Patent ID: 7395818

Claim:
A gaseous fuel control device for a combustion engine with a carburetor having an air and gas fuel mixing passage with a throttle valve movable between idle and wide open positions, comprising: a body; a plurality of fuel inlet passages in the body, wherein each one of the plurality of fuel inlet passages communicates with a supply of a respective one of a plurality of gaseous fuel types; a fuel outlet passage in the body communicating with the mixing passage to supply any selected one of the plurality of gaseous fuel types to the mixing passage for mixing with air to supply the mixture of air and gaseous fuel to the engine; a gaseous fuel metering assembly having a fuel chamber, a metering diaphragm communicating with the fuel chamber, and a metering valve movable by actuation of the metering diaphragm between open and closed positions and having an outlet communicating with the fuel chamber and an inlet which receives gaseous fuel from a selected one of the plurality of fuel inlet passages when the engine is operating; and a separate restricted orifice for each of the gaseous fuel types which when the engine is operating selectively communicates the fuel metering chamber with the mixing passage upstream of the throttle valve to both supply the selected gaseous fuel from the metering chamber through the restricted orifice to the mixing passage and to actuate the metering diaphragm to move the metering valve between its open and closed positions to vary the flow rate of the selected gaseous fuel into the mixing passage in proportion to the rate of air flow through the mixing passage when the engine is operating with the throttle valve movable between its idle and wide open positions.