US1373550A - Carbureter - Google Patents

Description

M. G. CHANDLER.

CARB-URETER.

. APPLICATION FILED {HAY 12, 1917. 1 1,373,550, V Patented Apr. 5, 1921.

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CARBURETER. v APPLICATION FILED MAYIZ, 1911.

1,373,550. Patented Apr. 5, 1921.

2 SHEETSSHEET 2.

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T 0 all whom it may concern: v

Be it known that I, MILFORD G. CHANDLER, a citizen of the United States," residing at Chicago, in the county of Cook and"St ate of Illinois,"have invented a certain new. and

particularly to a carbureter arranged for lifting liquid fuel from a main source at a lower level to the level of the carbureter.

Fuel lifting carbureters are desirable because they make it possible to locate the main fuel tank in a convenient place at the rear of an automobile and they at the same time prevent waste of fuel by leakage at the carburetor float valve during non use of the automobile.

Carburetors have been proposed for this purpose which maintain a high vacuum in the mixing chamber and utilize this unen hanced vacuum suction for lifting the fuel to the float chamber of the carbureter. Such carbureters are somewhat unsatisfactory because the vacuum maintained in the mixing chamber, if sufiicient under all conditions 'to lift the fuel, is such as to decrease the power of the engine because of the rarefaction'of the explosive mixture entering the engine. This reduces the efficiency of they carburetor. By my present invention ll am able to maintain in the floatchamber of the carbureter a greater reduction of pressure than that of the 'mixin'g'chamber. ll am at the same time able to maintain at the opening through which fuel is delivered from the float chamber into the mixing chamber a still greater depression than that of the float chamber, so that a sufiicie'ntipressure differential is continually maintained for delivering the proper proportion of fuel to the passing column of air. I

One feature of my invention resides in the peculiarly shaped primary Venturi tube which'i's' arranged to provide a sudden volumetric-increase in size at the point where fuel is delivered to the Venturi tube, the object ofthis being to avoid a reduction of the degree of vacuum maintained at such point, which is, ordinarily incident to the ,admission of hydrocarbon fuel into a column of air passing through a Venturi tube.

Specification of Letters latent.

PATENT OFFICE.

MILFORD e. CHANDLEBLOF cnrcaeo, ILLI$QIS,;ASSIGNOR; BY MESN'E Siemens, T0 LYNN a WILLIAMS, or nvan sronif lrnmom, .AND owners 1 cm, or on x-f I Another feature of my inventioii is the partlcular form of regulating device which 1s so arranged as to maintain substantiallyconstant the speed of the passage'of air past the point in the primary Venturi tube at which communication is taken off from the Venturi tube to the upper spaces of the float chamber. By means of this arrangement the fuel delivery is kept properly proportioned by a slight change in the degree of vacuum applied to the fuel jets of the fuel nozzle;

Other features of my invention reside more particularly in the features of construction fully set forth in the specification and claims.

My invention is illustrated in the accompanying drawings in which like characters represent like parts in the several views, and in which v Figure l is a horizontal cross sectional View of the carburetor of my invention; and

Fig. 2 is a vertical cross sectional view taken along the line 2-2 of Fig. 1 looking in-the direction indicated by thearrows.

Referring first to Fig. 1, the carburetor of my invention comprises a casing 3 and a casing 4: secured to the former, as 1llus-' following Patented Apnfi, 1921 Application filed May 12, 1917. SeriaINo. 168,325.

trated. The casing 3 has secured thereto or forming partthereof a float chamber 4 provided with. the usual float and valve mechanism for controlling the supply of fuelto the float chamber. 'As most clearly shown in Fig. 2, the lower end of the float v chamber is provided with a coupling 5 arranged to communicate with a supply conduit 5 in turn extendin downwardly into a fuel supply reservoir located below the normal level of the fuel in thefloat chamher. The casing 3 carries the usual flange 6 adapted to be attached to the intake manifold of an internal combustion engine. Extending'longitudinally through the casing 3 is a bore 7. containiI-Ig a throttle valve 8 at a point posterior to the fuel nozzle, a'swill be;

The bore 7 is enlarged at 9 where it communicates with the bore 10 provided in the casingl'. The

described in detail hereinafter.

fuel nozzle is desi nated in its entirety at 11' and is disposed wlthin the bore 7 of the easing 3. An auxiliary air valve is provided at 12 in the bore 10 of the casing 4 at a point anterior to the fuel nozzle. The fuel nozzle 11 is centrally disposed within the bore 7 as illustrated, and is supported by a vertically, extending support 13 most clearly shown in Fig. 2. The support 13 carries the internal threads 14 adapted to ffxcoiiperate Y with the external threads of a primary Venturi tube- 15. The Venturi tube 15 contains the two annular grooves shown at '16 and 17 which cooperate with thesupport 13 so as to provide two annular chambers, as shown in ig. 1. The Venturi tube 15 contains the primary air passageway 18 extending longitudinally therethrough. Aflordingcommunication between the passageway 18 and the chamber 16 at a point slightly, anterior to the greatest constricted portion of the passageway 18 is an opening 19 which serves to provide a vacuum or reduction of pres-- sure in the chamber 16 when the internal combustion engine with which the carbureter is associated is operated. Extending through the support 13 and communicating ing through the wall of the casing 3 and into the wall of the float chamber 4 where it c'ommunicates'with the float chamber at a point above the normal level of fuel therein. Slightly to the right hand side of the opening 19 (Fig. 1) the passageway 18 enlarges abruptly, as shown at 20, and then gradually increases'in size'to the extreme right hand end of the Venturi tube. Ex-g tending between the chamber 17 and the passageway 18 at the point 20 where the passageway sudden-1y enlarges I provide a plurality of fuel openigs 2 121, the openings being preferably disposed at an angle tapering toward the head endof the Venturi tube. The chamber 17 communicates with a; bore 22 extending vertically through the casing 3, as most clearly shown in Fig; 2. The lower end of the bore 22 communicates with the horizontally disposed .bore 23 in turn communicating with the lower end of a vertically disposed bore 24 in which an adjustable needle valve 25 is mounted. The needle valve 25 is adapted to cooperate with the shoulder shown at 26 to regulate: the passage of fuel through-thebor '24. Gommunicating with the'bore 24 at a pointabove the shoulder26. is a bore 27 extending to the float chamber 4 and at a relativelv low point therein So. as tofeedthe fuel from the float chamber to the bore 24 from which it is fed through the bores 23 and 22 into the chant, ber17. 1' 55 Carried'by the casing '4 and having communication with the passageway 18 is a pipe 28 having its end 29. extending through the casing 4' and communicatingwiiththe atmos phere; The inner end of the pipe .28carri'es'g a spider 30 which serves to mountla regulating deviee31 havin an enlarged end. or-

head 32-=disposed in t ejpassageway 18 and"f at., a point' adjacentfthe opening 19. The outer end of. the regulating device 31" ex t5 tends through the pipe 28, as shown, andgisg the. ,oint '36 is pivotally connected .to the with the chamber 16 is a conduit 20extendp pivotally attached at 32 tO'a' link 33 in turn I pivotally connected at 34-with ailever arm 35.- One end of the lever arm. 35 is-coihv nected at 36 with a rod 37 r'eciprocably mounted in the casing 4 and connected to a piston 38 arranged to reciprocate within the chamber39. A coiled compression spring 40 is interposed' between the piston 38 and the casing 4 and tends normally hold the parts in the position shown in the drawings. The outer. end of the chamber 39, or that] portion disposed on the outside of the piston 38, has free communication with the atmosphere through the aperture 41 provided in the cap42. 'The end of the lever 35 opposite auxiliary air valve 12 at 43 so that upon in ward ovement of the piston 38 the auxilr valve 12 will be swung upon its to permitthe passage of air through the bore 10 into and through the bore 7.

The bore 7 is provided with a'secondary Venturi tube shown at 44 containing aconstricted portion 45 locatedsubstantially opposite the head end of the Venturi tube 15. Communicating with the atomizing chamber Aand at av point slightly'posterior to the constricted portion 45 is'a-conduit47 "terminating at and communicating with the inner end of the chamber 39 under the pis-' .ton38. The operation of the device is as follows: Assuming the flange 6 'to be attached to the intake manifold of an internal. combustion engine, that the engine is operating at idling speed,'and that the throttle valve 84is opened, a vacuum or reductionfofpgessure will be a produced in the mixing chamber A which results in the intake of air through the ort Y 29', through the pipe 28, through the enturi tube 15 into the mixing chamber. from which it 1s taken into the engine cylinders.

Since the'head 32 of the regulating pin assumes a position where it restricts the p assageway 18 to a considerable extent. at 1 relativel-y slow engine speed, the. air is caused to pass around the head 32 and in doing so attalns great velocity which re- 'sults'in a vacuum or reduction of pressure 5 in the chamber 16,-due to the fact thatthe'11 chamber 16 communicates: with the passageway 18 through the opening :19 at a, point. where the velocity ofthe incoming air is great, Sincethe chamber 16 com-mu nicates' withthe upper end of the float chambei a'high degree of vacuum or reduction of pressure-will be provided above the level fof'the fuel in the chamber. 1 Asthe speed "of the en -ne' increasesthe vacuum orreductiono pressure increases in the atomlzing chamber A with the result that a vac- 1111111: or reduction of, pressure "will be pro vided "in the chamber 39 below the piston 38 duefto the conduit connection 47 Sinc'ethe outer side otthe piston-is subjected "to I,

engine increases it is necessary to supply a greater amount of fuel to the incoming air.

To accomplish this. object th regulating device 31 is moved outwardly away from the passageway 18 as the engine speed .increases. As the piston 38 moves inwardly and the auxiliary air valve 12 swings about its pivot in a clockwise direction (Fig. 1) the lever 35 will be moved toward the auxiliary air valve 12 and at the same time the end of the lever 35 attached to the auxiliary air valve will be moved away from the Venturi tube with the result that the regulating device 31 is withdrawn from the passageway 18. As the head 32 of the regulating device recedes from the passageway 18 it provides a greater area in the passageway through which the air taken in through the pipe 28 may pass and thus prevents increase of velocity of the air at the point where the air passes the opening 19. As, the volume of air taken into the carbureter increases, the regulating device moves outwardly, admitting a larger volume of air to the passageway 18, but as the movement of the regulating device makes the area of the passageway at the point 19 greater, the increase of volume of air passing through the passageway does not cause an increase in the velocity of the air at the port 19. For this reason the vacuum at point 19, and consequently in the top of the float chamber is substantially constant. The area of the passageway 18 at the ports 20 does not change, however, and as the volume of air passing through the passageway increases the velocity at ports 20" must also increase. Such action would therefore produce adegree of vacuum at higher speeds. ence,

there would be a greater fuel feeding head at higher speeds and the flow of fuel would be greater at higher speeds ,than at low.

As'the air passes the fuel openings 21 fuel is injected into the air and the intermixed fuel and air delivered to the atomizing chamber The abrupt enlargement of the passageway 18 at the point 20 is provided so as to produce a sudden volumetric increase in size of thepassageway 18 at'the than if the bore is only point of delivery of fuel 'to the Venturi tube, it having been found by experiment that such an enlargement produces a greater local pressure reduction on the fuel ports radually enlarged as is common practice. have no satisfac tory explanation for this action;

aving thus described my invention what I claim as new and desire to secure by Letters Patent of the United States is:

1. In 'a carbureter, a primary venturi, a

eater a fuel chamber, a fuel supply conduit ex umentioned conduit and the Venturi tube,

a low level source of fuel supply, a conduit directly connecting the low level source and the fuel chamber, a passage'connecting the lower part of the fuel chamber and the throat of said venturi, a second passage from a point near'the throat of said venturi but anterior to the fuel delivery opening'therein to the upper space of the fuel chamber for maintaining a vacuum in the upper part of the fuel chamber, a movable regulating device for regulating the velocity of air past the said vacuum maintaining opening in said venturi for regulating the suction at said opening, and meansfor automatically moving said regulating device to different positions dependent upon the quantity of air drawninto the carbureter.

2. In a carbureter, the combination of a constant level float chamber, a fuel delivery port slightly above the normal level of fuel in said float chamber, a main supply reservoir at a lower level, a primary Venturi tube, ,a conduit extending from the upper part of the float chamber to a point near the throat of said Venturi tube for maintaining a partial vacuum in the float chamber, a conduit for delivering fuel from the float chamber to said delivery port, and a regulating device automatically moved into and out of the opening in said Venturi tube to regulate the velocity of air past the point at which said vacuum producing conduit terminates in said venturi, and means for operating said regulating device proportionately to the quantity of air taken into the carbureter,

whereby the vacuum in the float chamber with and extending between the induction passage and the upper spaces of the fuel chamber, means for changing the flow of air through the induction passage at both the fuel inlet and the point of communication of said conduit with said inductionpassage, and further automatic means for maintaining the velocity of air past the point of com- '115 m'unication of said conduit with the induction passage substantially constant. 4:. 'A carbureter provided with an induction passage, a Venturi tube located therein,

tending between and communicating with the Venturi tube and the fuel chamber, a second co duitextending between the upper space of t e fuel chamber and said Venturi tube and terminating in the latter at a point near the throat thereof, and automatically operating means for regulating the velocity of air through said Venturi tube and past the point of communication between said-last said regulating device being, adapted to differently regulate the velocity ofvair past the fuel delivery port in saidVenturi tube, said regulating device being soshaped and p erated as to provide a greater pressuredifferential between the openings of'said con-- 'duits intosaid Venturi tube at higher. en

gine demands than at lower engine demands.

5. A carbureter Comprising a casing containing an atomizing chamber, a primary 1 a1r intake passageway and asecondary air intake passageway communicating withthe atomizing chamber, a Venturi tube. forming a part of the primary air intake passageway,

a fuel chamber, a conduit afi'ord-ingcommunication'between the Venturi and the fuel chamber at a relatively low level therein for feeding fuel to the Venturi tube, a second conduit affording communication between the Venturi tube andthe fioat' chamber above the normallevel of fuel'therein, a regulating device disposed within'the Venturi tube and arranged to restrict the passage of air therethrough, a throttle for the secondary air intake passageway, a cylinder, a piston reciprocably mounted within the cylinder, a conduit'extending between the cylinder and the atomizing chamber of the carbureter for producing a reduction of pressure within the cylinder whereby the piston is moved in the cylinder, linkage extending between the throttle valve and, piston and adapted toopen the throttle upon operation of the piston, and devices connected with the piston and operated thereby for-withdrawing the regulating device from the Venturi tube upon operation of the piston in the direction 4 I to open the throttle.

' 6. A carbureter comprisinga-fueh cham- 4 ber and mixing chamber, an air passage discharging into said mixing chamber, means for conveying fuel from said fuel chamber, A

- Levaeeo ber and mixing chamber, an air passage discharging into said mixing chamber, means for conveying fuel from said fuel chamber,

and discharging it into said 'air passage, a duct having one end communicating with the upper spaces of saidfuel chamber and the other end discharging into. said air passage, and means for varying thevelocity of 'fiOW of air past-the point at which the fuel is discharged into said passage without substantially changing the velocity of flow of I air past the discharge end of said duct.

8. A carbureter comprising a fuel chamher and mixing chamber, an air passage communicating with said mixing chamber, a fuel duct leading from said fuel chamber and discharging into said airpassage, a second duct leading from the upper spaces'of said fuel chamber and discharging into said air passage, and automatic means for varying the velocit .of flow of air past the discharge end of sai fuel duct without materially changing the velocity of How of air past the discharge end of said second duct.

and discharging it into said air passagma In witness whereof, I hereunto subscribe my name this 10th day of May, A. D. 1917.

MILFORD G. OHANDLER. Witnesses:

vRoBrm'rF. DRAKE,

ALBERT S, MCCALEB,

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