Hydrostatic engine and sheave assembly

Claim 1

A SHEAVE ASSEMBLY COMPRISING A HYDRAULIC CYLINDER AND PISTON ASSEMBLY HAVING MOVABLE PISTON DEFINING IN PART A FLUID PRESSURE CHAMBER, A FIRST SHEAVE ADAPTED FOR ROTATION ABOUT A FIXED AXIS, A SECOND SHEAVE ADAPTED FOR ROTATION ABOUT AN AXIS THAT IS PARALLEL TO THE AXIS OF SAID FIRST SHEAVE, A MECHANICAL CONNECTION BETWEEN SAID PISTON AND SAID SECOND SHEAVE WHEREBY SAID SECOND SHEAVE MAY BE ADJUSTED TOWARD AND AWAY FROM SAID FIRST SHEAVE AND SAID PISTON IS MOVED, FLEXIBLE CABLES EXTENDING FROM AN ANCHOR POINT AROUND SAID SECOND SHEAVE AND HENCE AROUND SAID FIRST SHEAVE TO A DRIVEN PORTION OF THE MECHANISM, A FLUID PRESSURE SOURCE, A CONDUIT STRUCTURE INTERCONNECTING SAID PRESSURE SOURCE AND SAID WORKING CHAMBER, FLOW CONTROL VALVE MEANS IN SAID CONDUIT STRUCTURE AND PARTLY DEFINING THE SAME FOR CONTROLLING THE RATE OF DISTRIBUTION OF PRESSURIZED FLUID TO SAID CHAMBER AND FOR CONTROLLING THE RATE OF DISPLACEMENT OF SAID FLUID FROM SAID PRESSURE CHAMBER, SAID FLOW CONTROL VALVE MEANS HAVING A MOVABLE VALVE ELEMENT ADAPTED TO CONTROL FLUID COMMUNICATION BETWEEN SAID PRESSURE SOURCE AND SAID PRESSURE CHAMBER AND HAVING FIRST AND SECOND OPERATING POSITIONS ON OPPOSED SIDES OF A NEUTRAL POSITION, SAID VALVE ELEMENT ESTABLISHING COMMUNICATION BETWEEN SAID SOURCE AND SAID PRESSURE CHAMBER WHEN IT IS ADVANCED TO SAID FIRST POSITION, SAID VALVE ELEMENT ESTABLISHING COMMUNICATION BETWEEN SAID PRESSURE CHAMBER SAID EXHAUST REGION WHEN IT IS ADVANCED TO SAID SECOND POSITION, A VALVE CONTROL LINKAGE CONNECTED TO SAID MOVABLE VALVE ELEMENT, A FEED-BACK CONTROL MECHANISM HAVING A POWER INPUT ELEMENT AND A POWER OUTPUT ELEMENT, MEANS FOR POWERING SAID POWER INPUT ELEMENT AT A CONSTANT SPEED, MEANS FOR CONNECTING SAID POWER OUTPUT ELEMENT TO SAID VALVE LINKAGE, AND ANOTHER ELEMENT OF SAID FEED-BACK MECHANISM BEING CONNECTED MECHANICALLY TO ONE OF SAID SHEAVES, SAID POWER OUTPUT ELEMENT BEING SENSITIVE TO THE DIFFERENTIAL IN SPEED BETWEEN SAID POWER INPUT ELEMENT AND SAID ONE SHEAVE WHEREBY OPPROPRIATE ADJUSTMENTS OF SAID VALVE ARE OBTAINED UPON A DEVIATION IN THE SPEED OF SAID DRIVEN MEMBER FROM A PREDETERMINED DESIGNED SPEED.