US1485547A - Carburetor - Google Patents

Description

Filed Aug. :H1917 W11! i ll i j' N 1, ll l.

U EDWARD F. ANDREWS. M

.nw D NLDE lill'. In'

Patented Mar. -4, 19u24.

Unno STATESy PATENT GFI-1GB.

EDWABDIF. ANDREWS, 0F CHICAGO, ILLINOIS, ASSIGNOIR,A TO UNIVERSAL ENGIN'EER- ING COMPANY, 0F MAYWOOD, ILLINOIS, A. CORPORATION' 0F ILLINOIS.

cARBUnE'roR.

Application led August 3, 1917.' Serial No. 184,205.

To all whom t may concern:

Be it known that I, EDWARD F. ANDREWS, a citizen of the United States, residing at` Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Im rovement in Carburetors, of

which the ollowing is a full, clear, concise,

and exact description.

This invention relates to carburetors and more particularly to carburetors of the type adapted for use in `connection with hydrocarbon engines.-

It is well'known that in the use of carburetors in which fuel is raised from a low level main supply tank directly to the carburetor spray nozzle by the partial vacuum created in the carburetor by the engine intake suction, the change of fuel level in the supply tank changes the richness of the mixture entering the engine, unless some needle valve adjustment is provided which is frequently adjusted during the change in level of fuel in the low level supply tank.

Gravity feed oarburetors ,supply with constant level float chambers are not subject to this defect, but are objectionable because of the dangers and inconvenience caused by ooding due to leaky or dirty loat valves.

The object of the present invention is to rovide a suction feed carburetor arranged or raising the fuel from a low level supply tank to the level of the carburetor, in which means are provided so that the effective lift of fuel from the low level tank to the carburetor does not vary with the change of fuel level in the low tank. y

In carrying out my invention I provide a standpipe which extends upwardly from the low level chamber,'and whlch rises and falls with the fuel in the supply tank, so that the effective lift of fuel through the standpipe is always the same. I also provide what I term a rain chamber, into which the fuel is delivered from the upper end of the said standpipe, and in which the fuel falls in the form of mist or rain, the result being that while the fuel may be lifted to a higher point under some conditions than others, the fall of the fuel in the rain chamber exerts no energy on the rising column of fuel in the standpipe, so that the suction reuired for delivering a s ecific amount of guel up the standpipevan permitting that amount to fall into the bottom of the rain chamber is exactly the same whether the `stand ipp is delivering to a point near the top o t e rain chamber, or to a point near the bottom thereof.

In -carrying out my invention I preferably construct the rain chamber at least partially of" lass, so Athat the fuel delivery may be rea ily observed.

In oneembodiment of my invention the fuel from the rain chamber is drawn through the same opening through which the movable standpipe extends, as under these conditions the movement of the stand-V pipe prevents the accumulation of dirt in the small opening, serving as a fuel delivery port between the rain chamber and the carburetor mixing chamber.

The power outputof an internal combustion engine depends upon the quantity of combustible mixture drawn into the cylinder at each stroke'. The quantity of mixture is less when the suction or partial vacuum under which the mixture is drawn into the cyllnder is great, than when the suction is only slight. In order that fuel may be lifted to the carburetor with a slight suction, I have found it advantageous to permit a small quantity of air to be drawn into the standpipe at a point near the surface of the fuel in the mam tank, thus lightening the rising column of fuel to such an extent that it may be drawn up with less suction. The admission of air at this point also diminishes the delicacy of the carburetor adjustment, because the fuel as delivered to the carburetor, being mixed with air, is in less concentrated form, by reason of which slight variations in the quantity delivered into the -incoming stream of air do not change the proportions of the resultant mixture of air and fuel as much as would the same varia- ;iorll. in the quantity of a more concentrated In the preferred form of my invention I calibrate the vertical portion of the rain 'chamberV so that the upper end of the standpipe may indicate on the calibrations the amount of fuel in the maintank.,

.AV further object of the invention is to provide a carburetor wherein the fuel, as the same is supplied thereto, is visible to the operator, thus enabling him to determine whether or not the carburetor is operating properly, While at the same time means is afforded whereby very accurate ad justments of the carburetor may be made.

Many other objects and advantages Wiil.

the present invention, said carburetor beingy shown mounted in operative position on a fuel tank.

Fig. 2 is a similar view of a modified form of carburetor. Q

Fig. 3 is a detailed View illustrating a further modification of the invention, and

Fig. 4 is a section on the line A-A of Fig. 1.

The carburetor, several forms of which are illustrated in the accompanying drawings, is particularly adaptable for use with hydro-carbon engines of the stationary type, such, for instance, as those used in connection with storage battery charging systems, although it will be obvious from the following that said carburetor is not limited to this particular use, but may be used 1n connection with other forms of hydro-carbon engines.

Referring more in detail to the drawings the referred embodiment of the invention is il ustrated in Fig. 1 and as shown, comrises a casting 1 provided with an annular -ase 2 which affords means whereby the device may be conveniently and preferably rigidly secured to the fuel tank, substantially as shown at 4, said casting comprising an elongated mixing chamber 5 adapted to communicate at one end thereof at 6 'with the cylinder or cylinders of the hydro-carbonengine (not shown), the other .end 7 thereof bein upturned and provided with a suitable a justable air valve 8 whereby the richness of the mixture supplied tothe engine may be regulated. The air valve 8, as shown, comprises a disc held yieldingly against the ad]ustin nut 9 onithe pin' 10 by means of the lcoi ed spring 11, said pin being screw-threaded or otherwise mounted in the base 2 of the casting 1. If desired, a lock nut or other suitable means may be employed to lock the adjusting nut 9 in its ad]usted position. From the above it will be noted that in starting the'engine an extremely rich priming mixture may be' supplied thereto by merely pressing saiddisc own over the upturned end 7 of the casting 1, thereby cutting o if the, air entirely or any desired portion of it, as may be desired. It will be readily noted that this depression of the disc in addition to diminishmg the supply of airalso increases the suply of fuel, owingto the increased suctior. 1n the carburetor caused by such depression. As soon as the engine is started, the disc is released, the spring 11 forcing the same beek to its normal adjusted position. n

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view of the construction of the air valve and the relative arrangement of its parts it will be noted that the reverse blast of fuel which results in the event the engine back-fires, .will impinge against the under surface of the disc as a result of which a large amount of said fuel will be directed back into the mixing chamber thereby avoiding Waste, while that which is blown out will be discharged downwardly by the downturned edge of the disc, instead of being forced up into the operator-s face, as is commonly the casc.

Communicating with the mixing chamber 5 near the end 6 thereof by means of a small aperture 12 is a suitable priming cup 13 adapted to ador-d means whereby, in the event the hydro-carbon engine is operated on kerosene, said engine may be primed with gasoline in starting the same.

Mounted uprightly on tlievcesting 1 and preferably intermediate the priming cup 13l and the air valve 8 is a tubular member 14 adapted to receive a clear vision tube 15 preferably of glass. This glass tube 15 is clamped securely in osition within the member 14 between sultable gaskets 16 by means of the screw cap 17 adapted for engagement with the upper end of said member 14. The tubular member 14 is preferably provided with vertical slots 18 (see Figure 4) through which the action of the carburetor may be viewed.

Mounted Within the fuel tank 3 is a suiti able oat 19, said float being provided with a stand pipe 20 preferably of small bore, said pipe being adapted to project upwardly from the ioat through apertures 21 and 22, formed in the walls of the casting 1, into the fuei or rain chamber 23 formedby the glass tube 15. The pipe 20 is made to fit snugly within the aperture 21, but at the same time slides freely therein to permit of said pipe rising and falling with the fioat 19. The aperture 22, however, is constructed slightiy larger than the diameter of the pipe' 20 so as to provide a slight clearance therearound which forms the discharge or atomizing nozzle of the carburetor.

The operation of the carburetor isA substantially as follows: l

0n each suction stroke of the engine a partial vacuum, or reduction in pressure is created in the chamber 23 as a result of which fuel is drawn from the tank 3 up through the pipe 2O into said chamber 23, the fuel descending to the bottom of said chamber from whence it is sprayed out through the atomizing nozzle l22 into the mixing chamber 5. In the chamber 5 it is thoroughly mixed with the air supply which is drawn in past the valve 8, said mixture being then charged into the cylinder or cylinders cf the engine. It is obvious llO being mounted -on the float and adapted to move therewith, rises and falls within the chamber 23 with the rise and fall of the level of the fuel within the tank 3. Accordingly, if desired, a suitable graduated scale, such as shown at 14a, may be provided on the tubular member 14 whereby the rise and fall of said standpipe 2O may be utilized to indicate the level of the fuel within said tank 3. If desired, the vscale may be etched or otherwise placed directly on the glass tube 15. It is obvious from the foregoing that the operation of the carburetor is substantially the same regardless of the level of the fuel within the tank 3, the only difference occasionedA by variations in the level of the fuel being in the distance the fuel falls from the upper end of the pipe 20 to the base of the chamber 23 as the same is drawn upwardly through said pipe by the suction of the engine. In other words, lthe fuel falls a greater distance when the tank is full than when 'the same is partly empty. This, however, it will be noted, has no effect whatever on the uniformity of the mixture drawn into the engine as the mixing is effected within the chamber 5 as the fuel is sprayed into said chamber through the nozzle 22. During the operation of the carburetor, the fuel is sprayed upwardly into the chamber 23 from the upper end of the pipe 2O in much theV same manner as water would be sprayed upwardly in a small fountain. This action is clearly visible through the vertical slots 18 and the glass tube 15. Accordingly, itmay readily be determined whether the carburetor is o erating properly without removing any o its parts or dismantling it in any way. Furthermore, as the lubricating medium for the engine may, if desired, be mixed with the fuel and thus conveyed tothe various bearings, the operation of the carburetor, -as viewed through the glass tube, also indicates to the operator whether the engine is being properly lubricated.-

In Fig. 2 is illustrated another formof the invention wherein a 4slightly modified form of standpipe 20 is provided, said pipe having its lower end upturned as at 24, and projecting above the level of the fuel within the tank 3, the end of said projection 24 being open as shown at 25, whereby air may be drawn into said pipe and mixed with the fuel as the same is drawn in through the aperture 26 formed in the portion of the pipe which projects beneath the surface of the fuel. It will thus be noted that means has been provided whereby an initial mixing of fuel and air is effected in the pipe 2O as the same is drawn upwardly therethrough and prior to its discharge into the chamber 23. From the chamber 23 the artial mixture of fuel and air is drawn ownwardly by thesuction of the en gine and out through the pipe 27 and discharged through the atomizing nozzle 28.

` whereby the engine, if it is desired to operate the same on kerosene, may be prlmed with gasolene in starting the same.

As a means of supplying the engine with a mixture rich in hydro-carbon when it is desired ,to start the same, a lplunger rod 33 slidably mounted .in the casting' 1 is vided, said plunger rod being normally eld in the position shown in Fig. 2 by means of the coiled spring 34. The lower end of the rod 33 is substantially ring-shaped and is positioned in a plane substantially horizontal, as'shown at 35, it being adapted to engage the upper surface of the float 19 to thereby submerge the same and the upper end of the projection 24 of the ipe 2O when the plunger rod is forced against the action of the spring 34.- This,

it will be noted, cuts off the initial supply of air through the opening 25, the suction produced by the engine acting to drawa solid column of fuel upwardly into the chamber 23 whereby a richer mixture is supplied tothe engine for starting purposes. After the engine has started, the rod 33vis released, thus allowing the float to resume its normal position, in which position the initial mixture of air .and fuel in the pipe 20 is effected priorto its discharge into the chamber 23, as above pointed out.

This same result may also be accomplished by the further modification of the invention as illustrated in Fig. 3 wherein means is provided whereby the engine maybe automatically primed vwith a mixture rich in hydro-carbon during its initial operaation, said means comprising a small conown by the operator` tainer 36 mounted within the float 19 and i provided with a fuel inlet 37. An inlet air f It will be noted from this construction thatl when the engine is at rest, the fuel within the tank 3 being at a level, substantially as indicated, will flow into the container 36, thereby filling the same. Accordingly when the engine is started no air is drawn in through the air supply pipe 38 until the fuel within the container 36 is exhausted. Thus the auxiliary air supply is cut olf during the initial operation of the engine and accordingly a much richer mixture of fuel and air is supplied to the engine. lAfter the fuel within the container 36 has beenexhausted, however, it will `be noted that air is again drawn in through .the air supply pipe 38 and is mixed with the fuel as the same is drawn in through the inlet 37 in substantially the same manner as that illustrated and described in connection with the form of invention illustrated in Fig. 2. The operation of the carburetor shown in these forms of the invention is substantially the same as that heretofore described in connection with Fig. 1 with the exception that a partial mixture of fuel and air 1s effected, prior to the final mixing of the fuel with the main air supply in the mixing chamber 29.

In all of the forms of the invention herein illustrated, it is obvious that the standpipe 20 may be used as a fuel level indicator and further, that a carburetor has been provided which can under no circumstances leak, owing to the fact that said carburetor is mounted in a plane above the level of the fuel at all times. It is also obvious that in the carburetor herein described the mixture of fuel and air is uniform at all times regardless of the level of the fuel within the fuel tank. Thus, a carburetor has been provided which overcomes the disadvantages of the gravity feed carburetor in that it has no outlet below the level of the fuel in the fuel tank and hencel no fuel from said tank can leak throu h said carburetor. The objections Tto t e standard suction feed carburetors, as above pointed out, are also obviated in the present structure in that no variation in the mixture results from changes in the level of the fuel within the tank.

If desired a small aperture 39 may be provided in the standpipe 2O of Fig. 1 just above the upper surface of the float 19, in order that a partial mixture of Vair with the fuel as it is drawn upwardly through said pipe may be eected.

This aperture is preferably positioned so that air from the tank may be drawn therethrough into the pipe 20 as the float descends, in much the same manner as the initial mixing' is effected in the construction illustrated in Fig. 2. The aperture 39 is preferably of such size that only a small proportion of air can be drawn therethrough, the main mixing being effected in the chamber 5 which is provided with the adjustable air valve 8, whereby the proportion of air and as mixed in said chamber may be regulated. It is obvious that if'the aperture 39 was of sulicient size to permlt o a substantial amount of air passing therethrough into the pipe20 it would be diilicult to regulate the amount of fuel drawn up through said pipe and that accordingly 1t would be dicult to regulate the mixture fed to the engine. The aperture 39 not only affords' means whereby a Slight initial mixing is effected in the pipe 20, but also enables the fuel to be raised a greaterheight by a given amount of suction owing to the reduced weight of the column of fuel due` to the presence of air therein.

It is apparent that many changes and modifications may be made in the construction herein illustrated and described and the right is therefore reserved to make such changes and modifications as fall within the sco e of the appended claims.

aving thus described my inventiomwhat I claim asnew and desire to secureby Letters Patent of the United States is 1. The combination with a carburetor and 'a fuel supply tank therefor, at a level below the carburetor, the fuel level in which conl tinuousl falls as the fuel is consumed by the engine, of devices through which fue] may be raised from sai-d tank to said carburetor upon each` suction stroke of the engine, said devices comprising a tube supported on the surface of the fuel in sald tank, and having an openin through which fuel is supplied thereto, be ow the level of the fuel in the tank so that the distance through which the fuel is raised remains constant from the full to the empty level of the fuel in said tank.

2. The combination with a main fuel tank wherein the fuel level varies as the fuel is consumed, of a float in said tank, acarburetor comprising a rain chamber and means carried by said float for delivering fuel into said rain chamber at aconstant height above the surface of the fuel in said main tank, a mixing chamber, and-a passage between said rain chamber and said mixing chamber for delivering fuel from the former to the latter.

3. In a carbureting device for internal combustion engines, the combination with a fuel tank of a float in said tank, a carburetor mounted above said oat, a rain chamber, a fuel pipe carried by said fioat and projectln upwardly into said rain chamber, sai rain chamber being subject to reduction 1n pressure created in the mixing chamberof said carburetor by the suction of the engme whereby fuel is lifted from 'said tank .upwardly through said pipe and sprayed into said rain chamber.

4. In a carburetting device for internal combustion engines, the combination with a fuel tank of a float in said tank, a carbuj retor mounted above said oat, a transparent fuel chamber, a fuel pipe carried by said oat and projecting upwardly into said fuel chamber, said fuel chamber being subject to reduction in pressure created in the mixingchamber of said carburetor by the suction of the engine whereby fuel is lifted from said tank upwardly through said pipe and sprayed into said fuel chamber, and in-` dicia on said fuel chamber relative to fuel supply, whereby the quantity of fuel contained in the supply tank may be ascertained. I

5. In a carburetor for hydrofcarbon enines, the combination with a fuel tank having a float, of a mixing chamber and a fuel chamber mounted above said tank, a ,passage between said chambers, a fuel pipe projecting from said float upwardly through one of said chambers and said passage, into the other of sai-d chambers, and means for establishing communication between said chambers, said means being subject to reduction in pressure created in said mixing' chamber by the suction of the engine whereby to draw fuel from said tank throu h said pipe into said fuel chamber, and t rough said passage into said mixing chamber.

6. In a carburetor for hydro-carbon engines, the combination with a fuel tank having a float, of a fuel pipe carried by said float, and rising upwardly therefrom, a.

chamber surrounding the upper end of said fuel pipe, la nozzle connected with said chamber having its discharge opening vin the base of said chamber, said discharge opening being -subject to reduction in pressure created in the mixing chamber of the carburetor by the suction of the engine to draw fuel throu h said pipel into said chamber and throug said nozzle.'

7. A mam tank wherein the fuel level continuously falls as the fuel is consumed by the engine, a carburetor receiving fuel from said main tank, and means for raising fuel through a constant distance, regardless of the level of the fuel in said tank, and for delivering the same to said carburetor, comprising a tube havinguets intake opening below the level of the l in said main tank.

8. A fuel tank wherein the fuel level continuously falls as the-fuel is consumed by the engine, a carburetor comprising a rain chamber, a mixing chamber, a single fuel passage communicating therebetween, and` means whereby the fuel fed through said passage into said fuel chamber is raised through the same distance regardless of the level within the fuel tank.

9. The combination with a fuel tank wherein the level of the fuel continuously falls as the fuel is consumed by the engine, of a carburetor positioned thereabove, vand means for raising fuel from said tank through a constant distance to supply said carburetor, regardless of the level of 'the fuel within 'said tank, said means comprising a tube having an intake opening below the level of the fuel in the tank, said tube being subject to reduction in pressure created in the mixing chamber of the carburetor bythe suction of the engine.

10. The combination with a fuel tank in which the level of the fuel falls as the fuel is consumed by the engine, of a movable element provided with a fuel. discharge port receiving fuel from said tank, means causing said port to rise and fall at a constant helght relative to the surface of the fuel in said tank, a chamber wherein the port rises and falls, and wherein the fuel-from said port falls by gravity, said chamber having sure created in the mixing chamber of a p carburetor by the suction of the engine vwhereby fuel is drawn into said chamber from said tank and supplied to said carburetor.

'11. The combination with a carburetor having a mixing chamber of given diameter of a fuel tank for supplying fuel to said mixing chamber, said tank lying below the level of said mixing cham-ber, and means for lifting fuel from said fuel tank through a constantl distance, and deliverin it to said mixing chamber while the leve of the fuel in said fuel tank varies through a distance greater than the diameter of said mixing chamber, comprising a tube havin an intake opening below the level of the fue in said tank, said tube being subject to reduction in pressure created in the mixing chamber of the carburetorv by the suction of' EDWARD F. ANDREWS.

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