The carbureter shown in partial section in the accompanying illustration is an extremely simple device, with less parts to give trouble than are found in the usual automatic float-feed carbureters now generally in vogue. The gasoline enters through the feed pipe, seen at the bottom, and flows upward through a vertical pipe, 1, to a horizontal feed needle valve, V. This valve is operated by a vertical lever and clapper, J, which has a weighted disk, W, for the purpose of returning the valve to the closed position. The suction of the motor, as it draws air in through the inlet, I, causes the clapper to move inward, and the feed valve to open. The fuel, as soon as it passes through this valve, flows downward through the adjoining vertical pipe, 2, and then upward once more, through the spray nozzle pipe, 3. This pipe terminates at its upper end in a spray nozzle, and contains a needle valve, F, which can be adjusted from below. This valve gives the proper mixture at high speed. The carbureter has a cylindrical throttl') sleeve, E, which is moved by the lever, B. By means of suitable connections within, when the throttle is closed, another needle valve, D, located above the spray nozzle, is brought down into the latter, and has a throttling effect. This extra spray nozzle serves to keep the mixture uniform, for when the throttle is closed, on account of the small passage for the gas, the suction is very much increased at the spray nozzle, and there is a tendency to get too rich a mixture. The lever, A, seen on top of the carbureter, operates another sleeve on tho opposite side of the spray nozzle to the throttle sleeve, and makes it possible to decrease the size of the orifice for the gas in case this is too large to obtain the proper suction. The Automobile Editor of this journal has given this new carbureter a thorough trial upon a double-opposed-cylinder motor of the air-cooled type, and also upon a standard 4-cylinder, vertical motor. In both cases the carbureter has given very good satisfaction and proved its economy. As there is no float or float-operated needle valve, trouble from these sources is obviated. Another good point about the carbureter is that there is so minute a quantity of gasoline in it at any time that there is no danger of fire in case of a back fire from the motor. For air-cooled engines, especially, this carbureter will be found t) give excellent satisfaction, as the needle valve which controls the fuel can be closed almost to the limit, and the mixture fed to the motor can be made so poor that there is little danger of the engine overheating and_ giving premature explosions, even though there are carbon deposits in the cylinder heads. The inventor of this carbureter is Mr. John H. Miller, of 94 Denver Avenue, Bridgeport, Conn.
This article was originally published with the title "A Novel Floatless Carbureter" in Scientific American 97, 19, 345 (November 1907)