Variable delivery multi-liquid pump

Claim 1

A VARIABLE DELIVERY PUMP COMPRISING AN ELONGATED CYLINDER BLOCK HAVING A PLURALITY OF PARALLEL BORES FORMED THEREIN WHICH ARE RADIALLY SPACED SYMMETRICALLY AROUND THE PRINCIPAL AXIS OF THE BLOCK, EACH BORE HAVING A FIRST AND SECOND COUNTER-BORE TO DEFINE FIRST, SECOND, AND THIRD CYLINDERS IN EACH BORE, SAID BLOCK HAVING A FIRST SET OF RADIAL PASSAGES FORMED THEREIN TO DEFINE AN INLET PASSAGE AND AN OUTLET PASSAGE FOR EACH OF THE CYLINDERS, SAID BLOCK HAVING A SECOND SET OF RADIAL PASSAGES FORMED THEREIN TO DEFINE A BY-PASS MEANS FOR EACH CYLINDER WHICH PROVIDES FLUID COMMUNICATION BETWEEN A PORTION OF EACH CYLINDER AND ITS RESPECTIVE INLET PASSAGE, CHECK VALVES POSITIONED IN EACH INLET AND OUTLET PASSAGE, A PISTON ASSEMBLY POSITIONED WITHIN EACH BORE AND HAVING ONE END EXTENDING OUTWARDLY OF THE BORE, EACH PISTON ASSEMBLY COMPRISING FIRST, SECOND, AND THIRD PISTONS CONNECTED TOGETHER AND HAVING DIAMETERS SUBSTANTIALLY EQUAL TO THE INTERNAL DIAMETERS OF SAID FIRST, SECOND, AND THIRD CYLINDERS RESPECTIVELY, A SPRING POSITIONED WITHIN EACH BORE TO RESILIENTLY BIAS THE PISTON ASSEMBLIES OUTWARDLY OF THE BORES, A DRIVE SHAFT MOUNTED FOR ROTATION ABOUT THE AXIS OF SAID BLOCK, A DRIVE SHAFT HOUSING CONNECTED TO THE END OF SAID BLOCK FROM WHICH SAID PISTON ASSEMBLIES EXTEND, A SWASH PLATE MOUNTED UPON SAID DRIVE SHAFT WITH ONE SIDE THEREOF IN ABUTTING RELATIONSHIP WITH THE ENDS OF SAID PISTON ASSEMBLIES AND BEING KEYED TO SAID SHAFT TO PERMIT ROTATION THEREWITH AS WELL AS LONGITUDINAL SLIDING MOVEMENT ALONG SAID SHAFT, AN ANNULAR ACTUATOR PISTON CONCENTRICALLY POSITIONED AROUND A PORTION OF SAID DRIVE SHAFT IN ABUTTING RELATIONSHIP WITH THE OTHER SIDE OF SAID SWASH PLATE, AND FLUID PASSAGE MEANS IN THE END OF SAID DRIVE SHAFT HOUSING ON THE SIDE OF SAID ACTUATOR PISTON REMOTE FROM SAID SWASH PLATE FOR RECEIVING THEREIN A CONTROL FLUID FOR MOVING SAID ACTUATOR PISTON INWARD AND THEREBY ADJUSTABLY POSITIONING SAID SWASH PLATE LONGITUDINALLY ALONG SAID SHAFT, WHEREBY ROTATION OF THE DRIVE SHAFT ROTATES THE SWASH PLATE TO RECIPROCATE THE PISTONS WHILE ACTUATION OF THE ACTUATOR PISTON MEANS CHANGES THE EFFECTIVE STROKE OF THE PISTONS.