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. 02, 2016
Filed:
Jan. 15, 2014
Jorg Arnold, Immenstaad, DE;
Georg Mihatsch, Lindau, DE;
Jorg Arnold, Immenstaad, DE;
Georg Mihatsch, Lindau, DE;
ZF Friedrichshafen AG, Friedrichshafen, DE;
Abstract
A method for operating a 9-speed transmission which changes operating states by actuating shift elements. At least one of the shift elements is a form-locking shift element, which disengages to implement a defined transmission operating state during which the power flow, between transmission input and output shafts, is present or interrupted. A sensor is associated with the locking shift element. An operating state of the locking shift element can be determined by the sensor. Upon a request to disengage the locking shift element, a disengagement control signal is generated and the locking shift element is actuated in the disengagement direction, depending on the disengagement control signal. The transmission is shifted to a safe operating state, in which at least the transmission output shaft can rotate, when an engaged operating state of the locking shift element is determined by the sensor even though a disengagement control signal was generated.