US2038785A - Carburetor - Google Patents

Description

April 28, 1936.

R. E. GOULD 2,038,785

CARBURE'TOR Filed Sept. 9, 1933 2 Sheets-Sheet 1 INVENTOR. E. Gould;

ATTORN? e4 R. E; GOULD CARBURETOR Filed Sept. 9, 1933 2 Sheets-Sheet 2 Div. 7 VWM INVENTOR. Ralh E. Gould;

Patented Apr. 28, 1936 UNITED STATES PATENT OFFICE one-half to Newell N.

Calif.

Smith, Los Angeles,

Application September 9, 1933, Serial No. 688,736

3 Claims.

This invention relates to and has for a primary object the provision of an improved type of carburetor embodying a mixing chamber for the reception of fuel under control, and a vacuum chamber adjacent thereto and offset from the air inlet in which a throttle valve is mounted and arranged for semi-automatic operation, and means connected with said vacuum chamber whereby suction from an internal combustion motor, to which the carburetor is attached, may be created in the vacuum chamber and the extent of the vacuum regulated for inducing the opening of the throttle valve in accordance with the varying requirements of the motor.

Another object is to provide in the mixing chamber an improved means of introducing the fuel and for thoroughly distributing the liquid fuel throughout the mixing chamber for mixture with air introduced thereto, said mixing means being controlled and automatically operable by and with the movement of the throttle valve.

A further object is to provide manually oper able means for regulating and limiting the operation of the throttle valve rather than for actually operating said valve whereby the valve may be opened by vacuum and the extent to which it is opened limited by the operation of said manually operable means, the closing of said throttle valve being under the control of the operator of the vehicle through the release of pressure on the accelerator.

Other and more detailed objects of invention may appear as the description progresses.

In the accompanying drawings I have shown a form of the invention in which the fuel feed mechanism is shown as separate from but connected with the carburetor. In said drawings,

Fig. 1 is a top plan view of the carburetor including connections for operating the throttle valve and for affording communication between the mixing chamber and the fuel feed apparatus.

Fig. 2 is a sectional elevation of the same on a medial longitudinal line.

Fig, 3 is a sectional plan on line 3-3 of Fig. 2 thru the mixing chamber.

Fig. 4 is a fragmentary sectional elevation of the fuel feed control valve mechanism on line 4-4 of Fig. 1.

Fig. 5 is a transverse section on line 55 of Fig. 3.

Fig. 6 is a fragmentary rear view of the carburetor showing the throttle valve control means.

Fig. 7 is a fragmentary section of the throttle valve and vacuum chamber showing means for urging the throttle valve into closed position when the motor is decelerated.

Fig. 8 is a transverse section on line 8--8 of Fig. 2.

Briefly described, a carburetor embodying my 5 improvements is preferably formed of an integral body member I with front and rear sides 2 and 3 in the form of sectors attached thereto, as by means of bolts or screws 4, 4 etc. The body I is provided with a vertical extension 5 of tubular form within which a mixing chamber 6 is provided and at the top of which a flange l is formed for attachment to the intake manifold of an internal combustion motor.

The lower portion of the body is segmental with a circular upper wall 8 forming a vacuum chamber 9 within which a throttle valve Ill is oscillatably mounted on a shaft II, the outer wall 8 being concentric with the axis of said shaft and the throttle l9 havingan arcuate upper web [2, the outer surface of which contacts with the inner surface l3 of the wall 8. Said throttle also has a radial web l l'which extends from the portion I 2 inwardly to the hub l 5 of the valve.

The lower portion of the mixing chamber 6 is arranged for communication with an air inlet chamber l6 formed in a tubular inlet member I? attached to a portion of the body l8, as by means of screws It. An opposite portion of the body is closed by means of a plate 20 held in position by screws 2|, thereby closing the vacuumchamber 9 at the bottom of the body, while the web l4 of throttle valve l0 forms a closure for the opposite extremity of said chamber.

On the rear side of the carburetor adjacent the plate 3 a stop arm 22 is fixed to the end of shaft H and is provided with an inwardly bent lug or pin 23 which overlies a concentric portion 24 of an arm 25 to which the usual throttle operating rod 26 is attached for connecting the throttle with the accelerator lever or pedal in the drivers compartment of a vehicle. Thus as the rod 26 is moved f-orwardy by correspondingly depressing the accelerator lever or pedal the movement of the throttle valve I0 is limited by the engagement of the lug 23 with the arm 25, but a reverse movement of rod 26 and arm 25 would effect a corresponding reverse movement of throttle valve In, as more fully explained hereinafter. The rearward movement of arm 25 is limited by means of a set screw 24 held in a lug 25 on plate 3 and adapted to adjustably engage a stapling 23' on arm 25.

The vacuum chamber 9 is in communication with the mixing chamber 6 through the instrumentality of a tube 21 which has an inlet 28 to mixing chamber 6, and at its other end has a vacuum cylinder 29 connected therewith. The cylinder 29 isprovided with a bore v3|] in which a hollow piston 3| is reciprocably mounted and has an end closure 32 detachably held thereon. A

, tension spring 33 is carried internally of piston 3| andis connected at itsouter end with an adjustment screw 34 and at its inner end with a pin 35 threaded in the head of the piston and projecting therefrom.

The pin slidably engages a reduced bore 36' in communication with tube 21, and bore 36 communicates with chamber 9 ,by means of a a passage 31 in the wall of "cylinder 29 and continuing through a nipple 38 attached to said cylinder, as shown in Fig. 2. Thus suction from the 'mixing chamber 6 is applied thru tube 2 1 and cylinder 29 to the vacuum chamber 9, and communication between cylinder 29 and vacuum chamber 9 is 'regulated,as hereinafter described, by means of the piston 3|.

' A spraynozzle for thefuel is provided within the mixing chamber 6 and includes a base 39 which'is diametrically positioned'within chamber 6 and has a nipple 48 extended through an aperture 4| in the wall of said chamber. 48 is centrally positioned within a boss 42 which is bored to receive the reduced inner endof a fitting 43 to which, a fuel feed tube "44 is connected. Thus fuel fromrtube 44 is delivered to a chamber 45 in the fitting 43 and. thence thru a: strainer '46 and an inlet passage 41 formed in in an inclined bore 59in the member 39.

valve is carried by a'movable body member 5| which is slidably supported, as shown in Fig. 2,

hereinafter described. 7 nTheinner end of passage 41 forms a seat for the base 39 from whence the fuel enters a central chamberj48 in said base and is distributed, as

a needle valve 149 which is adjustably mounted Said 4 on one or more pins 52 outwardly extended from a' boss 53 on -extension 5.. Said member 5| is bi furcated to vprovide inner and outer portions '54 and 55 respectively, and the portion '54 has a cylindrical extension 56 which slidably :engages The outer furcation 55 of member 5| has a bore 62 which is closedat one end by means of an externally headed screw 63, and a plunger'64 extends thru the opposite end of said'bore and is provided within the bore with an enlarged head55 and. inwardly of said head with a reduced stem 66. The nut 63 is bored andthreaded to receive a smaller screw 31' and the screw 61 is bored at;68 to receive the-outer end of stem 66. (See Fig. 4.) v

. A compression spring '69 is mounted conveniently within the bore 6-2-and maybe interposed as shown between a pair of collars, 10 and H or betweena corresponding extension from plunger 64 and the "end of screw "61; The spring 69Vthus serves toforce the plunger to the left, as seen in Fig. Lat which point the flange 65 will engage the bottomof the bore,

Said nipple Belowthe member 5| a rock' shaft 12 is mount- 7 ed on. the wall 8 of the housing member in a pair of laterally spaced lugs'l3 and 14. One end of said shaft 12 is bent downwardly at 15 and outwardly at 16 to form a pivot on which a lever 11 is swiveled. Intermediate the lugs 13 and l4' an arm 18 is fixedly mounted on shaft 12 and has a rounded upper end 19 which engages the outer end of plunger 64. Preferably the arm has an extension which, when the plunger 64 is in body and mechanism from normally operative position on the housing V The lever '11 has oppositely extended arms 82 V the position shown in Fig. 4, engages a shoulder 8! on member 5| for limiting the movement of arm'18 in a counter-clockwise direction and preventing the dislodgement of the assembled valve and 83, thelowermost of which (arm 83) operatively engages a cam 84 which is fixed to shaft externally of the cover plate 2. Said cam has 'anelongated eccentric dwell 85, a shorter dwell 86, and a projection 81 formed on its periphery,

' as shown inFig. 2; When the motor is inoperative and the throttle valve I0 is in closed position with the web |4 thereof substantially below the position shown in Fig. 2, the lower 'ex-' tremity of arm '83 will rest upon thedwell or V projection 81 of the cam. Under such a condition the needle valve 59 will be entirely closed and the member 51 will be thrust inwardly to a maximum. extent thru its connection with arm 18 and by reason of the tension of spring 88 which'is carried on and'serves to tension shaft 12, as shown in Fig.1.

-When the motor is started and the throttle valve is in idling position substantially as shown in Fig. 2, the lower end of arm 83 will engage the short. dwell 86 of cam 84 and the valve body 5| will be slightly projected from engagement with the 'boss 53 to an extent suflicient to slightlyopen the needle valve'5il, thereby supplying sufficient fuel thru inlet 41 for" operating the 'motor'at idling speed.

As the motor is accelerated arm'83 is elevated, from the dwell 86 to and gradually traverses the ascending dwell on cam 84, thereby gradually extending'the valve body 5| outwardly and correspondingly opening needle valve 59. The mixture of air and fuel is controlled by means of an adjustable arm 89 which is pivotally mounted on a rock shaft 99-carried in lugs 9|, 9| on member 1, and at one'end said shaft has an arm 92 fixed thereto .for connection with'a rod 93 leading to thedrivers compartment of a vehicle and tothe instrumentboa-rd for manual operation and adjustment of the arm 89.

Said arm 89 underlies the *arm*82 'of lever ll r and the lower surface 94 of arm-82 is curvedso that when throttle valve I9 is in idling position and lever Fl is correspondingly positioned relative to its-cam 84 the surface 94 will be concentric with the axis of-arm 90. The upper extrem ity 95 of arm 82, however, is eccentric withrespect to the axis of arm. 89 so that when start-'- ing the motor for the purpose of richening the fuelmixture the rod 93 maybe pulled forwardly, thereby correspondingly elevating arm .89 and moving the same into contact with 'theeccentric portion 95 of arm 82, which adjustment serves to project the member 5|"outwardly and open needle valve 50. r

When the motor is started and is operatedat idling speed the rod 93 may be retracted manu'alls or by means :of aisuitable spring for restoring '89 to the position "shown in Fig. 2.

Throttle valve I0 is urged into closing position by means of a spring 96 which is wound around a pin extended through plates 2 and 3, and has a portion 96' thereof engaging an arm 91 which is detachably held at its inner end on the hub 98 of valve I0.

From the foregoing description it will be noted that the vacuum in chamber 9 tends to open throttle valve I0 and accelerate the speed of the motor and that the opening of said throttle valve is accomplished against the tension of the spring 96. The spray nozzle in the mixing chamber is centrally mounted on the base 39 and includes a circular body 99 having a conical portion I00 which is slightly smaller than and seats in a conical opening IIlI on the upper side of member 39 above the chamber 48.

Intermediate the outlet I00 and the chamber 48 the member 39 is internally threaded to receive the lower externally threaded end I02 of the member 99. Communication between chamber 48 and outlet I00 is established by means of a plurality of radial slots I03 which are formed in the portion I02 of member 99. Thus the fuel from the inlet 41 is directed upwardly thru passage 48, slots I03 and the annular outlet IOI into that portion of chamber 6 which is above the member 39. Above the outlet IOI, however, I provide a distributor I04 which has a plurality of preferably pointed projections I05, as shown in Figs. 1 and 2. Said distributor is held in p0- sition on the member 99 by means of a nut I06 into which a screw I0? is threaded, said screw being extended through the member 99 with its head at the bottom thereof, as shown in Fig. 2.

The purpose of the distributor I04 is to deflect portions of the jet of fuel from the annular outlet I M into the outer portion of chamber 6 so as to thoroughly atomize the fuel for complete mixture with the air which enters through the air tube I'I around the member 39 in passage 6.

I have shown in Fig. 2 a downwardly inclined passage I01 in member 39 which communicates with a tube I08 leading to a recess I09 within the lower portion of the throttle valve chamber and which serves as a scavenger for fuel from chamber 48, particularly when the engine is operating at an idling speed. At idling speed the air velocity through the mixing chamber 6 .is very low, thereby permitting the draining of liquid fuel from chamber 48 to a lower point of higher velocity. Under such conditions fuel thus drained will fiow downwardly thru passage I01 and tube I08 into recess I09, where it will be siphoned from the tube by the inflow of air through the air inlet I1.

As the motor is accelerated the need for the scavenging tube I08 becomes gradually less until a point is reached in the operation of the motor when all of the fuel so introduced into chamber 48 is completely and properly vaporized and mixed with the air at the nozzle in chamber 6, due to the greater air velocity at this point.

A certain amount of air may be drawn thru tube I08 into the lower portion of chamber 48, thereby facilitating the mixing and vaporization of the fuel. The tube I08 thus serves the purpose of diverting liquid fuel from the bottom of chamber 48 to the air inlet when the carburetor is changed from a high to a lower engine speed.

I call particular attention to two important features of my carburetor. First: The throttle valve I0 is located below rather than above the fuel nozzle, as mother types of carburetors, and said throttle valve instead of being centrally ing chamber.

mounted in the mixing chamber, has an axis offset from the axis of the air inlet and the mix- Second: I provide the vacuum chamber 9 at the rear of the throttle valve and therefore offset from the air passage and the mixing chamber, and the area ofthe vacuum chamber varies with the opening and closing of the throttle; I

As shownin Fig. 7, the application of the spring 96 to the throttle I0 is suchthat as the throttle valve is rotated in a clockwise direction, 1. e., when the valve is being opened, the fulcrum 91 of the arm 91 will gradually approach a dead center position with respect to the axis of shaft II and the point 98 on arm 9'! at which the portion 96' of spring 96 is connected. Accordingly the effect of the spring 96 on the throttle is gradually reduced. As'the'throttle is moved to closing position the effect of spring 96 is gradually increased, thus insuring the positive closing of the throttle.

Incidentally, when the throttle I0 is in closed position the lower side of the web I4 rests upon a lug I3 extended inwardly in the bottom of the end I 8 of the housing. When the throttle is completely open the rear edge of the arcuate portion I2 thereof will engage the inner side of the closure plate 20.

In operation, when the several elements of the carburetor are'adjusted substantially as shown in Fig. 2 with a rod 26 connected with the accelerator pedal, the motor is started in the usual Way by adjusting the arm 89 relative to lever Ti, which operation is accomplished by pulling on the rod 93, as in an ordinary choke device. As hereinbefore described the movement of the arm 89 upwardly on the edge 94 of lever TI changes the fulcrum for said lever so that the operation of needle valve 49 is open to a sufiicient extent to richen the fuel for a starting operation.

The rod 26 is subject to the tension'of a spring (not shown) which is usually connected with the accelerator pedal or throttle lever and serves the purpose of restoring the rod 26 to normal position. The connection of rod 26 with throttle valve I0 thus places the movement of the throttle valve under control of the operator, said valve being limited as to its opening movement by the position of rod 26 and arm 25 which are under control of the operator.

It will be understood that the rod 26 in no case serves to open the throttle valve, the opening of said valve being accomplished entirely thru vacuum in chamber 9 and the extent of its opening limited by rod 26. Throttle valve I0 serves a dual purpose of closing the air inlet I1 and the mixing chamber 6 against communication with vacuum chamber 9, the wall I4 serving the first mentioned purpose and the arcuate wall I2 serving the latter purpose.

With the motor operating at idling speed the lower end of lever 11 is positioned as shown in Fig. 2 on the short dwell 86 of cam 84, and as the motor is accelerated the throttle valve I0 is gradually opened by the vacuum in chamber 9, whereupon the lower end of lever 'I! will gradually traverse the ascending dwell 85 on the cam, thereby opening the needle valve 49 to meet the gradually increasing requirements of the motor. The volume of fuel delivered thru inlet 41 to chamber 48 is increased above a normal flow so long as arm 89 is adjusted from its lowermost position shown in Fig. 2 to any upper position. Said arm 89 provides a variable fulcrum forlthe lever 11 and causes the supply of an abnormal quantity of fuel as long as a is adjusted mm its normal position.

V The regulator 29 serves to maintain a substantially uniform degree of vacuum in the chamber ,9 for gradually opening the throttle'valve 10 as I 'At starting position the lower end of lever 11 is engaged bythe short dwell 81, and all tension on the needle valve is relieved. The .fuel delivered to chamber 45 is transmitted to chamber 48 from which it is sprayed upwardly beneath the distributor I04 and thoroughly atomized for mix ture with the air delivered thru inlet l1.

The purpose of regulator is to limit the degree of vacuum at all times in chamber 9 to a substantially uniform extent so that upon the release of rod 26 the throttle valve II will be free to close by the tension of spring 96. The tension of spring 96 on throttle valve l gradually increases as the throttle valve is closed from a completely open position and is at a maximum when the valve is closed.

The throttle valve l0 being disposed in the vacuum chamber .land forming one of the closures therefor varies the cross sectional area of said chamber as the valve is moved to or from closed position, but the suction in said chamber is not varied by the movement of the throttle valve.

The position of the throttlevalve below the atomizing nozzle-efiects the atomizationof the fuel in a vacuum ratherthan at atmospheric pressure in the caseof an atomizer located below the throttle valve, as in ordinary'carburetors.

It will be observed that I have provided a novel carburetor with a vacuum chamber offset from the path of the air thru the carburetor in which the throttle valve is rotatable mounted and serves to prevent communication between the air passage and said chamber; a fuel control valve for regulating the inflow of fuel to the mixing chamher, and means under the control of the throttle valve for regulating the opening of said inlet valve.

What I claim is: V

1. A carburetor comprising a housing having a chamber therein with an air inlet, a vacuum chamber ofiset from said mixing chamber, :a throttle valve rotatably mounted in said vacuum chamber andforming a closure against communication between said mixing chamber and said air inlet and said vacuum chamber, said mixing chamber having a fuel inlet, a spray nozzle centrally mounted'in said chamber, means on.

said nozzle for deflecting and distributing the fuel thruout the area of said mixing chamber for mixture with the'air from said air inlet, a fuel control valve for regulating the flow' of fuel through said inlet to said nozzle, and means vfor operatively connecting said control valve with said throttle valve for automatically opening said control Valve to correspond to the 0peningmovement of said throttle valve.

2. A carburetor comprising a housing having a passage therethrough and forming a mixing chamber at one end and an .air inlet at the other end of said passage, an extension having a recess at one side of said housing having across'section of a sector, the axis of which is substantially alined with a point onthe periphery of said pas-'- sage, a throttle valve pivotally mounted in said housing coaxially with said extension at a point below the opening between said air inlet and said mixing chamber and formed with connecting radial and arcuate walls, said radial wall adapted to completely overlie said opening for regulating communication between said air inlet and said mixing chamber and said arcuate wall adapted to prevent communication between said mixing chamber and the recess in said extension, for the purpose described. 7

3. A carburetor comprising a housing provided with a passage therethrough and an extension on said housing having a chamber ofiset from 7 said passage, a throttle. valve pivotally mounted on said housing on an axis ofiset from the axis of said passage, saidvalve havinga radial 'wall and a connecting arcuate wall, said radial wall adapted to regulate communication between the opposite portions of said passage, said arcuate wall adapted to completely close said passage when disposed transversely so as to'prevent communication between said passage and the chamber in said extension, for the purpose described. 7

RALPH E. GOULD.

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