US1848036A - Carburetor - Google Patents

Description

w. H. WEBER March 1, 1932.

CARBURETOR 2 Sheets-Sheet Filed Sept. 9, 1927 avwemtoz Patented Mar. 1, 1932 wamnnf tywnnnnrownmaon, MICHIGAN, ASSIGNOR 'ro iinrnorr Lnnmoaroa or person,

MICHIGAN, A CORPORATION OF MICHIGAN CARBURETOB n, filed September 8, 1927. Serial No. 218,407.

I My invention is for a new and useful improvement in carburetors, and relates more particularly to means by which the supplies of air and fuel admitted to the mixing chamher may be controlled.

An object of my invention is to provide a carburetor which will operate efiiciently over the complete range of engine speeds.

Another object is to provide a carburetor m in which the response of the air and fuel control means to movement of the throttle valve may be regulated.

The invention consists in the improved construction and combination of parts, toqbe more fully described hereinafter, and the novelty of which will be particularly pointed out and distinctly claimed.

In the accompanying drawings, I have fully and clearly illustrated a preferred embodi- 29 ment of my invention, to be taken as a part of this specification, and wherein- Figure 1 is a viewv in side elevation of my invention, with parts broken away and partly in section;

Fig. 2 is a top plan view thereof;

Fig. 3 is an end view looking from the right of Fig. 1 and having parts broken away andpartly in section;

Fig. 4 is a section on the line 4-4 of Fig. 2;

Fig. 5 is a detail view in section of the float chamber on the line 55 of Fig. 3, and

Fig. 6 is a detail central sectional view of the fuel valve assembly.

Referring to the drawings by characters of reference, 1 designates, generally, a carburetor embodying my invention, and having a throttle body 2 and a carburetor body 3. The throttle body 2 is fixed to the carburetor body 3 in any desired manner, but

preferably by screws 4, and the union sealed y a gasket 4.

'VVithin the throttle body 2 is a mixing chamber 6 which may be of any desired shape, and from which leads a mixture outlet passage 7. An external flange 8 having bolt or screw holes 8 is provided at the end of passage 7 by which the carburetor 1 may be secured to an engine intake manifold (not shown). The outlet passage 7 is controlled by a throttle valve 9, preferably of .the plate or butterfly type,

which is carried by a shaft wall of passage 7 and receives an operating lever 12 provided with a fixed stop 13 to limit opening'movement of the valve 9 and with an adjustable stop 14 to limit closing movement of said valve. The stops 13 and 14 are limited in movement by engagement with opposite sides of an abutment 15 fixed on the wall of the passage 7. Beyond the valve 9 and opening through the wall of passage 7 adjacent the flange 8, is apassage 16 for connection to a vacuum tank (not shtown) in-the fuel supply line to. the carbure or. I The carburetor body 3 has an air chamber 17 supplied with air by a conduit or tube 18 which is preferably detachably connected to the body 3. The air tube 18 may, if desired, be connected to'a-n air heating means such as a stove (not shown) surrounding the engine exhaust pipe, as is well known in the art. In order to regulate the temperature of the incoming air through tube 18, cold air Also carried by the carburetor body ass-a I fuel reservoir or float chamber 21 which maybe of any desired construction,-and specifically forms'no part of my invention, except in so faras it provides for proper operation of the carburetor by maintaining the fuel supply at a constant level at the carburetor. In the base 22 of the reservoir is a valvecontrolled inlet 23, which is opened and closed automatically by a valve 24 controlled by a float'25 acting through levers 26 upon the valve stem 27. The levers 26 are preferably supported on pivot pins 28, carried by the reservoir cover 29; iquid fuelin the reservoir is maintained at atmospheric pressure by means of the atmospheric airinlet aperture 29*.

The air to be used in forming the combustible mixture is fed to chamber 17 by the conduit 18, and is admitted to the mixing chamber 6 through a port 30 which is controlled by a conical suction-controlled air valve 31 having a seat 32 about said port. Through valve 31 are a plurality of air ducts 33 which converge to form a nozzle 34 which feeds into chamber 6. Depending from and operatively connected to the valve 31 is a valve stem or fuel delivery member 35 having a longitudinal internal hollow bore 36 which opens at its upper end through a calibrated jet 37 into the nozzle 34. Beneath the port 30 and within the air chamber 17 and supported on the bottom wall thereof, is a boss 38 having an internal open-ended guideway 39 in which the valve stem 35 has a free sliding fit. The stem 35 projects through the" lower end of the guideway 39 and into a.dash-pot chamber 40 having an open bottom which is closed by a cover 41, preferably secured to the chamber by screws or bolts 42. Within the chamber 40 and rigidly secured to the stem is a piston 43 which has a slight clearance with the side walls of the chamber, say, .0025 inches. The piston 43 has a plurality of passages 44lead mg through it and which are provided with as check valves 45, preferably, but not necesfuel can only pass below the piston throughv the clearance at the sides thereof, Fuel 131 fed to the chamber above the piston by a conduit 46 from the reservoir 21 (see Fig. 35 3). The hollow bore or passage 36 in the stem 35 extends through the piston 43, but is sealed at its lower end by a disc 47 Fuel is fed from the top side of piston 43 and into the passage or hollow bore 36 through pas- 40 sages 48, of which but one is shown.

Depending from the cover 41 is a hollow sleeve 49 having a laterally extending offset hollow boss 50 which is in communication with sleeve 49. The boss 50 is open and internally threaded at one end, as at 51, to receive a packing gland 52 having a journal bearing 53 for a shaft 54, packed at 55 by any suitable material which is secured in place by a nut 56 and lock nut 57. One end of shaft 54 projects through and beyond the gland and carries a lever 58 secured on the shaft by a screw 59. The lever has a stop arm 60 which contacts an adjustable abutment 61 carried by the cover 41. A tension spring 62 having one end fixed to a lug 63 on the carburetor body 3 and the other end fast to the arm normally tends to rotate shaft 54 clockwise of Fig. 3 to maintain the stop arm 60 in engagement with its abutment 61. Operating means 60 (not shown) are preferably connected to the lever 58, as at 59*, and extended to a position adjacent the operatoryfor example, to the dash-board of a motor vehicle. Fixed on the opposite end of shaft 54 from lever 58 and within the hollow boss 50, is a toothed pinion 64, a portion of the circumference of which projects through the communieating opening (not shown), and engages a toothed rack 65 which is longitudinally reciprocable in the sleeve 49. The rack is preferably in the form of a hollow cylinder having an internal flange 66 and shoulder 67 for receiving a metering pin or needle valve assembly (see Fig. 6). The tapered valve or pin proper 68 has a depending valve stem or conduit member 69 with a hollowbore or passage 70 which terminates at its upper or inner end adjacent the pin proper 68 and which is sealed at its lower open end by a head 71. Around the head 71 is a circumferential groove 72 which fits loosely for rotation into the center opening of a slotted sup- )orting washer 7 3. This much of the assembly is then passed through the hollow rack 65 until the washer 7 3 abuts the underside of the flange 66. The washer 73 and parts carried thereby are then fixed in the rack in any desired manner, as by soldering, or the like, though I prefer to do so by staking the shoulder 67 in tightly around the washer 73, as at 67, see Fig. 6. The stem 69 extends upward through a horizontally floating close iitting guide sleeve 74 carried by a plate 75 fixed across the sleeve 49 in the plane of .cover41, and through a guide aperture 76 in the closure disc 47. The'tape1'ed valve gpm er 68 extends up into the passage 36 and cooperates witha calibrated port 77 therein "to control the flow of liquid fuel'to nozzle 37. It is to be noted that the valve 68 never seats against port 77, so that fuel is free to pass through bore 36, even with all parts at rest, as shown in Fig. 4.

At a point adjacent the upper end of hollow bore 70 I provide a calibrated orifice 78 in the stem 69 which opens into the fuel passage 36 above piston 43. At a second determined point in the length of bore or passage 70, I provide a second calibrated orifice 79 which opens directly into the dash-pot chamber 40 below the piston 43. The lower end of the sleeve 49 is threaded and closed by a screw cap 80 threaded thereon and containing a gasket 80" to seal the joint. Within the sleeve 49 is a helical spring 81 which is supported on cap 80 and which extends upward into the hollow rack 65 and engages the shoulder 67 to keep the rack in proper mesh with its pinion 64 and prevent back lash between the rack and pinion.

The operation of my carburetor is as follows: When it is desired to start the engine (not shown), to which the carburetor 1 is operatively connected, the parts being at rest as shown in Fig. 4, the throttle 9 is opened and the lever 58 is rotated counterclockwise of Fig. 3, which will lower the metering pin 68 into sleeve 74, controlling or cutting off the by-pass through the metering pin at orifice 7 9. If the engine is now started, the sub-atmospheric pressure created in the mixing chamber 6 will raise the air valve 31'; but this movement of valve 31 will be very slow, due to the fact that fuel can pass tothe underside of piston 43 only through the clearance around the sides thereof, since the bypass or passage through the metering pin stem 69 by way of orifice 78, bore 70, and orifice 79, has been cut off by sleeve 74. However, since fuel port 7 7 is opened wide by the lowering of the valve 68,- a ver rich mixture of fuel from bore 36 and re atively little air 7 from chamber 17 will be drawn into the mixing chamber 6 and fed to the engine. When the engine has started and the throttle 9 is moved toward closed position, Fig. 4, the suction in the mixing chamber 6 will be lowered, allowing the air valve 31 to drop. The air valve will close rapidly, due to the .upward opening check valves 45. Should it be desired to warm up the engine, the metering pin may be left depressed to cut off the by-pass and the engine accelerated'and cut down several times. On each acceleration the air valve 31 will open slowly and supply a rich mixture to the engine cylinders, as described for motor starting. After the engine '70 to opposite sides of piston 43, an

has been properly warmed up, the metering pin 68 is returned by the operator to its normalrunning position, Fig. 4, by clockwise movement of lever 58 until arm 60 engages stop 61 and orifice 7 9 has been raised out of sleeve 74. For normal running the metering pin by-pass through orifice 78, passage 70, and orifice 79, is open so .thatthere is unrestricted communication through assage d liquid fuel may flow freely through the bypass from the dasht above the piston to the dash-pot beneat h the piston, or vice-versa, upon movement of piston 43. This will permit the air valve 31 to open rapidly in response to the suction in the mixing chamber,

- as it is substantially unretarded by piston 43 and will therefore supply the necessary volume of air to the mixture to give the desired thermal efliciency. When the by-pass is open, the motor will respond quickly to the throttle, because the quickly opening valve 31 will pass a greater volume of air than when the y-pass is closed, and therefore supply the required greater volume of mixture for rapid acceleration.

It will be understood from the foregoing description, that by the use of my improved carburetor, the operator can control the opening movement of the air valve 31 and therefore the vacuum within mixing chamber 6 through the medium of the dash-pot by-pass. When the by-pass is closed by lowering the needle valve 68, the opening movement of the air valve 31'will be additionally retarded,

causing a relatively higher vacuum in the mixing chamber, and since the port 77 will have been opened wider by the lowering of valve 68, there will be a 'greaterdischargeof liquid fuel through calibrated orifice '37 while the quantity of air admitted to the chamber 6 around valve 31 will be comparatively small, resulting in a rich fuel mixture. The metering pin 68 may be adjusted relative to a fixed position of the air valve 31 by adj ustment of lever -58about shaft 54 to give suflicient fuel for cold motor operation; but in order to get a proper mixture which is sufliciently rich for acceleration from low speeds ('5 to 10 miles per hour) to a speed at which the air valve 31 reaches its fixed position '(20 miles per hour), I provide the carburetor with my metering pin by-pass, whereby I am enabled to increase the drag of the dash-pot upon the air valve 31 simultaneously with the adjustment of the metering'pin 6'8, and thereby obtain efficient acceleration of a cold motor or engine. However, when the by-pass is open and the needle valve is the position of normal carburetor operation, Fig. 4, then since liquid fuel can readily pass from the space above the piston 43 through the by-pass to the space in the chamber 40 below the pistion, or in response to throttle positions lVhat I claim and desire to secure by Let- 'ters Patent of the United States is 1. A carburetor comprising a'casing including a mixing chamber having an airinlet, afuel inlet and a throttle-controlled mixture outlet, a suction operated, valve for controlling said air inlet, means for automatically regulating the opening and closing movements of said suction-operated valve, and means under the control of an o erator for increasing the area of't'he fuel in ct an simultaneously decreasing the rate of opening movement of said suction-operated valve.

2. A carburetor comprising a casing ineluding a mixing chamber having an air inlet, a fuel inlet, and a throttle controlled mixture outlet, a suction operated valve for controlling said air inlet, a dash-pot forautomatically regulating the opening and closing movements of said suction-operated valve, and means under the control of an operator for simultaneously increasing the resistance of said dash-pot and the area of said fuel inlet.

3. A carburetor comprising a casingincluding a mixing chamber having an an in-- let. a fuel inlet and a mixture outlet, an air valve for said air inlet, means for retarding opening movement of said air valve, a fuel valve for said fuel inlet, and means under the control of an operator for operating said fuel valve to control the fuel supply relative to the air supply and simultaneously therewith to retard the opening movement of said air valve. I

4. A carburetor comprising a casing 1ncluding a mixing chamber having an air in let, a main fuel inlet and amixture outlet, a suction-operated valve for controlling said .airfinlet and said fuel inlet, a dash-pot cham ber, a piston'in said dash-pot chamber and "coniiected"to, said suction-operated valve, *f gjmeanfs'iiig passing a fluid in said dash-pot *c'ha'riiberffromone side to the other of said piston'to' regulate movement of said suction- ";Top'erlated valve-,and means operable to re- 'sti'ict -tlie fiovv'of said fluid from one side to "y tlieothero fsaid piston to retard opening *moveme'ntof said suction operated valve and joperableto increase the effective area of said 'yiiiainj'fuelinl'etto increase flow of fuel to said 1 miiriiig' chamber, said last-named means bein'g operable, to reestablish flow permitting morekrapid opening movementof said suc- EMA carburetor comprising a casing ,in-

9' cluiilinga mining chamber having an air in let, a main fuel inlet and a mixture outlet,

ais'uction-operated valve for controlling said airinlet and said fuel inlet, a dash-pot chamber, a piston in said dash-potchamber and connected to said suction-operated valve,

1 means for passing a fluid in said dash-pot chamber from one side to the other of said piston to re ulate movement of said suction- 0 rated Iva ve, and slide valve means 0 era le manually to restrict the flow of said uid from one side to thevother of said piston to retard opening movement of said suction operated valve and operable to reestablish fiovv permitting more rapid opening movement of 's'aid suction-operated valve to de crease the flow of fuel to said mixing chamber.

' 6. A "carburetor comprising a mixing chamber having air and fuel inlets and a mixture outlet, a suction-operated valve conr trolling said air inlet and said fuel inlet, a

dash-potchamber, a piston in said dash-pot chamber and. connected to said suction-operated valve to regulate movement thereof,

means to permit flow of fluid through said piston, and means manually controlled for regulating said last-named means.

7 i A carburetor comprising a mixing chamber. having air and fuel inlets and a mixture outlet, a suction-operated valve controlling said air inlet and said fuel inlet, a dash-pot chamber, a piston in said dash-pot chamber and connected to said suction-operated valve to regulate movement thereof, a conduit member to permit flow of fluid through said piston, and manual means to close said conduit member to retard opening movement of .said' suction-operatedv valve to increase flow of fuel to said mixing chamber.

8. A carburetor comprising a mixing chamber having air. and fuel inlets and a mixture outlet, a' suction-operated valve controlling said air inlet and having a. fuel pas-,

sage therein, a dash-pot chamber, a piston in said dash-pot chamber to regulate movement 95 of said valve, a fuel valve cooperating With said fuel passage to regulate flow of fuel therethrough, said fuel valve containing a bypass opening on opposite sides of said is ton, and means for regulating flow of f nal through said by-pass.

9. A carburetor comprising a mixing chamber having air and fuel inlets and? a. mixture outlet, a suction-operated valve controlling said air inlet and having a fuel passage therein. a dash-pot chamber, a piston in said dashnot chamber to regulate movement of'said valve, a fuel valve cooperating with said fuel passage to regulate flow of fuel therethroug h, said fuel valve containing a by-pass opening on opposite sides of said piston, and manual- 1y operable means for regulating flow of fuel through said by-pass.

10. A carburetorcomprising a casing including a. mixing chamber having air and fuel inlets and a mixture outlet, a dash-pot chamber having a piston, a valve for said air inlet, means connecting said valve and said piston, and a metering-pin for said fuel inlet projecting through and slidable in said piston, said metering-pin having a passage to by-pass fuel through said piston.

ll. A carburetor comprising a casing including a mixing chamber having air and fuel inlets and a mixture outlet, a dash-pot chamber having a piston, a valve for said air inlet, means connecting said valve and said piston, a metering-pin for said fuel inlet projecting throughand slidable in said piston, said metering-pin having a passage to bypass fuel through said piston. and means to control said passage.

12. A carburetor comprising a casing including a mixing chamber having an outlet and an air inlet, a valve for said air inlet and having a stem, a dash-pot chamber having a reciprocable piston therein connected to said stem, said stem having a hollow longitudinal bore communicating with said dash-pot chamber and with said mixing chamber, and a reciprocable metering-pin projecting through said piston into said bore for cooperation therewith, said metering-pin having a by-pass for passage of fuel from and to opposite sides of said piston.

13. A carburetor comprising a casing including a mixing chamber havin an outlet and an air inlet, a valve for said air inlet and having a stem, a dash-pot chamber having a reciprocable piston therein connected to said stem, said stem having a hollow longitudinal bore communicating with said dash-pot chamber and with said mixing chamber, a reciprocable metering-pin projecting through saidpiston into said bore for cooperation therewith, said metering pin having a bypass for passage of fuel from and to opposite sides of said piston, and means to control said by-pass upon reciprocation of said metering pin.

14. A carburetor comprising a casing including a mixing chamber having an outlet whereby the rate of opening movement of having a stem, a dash-pot chamber having a reciprocable piston therein connected to said si stem, said stem having a hollow longitudinal bore communicating with said dash-pot chamber and with said mixing chamber, a reciproeable metering-pin projecting through said piston into said bore for cooperation-therewith, said metering pin having a by-pass for passage of fuel from and to op osite sides of said piston, a sleeve surroun ing said metering pin adjacent said byass and having a sliding fit on said meterlug-pin, and means to move said meteringpin into said sleeve to close said by-pass.

15. A carburetor comprising a casing including a mixing chamber having an outlet and an air inlet, a suction-controlled air valve for said air inlet, a stem for said air valve having a longitudinal bore, a dash-pot chamber into which said-valve stem projects, a piston on said valve stem in said dash-pot chamber, a fuel inlet to said dash-pot chamber, an aperture for admission of fuel to said bore, a fuel valve cooperable with said bore and having a stem projecting through said piston, means to move said fuel valv'e relative to said bore, said fuel valve stem having means for passage of fuel from and to ops posite sides of said piston, and means to cut off said passage means.

16. A carburetor comprising a casing having a mixing chamber and a main air inlet to said chamber, an air valve controlling said air inlet, a reciproca-ble fuel delivery member insaid air inlet and having a. passage therethrough for opening directly into saidmlxing chamber, a metering pin to regulatethe cross-sectional area of and extending into said passage, said air valve having operable engagement with said member to control flow of fuel through said passage, a'dash pot eontrolling the opening movement of said air valve, and means to increase the resistance of the dash-pot to opening movement of the air valve.

17. A carburetor comprising a casing having a mixing chamber and an air inlet to said chamber, an air valve having a stem and responsive to suction in said mixing chamber for controlling said air inlet, said stem and valve having a passage therethrough for flow af fuel to said mixingchamber, a metering pin to regulate the crossesectional area of said passage, said 'air valve controlling flow of fuel through said passage, a dash-pot having a piston therein controlling the opening movement of said'air valve. by-pass means normally establishing fuel flow from and to opposite sides of said piston, and manually operablemeans to decrease the effective area of said by-pass means whereby to decrease the flow of fuel to the suction side of said piston upon opening movement of the air valve In testimony gned my name and an air inlet, a valve for said air inlet and said air valve is decreased.

whereof I have-"hereunto WA TEaH; WEBER.

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