Patent ID: 8187148

Claim:
A clutch system for producing and interrupting a force flow between an engine and a transmission of a motor vehicle, the clutch system comprising: one of a hydraulic fluid and a pneumatic fluid comprising a pressure medium; a clutch ( 2 ) being arranged between the engine and the transmission and normally being in a disengaged operating condition unless actuated and being actuatable by way of a pressure medium pressurizable clutch actuator ( 1 ) to an engaged operating condition, and at least one valve arranged in a pressure line system of a control valve arrangement ( 16 ), which regulates a volume flow of the pressure medium and being electrically actuatable by an electronic control and regulation unit ( 5 ), wherein the at least one valve ( 3 a , 3 a ′, 3 b ; 4 a , 4 a ′, 4 b ; 9 , 10 ) is designed such that if a failure of the voltage supply and consequently a failure of actuation of the at least one valve ( 3 a , 3 b ; 4 a , 4 b ; 9 , 10 ) by the electronic control and regulation system ( 5 ), a currently set operating condition of the clutch ( 2 ) existing at a time of the failure remains and is maintained so that if the voltage supply fails during driving and with a gearshift system inactive so that a gear is engaged, transmission of full clutch torque or a defined part thereof is ensured, and if the voltage supply fails when the motor vehicle is at rest, the engine is running and a transmission gear is engaged, an unintended engagement of the clutch is prevented.