsboro, IN (US);
Mark A. Rader, Avon, IN (US);
Bradley L. McCafferty, Zionsville, IN (US);
General Motors Corporation, Detroit, MI (US);
Abstract
A hydrodynamic retarder control apparatus includes two valve spools, one, a retarder control valve, functions as a relay valve to control the on/off operation of a hydrodynamic retarder and the other, a regulator valve, functions to control the regulation of pressure at the hydrodynamic retarder. During abnormal periods of operation of the regulator valve, the retarder control valve will also function as a pressure control valve thereby limiting the maximum pressure at the hydrodynamic retarder.