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US 7,007,930 B1Granted
Dual fuel feed system carburetor
AssigneeWalbro Engine Management, L.L.C.
InventorDonald W. Warner
Life of this patent
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AssigneeWalbro Engine Management, L.L.C.
InventorDonald W. Warner
Estimating the term…
A carburetor dual fuel feed system has a primary passage for flowing fuel into a venturi of a fuel-and-air mixing passage, and a supplemental channel flowing fuel into a mixing passage upstream region. Sizing of the primary passage and channel with respect to pressure dynamics of each region disassociates low from high power engine fuel calibration. This disassociation ultimately achieves a leaner fuel-and-air mixture flow during low power conditions which reduces carbon monoxide emissions, and achieves a richer mixture flow during high engine power conditions which reduces NOx emissions. During low engine power conditions, substantially all of the fuel which mixes with clean air flowing through the venturi of the mixing passage flows from the primary passage. During high engine power conditions, supplemental fuel flow into the mixing passage is induced by a vacuum created about a nozzle of the channel.
A carburetor for a combustion engine comprising:
A dual fuel feed system of a carburetor having a body, a fuel-and-air mixing passage through the body for supplying a mixture of fuel-and-air to a combustion engine, a choke valve operatively in an upstream region of the mixing passage for controlling air flow through the mixing passage during cold starting of the engine, a throttle valve operatively in a downstream region of the mixing passage for controlling engine power by controlling the amount of fuel-and-air mixture entering the engine, a venturi region of the mixing passage disposed between the upstream and downstream regions, and a fuel chamber at least in-part carried by the body for supplying fuel to the mixing passage, the dual fuel feed system comprising:
A dual fuel feed system of a carburetor having a body, a fuel-and-air mixing passage through the body for supplying a mixture of fuel-and-air to a combustion engine, a choke valve operatively in an upstream region of the mixing passage for controlling air flow through the mixing passage during cold starting of the engine, a throttle valve operatively in a downstream region of the mixing passage for controlling engine power by controlling the amount of fuel-and-air mixture entering the engine, a venturi region of the mixing passage disposed between the upstream and downstream regions, and a fuel chamber at least in-part carried by the body for supplying fuel to the mixing passage, the dual fuel feed system comprising:
A dual fuel feed system of a carburetor having a body, a fuel-and-air mixing passage through the body for supplying a mixture of fuel-and-air to a combustion engine, a choke valve operatively in an upstream region of the mixing passage for controlling air flow through the mixing passage during cold starting of the engine, a throttle valve operatively in a downstream region of the mixing passage for controlling engine power by controlling the amount of fuel-and-air mixture entering the engine, a venturi region of the mixing passage disposed between the upstream and downstream regions, and a fuel chamber at least in-part carried by the body for supplying fuel to the mixing passage, the dual fuel feed system comprising:
Dependencies are inferred from the claim text.