Hydraulically operated clutch

Claim 1

A CLUTCH COMPRISING INNER AND OUTER ELEMENTS, THE INNER ELEMENT COMPRISING A HUB, A SERIES OF INTERLEAVED ANNULAR DISKS RESPECTIVELY CONNECTED WITH DIFFERENT ELEMENTS, AN ABUTMENT RING BETWEEN SAID ELEMENTS AND DETACHABLY FIXED TO ONE OF SAID ELEMENTS AT ONE END OF SAID SERIES OF DISKS AS A MEANS OF CONFINING SAID DISKS, AN ANNULAR PISTON OPPOSED TO SAID ABUTMENT RING AT THE OTHER END OF THE SERIES OF DISKS, AND MEANS INCLUDING A HEAD ON THE HUB ELEMENT AND AN ANNULAR FLANGE CONNECTED WITH THE HEAD AND RADIALLY SPACED FROM THE HUB ELEMENT AND PROVIDING A CYLINDER IN WHICH SAID PISTON IS RECIPROCABLE, SAID FLANGE AND HUB ELEMENT HAVING OUTER AND INNER CYLINDER WALL BEARING SURFACES BETWEEN WHICH THE PISTON IS GUIDED, INNER AND OUTER PACKING RINGS BETWEEN THE PISTON AND THE CYLINDER, ONE OF SAID RINGS BEING MOUNTED ON THE PISTON AND THE OTHER BEING MOUNTED ON THE CYLINDER, THE PISTON HAVING AN EXTERNAL PERIPHERAL CHANNEL IN WHICH THE OUTER PACKING RING IS DISPOSED, SAID HUB HAVNING A CHANNEL IN WHICH THE INNER PACKING RING IS DISPOSED, SPLINE GROOVES OF SAID HUB TO WHICH RESPECTIVE CLUTCH DISKS ARE KEYED BEING IN COMMUNICATION WITH SAID LAST MENTIONED CHANNEL.