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:
Feb. 26, 2019
Filed:
Jun. 17, 2016
Zf Friedrichshafen Ag, Friedrichshafen, DE;
Markus Herrmann, Scheidegg, DE;
Thilo Schmidt, Meckenbeuren, DE;
ZF FRIEDRICHSHAFEN AG, Friedrichshafen, DE;
Abstract
A hydraulic system for an automatic transmission a valve slide longitudinally adjustable in a valve housing between a first axial position and a second axial position such that a plurality of valve seat pockets are selectively brought into operative connection with each other. A control surface of the valve slide, first and second additional control surface of the valve slide and a spring of a parking brake valve are matched to one another such that the total actuating force applied to the slide valve displaces the slide valve to the first axial position when an actuating pressure of the parking brake unit, a pressure signal at the control surface of the valve slide and an additional pressure signal at the second additional control surface of the valve slide are applied.