US Patent 7571795 Coupling device of a motor vehicle

A coupling device of a motor vehicle with a clutch arranged in the force flow between a drive motor and a transmission and a dedicated servo-assisted control mechanism. The clutch is designed by way of a pressing spring as a passively lockable and via a clutch release sleeve disengageable and insertable dry friction coupling and the control mechanism includes an operative primary drive between a clutch pedal and the clutch release sleeve and a pneumatically operative servo drive with a pneumatic actuator ordered immediately to the clutch release sleeve and with a control valve controllable by the clutch pedal.