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. 11, 2019
Filed:
Jun. 22, 2017
Zf Friedrichshafen Ag, Friedrichshafen, DE;
ZF FRIEDRICHSHAFEN AG, Friedrichshafen, DE;
Abstract
An electrohydraulic transmission control system () includes a parking lock valve (). The electrohydraulic transmission control system () is configured such that, during normal operation of the electrohydraulic transmission control system () in which at least one electrohydraulic pressure adjuster (EDSSYS) is actuatable with current, the parking lock valve () can be held in a defined operating state in which an actuation pressure (p_sys) acts on a parking lock cylinder () above a normal pressure level. The electrohydraulic transmission control system () is configured such that, during emergency operation of the electrohydraulic transmission control system () in which the at least one electrohydraulic pressure adjuster (EDSSYS) is not fed with current and the actuation pressure (p_sys) is at least temporarily set to an emergency pressure level higher than the normal pressure level by the at least one pressure source (), a pressure level of the actuation pressure (p_sys) that holds the parking lock valve () in the defined operating state corresponds at least approximately to the emergency pressure level.