US Patent 7090203 Carburetor for internal combustion engine

A carburetor for an internal combustion engine has an intake pipe having a throttle valve plate therein. An annular venturi tube is disposed upstream or downstream of the throttle valve plate inside the intake pipe. The annular venturi tube is located at a predetermined interval with the throttle valve plate. The annular venturi tube has a fine continuous annular slit or four or more annularly arranged fuel discharging pores so as to atomize the fuel thereat. Atomization is always carried out near a position where a fastest air moves so as to improve the atomization and a uniform air-fuel mixture, thereby improving an output, fuel consumption and exhaust gas emission of the internal combustion engine.