US2095739A - Carburetor - Google Patents

Description

Oct. 12, 1937. w. B. GOODMAN I 2,095,739

CARBURETOR Filed Jan. 29, 1935 INVENTOR.

illara' B. Goodman Patented Oct.12,1937

UNITED STATES 2,0 5,13 CARBUBETQR.

, I Willard B. Goodman, Paterson, N. 1.; assignor to Wright Aeronautical Corporation, a corporation of New York Application January 29, 1935, Serial No. 3,923 2 Claims. (01. 261-72) This invention relates to carburetors in general and more specifically to carburetors for high output engines, such as used in aircraft.

A prime-object of the invention is to provide an improved and simple means for completely shutting off the fuel flow when it is desired to stop the engine, to prevent the after-firing which often occurs, on high output engines, after the ignition switch has been out, which firing is due to hot plug points or carbon particles in the combustion chambers.

Further objects will be apparent from a reading of the subjoined specification and claims and from a consideration of the accompanying drawing, in which:

Fig. 1 is a diagrammatic axial section through an inverted carburetor incorporating the invention;

Fig. 2 is a plan view of a the-carburetor;

Fig. 3 is a plan view of a disc valve; and

Fig. 4 is a plan view showing the valve in position on the seat.

Referring first to Fig. 1, l0 designates the body valve seat formed in of an inverted carburetor having an air entrance 12, a usual venturi l4, and throttle Hi. The carburetor is bolted to the inlet of the engine (not shown) at the lower face iii. A main discharge" jet is indicated at and a main-air bleed at 22. An idle feed passage is indicated at 24 and an idle metering jet at 26, while an idle air bleed at 28 connects to the discharge jets 30. A main metering jet is indicated at 32 as disposed in.a float chamber 34, the latter being provided with a vent 36 entering the venturi l4 to balance the chamber pressure with the venturi pressure.

The parts so far described represent a conventional carburetor arrangement, and the object of the back suction control of this invention, now to be described, is to provide a positive means whereby the fuel flow can be shut off from all of the various passages described above. j

Above the float chamber 34 there is an altitude or mixture control valve which normally comprises a rotatable disc 40 having a cut-away portion 42 (Fig. 3) by which the opening area at a float chamber vent hole 44 may be controlled. 'A fixed seat 46 is provided for this valve, which has a stem 48 extending through a cover plate 50 to carry the control lever 52. The elements just describedrepresent a conventional altitude control, but, according to the provisions of thisinvention the following elements are added.

From the under side of the throttle IS a suction passage 54 is led around the float chamber 34 to a hole 56 in the valve seat 46, the seat having an additional hole 58 (Fig. 2) communicating with the interior of the float chamber. In the under-side of the disc valve 40 there is added an arcuate groove 60 (Figs. 3 and 4) so arranged cations and changes.

that when the valve is moved to the positio shown in Fig. 4 the holes 58 and 56 are connected by the groove 60, placing the float chamber in communication with the under side of the throttle through the passage 54. This position of the valve 40 occurs beyond the range of its normal movement for altitude control so that the altitude control hole 44 is covered when the extra -movement is utilized to connect the holes 58, 56.

This'closed position for the altitude control hole 44 corresponds to the full-rich condition of that control, which is always in force when the airplane is on the ground. The operation of the device is as follows: i

In order to stop the engine it is first brought to idle by closing the throttle in the usual way.

which creates a high suction below the throttle valve l6. Then, by movement of the altitude control lever 52 beyond the normal full-rich position, this suction is communicated to the interior oi the float chamber through the passage 54, the

holes 56, 58, and the groovefili, as already de- 4 scribed. This instantly draws back into the float chamber all of the fuel in each of the various J'et passages, so that no fuel can issue to the inlet air and the engine accordingly immediately stops and the possibility of after-firing is eliminated.

While I have described my invention in detail I x in its present preferred embodiment, it will be obvious to those skilled in the art, after understanding my invention, that various changes and modifications may be made therein without departing from the spirit or scope thereof. I aim in the appended claims to cover all such modifi- What is claimed is:

1. Means to shut off the fuel flow from an engine carburetor having a throttle and a float chamber, comprising a passageway connecting only the-engine side of said throttle and said float chamber, means to keep said connection normally closed and movable to establish the connection at will, saidmeans being incorporated injan otherwise conventional altitude control valve.

2. The'combination with a carburetor having a throttle, a float chamber, an altitude control valve separately operable from said throttl and passages connecting the atmosphere wit said float chamber through said valve, of passages connecting said float chamber-with/the engine side of said throttle, through said valve, said valve hav--. ing openings adapted, in difierent positions thereof, to establish communication in one position,

between said chamber and the engine side of said throttle, and, in another position, to establish communication betweenthe float chamber and the atmosphere.

WRLARD B. GOODMAN.

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