Patent ID: 7861837

Claim:
A hydraulic clutch actuation system comprising: a hydraulic clutch control device including a first clutch master cylinder communicating via a first pressure-medium line with a first clutch slave cylinder used for actuating a first clutch device, and a second clutch master cylinder communicating via a second pressure-medium line with a second clutch slave cylinder used for actuating a second clutch device; and at least one emergency release valve device capable of relieving the pressure prevailing in the first or second pressure-medium lines to permit disengagement of at least one of the first and second clutch devices in an emergency situation, the emergency release valve device including: a 4/2-way directional control valve, the control valve having a connection for coupling to the first pressure-medium line, a connection for coupling to the second pressure-medium line, a connection for a first pressure-relief line, and a connection for a second pressure-relief line, the first pressure relief line being connectable via the 4/2-way directional control valve to the first pressure-medium line, the second pressure relief line being connectable via the 4/2-way directional control valve to the second pressure-medium line, and the control valve including an actuator disconnecting both the first pressure relief line from the first pressure-medium line and the second pressure relief line from first pressure-medium line in a first switching position and connecting both the first pressure relief line to the first pressure-medium line and the second pressure relief line to the first pressure-medium line in a second switching position.