US1440940A - Carburetor - Google Patents

Description

J an. 2, 1923.

II NL'SIVIITH ET AL.

3 SHEETS-SHEET l.

J an. 2, 1923. 1,449,940.

|. M. SMHH 'ET AL.

CARBURETOR.

FILED JAN. 2l, |918.

3 SHEEIS-SHEET 2.

Jan. 2, 1923.

3 SHEETS-SHEET 3.

S 3o fw WITNESSES: nel; @y INVENIQR l y l A e l fl/ M@ BY ATTORN EYJ Patented dan. 2, i923.

einen@ in sterne ,netgear entice.,

IVAN M. SMITH, OF MILWAUKEE, AND-MIKJEL I... FYKSE, OF SOUTH MILWAUKEE, WISCONSIN, ASSIGNORS TO TURBOCRBUBETER CO., OF MILWAUKEE, WISCONSIN,

A CORfPORATION OF WISCONSIN.

CARBURETOR.

Application filed January 21, 1918. Serial No. 212,876.

To all whom t may concern.:

Be it known that we, IVAN M. SMITH and MIKJEL L. `FitsngcitizensA of the United States, residing at Milwaukee` and South Milwaukee, county of Milwaukee, and State l low speedf fuel nozzle.

' of Wisconsin, have invented new and useful Improvements in Carburetors, of which the following is a specification.

,y Our invention relates to improvements in carburetors l The object of ouiinvention is to provide a carburetor with a wide range of adaptability, which will furnishl a combustible mixture suited, at alltimes, to the speed retor, embodying our invention, theflOat A of Figure 4,

and load of the engine to which it may be attached. A. second object ofv our invention is to provide improved means lfor breaking up the hydrocarbon fuel so that, even though low grade fuel be used, it will be thor-V oughly atomized. 1

It is well knownthat when the speed of a gasoline engine is varied, especially'when starting, or under varying loads, it is dif licult to deliver correct mixtures of fuel and air to the engine, and'itis also diilicult'to deliver the correct quantity required, 'these difficulties beingy particularly experienced during the periods of speed and load varia-A tion.. But it is necessary that the fuel should be thoroughlymixed with `air' and that it4 shouldbe supplied in the correct quantity in order that it may not be wasted, and the eciency of the engine impaired. Our im'-l proved carburetor is therefore designed' to provide the exact amount ofv fuel needed for perfect .combustion at all engine speeds and loads and is so constructed that the fuel will be completely atomized and' mixed with the air entering the canburetor.

In the drawings: Figure 1 is a front elevation of a carbuchamber beine partially broken away.

Like vparts are identified Yby the same refverence characters throughout the several views. f

, The vcarburetor casing includes a mixing chamber 1, provided with a water jacket 2, the outlet of the vmixing chamber having a throttlevalve 3 of' ordinary construction,

and the lower, or inlet, end being mounted pona base casting 4, which-is secured to the. mixing chamber by screws 5 extending' through the outwardly projecting ears 6 on the mixing chamber and base respectively.

The base has an extension which carries a float chamber 7, which may be assumed to be of any ordinary construction.

A fuel nozzle 8, centrally located in the 'lower portion of the casing 1, is connected with the float chamber by 'a passage 9, andA hydrocarbon deliveries through the fuel noz zle are controlled by a needle valve 11. vThe f fuel nozzle extends through a hollow, auxil- Figure 2 is a sectional view drawn on line i 2--2 lof Figure 1.

Figure 3 isa section taken on line 3-3 of Fig're 1,' but showing a slightlylmodified desi7 Figu 4 is a vertical linee-4 of Figure 3. v

section taken on Figure 5 is a section taken on llinemffe'v iary nozzle member 14 enlarged in its central portion and conically tapered downwardly and upwardly from the central portion, this hollow member forming the inner wall of the'main air inletpassage to the mixing chamber and also constituting the outer'wall of an annular air nozzle. formed between it Iand the fuel nozzle. An annular.slide valve 15 forms the outer wall of this passage, and its inner surface is in substantial .contact with the member 14 at 15', the 'inner wall of the slide Vvalve being conically enlarged downwardly and upwardly from the circle at 15 A vertically. disposed tubular member r17 l is supported lby the base casting, and provided'with an enlargement 18, which serves -as a dash pot and receives a'piston 19, connected with a tubular piston rod 20 adapted to serve as a meterin tube to regulate fuel deliveries, as hereina er explained. Alight sprinV 21tends to force'the piston 19 downward y tothe position in which-itis shown by fulllines in Figure 4f. A-by-pass 23 ex- -tends around the `field of piston.- movement,

cavity 32.

and delivery through thebyfpassy is closed by a needle valve 24. vThe upper end of theV dash pot is closed by a 'gulde sleeve' 26, through which the piston rod passes.v

The tubular member 17 has its upper portion subdivided by a partition 30 to form aset of - cavities 31 and 32, the upper cavity 32 being open to the exterior through a set lof air inlet ports 33, and registering ports 35 formed in a sleeve 37,' which is adapted to be rotatively adjusted, and therefore serves as a valve to control air admission to sure, and which is always open to some ex' tent since a cross pin42 prevents the valve from wholly seating. In all other respects the member 17 and its chambers may be asi siimed to be identical in Figures 1 and 2,' with those shown in Figures 3 and 4. The

outer portion of the cavity 31 communicates through a passage 45 with the interior of the member 14, whereby air may be drawn intothe mixing chamber under light engine suction, through the. passage 40, cavity 31,

passage and member 14, the latter having an opening at the top around the nozzle 10, which forms an, annular air outlet 48. A series of openings 49 is also provided in the wall of the member 14, these openings ex tending through the upwardly tapering portion of the member near the circular point of contact 15 with the slide valve 15. These openings provide for a delivery into the main 'air passage of a rich mixture of air and fuel from the metering chamber hereinafter described, and the quantity of the mixture thus delivered will be varied in proportion to the upward movement of the slide valve 15, for the reason'that, when this valve opens. deliveries through these apertures 4 will be accelerated, owing to the aspirating effect produced.by the rushvof air inthe mam air-passage, a

The tubular piston rod 20 is provided with a slot 50, the walls of which preferably converge upwardly. This slot affords communication between the interior of the piston rod and cavity 31.

end thereof, i sl normally enclosed by guide sleeve 26, and the lower end portion of the The slot is: so lo-, ,cated that all of it, except the small upper with the lower or' dash pot cavity above fthe piston. The float chamberfis in-jco'mmunication with the dash pot cavity throu the passage 9 and a branch-passage 9,"( igure 4). fhereforeihe liquid will au., the dash pot cavity, and will rise inthe tubular piston rod `20 to thelevel of the liquid in the float chamber.

Normallythe lower portion of the dashI pot cavity is in' communication with the up'- per portion, not only through theby-pass- 23, but also through a central port in the piston itself, this port being controlled. by

an upwardly seating check valve,57, `conu nected with the tu lar piston rod by a screw 58, and constituting the means for connecting the piston rod with the piston, a disk or washer 59 serving to limit .the

downward movement of the valve and pis-- The upper portion ot the pistonrod 20 is provided with a slot 60. the side walls of which preferably converge downwardly. lVhen the piston rod is lifted, this slot is progressively closed from its upper end downwardly by means of a bearing sleeve 62, forming part of thecap nut l63 which covers the upper end of the tubular member 1.7. The sleeve portion of this cap nut is screw' threaded in an aperture formed in the upper end of the member 17, and it is therefore vertically adjustable tocover slot 60 to the desiredextent. It should nearly close the slot when the metering. tube 2U is raised to the fullest extent.

l Piston rod 20 projects through cap nut 63.

and is connectedby van arm 70 with a slide Y 71, guided by the vertical rod 72. The lower end of this slide has a foot piece 74 which rojects through a slot- 75 in the wall ot' (Slamber 1, in the path of an annular shoulder 77 carried by the annular slide valve 15. the arrangement being such that when the slifie valve 15 is lifted, motion will be transmitted from it to the piston rod 17, through this foot piece-.74, sleeve 71 and arm 70.

vWhen the engine is ruiming slowly under light load. air will be admitted to the mixing lchamber through the passage 40, and will pass downwardly in cavity 31 and through passage 45'to the interior oi' member 14 through which it passes upwardly. nearly all of it being delivered to the mixair, for the reason that slot50 is nearly closed under the assumed conditions,- but suiicient fuel will be delivered through the nozzle 10 to form a correct mixture underchamber, whereuponslide valve 15 will be lifted, thereby admitting a much larger volume of'air through the main air inlet 13. The movement of the slide valve will be retarded, not only by the weight of the metering tube 20, but also by the .resistance afforded by piston 19, and by the vacuum pull below it. The time required for the upward movement of the slide valve 15 will .therefore be sufficiently equal to the 4time required for liquid delivery through the bypass 23 to satisfy the vacuum in the lower portionof the dash pot. The liquid above the piston may flow back into the Float chamber through the passages 9 and 9, but this tends to slightly raise the level of the liquid in the float chamber, and also in the metering tube 20. As the metering tube rises the open area of slot- 50 is increased, and the open area of slot 60 is diminished. Therefore, air delivery from cavity 32 to cavity 31, through theslot 60 and the metering tube, will be progressively diminished, as slot 60 is closed by sleeve 61. The suction exerted by the engine piston upon cavity 31 will, however, be increased, andthiswill tend to additionally raise the liquid in the metering tube 20. While the slide and metering tube are` moving upwardly, the column ofliquid in themetering tube 20 also tends to lift to a somewhat higher level than the liquid in the float chamber, owing to the fact that its inertia prevents it ,from instantly escaping through the holes 22. Therefore, if the carburetoris to be made sensitive, and quickly responsive toan topen' throttle, or to sudden engine acceleration,it is desirable to provide the metering tube with a nozzle member 65, having a restricted passage 66 for liquid delivery into that portion of the metering tube which is provided with the slot 50'." The nozzle member projects `upwardly above l,the level" of. the 'fluid in. the

'oat member, and therefore liquid delivery ,l through the nozzle memberis not affected by a lifting of the metering tube except"` in so far as this tends to raise the outlet-ofthe` nozzle, and increase the height ofthe .liquid column above the level of the "liquid in the float .chamber induced by engine suction.

The liquid drawn by engine-suction through this nozzle is atomized by the downwardly moving air current `which enters the metering tube through the partially closed slot 60, and both the liquid and air are delivered through the slot 50.to passage 45, through the annular space 68, between sleeve /and the wall of chamberl.

In Figure 4, thev nozzle member 65 is omitted, and therefore in thi-s construction liquid in the metering tube 2O may flow directly across the metering edge formed by the upper end of the sleeve 55. This tends, however, to permit an abnormal flow of hydrocarbon through slot 50 during accelerating periods, unless the needle valve .24 is so adjusted as to make the upward movement of valve 15 and of the metering tube extremely slow, whereby the column of liquid in the tube-20 may escape through the openings 22, substantially as fast as the metering tube 20 is lifted.

iVith the construction shown 'in Figures 1 and 2, the quantity of fuel delivered through the nozzle member 65 may be accurat/ely'proportioned to thev added quantity of air delivered to thev mixing chamber of the carburetor by the opening movement of slide valve 15, it being possible, by adjusting the cap nut 63, to accurately control'the suction to be exerted on the nozzle 65, by regulating the amount of air `admitted through the slot 60. It will be observedthat the nozzle 65 has its outlet ata lower level than the nozzle 10 under normal conditions, but that as the nozzle 65 is lifted and proportioned tothe quantity of air drawn into the engine, the outlet of this nozzle tends to app-roach more nearly to the vlevel of nozzle 10 under full speed and load conditions, and the action ofthe two nozzles is therefore more nearly equalized, and therefore the volume of liquid discharged through the respective nozzles will be more nearly in direct proportion to their capacity. When slide valve 15 is raised, the air entering through the main air inlet rushes through the venturi pass-age formed between. the member 14 and they slide valve, in sucha manner as to exert an aspirating effect` at the openings 49 in the member 14, whereby a larger proportion of the mixture within lthe member 14 will be drawn through these openings than when the engine is 'idling The openings 49. therefore prevent throttling effects at the opening 48.

Except as herein noted, the constructions disclosed'in Figures 1 and 2 are substantially vthe same as 1n the remaining views, and for the purposes of this invention they may be assumed to be identical. In both cases, fuel charges whenthe engine is idling are regulated entirely by air suction in the. chamber 14, and fuel suction exerted upon the nozzle 10, the amount of fuel receivedl from the metering tube being negligibleunder such conditions. .But when the throttleV 4is o-pen, or the engine accelerated, a correct mixture is maintained, not only during the accelerating period, but also subsequently thereto by mechanically controlling the` increased fuel delivery in direct proportion to the increased air del-ivory permitted by the movements of the slide valve 15. We attach great importance to the fact that our improved construction p-rovides for-progressively changing the suction upon or within the meterii'ig tu e in proportion to its vertical movement, by progressively cutting ofi' Ythe Jadmission of air to the metering tube,-this being accomplished in the construction shown, by progressively closing the slot 60.

The term correct mixture as herein used is not intended to indicate that the proportions of'fuel to air are exactly the same under all conditions, it being understood in this art that variations in the proportionate quantity of fuel employed are rrmissiblewithin cer; tain well defined limits, and that when an engine is running at uniform speed aiidvload a. relatively lean mixture is -permissible,`

whereas when the engine is suddenly acceleratedl or an increased load suddenly applied a richer mixture is needed during the period in which the engine is adjusting itself to the new conditions. In this 'respect our improved carburetor is particularly adapted to meet the requirements, and we prefer the construction sho-wn in Figures 1 and 2 for this purpose, since the variations Iin -fuel supply can be more accurately conm trolled than with the construction illustrated in Figure 3.

During starting periods when the fuel is cold, we are enabled by manually adjusting the sleeve valve 37 toincrease the suction upon themeterin tube, by partially cutting 'oil'l the supply o air through the ports 33.

This is of great importance since it avoids the necessity of priming,l or of changing any other` adjustments upon the carburetor.

We claim:

' 1. A carburetor for internal combustionI engines comprising a ioat chamber, a mixing chamber, means for delivering a substantially constant supply .of fuel to the mixingchamber, a-main air valve surrounding said means, auxiliary fuel feeding .means, provided with a metering device 'ing device being adapted to deliver4 additional air and fuel to the mixing chamber in varying proportions depending upon the position of the main air valve.

l2, A carburetor for internal combustion engines, including the combination with a mixingchamber, of an annular slide valve therein, the inner wall of which is conically enlarged from an intermediate point towardand'an annular row of outlets adjacent tothe zone of substantial contact with the slide. valve, a fuel nozzle projecting upwardly through the air nozzle, a main air inlet passage adapted for air delivery to the mixing chamber when `the slide valve israised,

. means for delivering air and fuel to the air nozzle in inversely varying quantities, and means controlled by the Islide :valve for varying the quantity of-,fuel and air delivery through the air nozzle.

3. A carburetor for internal combustion engines, including the combination with a lioat chamber, a mixing chamber provided with a fuel port and a valved main air passage, respectively adapted for delivering a 'substantially constant supply of fuel and air to--tlie mixing chamber when the engine is. operated slowly,'of an auxiliary air and fuel feeding device interposed between the i'ioat and ,mixing chambers, and connected therewith by fuel feed and mixture outlet ducts independently of said fuel port, and means connected with' the main air valve for progressively increasing the supply of fuel, and decreasing the supply of air deiivered to the auxiliary feeding device inl proportionto the' opening movement of said valve. v l

4. A carburetor for internal combustion engines, including the combination with a mixing chamber provided with fuel and air inlet passages, and a main air valve adapted.

to open under air pressure lin the air passage, of an auxiliary inlet passage for fuel y andair, and means controlled by the main air valve for increasing the fuel supply and diminishing the air supply in said auxiliary passage in proportion' to vthe opening movement of said valve.

- 5. A carburetor forl internal combustion engines, including the combinationwith a mixing chamber provided with air and fuel f inlets, and with a mixture outlet, of a slide valve in the air inlet adapted to be 4actuated by pressure of the air from `a normally nearly closed position to full open position,

leadingv to the` mixing chamber, a receptacle adapted for upward and downward movement in said passage, and provided with a ,an auxiliary'passage for both airand fuel f tion of a mixing chamber, provided with' valve for varying the relative positions of' said receptacle and member to vary the Vquantity of liquid overflow into saidl passage.

6. A carburetor including the combinaan'- air inlet passage, a slide valve controlling air delivery through said passage, another air passage leading -to the mixing chamber, a tubular member thereinfin communication with a source of fuel supply,

l and provided with an air port of variable capacity, said tubular member also having a fuel delivery port of variable capacity adapted to permit fuel `delivery into said last mentioned air passage, andmeans connected with the slide valve for'varying the capacity of said air and fuel ports.

7. A carburetor including the combination of a mixing chamber, provided with an air inlet passage, a slide valve controlling air delivery through saidpassage, an-

-other air passage leading to. the mixing chamber,` a, tubular member therein, in -ccmmunication with a source of fuel supply, and provided With an air port of variabe capacity, said tubular member also having a fuel delivery port of variable capacity adapted to permit fuel delivery into said last mentioned air passage, and means connectedfwith the slide valve for lifting said tubular member, and thereby varying the capacity' of said air and 'fuel ports, together with a fuel supply chamber, a piston therein connected Witli said ,ported 'tubular member, and adaptedto utilize the pressure of liquid in said chamber to delay the movement of the tubular member when the latter is being actuated by the slide valve.

8. A carburetor provided'with a main air passage, a'slide valve controlling air delivery' through said passage, Aa source of fuel supply at constant -level, a. nozzle leading into said passage from the source of fuel supply, an auxiliary .passage in communication with said fuel supply, and also in communication with the open air, a metering tube in said passage, ,having fuel and air inlets, and a lateral 'outlet intermediate 'of the `fuel and air inlets, a relativel n stationary member controlling fuel de ivery through said lateral outlet, and connections between the slide valve and metering tube.' 9.Y AA 'carburetorv for internal .combustion` engines, including the combination withja mixing chamber provided Vwith air and fuel inlets, and with a mixtureoutlet, of a slide valve vin the air inlet adapted to be actuated by pressure of the air from a normally nearly closed position to full open position,

an auxiliary' passage for both air and fuel leading to the -mixing chamber, a receptacle adapted forupward and downward'move- 4 nient in said passage, and provided with a ceptacle and member to vary the quantity of liquid overilow into saidpass'age, together with means, for inversely controlling air admission to the upper portion of said receptacle.

ll0. A metering device for carburetois, comprising a fuel passage having an upwardly and downwardly movable receptacle therein, a v:relatively stationary member embracing avportion of said receptacle -intermediate of its ends, and adapt/ed to serve as a slide bearingtherefor, said receptacle being provided with a fuel inlet below said member, an air inlet above said member, and an outlet for air and fuel in registry with said member, and ,means for automatically varying the capacity-"of thatportion of the' receptacle outlet which is above the upper margin of the member. v

11. A metering device for carburetors, comprising a fuel passage having an' u wardly and downwardly movable receptac e therein, a relatively stationary member embracing a portion of said receptacle interan outlet for air and fuel in registry with said member, and means for automatically lifting the receptacle to increase the discharge of liquid across the member from within the receptacle.

l2. A metering device for internal couibustion engine carburetors, including the combination of 'a' passage for liquid fuel,

a movable receptacle therein ported to receive fuel from said passage, andal'so having an outlet port' at a higher level, a rela-l tively mationary member in said passage partially covering said outlet port, means for admittin air to the upper portion of said receptac e, and means adapted to'be controlled by engine suction for raising and lowering said receptacle to increase and diminish the flow or liquid over the relatively stationary member through said outlet.

. A"13. A metering device for internal com-` bustion" engine carburetors, including the lcombin'atioiri of a passage for liquid' fuel, a movable receptacle therein ported to receive fuel from said passage, and also having an outlet port at a higher level, a relatively stationary member in said passage partially covering said outlet port, means for admitting air to the upper portion of said reiis ,1 member through said outlet, said receptacle t eeptacle, means adapted to be controlled hy I-n testimony whereof We aHiX our signaengine suction for raising and lowering said tures in vthe presence of two Witnesses. receptacle to increase and diminish the vloW v i of liquid over the said relatively stationary actuating means including means for initnessesr ver'sel-y regulating air delivery through said LEVERETI C. WHEELER, receptacle to the outlet therefrom. O. C. WEBER.

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