US1207029A - Carbureter. - Google Patents

Description

W. S. GUTHRIE.

CARBUHETEH.

APPucATIoN men Arnia. 1914.

1,207,029. Patented 11110.5,19162 2 SHEETS-SHEET 2.

Hg. v7.

' reter being of the vertical type.

other carbureter of the vertical type.

' OFFICE.

WILLIAM S. GUTHRIE, OF DETROIT, MICHIGAN.

CARBURETER.

'l Specification of Letters Patent.

Patented Dec. 5, 1916.

Applicatonled April 3, 1914. Serial No. 829,181.-

To all whom z't may concern: Be it known that I, WILLIAM; S. GUTHRIE, a citizen of the United States, and a resident Vof Detroit, in the county of 'Wayne and State of Michigan, have invented a new and Improved Carbureter, of which the following is a specification.

My invention relates to carbureters for internal combustion engines, and the primary object of my invention is to provide a carbureter in which elicient mixtures are produced for'a reasonable range of speeds when once properly adjusted to the engine.

The object of my invention is accomplished by a carbureter having a mixing chamber, primary and auxiliary fuel reservoirs, a fuel passage having a connection with each of the reservoirs, means whereby the liquid flows from said primary reservoir into said fuel passage in varying quantities during the operation of the carbureter, means adapted to discharge fuel into the mixing chamber from said fuel passage so that the said discharge includes the liquid contents of the auxiliary reservoirs, and means whereby fuel is supplied from the .auxiliary reservoir when the engine is normally running lat a low rate of speed. l

One feature of my invention consists in the combination of a mixing chamber, a main fuel feeding device communicating therewith, and a second fuel feeding device adapted to supply fuel when the engine is normally running at a low rate of speed,

which second fuel feeding device ceases to discharge fuel when the engine is running at higher 'speeds7 and compensates the fuel supply by admitting air to the main fuel feeding device.

The invention further consists in the details of construction shown, described and particularly pointed out in the claims.

In the accompanyingl drawings Figures 1, 2, 3 and 4 are central vertical cross sections of four modifications of a carbureter embodying the present invention, said carbu- Figs. 5 and 6 are longitudinal sections of fuel nozzles. Fig. 7 is a longitudinal section through an- Figs. 8 and 9 are corresponding sections of two modiiications of carbureters in each of which the mixing chamber is horizontal. Fig. 10 is a section on the line 10-10 of Fig. 8.

Fig. A11 is a section on theline ll-llof Fig. 9.

Similar reference characters refer to like parts throughout the several views.

The main fuel reservoir 1, of all the modications shown in the drawings, is provided with a top 2, having an inlet connection 3 and air vent 4. A float 5 has a stem 6, provided with a valve 7 at its upper end and guided at its lower end. Any other means may be employed to supply the liquid fuel to the main fuel channel onpassage.

'The mixing chamber 9 of theL different constructions has an air inlet 10, mixture outlet 11, a Venturi tube 12, a transverse shaft 13, a throttle valve 14 on the shaft, and a main fuel feeding device, or nozzle 15.V

IVhen the engine is normally running at the lowest speed this throttle valve is preferably set slightly open to permit a slight flow of air as shown in Fig. 1. This nozzle may have a single discharge opening 16 at its upper end, as shown in Figs. 1 to 4, and 7 to 11, it may have a plurality of discharge openings 17, as shownin Fig. 5, or it may be open ended and be in the form of a tube 18, having a restriction near the lower end as shown in Fig. 6 or the restriction may be nearer the top of the tube if desired. The various modified forms of this invention operate in substantially the same way, but each differs slightly from the others in construction, as will be hereinafter explained.

In each carbureter shown in the drawings, is provided a main fuel channelor passage to which fuel is supplied in varying quantities from a main source of fuel supply and an auxiliary reservoir is also provided, in which liquid fuel is temporarily stored, and

from which reservoir fuel is supplied to the main reservoir 1 permits it to flow into thesaid fuel passage. The jet 16 may be controlled by a regulating needle valve when desired. The constructions of the parts constltutlng the auxiliary reservoir and the fuel passages differ in the several constructions shown in the drawings.

The air flows to the mixing chamber 9 l and also to the auxiliary reservoir from the inlet passage 10, and by this means less air will fiow to the auxiliary reservoir at high speed than at low speed, because at high speed a partial vacuum is formed in the passage 10. Thus the air pressure in the auxiliary reservoir will be lower at high speed, and the fiow of the air from the auxiliary reservoir into the fuel passage will therefore vary with the speed of theyengine. The auxiliary reservoirs may be opened to the atmosphere if desired.

lln the carbureter shown in Fig. 1, an aux* iliary reservoir 20 connects to the mixing chamber 9 by means of a small passage 21.

'A pipe 22 extends down from the plug 23 into the well 24 mounted in the screw-plug 25. The well extends up above the level of the liquid fuel in the chambery 1, and the `pipe 22 extends below such level.

A calibrated orifice 26 in the plug 25 discharges fuel into the auxiliary reservoir 20 when the engine is running slowly and the throttle is nearly closed.

An opening 27 permits the fuel to How into the reservoir 20, and a calibrated orifice 28 in the bottom of the well 24 determines the fiow of fuel `from the auxiliary reservoir 20 into the said well for the low speed of the engine. Passages 29 and 30 permit communication between the air in-V let passage 10 and the reservoir 20. An auxiliary passage 31 is controlled by the valve 32 having a crank arm 33so that the valve may be opened Afrom va distance when a greater supply of fuel is desired than normally flows from the calibrated opening Y 34 into the passage 36. The opening 34 usually has a greater capacity than the orifice 26, and usually has less capacity than the orifice 16, that is, the opening or openings in the nozzle 15, when subjectedto a strong suction, are of greater discharge capacity than the orifice 34, even when the area of the orifice 34 is somewhat larger than the discharge opening or openings in the nozzle 15.

Air normally passes through the inlet 10 up around the nozzle 15 and through the outlet 11 to the engine, the flow being con? trolled by the valve 14. Some of the air` that enters at 10 flows through the passages 29 in the lower end of the Venturi tube and through the opening 30 into the reservoir 20, thence downinto the' well 24, up the pipe 22 and through the passage 21 into the mixing chamber 9, above the throttle 14. When the auxiliary reservoir is empty some of the air that enters the same fiows down around the well 24 and through the orificesl27 and 26, rinto .the fuel passage 36, where it mixes with the fuel and fiowing Leones@ up-through the Ynozzle 15 is discharged into f. the mixing chamber 9.

Part of the air that Hows down through the opening 27 will pass up through the orifice 28 into the well 24 and also up the tube 22. After the fluid once enters the well 24 through the orifice 28 it does not reverse in its direction of travel provided the air pressure in the well 24 is lower than it is in the auxiliary reservoir 20 which will be the case if the orifice 28 feeds the oil under the influence of suction. The air pressure in this reservoir, as in"the auxiliary reservoirs shown in Figs. 4, 7, 8 and 9, is atmospheric when the engine is normally running at a low rate of speed. The well 24 may be used in addition to the auxiliary reservoir shown in any of these figures when it is desired to get a more perfect adjustment.

By employing the well 24 in addition to the auxiliary reservoirs shown in the above figures it is possible to make a very fine adjustment of the carbureter for any motor, as the compensating jet 26 may be of such size as will permit entrance of air to the fuel passage in proper proportion without effecting the supply of fuel for the low speed, which is controlled by the jet 28 and which jet supplies fuel at a less rate than the compensating jet 26 supplies the same to the reservoir 20. Some motors may however be fitted without using the well 24. rllhe fuel flows up iiito the auxiliary reservoir 20 only when the engine is stopped or when it is running at a low rate of speed with the throttle nearly closed, and at which time the suction at the jet 16 may be insufficient to draw the full supply of the fuel from the nozzle 15.

When the throttle is nearly closed, a very V rich mixture of fuel will be drawn up from the well 24, through the pipe 22 and through the passage 21 into the chamber 9 above thel throttle, where it mixes with the air that passes up around the throttle valve. This constitutes the fuel supply of the engine when normally running at the lowest speed.

lf the throttle is opened to approximately the position shown in Fifi'. 2, air will flo-w more freely through the-Venturi tube 12 and the nozzle 15 will discharge fuel in addition to that which passes up the pipe 22. When the throttle is fully o-pened, a greater suction occurs at the discharge opening 16 because of the restriction at the lower end of the Venturi tube 12, and at this time the During the time the fuel in the auxiliary chamber flows from the opening 16, an abnormally rich mixture is being supplied to the engine, tending to cause an acceleration of speed. As the speed increases, the mixture becomes leaner through the supply from the auxiliary reservoir ceasing, and the sole supply coming from the orifice 34, which is of less discharge capacity than theopening 16. Air will now pass down around the well 20, through the opening 27, and the calibrated orifice 26, and mix with the fuel in' the fuel passage 36, and pass into thc mixing chamber through the jet 16,ihus causing the mixture to be of the proper leanness, the orifice 26 being calibrated to insure such a mixture. Thus it will be seen that the orifice 26 constitutes a compensator that supplies fuel for the low speed of the engine and at higher speed it acts as a vent for the suction controlled jet 16.

Under certain conditions, an additional 'supply of fuel may be desirable. This can be furnished by opening the needle valve 32 by means of the crank arm 33 to permit fuel to flow through the passage 31 to the main fuel passage 36. This is especially of value during cold weather when an additional amount of fuel is necessary to run the engine with reasonable power while being warmed up. The float chamber may be drained by removing the plug 38. Liquid fuel is temporarily stored in the space below the plug 26 and this liquid is discharged by the jet 16 in like manner with the liquid stored in the auxiliary reservoir. The volume may be varied by increasing or decreasing the length of the plug 26. The rate of flow of fuel through the passage 21 may be varied by the needle valve 37, provided the fuel is drawn through the orifice 28 by suction', which may be accomplished by restricting the air in'let to the well 24. By ,removing the well from the plug 25, it is obvious that the oil in its raw starte (without air) will be drawn up the tube 22 at the lowest speed, since the orifice 26 is capable of supplying the oil at ay faster rate than then required, and since the-intake end of the tube 22 is below the normal level of the liquid in the float chamber. l

In Fig. 2 the compensating jet 42 in the plug 41 is substantially at the bottom of the auxiliary reservoir 43. The flow of fuel and air through this-jet 42 is substantially theI same as it is through the jet 26 in Fig. 1 previously described. The pipe 44 does not extend down i'nto the fuel when the engine is stopped, but a` slight vacuum due to restricting the air through the opening`30 will cause the fuel to rise to the lower end of the pipe. up which it will be drawn with some air and discharge into the mixing chamber 9 above the throttle valve. As in the other views, the lower end of this pipe is beveled, which tends to mix the air and liquid as it enters the pipe. The fuel passage 36 is in this modification connected to the fuel chamber 1 by means of a plug 36 having an orifice 34u therein corresponding to the opening 34 heretofore described. 'lhe needle valve 45 may be turned back to admit air through the passage 46, thereby reducing the suction and flow of fuel. This construction is very convenient for varying the fuel supply for the engine when running at low-speed.l This passage 46 may be calibrated when the carbureter is to be used on only one type and size of engine, in which case the valve 45 may be omitted.

The carbureter 'shown in Fig. 3 has an auxiliary reservoir 48 in the form of a removable tube having a restricted opening 49 in its upper end, above the level of the fuel in the reservoir 1, its lower end having unrestricted communication with the fuel passage abat). In the operation of the engine when normally running at the lowest speed, air passes froln the inlet 10 through the opening 51 around the upper endof the reservoir 48, into the chamber 52 and finally into the outlet 11 through the passage 53. Fuel may then be drawn by suction through the jet 49 from the auxiliary reservoir 48 when the engine is normally running at the lowest speed provided the opening 51 is sufficiently small to cause a -slight sub-atmospheric pressure in the cham- I ber 52. lf the throttle is opened sufficiently the air pressure in the chamber 9 will naturally fall below that in the chamber 52 and the jet 49 will .cease discharging fuel because the jet 16 is now capable of' a greater discharge than the orifice 54 in the valve 55, which supplies the fuel from the main reservoir 1. The jet 49 will now admit air into the reservoir 48 from the chamber which permits the fuel in the reservoir 48 to be drawn downwardly into the passage 36 to supplement the supply that is -received directly from the reservoir l. Air will follow the liquid into the fue] passage 36 from the reservoir 48, which compensates the fuel supply as before described. The valve 55 may be adjusted in respect to its seat b v the lever 56 and threads 57 to afford an additional supply of fuel if desired.

In Fig. 4, the reservoir 61 extends up into the-chamber 62 which communicates with the air inlet 10 by means of the opening 63. For adjusting the low speed fuel supply the pipe 65 is mounted in a threaded bushing 64 so that it can be removed and an other substituted of a different length. The

lower the pipe extends into the liquid the i greater will be the How of the liquid for the low speed. lf, however, the orifice 69 is so largo that the oil flows therethrough too freely for the low speed, then this method of varying theoil supply will be of no use;

regulated by calibrating the passage 71, or

i this passage 71 may be controlled as by the valves 37 and lshown in Figs. 1 and 2, respectively. lln the latter operation of the auxiliary feeding device it will be seen that the oil in its raw state (without air) will be drawn up the tube 65 when the engine is normally running at the lowest speed, and at which time the air pressure in the 'auxiliary reservoir 61 will be atmospheric. rThis operation may be had with all the carbu reters shown in the drawings except those shown in Figs. 2 and 3.

YVhen the throttle is nearly closed, fuel will' fiow through the` calibrated orifice 66 in the spring held valve 67into thefuel passage 68 and up through the compensating liet 69 in the plug 70 into the reservoir 61 and up the pipe 65 to the mixing chamber at 71. Ai-r from the chamberA 62 'flows down intp the reservoir 61,*to the lower end of the pipe 65, and passing up, enters the mixing chamber through the passage 71. When the throttle is opened a certain distance the flow of fuel through the compensating jet 69 will reverse as heretofore described.

The lower end of the stem 6 of the float may be guided in the upper end of the drain cock 73, which'is provided to drain the'main reservoir 1. The valve 67 may be held against its seat by the spring 74, but by pulling on the stem 75 of this valve agreatly increased flow of fuel is obtained for starting theaengine without disturbing the normal adjustment of the other parts 'of the carbureter. l

The ,carbureter shown in Fig. 7 is formed with a horizontal outlet passage 11, which is sometimes /desirable for attaching lthe same to engines requiringa horizontal connection." The body of this carbureter is made in two parts, 95 and 9.6, and a proper flange with a series of screws 97 provides .suitable means for joining the two parts together, the upper end of the Venturi tube 12 being used to properly locate the said parts when assembling the same. l Air from the inlet 10 will flow up around the lower end of the Venturi tube 12 and through the opening 30 into the auxiliary reservoir 20 and down to the lower end of the tube, 22 and discharge into the mixing chamber 9 through the passageway 21, which, as in all the other. views, discharges into the said chamber 9 adjacent the throttle valve. This passageway 21 mav be positioned at any point where it will be subjected to the suction in advance of the throttle.

The calibrated orifice 26 will supply the liquid'to the `reservoir 20 as fast as it is drawn out through the tube 22 for the low speed of the engine when the throttle is nearly closed and when the throttle opened sufficiently, the dischargafrom the jet 16 -will include the liquid 'in the reservoir 20, lit

passing down through the compensatingjet 26 into the fuel passage 36 and up the nozzle 15. Air will follow the liquid from the reservoir 20 into theffuel passage'36 which compensates the fuel'supply for the higher speeds.

The carbureterssrhown in Fi s. 8 t011Y havef horizontal mixing chambers 9. r1`his type is especially desirablekwhere the carbureter is to be fastened directly to the en- .lg'ine casting `without the necessity of the usual manifold. Air enters the air inlet 10 and flows through the mixing chamber 9 and out the passage 11 to the engine.

1n Figs. 8 to 10 part of the air that enters at 10 will flow around the rear end of the Venturi tube 12 and into the reservoir 20 through the opening 30 eSand downto the lower end of the tube 22 up which it passes to the /passage 76 from the openings 77 and 'through the duct 7 8 and passage 21 to the mixing chamber 9. The liquid is likewise supplied to the said mixing chamber through the passage 21 from.the auxiliary reservoir 2() when the throttle is nearly closed andthe engine is running' slowly.

The calibrated orifice 26v supplies the liquid to the reservoir 20 as fast as it is drawn up the tube 22, as before described. At higher speeds this jet 26"compensates the fuel supply as also before described. The tube 22 is carried by the bushing 79which is threaded at 80 and Vprovided with a rknurled button 81. This provides a con-s /f'the mixing chamber 9 prevents the-chamber filling with the liquid should the nozzle overow from any cause, and this openingserves another valuable purpose in this particular type of carbureter. When the engine is running at only a moderate speed the suction causes the j et 16a to discharge the liquid with but slight force and as the air passing through the Venturi tube is traveling at a lia comparative slow rate it may sometimes fail to properlyvaporize the fueland cause a. loading up condition. 1f this loading up occurs, the engine will possibly miss firing. The opening 87 therefore tends to prevent a loading up fromthis cause,.by admitting air to the mixing` chamber at a position where the liquid may collect. l

ber from the auxiliary reservoir for the' low speed of the engine in the same manner as shown and described in Figs. 8 and l0.

Air enters the passage 82 through the adjustable opening 83 and flows to the auxiliary reservoir 20, the amount of air being controlled by the screw 84 which is adapted to close over the opening 83 for this purpose. After entering the auxiliary reservoir 2O the air passes up through the tube 22 to the mixing chamber as before de- 4 scribed. The fuel is supplied to the reservoir 20 through the calibrated orifice 26 as fast as it is drawn up the tube 22 for the low speed and at high speeds this orifice 26 compensates the fuel supply by admitting air to the fuel passage 36 in the same manner as before described. The tube 22 is mounted in a removable bushing 88 which makes it an easy matter to remove the same for the purpose before stated.

The liquid enters the fuel passage 36 through the orifice 34 in the plug 85 which being of tubular formation forms the 'fuel passage 36. The liquid passes freely through the openings 86 to and from the auxiliary reservoir 20, but the jet 26 restricts the communication between the said reser- `voirk 20 and the fuel passage 36.

The plug 85 may be removed easily so another can be substituted -when fitting the same to an engine, as will be apparent.

The space below the nozzle l5 will be filled with the liquid and emptied in like manner with the reservoir 20 and the size of this space may be varied, depending on the length of the various plugs shown in the drawings. The discharge orifices in the nozzles 15 in all the carbureters shown, being unusually large, will discharge fuel under moderate suction; a Venturi tube of reasonably large size may therefore be used to insure the maximum power of the engine.

The delivery of fuel from the orifice 16 may be slight until the throttle is opened to approximately the position shown in Fig. 2, and as the throttle opening is increased the suction becomes stronger and stronger and .unless some compensatm yfaster the speed may be it will properly lcompensate the fuel supply. This compensating jet 26 is made in the form of a bushing and is held in position by screw threads as shown, which makes it removable so that one of proper size of opening may readily be substituted to suit the particular engine on which the carbureter is used.

In each carbureter shown in the drawings will be found a fuel feed jet that compensates the fuel supply in the same manner as the jet 26 just described. It will be noted that these compensating jets all permit the passage of the liquid for the lowest speed 7, of the engine when running under normal conditionsy. and at higher speeds these jets admit air, for the purpose of checking the suction on the restricted passageway that connects with the main supply reservoir; and that the fuel supply through this restricted passageway varies with the speed of the engine.

The carbureters may all be provided with any of the usual means for limiting the air supply in order to secure rich mixtures for starting the engine.

The modifications shown indicate that many other Changes may be made in the construction of this carbureter without departing from the spirit of my invention as set forth in the following claims.

I claim:

1. In a carbureter for internal combustion engines, in combination7 a mixing chamber 95 having a fuel jet therein, a supply reservoir,

a fuel passage having restricted connection with the supply reservoir and supplying fuel to said jet, an auxiliary fuel tube for conveying fuel to the mixing chamber, an 10o auxiliary fuel container having restricted connection with said fuel passage, an additional fuel container within said auxiliary fuel' container, and from which additional fuel container the said auxiliary fuel tube sucks, means for varying the air pressure in said auxiliary. fuel container during the f, operation of the carbureter.

2. In a carbureter, a mixing chamber having a fuel opening communicating therewith, a main supply reservoir, afuel passage having restricted connection with said supply reservoir and feeding said fuel opening, an auxiliary fuel reservoir having 're. stricted connection with said fuel passage, an auxiliary fuel passage for conveying fuel from said auxiliary reservoir to the mixing chamber, and means whereby the air pressure in said auxiliary reservoir is caused to vary from atmospheric to sub-atmospheric. during the operation of the carbureter.

3. In a carbureter, the combination of a body having a 'mixing chamber therein, a throttle for controlling the flow of fluids through said chamber, a main fuel feed passage, restricted means for supplying fuel to said fuel passage, an auxiliary reservoir having restricted connection with said fuel passage, means for discharging fuel from said fuel passage into the mixing chamber, so that the said discharge includes initially liquid fuel and finally air from the auxiliary reservoir and means for discharging fuel into said .mixingY chamber on the exit side of the throttle valve from the said auxiliary reservoir When the engine is normally running at a low rate of speed.

4. ln avgarbureter, the combination of a body having a mixing chamber therein, a throttle for controlling the flow of Huids through said chamber, a, main fuel passage, restricted means for supplying fuel to said passage, an auxiliary reservoir having restricted connection with said passage, means means for discharging fuel into said chamcharge includes initially liquid fuel andl finally air from the said auxiliary reservoir, and. means for dlschargmg fuel from said auxillary reservoir into said chamber 1n ad- 4vancelof said1 throttle, when the 'engine is normally running at a low rate of speed.

5. fn a carbureter for internal combustion engines, the combination of a body having an air inlet passage, a mixing chamber having connection with the air inlet passage, a supply reservoir, a fuel passage having restricted connection With the supply reservoir, an additional reservoir having restricted connection with the fuel passage, means for supplying air to the additional reservoir from the said air inlet passage, means for supplying liquid fuel .from the additional reservoir when the engine is normally running at a. low rate of speed, and means for discharging fuel into the mixing chamber so that the said discharge includes lbushing substantially forming an additional initially liquid fuel and finally air from the said additional reservoir.

6. ln a carbureter for internal combustion A engines7 the combination of a body' having Laoaoae sage, means for supplying liquid fuel from the additional reservoir When the engine is normally running at a l10W rate of speed, and means for discharging fuel into the mixing chamber so that the said discharge includes initially liquid fuel and finally air from the Vsaid additional reservoir.

7. In a device of the character described,7 a. suction controlled fuel feed jet, an additional jet arranged in a plug and adapted to supply hydrocarbon fuel when the engine is normally running at a. low rate of speed, and to admitI air to the said suction controlled jet at a higher speed. v

8. ln a device of the character described,

lwhereby the fuel in theA auxiliary reservoir la suction controlled fuel vfeed jet, an` addimay be discharged into the fuel passage,

tional jet arranged to supply fuel When the engine is normally running at a low rate of speed, and to admit air to the said suction controlled iet at a higher speed, means for varying the size of the said additional jet.

9. ln a carbureter comprising a body having a mixing chamber therein, a suction controlled fuel feed jet communicating with said mixing chamber, an additional jet-removably mounted and positioned so that it.

supplies hydrocarbon fuel When the engine is running at a loW rate of speed, and toV admit air to the said suction controlled fuel feed jet at higher speed..

10. ln a carbureter, ya mixing chamber, a suction controlled fuel feed jet communicating with the said mixing chamber, an additional jet arranged so that it supplies fuel for certain low speeds ofthe engine, and to admit air tothe said suction controlled fuel feed jet at higher speed, means for regulating the said additional jet. f

lLln a carbureter, a mixing chamber, Ya suction controlled fuel feed jet therein, a

jet that supplies hydrocarbon fuel for certain low engine speeds, and admits air to the said suction controlled fuel feed jet at higher speeds of the engine.

ln testimony. whereof l have signed this specification in the presence of two subscribing Witnesses.

l WlLLlAM S. GUTHRIE. Witnesses:

L M. SPENCER, HUGO W. Knninnninc.

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