Fuel injection systems for internal combustion engines

Claim 1

A FUEL INJECTION SYSTEM FOR INTERNAL COMBUSTION ENGINES COMPRISING AT LEAST ONE ELECTROMAGNETICALLY OPERATED FUEL INJECTION VALVE, A CONTROL CIRCUIT PRODUCING ELECTRICAL PULSES FOR ENERGIZING SAID AT LEAST ONE INJECTION VALVE, SO THAT SAID VALVE IS OPENED FOR A PERIOD DEPENDING ON THE DURATION OF EACH OF THE PULSE TO PASS FUEL TO THE ENGINE, SAID CONTROL CIRCUIT COMPRISING A MONOSTABLE MULTIVIBRATOR HAVING A TIMING CIRCUIT CONSISTING ONLY OF COMPONENTS HAVING VALUES WHICH ARE INVARIABLE DURING THE OPERATION OF THE SYSTEM AND INCLUDING A TIMING CAPACITOR WHICH IS CHARGED THROUGH A CONSTANT CURRENT DEVICE, MEANS FOR FEEDING SAID TIMING CIRCUIT WITH FIRST AND SECOND VARIABLE VOLTAGES WHICH VARY AS A FUNCTION OF PARAMETERS OF ENGINE OPERATION TO CONTROL THE DURATION OF THE OUTPUT PULSES FED TO ENERGIZE SAID AT LEAST ONE INJECTION VALVE AND WHEREIN SAID VARIABLE VOLTAGES FED TO THE TIMING CIRCUIT ARE DERIVED FROM A COMPUTER DEVICE, INDEPENDENT OF THE CONTROL CIRCUIT AND COMPRISING A PLURALITY OF VARIABLE RESISTANCE DEVICES CONNECTED ACROSS A VOLTAGE SUPPLY, AND MEANS FOR RESPECTIVELY VARYING SAID RESISTANCE DEVICES IN RESPONSE TO DIFFERENT PARAMETERS OF ENGINE OPERATION, AND WHEREIN THE DURATION OF THE OUTPUT PULSES VARIES LINEARLY WITH RESPECT TO THE FIRST CONTROL VOLTAGE PRODUCED IN DEPENDENCE UPON MANIFOLD PRESSURE AND IS PROPORTIONAL TO THE SECOND CONTROL VOLTAGE PRODUCED IN RESPONSE TO OTHER PARAMETERS OF ENGINE OPERATION.