US2157074A

US2157074A - Fuel feed device

Info

Publication number: US2157074A
Authority: US
Publication date: 1939-05-02
Anticipated expiration: 1956-05-02

Description

May 2, 1939. G R. ERICSON FUEL FEED DEVICE Filed Feb. 20, 1937 65026.: E. fe/cso/v INVENTOR.

ATTORNEY.

Patented May 2, 1939 UNITED STATES PATENT OFFICE FUEL FEED DEVICE Application February 20, 1937, Serial No. 126,947

2 Claims.

This invention relates to liquid feed means and is applicable more particularly for delivering fuel to internal combustion engine carburetors where no constant level chamber or pump is provided.

Small stationary internal combustion engines,

such as are used for operating generators in isolated places, are frequently provided with separate carburetors mounted in connection with the fuel storage tank. Where the carburetor suction alone is relied upon to deliver fuel from an atmospheric tank, the rate of fuel delivery is obviously dependent upon the depth of the liquid in the tank and, accordingly, the fuel and air mixture provided with such an arrangement becomes gradually leaner, resulting in loss of power, and may cause the engine to stop before the tank is drained unless an adjustment is made.

An object of the present invention is to provide means for delivering a liquid, such as gasoline or other fuel, at a uniform rate from a storage tank to a source of intermittent suction outside the tank.

A more detailed object is to provide a measuring valve device for delivering fuel at a uniform rate to an internal combustion engine irrespective of the depth of fuel in the storage tank.

These objects and other more detailed objects hereafter appearing, are attained substantially by the structure illustrated in the accompanying drawing, in which:

Figure 1 is a sectional view of a carburetor and storage tank assembly embodying the invention.

Figure 2 is a detail longitudinal section showing the delivery device with the plunger valve in a different position.

Figure 3 is a horizontal section taken on line 3-3 of Figure 1.

The figures show a carburetor having a horizontal Venturi-shaped mixture conduit I, secured at one end to a tube 2 for connection with the intake of an internal combustion engine. At the opposite end of the carburetor is a cap valve 3, having slots 4 for cooperating with slots 5 in the carburetor for manual control of the air admitted thereto. A fuel delivery orifice 6 opens into the throat of the venturi and is controlled by a needle valve 1. The carburetor also has a base portion 8 secured to a pad 9 on top of fuel tank I0.

A tubular passage member II is threadedly secured at its upper end in the enlarged lower portion of carburetor fuel orifice 6, as at Ila, and extends through the tank cover well downwardly into the tank. The tank is also provided with a filling opening l2 having a cover l3 with a hole I4 for exposing the interior of the tank to atmosphere.

At the lower end of passage member I there is threadedly secured a chambered extension I5 having an inlet opening l6 controlled by inlet check 5 ball I1. A coiled spring l8 constantly urges the ball l1 against its seat in inlet l6 and at its upper end is seated against a separate shoulder stop l9 secured between the end of passage member II and the extension member. The central bore 20 10 in passage member I is enlarged at its lower end to form a chamber 2| which, at its lower end communicates with chamber 22 in member I 5 through central orifice 23 in stop member I9.

Movably received in chamber 2| is a plunger 5 valve 24 having a tapered lower end 25 for seating against stop member H1 at the lower end of the plunger stroke and a tapered upper portion 26 for seating against a shoulder 2| a in chamber 2| at the upper end of the plunger stroke. Plunger 24 20 is constantly urged downwardly by the coiled spring 21 which extends into the hollow interior of the plunger and at its upper end seats against a shoulder at the very top of chamber 2|. Spring 21 is preferably weaker than check spring I8. 5 Plunger valve 24 loosely fits within chamber 2| and is proportioned relative thereto so as to accomplish its function as described hereafter.

In operation, suction pulsations from the engine are transmitted through the carburetor and bore 30 20 to chamber 2|, raising both plunger valve 24 and inlet check |1 against springs 21 and I8 and drawing liquid fuel through openings l6 and 23 into

chambers

22 and 2|. At the end of the suction stroke, check |1 quickly closes inlet l6, trap- 35 ping liquid fuel in chambers 2| and 22 so that the downward movement of plunger valve 24 under the influence of spring 21 causes a quantity of fuel to pass around the plunger and into the upper part of chamber 2 On the next succeeding suc- 40 tion stroke, plunger 24 is drawn upwardly against shoulder 21 (Fig. 2) lifting this quantity of fuel into bore 20 and eventually when the bore is filled, fuel is delivered to the carburetor. When the plunger valve is against its upper valve seat, com- 45 munication between the tank and carburetor is sealed, preventing further delivery of fuel.

The space between stop member l9 and shoulder 21 and between plunger valve 24 and the wall of chamber 2| is made sufiicient to permit an ade- 50 quate delivery of fuel for the needs of the associated engine when the fuel level is near the bottom of the tank, and to insure full movement of the plunger valve under this condition. A uniform quantity of fuel is forced above the plunger 55 iii) valve during each downward stroke thereof under the impulsion of spring 21 and this quantity only is delivered to the carburetor during each suction stroke. Needle valve 1 provides an additional adjustment which, however, may be omitted where cheapness and simplicity are essential. Relatively low suction is applied to the fuel on each stroke of a small stationary engine of the type for which the present invention is especially adapted and the weight and stroke of plunger 24 must be correspondingly calibrated.

From the above description it is apparent that the stroke of plunger valve 24 remains constant regardless of the pressure differences between the tank and the carburetor, as long as this difference is sufiicient to cause the plunger to move its full stroke. Thus a uniform quantity of liquid fuel will be delivered to the carburetor regardless of the fuel head in the tank whereby the fuel tank may be drained and refilled without affecting the fuel delivery and without readjustment of the needle valve or of the air valve 3 other than may be necessary for cold starting.

The invention is not limited to the structure shown, but may be modified in various respects as will occur to those skilled in the art, and the exclusive use of all such modifications as come within the scope of the appended claims is contemplated.

I claim:

1. In combination with an internal combustion engine, a suction conduit and a fuel storage tank, structure connecting said conduit and said tank including a passage terminating near the bottom of said tank, an inlet check at the bottom of said passage, spaced valve seats above said check, and a plunger valve movable between said seats and proportioned relative to the space therebetween so that when suction is applied to said passage, said plunger valve is drawn upwardly against the upper of said seats restricting the quantity of liquid drawn into said conduit and at the end of the suction pulsation said plunger valve drops to the lower of said seats, said inlet check maintaining a full column of liquid in said passage during dropping of said plunger valve.

2. The combination of elements specified in claim 1 further including a spring constantly urging said plunger valve toward the lower of said valve seats and a stronger spring constantly urging said inlet check toward its closed position.

GEORGE R. ERICSON.