Flow control system

Claim 1

APPARATUS FOR MAINTAINING A CONSTANT-WEIGHT RATE OF DELIVERY OF A FLOWING MATERIAL, COMPRISING A LEVER SYSTEM SUPPORTED ON A FULCRUM, A RESERVOIR FOR SAID FLOWING MATERIAL, THE WEIGHT OF SAID RESERVOIR BEING SUPPORTED BY SAID LEVER SYSTEM TO ONE SIDE OF THE FULCRUM, A LEAD SCREW LONGITUDINALLY MOUNTED ON THE LEVER SYSTEM AND EXTENDING TO THE OTHER SIDE OF THE FULCRUM, A POISE WEIGHT RIDING ON THE LEAD SCREW, AN ELECTRIC MOTOR MOUNTED ON THE LEVER AND COUPLED TO THE LEAD SCREW, ELECTRICAL CONTROLLER MEANS HAVING THEIR OUTPUT CONNECTED TO ENERGIZE SAID MOTOR FOR ROTATING THE LEAD SCREW AT A PREDETERMINED CONSTANT RATE, WHEREBY SAID POISE WEIGHT IS CAUSED TO MOVE ALONG THE LEAD SCREW TOWARD THE FULCRUM AT A PREDETERMINED CONSTANT RATE CORRESPONDING TO A DESIRED RATE OF FLOW FROM SAID RESERVOIR, A SENSING ELEMENT ATTACHED TO AN END OF THE LEVER AND RESPONSIVE TO A DEPARTURE OF SAID LEVER FROM BALANCE POSITION TO PRODUCE AN ERROR SIGNAL PROPORTIONAL TO SAID DEPARTURE, OUTLET MEANS FOR SAID RESERVOIR, A VALUE IN SAID OUTLET MEANS, ELECTRICAL MOTOR MEANS FOR REGULATING THE FLOW THROUGH SAID VALVE, SECOND CONTROLLER MEANS HAVING THEIR INPUT CONNECTED TO SAID SENSING ELEMENT AND THEIR OUTPUT CONNECTED TO SAID VALVE MOTOR MEANS FOR ENERGIZING SAID VALUE MOTOR MEANS PROPORTIONALLY TO THE ERROR SIGNAL FROM SAID SENSING ELEMENT, WHEREBY THE FLUID FLOW THROUGH SAID VALVE IS REGULATED PROPORTIONALLY TO SAID ERROR IN SUCH A MANNER AS TO CORRECT THE CONDITION OF THE LEVER SYSTEM CAUSING THE ERROR SIGNAL.