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. 08, 2014
Filed:
Dec. 03, 2012
Zf Friedrichshafen Ag, Friedrichshafen, DE;
Klaus Steinhauser, Kressbronn, DE;
Andreas Schmidt, Bavendorf, DE;
Christian Villing, Langenargen, DE;
ZF Friedrichschafen AG, Friedrichschafen, DE;
Abstract
A method of controlling the system pressure in an automatic transmission having interlocking shifting elements in which, during shifts and gear engagement and gear disengagement processes involving interlocking shifting elements, as a function of the engagement and disengagement times of the interlocking shifting elements involved and the shift conditions of the frictional shifting elements involved, the system pressure is increased to an elevated pressure that enables rapid engagement or disengagement of the interlocking shifting elements, in such manner that the system pressure is increased in at least two phases whose timing depends on the shift conditions of at least one of the shifting elements involved.