Fluid pressure operated friction clutch

Claim 1

A FLUID PRESSURE OPERATED FRICTION CLUTCH COMPRISING A CLUTCH DRUM, FIRST CLUTCH DISCS CARRIED BY SAID DRUM, SECOND CLUTCH DISCS CARRIED BY OTHER PORTIONS OF SAID CLUTCH ASSEMBLY, AN ANNULAR CYLINDER DEFINED BY SAID DRUM, AN ANNULAR PISTON SITUATED WITHIN SAID CLUTCH DRUM AND COOPERATING THEREWITH TO DEFINE A FLUID PRESSURE CHAMBER, A CLUTCH PRESSURE PLATE SITUATED ADJACENT SAID DISCS, A BELLEVILLE SPRING WASHER LOCATED WITHIN SAID DRUM WITH ITS INNER MARGIN ENGAGING SAID PISTON AND ITS OUTER MARGIN LOCATED AT A RADIALLY OUTWARD LOCATION, AND A FLOW RESTRICTING ORIFICE FORMED IN SAID CYLINDER AT A RADIALLY OUTWARD LOCATION, A DEFORMABLE SEAL SITUATED ADJACENT SAID FLOW RESTRICTING ORIFICE AND ADAPTED TO REGISTER THEREWITH, THE OUTER MARGIN OF SAID BELLEVILLE SPRING BEING ENGAGEABLE WITH SAID SEAL TO MOVE SAID SEAL INTO REGISTRY WITH SAID ORIFICE THEREBY PROGRESSIVELY SEALING THE SAME AS FLUID PRESSURE IS DEVELOPED IN SAID WORKING CHAMBER, SAID PRESSURE PLATE ENGAGING SAID BELLEVILLE SPRING AT A LOCATION INTERMEDIATE ITS INNER AND OUTER PERIPHERIES.