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. 02, 2008
Filed:
Nov. 26, 2003
Thomas Knoblauch, Saarbrücken, DE;
Christoph Rüchardt, Bodolz, DE;
Otto Ebner, Friedrichshafen, DE;
Klaus Schweiger, Friedrichshafen, DE;
Matthias Winkel, Weingarten, DE;
Andreas Schwenger, Wolfsburg/Reislingen, DE;
Marcus Gansohr, Salem, DE;
Thomas Knoblauch, Saarbrücken, DE;
Christoph Rüchardt, Bodolz, DE;
Otto Ebner, Friedrichshafen, DE;
Klaus Schweiger, Friedrichshafen, DE;
Matthias Winkel, Weingarten, DE;
Andreas Schwenger, Wolfsburg/Reislingen, DE;
Marcus Gansohr, Salem, DE;
ZF Friedrichshafen AG, Friedrichshafen, DE;
Abstract
A known device for increasing the functional reliability for a hydraulic circuit of a hydraulic clutch having a pressure reservoir () and a release cylinder () which comprises a primary piston () and a secondary piston (). A compensation volume is developed in the sense that when the vehicle is at a standstill and the parking brake released, an unintentional release of the clutch is prevented. A pressure-monitoring/pressure-supply device () is used for determining a reference operating pressure and establishes a static pressure which, in case of any system error, only allows displacement of the secondary piston () such that the contact pressure of the clutch discs, against one another, is still sufficient to maintain the vehicle at a standstill.