In [Fig. 31] we have shown a well known construction, and which will illustrate the features of the sprayer type to good advantage. The body of the device, represented by A, has a flange by means of which it is secured to the pipe which carries the carbureted air to the engine. The lower end of this tubular body is contracted, as shown at B, so as to form what is called a venturi tube.
Exteriorly this contracted tube is threaded, as shown at C, so as to receive thereon a threaded body D, the lower end of the body having an enlarged disk-head E, integral therewith, and an upwardly-projecting annular flange F is formed around this disk to receive and hold a cylinder G, which constitutes the float and fuel chamber.
The upper end of this cylinder rests against a seat cast with the body A, and packing rings are placed at the ends of the cylinder to prevent the oil from leaking out. Within the tubular body D is a vertical tube H, integral with the disk head E, and oil is supplied to this tube through ducts I, which communicate with the chamber within the reservoir G.
A drain cock is at the lower end of this tube, and an adjustable cap K screws on the tubular stem of the drain tube, around which air is admitted, the air passing upwardly through vertical ducts L, as shown, and thus mixes with air at the contracted part of the venturi tube.
A ring-like float N is placed within the glass chamber, and this is adapted to engage with the inner end of a lever N´, this lever being pivoted at O, within a side extension P of the carbureter shell. The inner end of this lever has a link hinged thereto, the lower end of which serves as a needle valve to close the ejecting orifice of the tube L.
The outer end of the lever N´ engages a shoulder on a vertically-disposed needle valve Q, which has its point in the inlet opening of the pipe R, through which gasoline is supplied to the glass chamber. A spring T serves to keep the valve stem normally on its seat.
Directly opposite this chambered extension P is another extension U, also cast with the shell, through which is a vertical stem V. This stem carries a downwardly-opening valve W, that seats against a plug, and a spring X below the valve, serves to keep it against its seat, unless there should be an extraordinarily heavy pull or suction.
This is the auxiliary air inlet, and the lower spring is actuated only when the engine is running at moderate speeds, but when running at high speed and an additional quantity of air is required the upper spring Y is compressed, and thus a much greater quantity of air is allowed to pass in and mingle with the spray at the throttle valve Z.
The throttle valve is mounted in the discharge opening, and is controlled by a lever on the outside of the carbureter.