Truck with hydraulic spreader apparatus

Claim 1

IN COMBINATION WITH A TRUCK HAVING A DRIVE MOTOR FOR PROPELLING THE TRUCK, A HOPPER ON THE TRUCK FOR RECEIVING MATERIAL TO BE SPREAD, A SPREADER APPARATUS INCLUDING MEANS FOR SPREADING MATERIAL AND FEED MEANS FOR FEEDING MATERIAL TO THE SPREADER MEANS AT A RATE CORRELATIVE WITH THE SPEED OF SAID FEED MEANS, A FIXED DISPLACEMENT HYDRAULIC MOTOR FOR DRIVING SAID FEED MEANS, CONDUIT MEANS CONNECTED TO SAID HYDRAULIC MOTOR, A FIXED DISPLACEMENT PUMP MEANS CONNECTED TO SAID TRUCK DRIVE MOTOR TO BE DRIVEN THEREBY AT A SPEED THAT VARIES WITH THE SPEED OF THE TRUCK, MEANS CONNECTING SAID PUMP MEANS TO SAID CONDUIT MEANS TO SUPPLY FLUID UNDER PRESSURE THERETO, AND A FLOW CONTROL VALVE IN SAID CONDUIT MEANS FOR ADJUSTABLY REGULATING THE RATE OF FLOW OF FLUID THERETHROUGH TO ENABLE ADJUSTMENT OF THE SPEED OF THE FEED MEANS AND THEREBY VARY THE AMOUNT OF MATERIAL SPREAD, SAID FLOW CONTROL VALVE INCLUDING A SELECTIVELY ADJUSTABLE ORIFICE FOR REGULATING FLOW FROM THE PUMP MEANS TO THE HYDRAULIC MOTOR AND PRESSURE OPERATED VALVE MEANS RESPONSIVE TO THE PRESSURE DIFFERENTIAL PRODUCED ACROSS SAID ORIFICE MEANS FOR MAINTAINING A SUBSTANTIALLY CONSTANT PRESSURE DROP ACROSS SAID ORIFICE MEANS TO THEREBY MAINTAIN A PRESELECTED RATE OF FLOW THROUGH SAID ORIFICE MEANS DETERMINED BY THE ADJUSTMENT THEREOF AND SUBSTANTIALLY INDEPENDENT OF THE SPEED OF THE PUMP MEANS OR THE LOAD ON SAID HYDRAULIC MOTOR.