Fuel injection systems

Claim 1

IN A CHARGE FORMING SYSTEM FOR AN INTERNAL COMBUSTION ENGINE HAVING A THROTTLE CONTROLLED AIR PASSAGE LEADING TO SAID ENGINE AND A CONTINUOUS FLOW FUEL FEEDING SYSTEM INCLUDING A FUEL PUMP OF THE POSITIVE DISPLACEMENT TYPE DRIVEN FROM SAID ENGINE, A PASSAGE SUPPLIED WITH FUEL AT PUMP PRESSURE, A CHARGING FUEL CIRCUIT SUPPLIED WITH FUEL AT PUMP PRESSURE AND DELIVERING FUEL TO SAID AIR PASSAGE, A VARIABLE AREA FUEL METERING RESTRICTION IN SAID FUEL PASSAGE AND A PRESSURE REGULATING MEANS TO MAINTAIN ACROSS SAID ORIFICE A PRESSURE DROP OF A PREDETERMINED AMOUNT INCLUDING A BYPASS FUEL CIRCUIT SUPPLIED FROM SAID PASSAGE, MEANS FOR ESTABLISHING A FUEL FLOW AT THE DELIVERY END OF SAID BYPASS CIRCUIT PROPORTIONAL TO ENGINE SPEED, A FUEL FLOW REGULATING VALVE CONTROLLING THE PRESSURE OF FUEL DOWNSTREAM OF SAID VARIABLE AREA RESTRICTION AND REGULATED BY OPPOSITELY ACTING FUEL PRESSURES THROUGH CONNECTIONS WITH SAID CHARGING FUEL CIRCUIT AND THE DELIVERY END OF SAID BYPASS CIRCUIT, THE IMPROVEMENT COMPRISING MEANS FOR POSITIONING SAID VARIABLE AREA FUEL METERING RESTRICTION IN A FLOW INCREASING DIRECTION BY A FORCE PROPORTIONAL TO AIR PRESSURE DOWNSTREAM OF SAID THROTTLE BIASED AGAINST A YIELDING FORCE DECREASING WITH THROTTLE OPENING AND DIRECTLY CONNECTED TO SAID THROTTLE.