Patent ID: 7370745

Claim:
A hydraulic clutch-release system comprising a dual-piston clutch actuator for actuating a twin clutch of an automated manual transmission of a vehicle, the actuator comprising: a cylindrical housing; a first piston movably received in a first cylinder chamber in the housing and configured to actuate a first diaphragm spring of a first clutch of the twin clutch, the first piston having a first lateral surface with a first region; and a second piston movably received in a second cylinder chamber in the housing coaxially relative to the first piston and configured to actuate a second diaphragm spring of a second clutch of the twin clutch, the second piston having a second lateral surface with a second region facing the first region and in contact therewith, the first piston being movable in the first cylinder relative to the second piston, the second piston being movable in the second cylinder relative to the first piston, wherein the first and second regions are configured to slide sealingly against each other over an entire circumference of the second piston so as to separate the first and second cylinder chambers from each other.