US1552008A - Carburetor - Google Patents

Description

C. L. RAYFIELD CARBURETOR Sept. -1, 1925 1,552,008

Filed Feb. 1919 I s Sheets-Sheet 1 E ai 5% se i. 1 1925 1,552,008 C. L. RAYFIELD CARBURETOR Filed Feb. 4919 a Sheets-Sheet 2 lbw E 5:1 f H 6% 46.25

1:1 Ka y/626d C. L. RAYFIELD CARBURETOR Filed Feb. 6, 1919 3 SheetS Sheet 3 i i i I'm-W y I 0% e51, @j/ZE/d Patented Sept. 1, 1925.

UNITED STATES PATENT OFFICE.

GHARIES L. RAYFIELD, OF CHICAGO, ILLINOIS, ASSIGNOR flO BENEKE MANUFACTUR- ING GQMIPANX, OF CHICAGO, ILLINOIS, :A CORPORATION OF ILLINGIS GARBURETOR.

Application filed February e, 1919] Serial No. 215,4os.

Tb all whom it may concern: I

Be it, known that I, CHARLES L. RAYFIELD, a citizen of the United States, and a resident of the city of Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in a Carburetor; and I do hereby declare that the following is a full,.clear, and exact description of the same, reference being bad to the accompanying drawings, and to the numerals of reference marked thereon, which form a part of this specification.

My invention has reference more. particularly to a carburetor wherein the fuel is maintained at several levels and supplied therefrom to the mixing chamber of the carburetor in sucha manner so as to provide a variable mixture which is proportioned to I afford a proper mixture to operate the enme. g The object of my invention is to provide a carburetor in which the proportion of the mixture is automatically varied by the draft or suction acting directly upon vthe fuel liquid which is arranged in pockets or wells affording a differential supply of fuel liquid and which is introduced into the mixing chamber in such a manner so that the mixture is properly proportioned in accordance with the requirements of the engine.

Another object of my invention is to provide a plurality of fuel compartments wherein the fuel is maintained at different levels, and ducts leading therefrom to the mixing chamber so that the proportion of fuel drawn from the different'chambers is regulated and proportioned by the suction in the mixing chamber so as to ailord a mixture to accord with the requirements of the engine under the various conditions'of its operation.

Another object of my invention is to 'pm- I vide a carburetor with a plurality of fuel chambers, one of which is provided with a float whereby the liquid is regulated in'both chambers, 'and. ducts leading from both I chambers to the mixing chamber of the carburetor so as to supply varying amounts of fuel from the fuel chambers and proportion the mixture properly in accordance with the I'GfRllIBITIBDtS oi? the cngine.

nother object of my invention is to provide a carburetor with a mixing chamber having a Venturi tube, and a plurality. of

fuel chambers wherein the li uid fuel is automatically maintained at 'di erent levels,

and ducts leading from'the fuel chambers and having the outlets therefrom positioned with reference to the Venturi tube so that the drafttherethrough automaticall varies the amount of fuel drawn from the ifi'erent fuel chambers so as to aiford a mixture which is properly proportioned to accord with the requirements of the engine under all conditions.

My invention also has other important objects which will be apparent fromthe dis,-

closure in the specification and the accom-; panying drawings, in which I ha e shown. and described myinvention in a preferred form. i

On the drawings: I I I Figure 1 is a side view of the carburetor embodying my invention.

Figure 2 is a top view thereof. 'Figure dis a sectional view on 3-3 of Figure 2.

Figure 4 is a vertical sectional view on. l

the line 4-4 f Figur'e 2.

Figure 5 is a horizontal transverse sectional view on the line 55 of Figure 3.

Figure 6 is a transverse sectional view on the line 66 of Figure 3.

Figure 7 is a fra mentary sectional view on the line 7-7 of Figure 5. I

Figure 8 is a fragmentary sectional view on the line 8 8 of Figure 5.

Figure 9 is an'enlarged sectional View on the line 9 9 of Figure 7.

Figure 10 is a fragmentary sectional view on the line 10-10 of Figure 2. Figure llis an enlarged top View of the fuel nozzle having the cross tube into which it communicates removed.

As shown onthe drawings: I The reference numeral 1, indicates the carburetor casing which is formed with an air, chamber 2, having a tubular extension 3, at" one side thereof, with which an air inlet pipe 90, is connected, and a tubular extension 4, at the top thereof, provided with the usual flange 5, .for connectin the carburetor to the intake pipe of tie engine. Directly below the air chamber 2, is a chamher 6, which is separated from the mixing chamber by the partition 7, which l atter has a tubular internally threaded extension 8,

thereabove and a similar internally threaded the in ll L,

l-Id

extension S}, therebelow with an enlarged chamber 10, therein, all of which align with the tubular extension 4-, at the top of the air chamber 2, and secured to the bottom of the casing 1, directly below and in align- 'mcnt with the extensions 8 and 9, is a cup 11; which serves as a float chamber for the float 12.

A Venturi tube 1-3, is located in the out let extension d, from the air chamber 2, and immediately above this tube there is a butterfly valve 14, which is mounted on the stem 15, extending through bearings provided therefor on the under side of the flange :3, and there is a crank 16, on one end of the shaft 15, which may be connected for operation from a distance to control the opening and closing of the valve 14.

At one side (of the air chamber 2, the casing l, is formed with an auxiliary fuel compartment 17, which is separated from the chamber 2, by the partition 18, and from the fuel chamber 6 by the wall 19, which latter wall has a threaded hub 20, which is adapted to have the sleeve 21, screwed therein s) as to project upwardly through the auxiliary chamber 17, to a point adjacent the top wall thereof. The wall 22, of the float feed chamber, directly below the partition 19, has an enlarged threaded opening through which the sleeve 21, may be inserted, and this opening is closed by a threaded plug The side wall 18, of the auxiliary chamber 17,has a passageway 24, eXtending upwardly therethrough, the upper end of which opens to the auxiliary chamber 17, at a point near the upper wall 25, of this chamber, and the lower I end thereof opens into the float feed chamber 6, and this passage serves as an overflow outlet for the auxiliary chamber 17 and is also the means of supplying fuel to the float feed chamber 6, so that the auxiliary chamber 17, must be filled before fuel is supplied to the float feed chamber 6.

' The upper wall 25, of the auxiliary chamber 1'7, has a fuel inlet passageway 26, leading from the interior of the threaded hub 27, which latter has the bushing 28, connected therewith, and the bushing has the fuel supply pipe '29, connected therewith and communicating therethrough so as to supply fuel to the passageway 26. An opening 30, leads downwardly from a point adjacent the inner end of the passageway 26, in alignment with the opening through the sleeve 21, so that the upper tapered end 32, of the valve pin 31, which slides loosely in the sleeve 21, may engage in the lowerend of the openingBO, fuel therethrough.

'llic' stem 31, and valve 32, thereof, is

operated to control the admission of fuel through the opening 30, by the float 12, by means of the plate lever 33, which is pivto control the supply of 'sion 8, above the wall 7, and a nozzle 47, is

oted at 3i, and extends under and engages the lower end of the pin 3'1. and has the outer end forked and the arms 35'. thcreo'fi resting, upon the. top of the float 12, so that when the float is elevated by raising of the level of liquid in the fuel chamber 6, the plate lever 33, is swung on the pivot- I34, and lifts the stem '31, so that at a predetermined lever the tapered end 32, of the stem engages the fuel supply opening 30, so as to interrupt further supply of fuel to the car buretor.

Obviously the fuel suppliedto the float chamber 6, must overflow from theauxiliary chamber 17, and therefore the chamber 17 is filled before fuel is supplied to the float feed chamber 6, and when the float 12, is raised to the level to 'elose the valve 32, the float feed chamber will be filled to the predetermined level and the auxiliary chamber 17, will also be filled to the level at which it overflows. In order to afford free circulation of fuel to and from the auxiliary cha1nber 17, an air port 36, is provided in the rupper" wall of the auxiliary chamber 17,- and there is also a similar port 37, in the wall 7, intermediate of the air chamber and the float feed chamber 6, and likewise a port 38, leading from the top of the float feed chamber, through the side wall to the exterior of the carburetor. The port 37, however, serves primarily as a drainage outlet from the air chamber 2, for any liquid that may drain to the bottom of the air chamber from the nozzle, and there is a lip39, ex-- tending from the bottom of the air chamber at. the outer side thereof from the port 37, to retain any unused fuel in the air chamher so that it may drain through the port 37, into the float feed chamber.

For connecting the cup 11, Which contains the float 12, with the casing 1, there is a tubular stem 40, the upper end of which has a threaded connection with the tubular extension 9, from the wall 7, and formsa closure for the bottom of, the. chamber 10, and this tubular stem 40, extends downwardly loosely through a central opening in the float 12 formed by a hub 41, which extends axially through the float, and the lower end of the tubular stem 4,0, passes through an opening 42, in the bottom of the cup member 11, and has the cap- 43, threaded thereon against the washer 4a, which engages the bottom of the cup 11, thus sealing the joint between the cup and tubular stem and forcing the upper edge of the cup 11, tight into the annular seat 45, provided therefor in the carburetor casting ,1.

A bushing 46, is threaded into the exten threaded into the upper end of the bushing 46, and extends upwardly therefrom, so that the upper end of the nozzle is located in the Venturi tube 13, and slightly above the 54., for

port 60.

end of the nozzle.

a plurality of p 1,5 s2,0os

throat thereof, the said nozzle 47, being flared outwardly at the upper end to provide a contracted passageway between the nozzle and the throat of the Venturi tube so as to effect an increase in suction above the upper The nozzle 47, together with the bushing 46, closes the upper end of the fuel chamber or well 10, which is provided in the partition 7, and thereis a tube 48, which makes a close fit in an opening at the upper end of the nozzle 47, and projects a very slight distance thereabove, and this tube extends downwardly through the ,well 10, and through the upper end of the tubular stem 40, to which it is secured for support and to make a tight joint and extends downwardly through the enlarged passageway 49, of the tubular stem 40, to a point adjacent'the bottom of the cup 11. A plug 50, closes the lower end of the tube 48, and there are a plurality of openings 51, into the tube above the plug to admit fuel thereinto. The opening 49. through the tubular stem 40, is larger than the outside diameter of the tube. 48, so asto provide space for fuel therebetween, and. there are orts 52, leading into the interior of the tubular stenr40, adjacent the bottom of the cup 11', to supply fuel thereto, and there is an air port 53, at the top of the chamber 49, to avoid pocketing of air in the tubular passageway 49, so that the fuel therein is maintained at the same level as in the cup 11.

The nozzle 47, is bored out, except at the upper extremity thereof to a larger diameter than the'outside diameter of the tube 48, so as to provide an annular passageway fuel from of the upper end of this opening being reduced so that the tube 48, fits snugly there in and there are a plurality .of diverging passageways 55, leading from the upper end of the annular passageway 54, into an an nular groove 56, with which the upper end of the nozzle is provi led. Ports 57, are provided in the nozzle leading outwardly from the annular passageway 54, to a point below the Venturi tube 13, and above the level at which the fuel is maintained in the well 10, and passageway 54.

Fuel is supplied to the well 10, from the auxiliary fuel chamber, through the passageway 58, which is bored in the casingl, and has the outer'end thereof closed by means of the plug 59, and there is an open-v ing 60, leading upwardly from the assagcway 58, and communicating with he fuel chamber 61,, which chamber extends laterally from and is connected at the 'bottom of the auxiliary chamber 17. The supply of fuel tlreough the port 60, is controlled by' the valve 62, which is tapered at the lower end to engage inthe upper endof the the well 10, the diameter' The stem of this valve is threaded at 63, and engages in the wall of the. casing above the chamber 61, so that when thesi'em is turned in one direction, the valve is closed and when turned in the other direction is elevated from the opening 60, and affords a limited passage for supplying fuel to the passageway 58', and well 10. For operating the stem'62, there is a crank 64, at the upper end thereof, which may be connected by means of a'Bowden cable 65, or in other manner, for operation from a distance, and this crank 64, has a long hub 66,- which extends downwardly around the stem in a tubular opening provided therefor in the carburetor casing, and serves to control an auxiliary fuel passage as hereinafter noted.

In the normal operation of the carburetor, the crank 64, is moved to open the valve 62, a slight amount, and may be adjustedto regulate the supply of fuel to the well 10, to effect the desired operation of the motor,

or may beentirely closed. To enable the contents of the well 10, to be exhausted therefrom when the valve 62, is closed, there 1s a vent passage 67, leading upwardly from the outer end of-the passageway 58, and I the pipe 48, and there is an opening 71, in the lateral wall of the tube 70, throu h which the fuel is normally supplied to he mixed with the incoming air. A stem 72, is threaded through the wall of the easing into the end of the tube 70, and has a tapered end 73, which serves to obstruct the opening 71, to a greater or lessextent and thereby control the supply. of fuel furnished through the pipe 70. The stem 72, has a thumb mit 74, on the outer end, the serrated periphery of which is engaged, by aspring detent 75, secured to the casing of the earburetor, and which permits turning of the stem and holds the thumb nut 74, in any position to which'it is adjusted. The other end of the tube .70, communicates with a passageway 76, which leads therefrom upwardly through the wall of the tubular extension 4, of the carburetor, and has an outlet 76, at the upper end opening into-the carburetor outlet above the throttle valve 14, so that when the: throttle is closed, or nearly closed, the fuel may be supplied above the throttle valve. a

To furnish a supply of the engine, at which time the throttle valve .is usually opened only a limited degree,- thcre is a passageway for fuel'leading from the bottom of the float feed chamber to a therein to admit fuel into' the tube 70, from fuel for priming Yes point above the throttle valve, and controlled by the position of the crank 64., so that this passageway is normally closed but may be opened for priming purposes by moving the crank to the extreme right from the position shown in Figure 2. For this purpose, the sleeve or hub 66, with which the crank 64, is provided, has an arcuate groove 77, located therein in such position that when the crank is moved to the extreme right from the position shown in Figure 2, one end thereof communicates with a passageway 78, which leads downwardly and is connected by means of the pipe 79, with an offset chamber 80, at the bottom of and connected with the float feed chamber 6, so

that fuel is supplied thereto from this chamber. The other end of the groove 77, when the crank 64, is in the priming position, communicates with the passageway 81, which communicates with an upright passageway 82, in the wall of the tubular extension 4, of the carburetor, and has an opening 83, therefrom to the outlet from the carburetor above the throttle valve 14. As will be noted, when the hub 66, and groove 77 are in the position shown in Figure 9, in which the crank 64, is moved to the extreme right from the position shown in Figure 2, they afford communication between the passage ways 7 8 and 81. When, however, the crank 64, is moved back towards the original position, communication is interrupted with the passageway 81, and there is an air port 84, with which the end of the slot 7 7 comes into communication when the crank 64, is moved to the position substantially as shown in Figure 2, or that which is occupied by the valve in normal operation of the carburetor, and as the groove 77, is continuously in communication with the passageway 7 8, in closing the valve 62, the groove 77. will register with the port 84, andprovide air release to the passage 78, and permit he fuel liquid to return to the normal level.

The operation is as follows: v

The carburetor is connected by means of the attaching flange 5, so that the extension 4, communicates with the intake pipe of the engine, and the pipe 90, may lead to any convenient point to supply clean air to the carburetor, and the fuel supply pipe 29, is connected with a source of supply to main tain a constant supply of fuel to the carburetor. As the fuel enters through the port 30, the auxiliary chamber 17 is filled to the upper extremity of the passageway 24, during which time the air is exhausted from the chan'iber 17, through the port 36, and also through the passage 24, and .after the fuel reaches this level, it overflows through the passage 24, into the float chamber 6. When the liquid reaches a predetermined level in the float chamber, the float is elevated thereby and with it the plate leve .the point 32, of the stem into the opcni Lasaoos 33, which swings upwardly on its pivo lifts the stem 31. which constantly r the top of the plate lever 32), and pro,

m 30, and interrupts comnuiuicatiou of fuel is therethrough, and as the uel is used from the float teed chamber 6, the float operates to automatically furnish fuel and maintain the same at a {undetermined level and maintain a constant level of fuel in the auailiaryv chamber 17.

hen it is desired to start the motor, the valve 14, is u'eferabl v adjusted so that the passage through the extension 4, is par ially closed, and the crank (34, is moved to the right from the position shown in Figure 2, so that. the slot 77, in the hub or c al't'ords communication from the pi. i v 78, to the passageway 81. As the motor turned over or cranked, suction is created in the outlet extension 4, and the draft through the air chamber 2 and Veuturi tube 13, which is limited owing to the partially closed position of valve 14, draws a limited amount of fuel upwardly through the. arr nular passageway 54, and outthrougih the passageways 55, above the throat of the -Vern turi tube where it is mixed with in ing air. Owing to the contraction mouth of the Vcnturi tube and the pa closing thereof by the upperend of the no, zle 47, a greater suction ordinarily el tists above the throat of the Venturi tube than in the chamber 53, and air is drawn thrtuigh the ports 57, into the annular passageway 54, together with the gasoline from the well 10, which serves to otiset to some er tent the suction efiect on the gasoline in the well and furnishes the same through the annular passageway 54, in a spray which leaves the port in a finely atomized condition so as to thoroughly mix with the incoming air and form a uniform mixture.

As the throttle 14, is partially closed partial vacuum is formed above the throttle valve 14. which litts liquid fuel up through the pipe T9 and. passageway TSQfroni the off-set clu'unbcr 80. at th bottom of the lloat t'ccd chamber, and from the passageway '78, around the groove 77, and through the pas I sagcways 81 and 82, into the outlet opening lrom the carburetor above the throttle valve 14, where it mixed with the air and fuel. mixture which is being drawn past the valve "14. Fuel may also be supplied at such time above the throttle valve through. the passageway 76, from the cross tube 70, in the Venturi tube, such l'uel being drawn up through the tube 48, from the bottom of the float t'eed chamher, l'tthe throttle ales-14, is closed sutliciently so that the spctioir above the throttle valve exceeds thatt immediately thercbelow, the gasoline is introduccd through the passagew 76, and discharged above the throttle Eit} and when viously the amount of fuel supplied through the passageways 7(3 and 82. above the throttle valve dependsupon the position of. the throttle valve. a greater amount being supplied as the throttle valve. nears the closed position. and as thellllOltl l valve is opened a point is reached where the suction above the throat of the Venturitubc and below the throttle valve is the same that above-the throttle valve, whereupon supply of fuel through the passage 76, is discontinued and the fuel is drawn directly from the tube 70, through the side outlet 71. r I

The adjustment of the crank 64, topermit passage of fuel through the arcuate slot 77, opens the valve (32, sufficiently to keep the well 10, filled with fuelfso that it may readily be drawn up through the annular passageway 54 in starting the motor, and

we have therefore three sources of supply of fuel for startingthe motor or at such other time as the crank '64., may be moved to the priming position to afford a rich mixture.

After the engine is started the crank 64,, is moved to the left to the position shown in Figure 2, thereby interrupting communication from the passageway 78 to the passageway 81., which passageways supply fuel above thethrottle valve, and the valve 62, may be entirely closed or adjusted to permit a limited supply of fuel to the well 10, to. v att'ord whatever mixture is necessary. to operatethe motor. If the valve 62. is entirely closed the level of fluid in the chamber 17,

, is ofv course maintained at the normal level by the float l2, and because'of the vent passageway 67, fuel may be drawn from the well 10, until it is reduced to a level at which the suction is insufficient to withdraw a further supply therefrom, whereupon the fuel for the carburetor is supplied entirely from the float feed chamber through the tube 48'. However, in the normal'operation I of the device, the valve 62, is adjusted'to permit, a limited supply of fuel to pass through the opening 60, to the well 10, the

adjustment thereof determining the amount of fuel which will be supplied through the annular ,passageway 54, and through the of the engine. Inasmuch as the level of fuel in the well 10, is near to thetop of the nozzle, an abrupt opening of the valve 14,

creates 'a suction in the upper portion of the Venturi tube'above the. nozzle to augment the supply of fuel from the well it), sees.

slow speed or idling speed.

to afford immediately the rich mixture required by the engine when its throttle is suddenly opened. L

From the foregoing it will be observed that a supply of fuel is furnished from two Zsourees, namely. the fuel well 10, and the float feed chamber 6, the amount of which supplied from the former may be regulated by. the needle valve 62, and the proportions of which vary with the speed of the engine and also the opening of the throttle valve so that'the p'roperniixture may be obtained at all times, as required under the varying conditions of operation of the engine, and it will be further noted that as the throttle valve is movcdto the closed position the passage 76, serves to admit fuel above thethrottle valve to furnish a rich mixture for I While I have shown and described my invention in a preferred form, I am aware that various changes and modifications may be made therein without departing from the principles of my invention, and I therefore do not purpose limiting the patent granted hereon otherwise than necessitated by the prior art. I

I claim as my invention:

1. In a-carburetor the combination of a casing havinga mixing chamber, an air in let thereto, a fuel chamber, a fuel well, an outlet from the fuel chamber and from the fuel well to the mixing chamber, an auxil-i ary fuel reservoir through which fuel-is supplied to both chamber and well, a float for maintaining a uniform supply of fuel in the fuel chamber, and a manually adjustable valve for regulating'the. supply of fuel from the auxiliary fuel reservoir to the fuel well. 2. In a carburetor a float chamber, an auxiliary fuel chamber communicating, with said float chamber, a fuel well at a higher levelthan said float chamber and communieating with the auxiliary fuel chamber, and amulti-passaged nozzle extending through and having separate passages respectively in communication with said well and float chambers.

.3. In a carburetor the combination of a casing having a mixing chamber and an air inlet thereto, afloat chamber and a fuel well each havingan outlet to the mixing chambcr'for supplying fuel thereto by aspiration, an auxiliary fuel chamber for supplyingfuel to the fuel well and having an overflow passageway discharging into the float I chamber, and a float in the float'chamber for controlling the supply of fuel to the auxiliary fuel chamber. y I

4. In. a carburetor the combination of a casing having a mixing chamber and an airinlet thereto and an outlet therefrom,- a throttle valve inthe. outlet, fuel supply. means including a float chamber and having an outlet into the mixing chamber for supblying fuel by aspiration thereto, a fuel well having an ouvlet to'the mixing chamber and'an inlet with a. manually controlled valve for maintaining a supply of fuel therein at a higher level than the fuel in the float chan'iber, and a fuel lay-pass for supplying fuel to the carburetor outlet above the throttle valve controlled by the aforesaid valve so that the by-pass is opened simultaneously with the opening of the valve to admit fuel to the fuel chamber.

5. In a carlun'etor a throttle, two constant level fuel chambers maintaining fuel at different levels, a fuel Well, a passage feeding said Well from the chamber maintaining the'higher level a fuel duct delivering below the throttle from said Well, and

eeaooe a fuel duet delivering above the throttle from the chamber maintaining the lower level.

1 6. In a carburetor a throttle, two constant level fuel chambers maintaing fuel at (lif ferent levels, a-fuel Well, a passage feeding said Well from the chamber maintaining the higher level, a, fuel duct delivering below the throttle from said well, a fuel duct delivering above the throttle from the chem ber maintaining the lower level, a valve controlling said passage, a valve controlling Said duct, and a common operating means for said valves,

In testimony whereof I have hereunto "subscribed my name. v I CHARLES L. RAYHELD.

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