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:
Aug. 24, 2010
Filed:
Oct. 13, 2006
Georg Gierer, Kressbronn, DE;
Thilo Schmidt, Meckenbeuren, DE;
Anton Fritzer, Markdorf, DE;
Markus Herrmann, Scheidegg, DE;
Georg Gierer, Kressbronn, DE;
Thilo Schmidt, Meckenbeuren, DE;
Anton Fritzer, Markdorf, DE;
Markus Herrmann, Scheidegg, DE;
ZF Friedrichshafen AG, Friedrichshafen, DE;
Abstract
A control valve arrangement having a clutch regulation valve (), which pressurizes a device to actuate the clutch, and a valve that produces a controlled pilot pressure (P_VST). An electronic control unit (ECU) controls a valve to supply a control valve with the pressure (P_VST). The arrangement further having a hydraulic system which, if the ECU fails and the pressure (P_VST) ceases, the last shift condition of the clutch actuation device, prior to the ECU failure, can be maintained in an emergency. The arrangement includes a valve, which delivers an activation pressure (P_A), depending on an engine-speed-dependent control pressure (P_D), to an actuation valve (), which then delivers the pressure (P_A) to the valve () to prevent the emergency function initiation despite a lack of pressure (P_VST) and existence of the pressure (P_D) sufficiently high to initiate the emergency function.