US1850307A - Carburetor - Google Patents

Description

. A. MOORE CARBURETR March 22, 1932.

Filedl July 5o, 1928 2 Sheets-.Sheet l Mfg-raw coef ATTORNEY.;

9%@ 225@ www March 22, 1932. -A. MQORE 1,850,307

CARBURETOR- Filed July 30, 1928 2 Sheets-Sheet 2 ATTORNEYJ` Patented z2, 1932 VcalunnsurronD Appncguoa mea my ao, 192s. serial no. 296,216.

My invention relates to fuel metering and supplying apparatus for internal combustion engines,

Y *l gines subject to wide momentary variations in f6 power and. speed; and

object more efficient and the fuel in take pressure on the orair controlling fuel to the intake in accordance with the en- 4 gine requirements.

Another object of said invention is to rovide an apparatus of the character spec1iied in which a single fuel jet. is relied on at'all engine loads and speeds,

Further, said invention has for its object to provide an apparatus of the character specified in which a drop in pressure below atmospheric is constantly maintained about the mouth of the fuel jet to effect Athe delivery of fuel from a constant level fuel chamber in its usual position relative to said jet throughout the operating range of the engine, while controlling'the fuel jet orifice in synchronism with the variations in intake pressure within the intake conduit above the throttle,

whereby to balance saiddrop in pressure;

about the fuel jetpand the to roperl meter the fuel.

y(gther o jects will in part be obvious, and in part be pointed out hereafter.

To the attainment of the aforesaid objects opening thereof and ends my invention consists in the novel' combinations and arrangement of parts hereinafter more fully described, and then .pointed out in the clalms.

In the accompanying drawings:

and particularly transportation enmeans, and delivers said including idling, for i' supplying the requisitev fuel without reliance Figure 1 is a,sectional elevation of one form of device constructed according to and embodying my said invention; and Y 1g. a modification.

g my inventionI lof variable crossapproximately maximum power, and capable of being controlled to decrease the extent of opening thereof at part throttle positions for supplying fuel to the air stream by induction in proportions to approximately maximum economy. g I The extent of opening of the fuel passage is varied throughout the'operatu `range of the engine for supplying by the inductive effects of thevengine the requisite fuel to the engine in quantities metered in accordance with the requirements of the-engine at different speeds and loads. l v

In the apparatus of my invention, the opening of the fuel orifice is adjusted in accordance with the requirements to effect a balance between size of fuel opening and the reduction in pressure about the fuel jet-due to the inductive effects of the engine, so that the characteristics of the jet by orifice oarea variatlon. Y

Referring to the drawings, the fuel jet or nozzle 10 disposed within the' intake conduit 12 communicates through the assa'ge with the fuel receptacle or float el: 16,'the latter in which the trolled by the usual float 18.' Y

e conduit 12 is formed in part in two castings 12* and 12" secured together bysujtbeing of the constant level type valve actuated by the 1s a view similar to Fig. 1 showing amber supply-cof -fuel thereto is con-" 4engine while mamtaining the fuel metering able fastening means. Theoat chamber 16 in the casting 12EL is preferably annular in form to provide a space 16a therein registering with a space 16b in the casting 12b to form a bellows receiving chamber 20, the lower edge portions of the upper casting l2b serving to close the float chamber 16.

The nozzle 10 consists of a lower tubular portion l()a secured within a bore 1()b in the lower casting 12a, andcommunicating with the passage 14, and of a tip portion 10c havi'ng a relatively constricted passage 1()d therethrough. The lower end 21 of the passage 10d is located below the fuel level within the chamber 16, and the outer end 22 thereof is located above said fuel level, the end of the nozzle 10 extending into the Venturi passage 24 of the member 24a.

rlhe air admitted-to the Lintake conduit 12 through the horizontal opening 26 in the casting 12a is preferably controlled by the throttle valve 28 located below the nozzle 10, and by the throttle valve 3() located above or beyond said nozzle, providing above the throttle 30 a region of maximum reduction of pressure, and between said valves a region wherein fuel nozzle 10 is located having a pressure of a value intermediate between that of the atmospheric pressure below valve 28 and the pressure above valve 30, the valve 28 serving as a gate for maintaining a reduction of pressure aboutthe fuel nozzle 10.

The valves 28 and 30 are preferably connected by the link 32 to work in unison, and are preferably manually operated by a link 34extending to a point convenient for actuation. The size of the passage 12 at the point 36 where the valve 30 is less than that of the passage at the point 38 where the valve 28 is located. When the throttle 30 is slightly cracked the throttle 28 will open to a slightly greater extent so that a reduction of'pressure can be maintained about the jet 1() at the idling period for effecting the lifting of the fuel from its level in the chamber 16 to the tip 22 of the nozzle, without causing excessive -reduction in pressure about the jet 10 'and thereby preventing undue enrichment of the charge mixture. As the throttle 30 opens, the throttle 28 likewise opens until under maximum power conditions both throttles are open to the maximum eX- tent. The velocity of the air through the Venturi passage 24 as the throttle opens becomes effective in maintaining reduction of pressure about the fuel nozzle 10 for lifting fuel. By this arrangement upon acceleration of the engine the fuel nozzle 1() is subjected to a greater reduction in pressure than in the 4case of the usual carburetor, and air velocity upon acceleration is somewhat retarded by the two valves 28 and/30 so that fuel impoverishment. orlag is reduced, and stumbling of the engine upon accelerationr largely prevented. Further, in view of the located. is slightly I `initially relatively larger reduction inpressure acting y on the'fuel jet compared'to that acting on the ordinary carburetor fuel jet, upon acceleration, the inertia of the fuel,.or

the tendency thereof to travel at its velocity prior to acceleration, tends to effect the delivery thereof to the air stream without lagging, even though upon acceleration the fuel orifice is increased in size and more fuel is delivered. j

rlhe extent-of opening of nozzle l0;is regulated by a modulating valve pin 40, and provision is made for voperating said pin 40 in response to variations in the pressure difference between the engine intake pressure and the pressure of the amtosphere.

In the form shown, the interior of a pressure responsive member, such as the bellows or expansible-contractible element 42 dis.- poscd within the chamber 20 communicates through the inclined drainage channel 44 with the passage l2 leading to the intake manifold, and the bellows 42 operates a lever 46 by `means of stem 48; and lever 46, pivoted at 50 to the adjustable arm 52, actuates the fuel modulating pin 40. Pivotal connections are preferably made by slots 54, 56, in lever 46 to facilitate adjustments.

-Contracting movement of bellows 42 responsive to pressure reduction in passage 12 moves valve 40 toward its closing position. Such movement is opposed by the adjustable tension spring 58 encirclingstem 48 and interposed between the base 6() closing the lower end of the chamber 20 and the adjustable screw collar 62 on stem 48. The bellows chamber 2O has an opening 64 in its wall for admitting air to the interior thereof. Stem 48 is guided and bellows 42 kept straight by a guide bushing 66 adjustably threaded in an opening in the base portion 60, and constituting an adjustable stop for limiting the expanding movement of the bellows 42 and retaining the same under initial tension.

As the pressure in bellows 42 rises, the bellows (shown contracted at Fig. 1) expands, and valve 40 further opens by this movement, which is assisted by the spring 58. y The contracting movement of the bellows is limited by the adjustable stop 68 threaded at 70 into the casting 12"L and locked in position by a nut 72. As the bellows contracts, the lever 46 engages stop 68. The leverage of the member 46 is controlled by adjustment if 78. Then the serew is between the minimum madam'n cludes a member or clevis 80 threaded on vthe end of the stem 48 and carrying a pivot pin 82 riding in the slot 56. When the pivot pin' 82 and lever46 are disconnected from the member 80, the latter may be adjusted through one or more 180 turns and the parts reconnected thereto. The angularity ofthe lever 46 isthus adjusted which controls the extent of movement movement of the bellows.

Thevalve-4O has a cylindrical base portion 82 sliding within the secured within the bore 10.in the casting 12' of the device, a relatively constricted intermediate portion 86 disposed within the tubular portion 10l viding therewith an annular 'space 87 for the passage of the fuel, and a calibrated ta red end portion 88 extending into the cylin rical orifice or opening 2l of the fuel jet 10, and adapted to vary the size of the opening 21 andmaximum limits by axial movement for the purpose above described. I v

The tapered end portion 88 of the modulating valve 40 working in the opening 21 pro vides an annular orifice at y21 of variable cross-section located below the level of the fuel in the constant level chamber. The constricted character of the s'aid annular orifice upon passage of fuel therethrough tends toy disintegrate the fuel, while the portion 22 of the passage beyond the same is preferably made of relatively greater cross-sectional area, even greater than the area of the fuel jet orifice of the ordinary carburetor, to facilitate the passage .of the fuel therethrough in a finely divided state and its deliver air stream duly metered without su jecting the same to frictional resistance or capillary `effects resulting from constriction of the portion of the fuel jet above the fuel level as 1s the ordinary practice. Hence, by making the portion of the fuel jet below the fuel level the most constricted portion thereof and capable of `variation,the reduction of pressure maintained aboutthe fuel jet by the lower throttle and the Venturi means -is rendered moreefl'ective for lifting the fuel through the distance required, and upon acceleration for preventing lagging air stream. Further, rest it is not necessary to completely close the fuel orifice passage because the tip of the nozzle 10 is above the fuel level in the float chamber. n

The valve .40 is actuated in'substan'tially ex act synchronismwith the variations inthe intake pressure above the throttle 30. The value of the intake pressure above approaches the atmospheric pressure as the throttle opens, throttle opening. Hence the value 'of the intake pressure or of the intake depression (the.

of the pin 40 for a given bushing or bearing 84.-

of the, fuel nozzle .and pro-l 'shown' at Fig. 1,

to the of the fuel relative to the be when the engine'isat f the throttle and varies directly with the differential between the intake pressure and atmospheric pressure) varies with the load imposed on the engine, and lalso to a lesser extent with the speed, the throttle being lifting the fuel to the tip of In Fig. 2 I have illustrated a modification in which the fuel nozzle 10 is subjected to full intake depression above the throttle 28* actuated manuall in the usual manner and controlling the a mission yof air, the throttle above the fuel jet, suchas the throttle 30 at Fig. 1, being dis ensed with. In this latter form, because o the greater intake depression, or greater reduction of pressure about the nozzle 10, the' taper 88 of the pin 40* lis calibrated to form a relatively smallerfuel at idling than in the form or, if so desired, the member may bel adjusted to vary the movement of the pin 40 to obtain sueh smaller fuel orifice at idling. In such event the taper of the pin can be the same as that shown at Fig. l. As the throttle28a discharge orifice opens to admit more air to satisfy the load requirements, the l intake depression ,decreases and the extent of opening ofthe fuel nozzle increases. The increased air velocity through the Venturi passage 24. as the throttle 28a o ens compensates for the reduction in inta e depression and produces suflicientred-uction of pressure about the fuel nozzle 10 to cause the elevation of fuel from the float chamber 16 through the slight distance to the tip of the nozzle 10. In this form of the invention,

which in other respects is like the form shown at Fig. 1, the single fuel nozzle, without` the use of idling or compensating jets for suppleinenting the same, effectively delivers fuel duly metered to the air stream in synchronism with variations in intake depression throughout the operating range of the engine. Y

The quantit of fuel 'required for a given engine throng out the Voperating range may readily ascertained, and the inclination of the tapered portion 88 designed accordingly to vary the opening 21 to supply the requisite fuel as the bellows moves between its limits.

With my invention the'ordinary choke operated from the dash is omitted. In starting the two throttles shown at Fig. 1, or the single throttle shown at Fig. 2, are opened to an extent as not to spoil moderate Vchoking effect. The modulating pin is wide open when the engine is at rest; When the engine is turned over a relatively rich mixture is drawn into lthe cylinders. As the engine speeds up, upon ignition th reof, the modulating pin automatically moves towards orifice restricting position, due to the resulting increase of intake depression.

Among the features of advantage obtained 5 are simplicity of construction, enabling expensive and troublesome idling and compensating jets and the like to be dispensed with and yet metering the fuel accurately for all requirements by means of the modulating pin operated by pressure differential and in substantially inverse relation thereto; there is no appreciable loading up of fuel on the intake passage walls at periods of engine deceleration; and the fuel is self-regulating at all loads and speeds, and efficiently delivered into the air stream. For example, the fuel nozzle can be of opening area adapted, when such entire area is in use, for full load operationat low engine speed, and as the engine speeds up, for example, in accelerating, the excess supply of fuel which would result from increased air velocity past a. jet of fixed opening is avoided by intake depression being increased by increased piston speed, causing the fuel inlet opening to be reduced by movement of the modulating valve adapted to produce this effect. The fuel jet discharges at low engine loads into a region of relatively low-pressure, the reduction of pressure, however, being greater in the form shown at Fig.` 2 than in that shown at Fig. l. This reduction of pressure together with the relatively eonstricted annular orifice through which the fuel passes into the enlarged tip portion aids materially in securing a thorough atomizing of the fuel including the heavier ends thereof, and the delivery thereof to the air stream into homogeneous admixture therewith.

I claim: 1. In a fuel supplying and meteringy apparatus for internal combustion engines, an air conduit, means for controlling the air supply through said conduit, a fuel jet in said conduit subject to the pressure reduction thereinbeyond said air controlling means, a constant level 'fuel chambercommunicating with said fuelljet and having a fuel level below the discharge end of said jet, and a valve movable axially within said fuel jet, and lforming` a relatively constricted an nularv orifice of variable cross-section at a oint below the level of the fuel in said chamlier; the portion of said fuel jet beyond said annular orifice being of relatively enlarged cross section to permit of the free passage of fuel in a finely divided state therethrough 'from' said annular orifice into the air stream,

and means responsive to variations in pressure reduction in said conduit resulting from movement of said air controlling means for actuating said valve to vary said annular orilice in inverse relation to the variations in pressure reduction.

2. In a fuel supplying and metering ap`- '65 paratus for internal combustion engines, air

inlet means, means for restricting the extent of opening of the air inlet means, aventuri beyond said air inlet restricting means and traversed by the air stream passing the restricting means, fuel supplying means terminating in said venturi between the air inlet restricting means and the engine cylinders, a constant level fuel chamber communicating with said fuel supplying means and having the fuel level thereof below the discharge end of said fuel supplying means, a metering oritice in` said fuel supplying means below the fuel level, a calibrated modulating pin for controlling the extent of opening of the metering orifice of said fuel supplying means, and a pressure responsive device having a passage independent of the fuel supply passages for transmitting the variations in intake pressure above said air inlet restricting means and resulting from the movement thereof for actuating saidA modulating pin and controlling the sameto effect a balance between the extent of opening means and the reduction of pressure about the discharge end thereof, whereby to meter the fuel in accordance with the engine requirements.

Y 3. In a fuel supplying and metering apparatus for internal combustion engines, an air conduit, a fuel 'jet therein, air controlling throttles in said conduit at opposite sides of said fuel jet interconnected for joint operation, and the lower thereof serving to maintain a reduction of pressure about said fuel jet for elevating fuel, and means responsive to the variations in the differential between the atmospheric pressure and the pressure in said conduit above the upper throttle for controlling the extent of opening of said fuel 'et in inverse relation to the variations in pressure differential resulting from throttle movement. J l

4:. In a fuel supplying and metering apparatus for internal combustion engines, an air condiut, a fuel jet therein, air controlling throttles in said conduit below and above said fuel jet interconnected for joint operation; the lower of saidthrottles providing a relatively greater opening in said conduit than the upper of said throttles for a given movement of said upper throttle and serving to maintain a reduction of pressure about said fuel jet for elevating the fuel, and meansfor varying the passage of fuel through said jet in substantially inverse relation to the variations in intake depression substantially over the range thereof.

5. In a fuel supplying and metering apparatus for internal combustion engines, an air conduit, a fuel jet therein, air controlling throttles in said conduit below and above said fuel jet interconnected for joint operation; the lower of said throttles providing a relatively greater opening in said conduit than the upper of said throttles for a given of the fuel supplying and movement of said upper throttle and serving to maintain a reduction of ressure about said fuel jet forelevating the `responsive to the variations in the differential etween the atmospheric pressure and the pressure in said conduit above said upper throttle for controlling the extent of opening of said fuel jet.

6. In a fuelA supplying and metering apparatus for internal combustion engines,-an air conduit, a fuel jet therein, a constant level fuel chamber for s'aid fuel jet, air controlling throttles 'in said conduit at opposite sides of said fuel jet, and the lower thereof serving to maintain a reduction of pressure about said fuel jet, means for actuating said throttles in unison, means associated with said fuel jet for maintaining a reduction of pressure about the same as said throttles open wider, and means responsive to the variations in the differential between atmospheric pressure andA the intake pressure above the upper of said throttles for controlling the extent of opening of said fuel jet in inverse relation to the variations in 'pressure differential resulting from throttle movement.

7. In a fuel supplying and metering apparatus for internal combustion engines, air inlet means, a fuel jet-therein, valves in said means below and above said jet for restricting the extent of opening Aof the air inlet means maintaining a reduction of pressure about said fuel jet, means for actuating said valves in unison,`a constant level fuel chamber communicating'with said fuel jet, and

having the fuel level thereof below the discharge end of said fuel jet, a modulating pin for controlling the extent of opening of said a reduction of fuel jet, and a pressure responsive device subject to the variations in the difference between the atmospheric pressure and the intake pressure above the upper of said re.- stricting valves for actuating said modulating pin and controllingthe same to eifect a balance between the extent 0f Opening of saidfuel jet and the reduction of-pressure about the discharge end thereof, whereby to meter the fuel in accordance with the engine requirements. A

z8. In a fuel supplying and metering ap paratus forinternal combustion engines, an air conduit.- a venturi therein, a fuel jet having thedischarge end thereof in said venturi, means below said iet-for controlling the air sup-ply through said conduit and maintaining pressure about the discharge end of said jet, a constant level fuelchamber Ifor supplying fuel to'said jet having a fuel level below the discharge end of said jet, a member movable axially within said jet and forming therein a constricted orifice of variable cros's-section below said fu l level; said j et having relatively enlarged dlscharge 'p0rtionbeyond said orifice for the free passage of fuel in a finely divided state, and means el, and means l mospheric air responsive 'to variations inthe di'erence between the atmospheric pressure and the intake pressure for actuating said member to vary the extent of opening of said annular orifice in substantially inverse relation to the last named variations in difference of pressure.

9. In a fuel supplying and metering apparatus for 'internal combustion engines, a plurality of parts forming an air conduit; one of said parts having an annular fuel chamber therein, and the other of said parts having an'opening therein registering with the central 'opening in said annular fuel chamber; a fuel jet carried by one of said parts and extending into said air. conduit, and a pressure responsive device for controlling said fuel jet disposed Within the vchamber formed by said registering openings.

10. In a fuel supplying and metering apparatus for internal combustion engines, an air conduit, a venturi therein, 'a fuel nozzle having the discharge end thereof disposed in said venturi at the restriction thereof, and having a meterin for said el nozzle haying a fuel level in proximity to said discharge' end and submerging said metering orifice, means at the atside of said venturi for controlling the air flow through said venturi and .orifice,a constant' level chamber said condult, and maintaining a 4reduction of pressure about thedischarge end of the el nozzle, intake pressurereduction and flow through thfe venturi4 varying relatively inversely to maintain -a flow of fuel from said constant level chamber into Said conduit, and means for'controlling the fuel iow through said metering orifice in' inverse `relation to the variations in intake depression to counteract the inductive effects of the intake depression as the same approaches the greater values thereof. 11. In a fuel supplying and metering aplos paratus for internal combustion engines, an

air conduit, means for controlling the air supply through saidconduit, a fuel passage terminating in said conduit beyond the va1r controlling means for subjecting the fuel to the vpressure reduction therein, a constant level fuel' chamber communicating with said fuel passage and having a fuel level below the discharge end of the fuel passage, a valve movable within said fuel passage and forming a relatively constricted orifice of variable cross-section at a point below the level of the fuel in said chamber, the portion of said fuel passage beyond said orifice being of relatively enlarged cross-section to allow free passage of fuel in a finely divided state therethrough from said orifice into the air stream, and means for actuating said valve to vary said orifice in inverse relation .to the variations inpressure reduction.

12. In a fuel supplying. and metermgapparatus for internal combustion engines, an

4 throttles open wider` air conduit, a fuel jet therein, air controlling throttlesl in said conduit at opposite sides of said fuel jet, and the lower thereof serving .to maintain a reduction of pressure about said fuel jet, means for actuating said throttles in unison, and means responsive to the variations in the differential between atmospheric pressure and the intake pressure above the upper of .said throttles for varying the passage of fuel through said fuel jet in inverse relation to the dierential variations substantially throughout the range thereof.

13. In a fuel supplying and metering apparatus for internal combustion engines, an air conduit, a fuel jet therein. a constant level fuel chamber for said fuel jet having a fuel level in proximity to the discharge end of said fuel `jet, air controlling throttles in said conduit at opposite sides of said fuel jet, and the lower thereof serving to maintain a reduction of pressure about said fuel jet of reduced value compared to the pressure reduction above the upper throttle, means for actuating said throttles in unison, a venturi receiving said fuel jet for maintaining a re- A duction of pressure about the same as sai and means responsive to the variations in the differential between atmospheric pressure and the intake pressure above the upper of said throttles for varying the passage of fuel through said jet in inverse relation to the differential variations substantially over the range thereof.

passage of fuel in a finely 14.' In a fuel supplying and metering apparatus for internal combustion engines, an air conduit, a venturi therein, ing the discharge end thereof ling the airsupplythrough said conduit and maintaining a lesser reduction of pressure about the discharge end of said iet than that above the upper throttle, a constant level fuel chamber for supplying a fuel level below thedischarge end of said jet, a member movable axially within said jet and forming therein a constricted orifice of variable cross-'section said `iet having a relatively enlarged discharge portion beyond said orifice for the free divided state, and me ans responsive to the variations in pressure reduction above the upper throttle for actuating said member to vary the extent of opening' of said orifice in substantially 4inverse relation to said variations in pressure reduction. In testimony whereof I have signed my name hereto.

, ARLINGTON yMOORE a fuel jet havin said venturi,

throttles above and below said iet for controlfuel to said jet having i below said fuel level,l

mmcm or connection;

" Parent No. 1,850,307; Granted March zz, 1932, w

ARLINGTON noone'. 7

It is hereby' certified that error appears in the printed specification'of the above numbered patent requiring correction as follows: Page 5, line 69, claim 8, lstrike out the word "annular"; and that the said Letters Patent should-be read with this correction therein that the same may conform to the record of the case in the Patent Office.

' Signed and sealed this 26th day of April, A. D. 1932.

- f J. Moore, (Seal) AActing Connnssioner of Patents.

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