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:
Aug. 19, 2014
Filed:
Mar. 25, 2010
Applicants:
Georg Gierer, Kressbronn, DE;
Thilo Schmidt, Meckenbeuren, DE;
Christian Popp, Kressbronn, DE;
Inventors:
Assignee:
ZF Friedrichshafen AG, Friedrichshafen, DE;
Attorneys:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
F16D 31/02 (2006.01); F15B 13/04 (2006.01); F15B 11/08 (2006.01);
U.S. Cl.
CPC ...
Abstract
A hydraulic transmission unit comprises at least one pressure regulation valve () and a pilot control valve () which is connected to the pressure regulation valve () by a pilot control line (). A pre-filling valve () sets a pre-filling pressure (p) to avoid draining of a clutch () and the lines () connected to the clutch () in an operating condition in which the clutch () is not actuated. To avoid draining when the clutch when in the operating condition, the pilot control line () is also connected to at least one line () which is pressurized with a second pre-filling pressure (p).