US1625575A - Carburetor and fuel-feeding system therefor - Google Patents

Description

April 19. 1927.

w. 'r. SIMPSON CARBURETOR AND FUEL FEEDING SYSTEM THEREFOR Original Filed Oct. 21 1920. w

Patented Apr. 19,1927.

UNITED STATES WARD T. SIMPSON, 0]? ANN ARBOR, MICHIGAN, ASSIGNOR, BY MESNE ASSIGNMENTS, TO

PATENT OFFICE.

ALBERT G. DICKINSON, OF GRAND RAPIDS, MICHIGAN.

CARBURETOR AND FUEL-FEEDING SYSTEM THEREFOR.

Application filed October 21, 1920, Serial No. 418,423. Renewed March 16, 1925.

One objectof the invention is to rovide a. system for supplying fuel to a car uretor from a low tank. I

The invention is shown in the accompanying drawings in which:

Fig. 1 is a'view in the nature of a diagram of the invention in place on an automobile.

Fig. 2 is a sectional view of the carburetor, the two tanks and the connections between them.

Fig. 3 is a detail.

In these drawings 1 indicates the carburetor, 2 the main fuel tank and 3 an intermediate air tight fuel tank.

The carburetor has its fuel chamber 4 connected with the engine intake by apassage 5 so as to be subjected to the depression in the engine manifold, andthe lower part of the fuel chamber is connected to the et nozzle 6 which directs the fuel into the mlxing chamber 6. The inlet of fuel to the fuel chamber 4 is controlled by a valve 7 wh1ch is of a balanced character, being subJect to the depression within the fuel chamber acting in both directions on the valve. A float 8 controls the valve according to the level of the fuel in the fuelchamber.

The fuel is fed to this fuel chamber by a pipe 9 leading from the top of the tank 3 arranged intermediate the carburetor and the main tank 2, both of which tanks may be at levels lower than that of the carburetor, the main tank being lower than the intermediate tank. The intermediate tank 3 receives its supply from the main tank 2 through a pipe 12 connecting with the top of the intermediate tank. A pipe 13 extends from the top of the intermediate tank to a. part of the carburetor or engine manifold at which, in one a plication of my invention, there is adi erent degree of depression than that existing in the fuel chamber. For instance, this pipe may connect with the mixing chamber 6' of the carburetor at the point where the air supply enters the mixing chamber through the seat 14 of the throttle valve and where the depression 1s less than in the fuel chamber.

I do 'not limit. myself however, to this position of the connection as a means for. getting less depression in the pipe 13 in res ect to that in the fuel chamber and supp y pipe 9. An adjustable nozzle at the end of pipe 13, where it enters the carburetor,

might be mod to get this difference in the depression between pipes .13 and 9, the adustment of the nozzle'being such that it will receive more or less of the air from the.

body of air rushing past it.

The-small port 15 leading from the intermediate tank to the pipe 13 is controlled by a valve 16 operated by a float 17 in a compartment 18 which is open at its lower end to the interior of the intermediate tank. This float is of less diameter than that of the compartment. The pipe 13 is connected by a by-pass port 13' with the port leading from the pipe 12 to the intermediate tank.

This'by-pass is controlled by a check valve 13" closing towards the pipe 13.

For filling the intermediate tank the throttle valveis closed, and then cranking is performed. The fuel which is drawn by the'suction of the carburetor from the main tank passes through the intermediate tank into the fuel chamber 4 of the carburetor, the depression here at this time being about four inches of mercury.

As soon as the fuel chamber 4 is filled to the prescribed level, the intermediate chamber then completes its filling. This is due to the closingv of the fuel inlet valve by the rise of the float 8 and by the continued de pression in the intermediate chamber caused y the suction through the pipe 13 leading from the top of the intermediate tank to the carburetor or manifold.

During this filling action 'ofthe intermediate tank, the valve at the top of the intermediate tank controlling the suction ipe 13 will of course be open, due to its oat resting in its lowest position by gravity, the greater suction being through pipe 9 and not throu h pipe 13, and also due to the fact that t e suction when cranking is not strong enoliggh to close the valve in the intermediate tan The intermediate tank having filled up to a level approximately indicated by the line ww, the float valve '16, due to its buoyancy, will close the port 15 leading to the ipe 13 and cut off the suction from the car uretor or manifold, and there will be left a space a at the top of the intermediate chamber above theline 'w-w. In this space a some depression will exist. o

If the depression in the carburetor, or

rather pipes 9, 13, is now maintainedto the degree that the fuel will be drawn from the main tank through the intermediate tank and fuel pipe 9 to the fuel chamber of the carburetor. Under these conditions, the float valve 16 will remain seated because the level of the fuel in the intermediate tank will be maintained, as much fuel being drawn in or running with wide open throttle, provided, as above stated, the depression is maintained suflicient to lift the fuel from the low main tank.

For instance: 1

During the normal average operation of an automobile and after the intermediate tank has been filled, the check valve '13" of the pipe 13 and the float valve 16 will be closed, but ifan occasion should arise, for instance, at full or near full throttle and at low engine revolutions, when the suction through pipe 13 caused by the motor becomes insuflicient to hold the check valve seated, the contents of the intermediate tank will, be available 'to the carburetor, and in order that this may happen, the by-pass 13', with check valve 13", is provided to act as a pressure equalizing means between the pipe 13 and the upper portion a of the intermediate tank, thereby enabling the car-,

buretor, through its connection 9, to obtain its fuel, with the low depression then existing, and until such time as the depression in-the pipe 13 shall again be great enough to replenish the fuel in the intermediate tank to its maximum level, at which time the float valve will again seat itself and the check valve 18 being already seated, then the suction will automatically be induced through pipe 9 alone and until a repetition of the low depression condition again exists.

The point in the carburetor from which the control of the check valve and float is exerted is the point where pipe 13 connects with the carburetor. In the arrangement described above, this is in the lower part of the mixingchamber and because the depression here is less thanin the fuel chamber, the

lessening of this depression will allow the check to open and the float valve to fall.

To state the operation in another way: As

long as the normal conditions above noted prevail, the depression in the carburetor fuel ,chamber will draw the fuel through the' intermediate: tank and while this is going on the ball valve will remain on its seat and the float valve will also remain seated, because the inflow to the intermediate tank will maintain the normal fuel level. When,

lunvever, the conditions as to the degree of open port 14.

During the time that this rare condition exists, the fuel will be supplied to the carburetor from the intermediate tank, butthere will'be no replenishing of the fuel from the main tank. This abnormal condition, however, will be but temporary, and as soon as the depression in the carburetor increases again to normal, the ball valve will close but-the'float valve will remain open. The fuel will nowbe drawn in from the main tank by the suction from pi e 13 and the port of the float valve, an drawn into the intermediate tank from the main tank until the float lifted by the rise of the fuel to the level wm will close this valve-and stop the suction through the pipe 13. The tank now having been replenished, the operation will go on as before.

It-will be noted that the intermediate tank is not open to the atmosphere and is thus not subject to explosion from fire, differing from those systems in which the intermediate tank is open to the atmosphere.

air should get into theintermediate tank through leakage or from another cause, such as the use of air introduced into the pipe 12 for lightening the fuel column, this air will be evacuated through the ports 19 and 15, when the float valve is opened, due to the fall of the level of the fuel caused by the presence of this air in the space a.

The intermediate tank may be placed at i any height where room may be found to accommodate it If placed below the level of the fuel chamber of the carburetor the suction ipe 13 must connect with the mixing chain er or manifold where 'the'depression fuel will be is less than that in the fuel chamber. If it is Y placed at the same level or higher than the fuel chamber, the pipe 13 may connect with the fuel chamber or passage 5, where the depression is the same as that in the fuel chamber.

A gauge 20 is used ;on the intermediate tankto indicate the height of the fuel therein. If the fuel gets below a prescribed level,

the operator may. know that his'main tank check his fuel purchases and consumption.

I therefore make the main tank of a-size to take a unit, or a. multiple of units, of the n'ieasure which is used at all .fuel statlons,

and in thisway the car user, when his main tankhas been refilled, will know that he has gotten this unit of measure or the multi ple thereof, and will be satistied to pay accordingly.

This gauge performs a' plurality of func tions. It may have within it, a. float 20" which, when in its uppermost position, is

arrested by the upper member 20 which will act as a'shield to hide it. This shield is slightly below-the fuel level in the tank 3 and hence as long as the tioat remains out of sight, the operator can feel assured either that he has fuel in the main'tank or that he still has at least the contents of the intermediate tank. As soon, however, as the float or fuel level appears below the shield, the operator will know that the main tank has become exhausted and he will then know how much he has left to reach the nextfuel station.

Further, this will indicate the height of the fuel in the intermediate tank, as this I is being used.

Instead of running the pipe 9 from the bottom of the intermediate tank to the fuel chamber, I prefer to introduce this pipe through the top of the tank and carry it down to near the bottom. thereof and at the point where the pipe crosses the space a I may place an air hole at 21 so as to lighten the fuel column and permit it to be readily drawn into the fuel chamber of the carburetor. To get thls result .I would also place an air inlet opening at 22 in the pipe within the main tank so that the air lifting ing of the mixing" chamber tube, where it crosses the mouth of said passage, and anyliquid fuel which has been carried along With'this air will be separated therefrom and will drain back into the fuel chamber to be delivered therefrom through the nozzle.

My invention is adapted for use not only in automobiles but also in motor boats and the'like.

One feature of my system is that the intermediate tank is at all times under the suction from thecarburetor. When the float. valve and check valve closes, the pipe .12 suction will take place through the fucl chamber and pipe 9 alone. At other periods in the operation, when the float valve is open, valve and check valve closes the pipe 13,

and some suction will continue to take place through pipe 9, and thus substantially at all times the whole system back to the main tank will be under suction,

The action is also such that fuel will be flowing into the intermediate tank from thc main tank at the same time that the fuel is being drawn from said intermediate tank by the depression in the fuel chamber.

The air passing intothe fuel pipe at the intermediate tank will be disposed of after reach ng the fuel chamber by passing otl through the vacuum passage and any fuel which is carried off from the body of fuel by this passing air will be separated from the air by striking the portion of the mining tube which extends across this vacuum passage.

The a-i1 hole 22 'ierforms an important function besides aiding the lifting of the fuel column, that is, if the check valve li-l or float valve 16 should leak, this air let in at 22, which passes through the conduit/12 from main tank 2 with the fuel, will seek the uppermost part of the intermediate tank 3 and will be in contact with said check valve and float valve at all times and pass through the leak, which will not interfere with the engine.

Now if there was no air let in at 22 and the check valve and float valve leaked, fuel would pass to the engine and interfere with its operations. I prevent this undesirable feature by the introduction of the air at 22 and at the same time aid the lifting of the fuel.

' I claim:

1. In combination in a fuel feed system for automobiles, a carburetor of the vacuum feed type having its fuel chamber subjected to the vacuum depression 'from the manifold, a main fuel tank, a tank intermediate the main tank and the carburetor, a pipe'for supplying fuel from the main tank to the intermediate tank, a pipe extending from the lower part of the intermediate tank to the 7 fuel chamber of the carburetor, a float valve in the fuel chamber controlling the inlet from the said last mentioned pipe, a second pipe connected with the carburetor at a point where there is less vacuum than in the fuel chamber, and with the intermediate tank through a port at the top of the latter whereby there will be a preponderance of vacuum depression in the fuel chamber in respect to that in the intermediate tank and a float valve controlling said port, for cutting ofi communication-between the said in- 'check valve closing towards the carburetor and controlling said communication to equalize thedeprcssion in the top of the intermediate tank with that of said carburetor part when the depression lessens, whereby the fuel in said intermediate, tank alone is availvable for supplying the fuel chamber of the.

carburetor, and additional float valve means for allowing said communicating means to create suction in the intermediate tank for replenishing its fuel supply from the main tank when the depression in the carburetor is restored to normal and for thereafter closing said communication when the fuel level in the intermediate tank reaches the prescribed level.

3. In combination in a fuel supply system for automobiles and the like, a carburetor, a main fuel tank, below the levelof the carburetor, a'tank intermediate the main tank and thecarburetor and receiving itssupply from the main-tank, a fuel cbnnection from the lower part of the intermediate tank to the carburetor, a connection from the upper part of the intermediate tank to a part of the carburetor where the depression is less than in the fuel chamber, valve means for controlling the said connection whereby at times the suction in the carburetor willdraw fuel from the said intermediate tank and at the sametime draw from the main tank into the intermediate tank, when 4 the depression in the fuel chamber of the carburetor is normal, and a gauge on the intermediate tank to indicate the height of the fuel therein, substantially as described. a

pipe) leading from said tank to the fuelchamber, and havin a port for the entrance of air to lighten the fuel column, the air after reaching the fuel chamber from said fuel pipe passing off through the said passage to the enginc'manilold, and batile'means in said passage to separate the liquid fuel from the air, said ball-1e means comprising the mixing tube extending across said passage.

5. In COD'lblllRtlOIl, a carburetor having a fuel chamber, a passage communicatin the same with the engine manifold, a mlxing chamber, a fuel conduit leading to the mixing chamber, a fuel. supply tank arran ed at a lower level than the fuel chamber, a uel pipe leading from said tank to the fuel chamber, and having a port for the entrance of air to lighten the fuel column, the air after reaching the fuel chamber from said fuel pipe passing off through the said passage to the engine manifold, a main fuel tank at a lower level than the tank first mentioned, a fuel pipe betweenthe tanks having a port for admission of air to lighten the fuel column and a connection leading from the first mentioned tank subject to the suction from the en ine for evacuating said tank of the air use for lightening the fuel column.

In testimony whereof I affix my signature.

WARD T. smrsou.

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