Axial piston pump or motor

Claim 1

AN AXIAL PISTON APPARATUS COMPRISING A STATIONARY SUPPORT STRUCTURE HAVING FIRST AND SECOND ANNULAR END PLATES, A ROTARY CYLINDER BLOCK HAVING A FIRST AND SECOND END PORTION, MEANS FOR ROTATIONALLY MOUNTING SAID BLOCK WITHIN SAID SUPPORT STRUCTURE, SAID BLOCK HAVING A PLURALITY OF CYLINDER BORES FORMED THEREIN AND EXTENDING IN A GENERALLY AXIAL DIRECTION, A PAIR OF PISTONS IN EACH OF SAID CYLINDER BORES, SAID FIRST AND SECOND ANNULAR END PLATES HAVING FIRST AND SECOND CAM MEANS DISPOSED THEREON, EACH OF WHICH HAS A CAM SURFACE INCLINED TO THE BLOCK ROTATION AXIS, SAID PAIR OF PISTONS IN EACH OF SAID BORES BEING BIASED INTO SLIDING ENGAGEMENT WITH THE CAM SURFACE OF SAID FIRST AND SECOND CAM MEANS, VALVE MEANS FOR CONTROLLING FLUID ENTRY TO AND FLUID DELIVERY FROM EACH OF SAID BOREA, MEANS SUPPORTING SAID VALVE MEANS SO THAT THE LATTER MEANS EXTENDS THROUGH THE CENTRAL OPENING IN SAID SECOND ANNULAR END PLATE AND SAID SECOND CAM MEANS SO AS TO ABUT THE SECOND END PORTION OF SAID BLOCK, PASSAGE MEANS IN SAID BLOCK FOR CONNECTING SAID VALVE MEANS TO SAID BORES, AND MEANS ENGAGING SAID SECOND CAM MEANS AND SAID VALVE MEANS FOR ANGULARLY ADJUSTING BOTH OF SAID LATTER MENTIONED MEANS ABOUT THE ROTATIONAL AXIS OF SAID BLOCK SUCH THAT THE ANGULAR ADJUSTMENT OF SAID VALVE MEANS IS HALF THE ANGULR ADJUSTMENT OF SAID SECOND CAM MEANS FOR ADJUSTMENT OF THE VOLUMETRIC DISPLACEMENT OF FLUID PER REVOLUTION OF SAID BLOCK.