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:
Jun. 15, 1999
Filed:
Aug. 18, 1998
Charles Francis Long, Pittsboro, IN (US);
Martin Robert Dadel, Indianapolis, IN (US);
Jeffrey Jay Cole, Plainfield, IN (US);
General Motors Corporation, Detroit, MI (US);
Abstract
A pressure control valve system for a friction device has a regulator valve with a plurality of pressure feedback differential areas which are selectively pressurized during the engagement of a friction device to control the apply pressure at one rate during normal operation and at a higher rate during high torque demand operation. A plug valve is disposed adjacent the regulator valve to establish two variable control forces acting on the regulator valve in response to a variable control pressure. The combination of the differential areas and the plug valve permit the regulator valve to establish two distinct pressure gain functions, each of which has a knee or inflection point resulting in two pressure gain ratios.