Automatic selective control of pumping engines

Claim 1

IN A PUMP CONTROL ARRANGEMENT FOR CONTROLLING THE OPERATING CONDITION OF A PLURALITY OF ENGINES WHICH OPERATE PUMP MEANS FOR A SYSTEM IN ACCORDANCE WITH THE VALUE OF THE SUCTION AND DISCHARGE PRESSURES IN THE SYSTEM, VARIABLE PREDETERMINED ENGINE OPERATING CONDITIONS BEING PROVIDED FOR VARIOUS VALUES OF SUCTION AND DISCHARGE PRESSURE, THE IMPROVEMENT COMPRISING INPUT MEANS HAVING TRANSDUCER MEANS OPERATIVE TO PROVIDE ANALOG SIGNALS REPRESENTATIVE OF SUCTION AND DISCHARGE PRESSURES IN THE SYSTEM, ANALOG TO DIGITAL CONVERTER MEANS CONNECTED TO SAID INPUT MEANS OPERATIVE TO PROVIDE DIGITAL SIGNALS REPRESENTATIVE OF THE SUCTION AND DISCHARGE PRESSURES IN THE SYSTEM, MEANS RESPONSIVE TO SAID DIGITAL SIGNALS TO PROVIDE A SUCTION RANGE SIGNAL REPESENTING A PREDETERMINED RANGE INCLUDING THE SUCTION PRESSURE REPRESENTED BY SAID DIGITAL SIGNALS AND A DISCHARGE RANGE SIGNAL REPRESENTING A PREDETERMINED RANGE INCLUDING THE DISCHARGE PRESSURE REPRESENTED BY SAID DIGITAL SIGNALS, AND MEANS RESPONSIVE TO SAID SUCTION RANGE SIGNAL AND SAID DISCHARGE RANGE SIGNAL TO OPERATE SAID ENGINES IN THE PREASSIGNED CONDITIONS FOR SAID SUCTION AND DISCHARGE PRESSURES.