Hydraulic apparatus

Claim 1

AN ENERGY TRANSLATING FLUID PRESSURE DEVICE COMPRISING, A HOUSING, A CYLINDER BARREL, MEANS ROTATIVELY SUPPORTING SAID CYLINDER BARREL IN SAID HOUSING, SAID CYLINDER BARREL HAVING A PLURALITY OF CYLINDER BORES, A PISTON DISPOSED IN EACH OF SAID BORES AND RECIPROCAL THEREIN, VALVING MEANS INCLUDING PORTS DISPOSED IN SAID HOUSING AND POSITIONED TO SEQUENTIALLY REGISTER WITH SAID CYLINDER BORES, SAID DEVICE HAVING A PRINCIPAL AXIS ABOUT WHICH THE CYLINDER BARREL ROTATES, SUPPORT MEANS DISPOSED IN SAID HOUSING, SAID SUPPORT MEANS INCLUDING A SURFACE INCLINED WITH RESPECT TO A PLANE NORMAL TO THE PRINCIPAL AXIS AND INTERSECTING SAID AXIS, A PRIMARY CAM PLATE HAVING A FIRST FACE PARALLEL TO AND SUPPORTED BY SAID SURFACE OF THE SUPPORT MEANS, SAID PRIMARY CAM PLATE HAVING A SECOND FACE OPERATIVELY ENGAGING SAID PISTONS, SAID SECOND FACE BEING INCLINED WITH RESPECT TO SAID FIRST FACE, MEANS TO ROTATE SAID PRIMARY CAM PLATE ABOUT AN AXIS INCLINED WITH RESPECT TO THE PUMP AXIS FROM A FIRST POSITION WHEREIN THERE IS A MINIMUM CAM ANGLE AND THE LENGTH OF THE PISTON STROKE IS A MINIMUM TO A SECOND POSITION WHEREIN THE CAM ANGLE IS A MAXIMUM AND THE LENGTH OF THE PISTON STROKE IS A MAXIMUM, THE LOCATION ON SAID PRIMARY CAM PLATE DEFINING THE POINT OF MAXIMUM PISTON DISPLACEMENT BEING MOVEABLE ANGULARLY WITH RESPECT TO THE VALVE PORTS WITH THE ROTATIONAL MOVEMENT OF THE CAM PLATE FROM ITS FIRST POSITION TO ITS SECOND POSITION, SAID CAM PLATE HAVING AT LEAST ONE ADDITIONAL OPERATIVE POSITION INTERMEDIATE ITS FIRST AND SECOND POSITIONS, WHEREBY ROTATION OF THE PRIMARY CAM PLATE WILL CHANGE BOTH THE LENGTH OF THE PISTON STROKE AND THE ANGULAR POSITION OF THE HIGH AND LOW POINTS OF THE CAM PLATE WITH RESPECT TO THE PORTS.