Fuel supply system

A fuel supply system for operating an engine in various positions including an inverted position, comprising:

• a housing,
• a mixing passage in said housing for supplying a mixture of fuel and air to the engine,
• a throttle valve in said passage for controlling the supply of air and fuel mixture to the engine,
• a pump operative in response to vacuum pulsations in the crank case of the engine and having an inlet for receiving fuel and an outlet for delivering fuel,
• a high speed metering system and a low speed metering system connected to said outlet and to said mixing passage,
• valve means at said fuel inlet responsive to the presence of vacuum resulting from rotation of said engine to permit delivery of fuel to said pump and responsive to lack of vacuum to prevent delivery of fuel to said pump, and
• fuel pressure regulating means responsive to the level of fuel pressure from said pump to regulate the level of vacuum pressure available from said crank case to regulate drive vacuum to said pump and the output pressure of fuel from said pump to said high and low speed metering systems.

A closed loop fuel supply system for operating an engine in all possible positions, comprising:

• a housing,
• a mixing passage in said housing for supplying a mixture of fuel and air to the engine,
• a throttle valve in said passage for controlling the supply of air and fuel mixture to the engine,
• a pump operative in response to vacuum pulsations in the crank case of the engine and having an inlet for receiving fuel and an outlet for delivering fuel,
• a high speed metering system and a low speed metering system connected to said outlet of said pump and to said mixing passage, said high speed and low speed metering systems each including a shut off valve responsive to the position of said throttle valve, said high speed metering system being open and said low speed metering system being closed to said mixing passage when said throttle valve is open and said low speed metering system being open and said high speed metering system being closed to said mixing passage when said throttle valve is closed,
• valve means at said fuel inlet responsive to the presence of vacuum resulting from rotation of said engine to permit delivery of fuel to said pump, and
• fuel pressure regulating means responsive to the pressure of fuel from said pump to regulate the level of vacuum pressure available from said crank case to said pump to regulate the level of drive vacuum to said pump and the output of fuel from said pump to said high and low speed metering systems whereby the amount fuel delivered to said mixing passage is equal to the requirements of the engine.