Variable delivery pump

Claim 1

A VARIABLE DISPLACEMENT PUMP INCLUDING (1) A STATIONARY BASE PLATE, (2) A DRIVEN SHAFT ROTATABLY CARRIED BY THE BASE PLATE, (3) A ROTARY ARM CARRIED BY THE SHAFT, (4) A ROLLER ON THE ARM, (5) A SCREW ELEMENT ROTATABLY CARRIED BY THE BASE PLATE, (6) A CYLINDER BLOCK ARRANGED IN AXIAL ALIGNMENT WITH THE SHAFT IN SPACED RELATIONSHIP FROM SAID BASE PLATE AND ARM AND HAVING A PLURALITY OF CIRCUMFERENTIALLY SPACED AXIALLY EXTENDING CYLINDER BORES, (7) A PART ON THE BLOCK ENGAGED WITH SAID ROTATABLE SCREW MEMBER ON THE BASE PLATE, (8) INDEXING MEANS CARRIED BY THE BLOCK AND ENGAGING THE PLATE TO PREVENT RELATIVE ROTATION BETWEEN THE PLATE AND THE BLOCK AND FOR FREE AXIAL SHIFTING THEREBETWEEN, (9) A PISTON IN EACH CYLINDER BORE, (10) SPRING MEANS NORMALLY YIELDINGLY URGING THE PISTONS TOWARD THE BASE PLATE, (11) A KEEPER ON THE BLOCK CLOSING THE ENDS OF THE BORES ADJACENT THE BASE PLATE, (12) TAPPETS SLIDABLY CARRIED BY THE KEEPER TO ENGAGE THE PISTONS AND PROJECTING AXIALLY FROM THE KEEPER TOWARD THE BASE PLATE AND ARM, (13) A SWASH PLATE ARRANGED BETWEEN THE TAPPETS AND THE BASE BASE PLATE AND ROTARY ARM AND ENGAGED BY THE TAPPETS AND ROLLER ON THE ARM, (14) HANGER MEANS CARRIED BY THE BLOCK AND SUPPORTING THE SWASH PLATE FOR LIMITED UNIVERSAL MOVEMENT, (15) A HEAD ON THE BLOCK CLOSING THE OTHER ENDS OF THE CYLINDER BORES AND HAVING INLET AND OUTLET DUCTS COMMUNICATING WITH SAID BORES, (16) CHECK VALVES AT SAID DUCTS RESTRICTING REVERSE FLOW THERETHROUGH, (17) AND ACTUATING MEANS CONNECTED WITH SAID SCREW ELEMENT TO ROTATE SAID ELEMENT RELATIVE TO THE BASE PLATE AND BLOCK AND EFFECT AXIAL SHIFTING OF THE BLOCK RELATIVE TO THE BASE PLATE AND TO THEREBY VARY THE STROKE OF THE PISTONS AND THE VOLUMETRIC DELIVERY OF THE PUMP.