Patent ID: 8839930

Claim:
A device for controlling a rotating shifting element of an automatic transmission for a start-stop operation, to supply the transmission with pressure and cooling oil, a hydraulic pump being driven by an internal combustion engine, the shifting element being actuated by an axially moving piston ( 9 ) which is acted upon, in a disengaging direction, by a spring force of a spring ( 16 ) and which is acted upon, in an engaging direction, by hydraulic pressure in a pressure space ( 10 ), at least one spring-loaded latch ( 1 ), which is fixed in an axial direction on a hub ( 2 ) and is guided and movable in a radial direction, being arranged in the pressure space ( 10 ), when the internal combustion engine is running, the at least one spring-loaded latch ( 1 ) rotates together with the piston ( 9 ) and acts upon the piston ( 9 ) such that if the engine stops, the previously engaged shifting element is locked by virtue of a spring force so that as the hydraulic pressure decreases, the shifting element disengages, at most only partially, and when the engine is re-started, the locking action is released by an effect of centrifugal force, in opposition to the spring force, such that the piston ( 9 ) of the shifting element remains engaged, or is again fully engaged, due to the hydraulic pressure build-up in the pressure chamber ( 10 ).