Fuel level control system

Claim 1

A FUEL LEVEL CONTROL APPARATUS FOR A CARBURETOR HAVING OVERFLOW MEANS COMPRISING A STORAGE TANK, A SUCTION PUMP, A FUEL SUPPLY LINE CONNECTING SAID STORAGE TANK TO THE SUCTION SIDE OF SAID PUMP, A VENTED OVERFLOW TANK MOUNTED BENEATH SAID CARBURETOR AND HAVING AN INLET AND AN OUTLET, MEANS CONNECTING THE INLET OF SAID OVERFLOW TANK TO RECEIVE OVERFLOW FROM SAID CARBURETOR, MEANS CONNECTING THE OUTLET OF SAID OVERFLOW TANK TO THE SUCTION SIDE OF SAID PUMP, OVERFLOW VALVE MEANS OPERABLE IN RESPONSE TO THE LEVEL OF FUEL WITHIN SAID OVERFLOW TANK CONTROLLING THE COMMUNICATION BETWEEN SAID OVERFLOW TANK AND SAID OUTLET AND PERMITTING OVERFLOW FLUID TO FLOW TO SAID OUTLET ONLY WHEN THE LEVEL OF FUEL WITHIN SAID TANK IS AT LEAST AT A PREDETERMINED LEVEL, AN INDEPENDENT SHUT-OFF VALVE INTERPOSED IN SAID FUEL SUPPLY LINE BETWEEN SAID STORAGE TANK AND THE CONNECTION OF SAID OUTLET TO SAID PUMP, AND VALVE OPERATING MEANS RESPONSIVE TO THE PRESSURE DIFFERENTIAL BETWEEN THE OUTLET SIDE OF SAID SHUT-OFF VALVE AND THE ATMOSPHERE TO HOLD SAID SHUT-OFF VALVE OPEN WHEN SAID PRESSURE DIFFERENTIAL IS ABOVE A PREDETERMINED LEVEL WHILE SAID PUMP IS EVACUATING ONLY SAID FUEL SUPPLY LINE, SAID VALVE OPERATING MEANS INCLUDING BIASING MEANS NORMALLY CLOSING SAID SHUT-OFF VALVE WHEN SAID PRESSURE DIFFERENTIAL FALLS BELOW SAID PREDETERMINED LEVEL.