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:
Jul. 27, 2021
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, when there is a demand to engage the parking lock device () originating from a disengaged operating condition of the parking lock device (), applying a pilot pressure (p_EDS) at the parking lock valve (PSV) and applying the main pressure (p_sys) at the parking lock valve (PSV), if necessary, via the positioning valve (POSV). The pilot pressure (p_EDS) and the main pressure (p_sys) are each guided to defined pressure levels at which the parking lock valve (PSV) is transferrable into the further operating condition range of the parking lock valve (PSV) by the active actuating force against the pilot pressure (p_EDS) and against the pressure between the parking lock valve (PSV) and the parking lock cylinder ().