Safety circuit for a fuel supply system

A safety circuit for a fuel supply system of a motor vehicle, which fuel supply system includes a fuel tank for containing a fuel, an air breather pipe connected to the fuel tank, a fuel flap and a valve interposed in the air breather pipe, the safety circuit comprising:

• valve actuation means for opening and closing the valve;
• an ignition coil driving circuit serially connected to a power source, an ignition coil and a key switch;
• a fuel flap switch operatively connected to the fuel flap such that said fuel flap switch is closed when the fuel flap is open;
• a boost switch operatively connected to the engine such that said boost switch is open when the engine is running;
• a valve control circuit serially connected to the power source, fuel flap switch and valve actuation means;
• a first relay interposed in the valve control circuit for cutting off power to said valve actuation means when said key switch and said boost switch are closed so that the valve closes;
• a second relay interposed in said ignition coil driving circuit for cutting off power to the ignition coil when the valve is in an open condition.

A fuel supply system, comprising:

• a fuel tank;
• an air breather pipe connected to said fuel tank;
• a solenoid valve interposed in said air breather pipe;
• a fuel flap;
• and
• a safety circuit, said safety circuit including,
• a solenoid for opening and closing said solenoid valve,
• an ignition coil driving circuit connected from a power source to an ignition coil via a key switch,
• a fuel flap switch operatively connected to said fuel flap such that said fuel flap switch is closed when said fuel flap is open and such that said fuel flap switch is open when said fuel flap is closed,
• a solenoid driving circuit for driving said solenoid, said solenoid driving circuit connected to said power source and a ground via said solenoid and said fuel flap switch,
• a boost switch connected from said key switch such that said boost switch is closed when the engine is stopped,
• a first relay interposed between the power source and said fuel flap switch in said solenoid driving circuit for prohibiting current flow through said first relay when both said boost switch and said key switch are closed,
• a second relay interposed between said key switch and the ignition coil in said ignition coil driving circuit, said second relay prohibiting current flow to the ignition coil when said fuel flap switch is closed and said first relay is closed.