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:
Oct. 27, 2020
Filed:
Mar. 20, 2017
Zf Friedrichshafen Ag, Friedrichshafen, DE;
Rainer Novak, Bregenz, AT;
Markus Terwart, Thundorf, DE;
Andreas Roedler, Taufkirchen, DE;
Alexander Hoffmann, Lebach, DE;
Andreas Feiner, Isny, DE;
Tobias Pfleger, Markdorf, DE;
ZF FRIEDRICHSHAFEN AG, Friedrichshafen, DE;
Abstract
A method for operating a parking lock device with a hydraulic system, the method including applying the pressure between the parking lock valve and the pressure chamber at the parking lock valve against the actuating force. Moreover, when there is a demand to disengage the parking lock device, the method includes applying the pilot pressure at the parking lock valve against the actuating force when the pressure between the parking lock valve and the pressure chamber of the parking lock valve is less than a threshold value at which the parking lock valve is transferred into a further operating condition range. Additionally, when there is a demand to disengage the parking lock device, the method includes adjusting the pilot pressure applied at the positioning valve to a pressure level at which the positioning valve is transferred into or held in its defined operating condition range.