Variable compression ratio piston

Claim 1

IN A VARIABLE COMPRESSION RATIO PISTON FOR AN INTERNAL COMBUSTION ENGINE COMPRISING FIRST AND SECOND PARTS MOVABLE RELATIVE TO ONE ANOTHER IN RESPONSE TO RECIPROCATION OF THE PISTON, SAID PARTS DEFINING FIRST AND SECOND FLUID CHAMBERS WITHIN SAID PISTON WHICH VARY IN INTERNAL VOLUME OPPOSITELY TO ONE ANOTHER IN RESPONSE TO SAID RELATIVE MOVEMENT AND TO VARIATIONS IN THE QUANTITY OF FLUID THEREIN, A SUPPLY PASSAGE ADAPTED TO RECEIVE AN INCOMPRESSIBLE FLUID UNDER PRESSURE FROM A SOURCE EXTERNAL TO THE PISTON, FIRST AND SECOND INLET PASSAGE COMMUNICATING BETWEEN SAID SUPPLY PASSAGE AND SAID FIRST AND SECOND CHAMBERS RESPECTIVELY, NON-RETURN VALVE MEANS PERMITTING ONE-WAY FLOW OF FLUID THROUGH SAID FIRST AND SECOND PASSAGES TOWARDS SAID FIRST AND SECOND CHAMBERS RESPECTIVELY, A FIRST DISCHARGE PASSAGE LEADING FROM SAID FIRST CHAMBER TO THE EXTERIOR OF SAID PISTON, A PRESSURE REGULATING DISCHARGE VALVE CONTROLLING FLOW OF FLUID FROM SAID FIRST CHAMBER THROUGH SAID FIRST DISCHARGE PASSAGE AND MEANS FOR REGULATING DISCHARGE OF FLUID AT A RESTRICTED RATE FROM SAID SECOND CHAMBER INCLUDING A THIRD CHAMBER IN SAID PISTON NORMALLY FLOODED WITH SAID PRESSURE FLUID FROM SAID SUPPLY PASSAGE AND A FLOW CONNECTION ADAPTED FOR DRAINING FLUID FROM SAID THIRD CHAMBER TO THE EXTERIOR OF THE PISTON.