US1824852A - Carburetor - Google Patents

Description

Sept. 29, 1931. w. H. WEBER 1,324,852

CARIBURETOR v med May 11, 1927 s sheets-sheet 1 G H M C) Siggi/v4 I N VEN TOR.

A TTORNE Y.

Sept. 29, 1931. w.k H. WEBER' CARBURETGR Filed May l1, 1927 3 Sheets-Sheet 2 FEVE- gt f I/" T 7/ .9X /07 my my y! 7M, l 7d mxI Il 1 El gv fj 7? L :can f/ u l@ n Z da INVENTOR.

,427 l Y I B Y 4X2 i 77 ATTORNEY.

Sept. 29, 1931. w. H. WEBER 1,824,852.

' GARBURETOB 'Filed'may 11, 1927 s sheets-sheet 5 Patented Sept. 29, 1931 uNITED STATES PATENT ori-"lola:4

WALTER H WEBER, F DETROIT, MICHIGAN, ASSIGNOR TO DETROIT LUBRICATOR COM- PAN'Y, oF DETROIT, MICHIGAN,

A CORPORATION 0F MICHIGAN CARBURETOR Application led May 11,

My invention relates broadly and generally to new and useful improvements in carburetors, and while not so limited, is articularly capable of embodiment 'in car uretors of the so-called Stewart type.

One object of my invention is to provide an improved carburetor in which proper supplies of fuel or fuel mixtures will be supplied during different periods or phases of operation of the engine, in order to produce desired performance of the engine, 'particularly when the same is employed to drive a motor vehicle.

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

In the accompanying drawings l have fully and clearly illustrated a preferred embodiment of my invention, to be taken as a part of this specification, and wherein- Figure 1 is an elevation of my improved carburetor, the same being shown partly 1n section;

Fig. 2 is a plan view thereof;

Fig. 3 is a side View from the right of Fig. 1

Fig.4 is a side view, partly in section, and

from the left of Fig. 1;

Figs. 5, 6 and 7 are detail sectional views on line 5 5 of Fig. 4, showing operative positions of a priming valve;

Fig. 8 is a vertical detail section on line 8-8 of Fig. 4, and

Fig. 9 is a detail view of a hinge member.

vReferring to the drawings by characters of reference, 1 designates a hollow carburetor body, which is preferably, but not necessarily, formed of built-upV sections comprising a fuel reservoir 2, a fuel and air inlet element 3, and a mixing chamber 4. The carburetor body 1` may be formed from cast-or sheet-metal, or both, as desired.

The element 3 is separated from the mixing chamber 4 and the fuel reservoir 2 by spaced walls or partitions 5, 6, respectively, which, with t-he side wall 7, provides an air chamber 8. A. suitable conduit 9 which is 50 fixed to the element 3 serves to admit air to 1927. serial No. 190,483.

the chamber 8, and is provided with a flange 10 for connection, if desired, to air preheating means of any Well known type, such as, for example, a sleeve surrounding the exhaust manifold (not shown) of the engine to be fed by the carburetor. The wall or partition 5 which is cup-shaped, having'a side wall 5, has an opening 11 therethrough for the passage of air to the mixing chamber 4. The upper edge 12 ofopening 11 forms a valve seat with which cooperates an air control valve 13 tobe described.

Coaxial with opening 11 and depending from the under side of wall 6, is a boss 14.- Which has an internally threaded bore 15. Threaded through the bore 15 is a guide sleeve 16, which extends into air chamber 8 adjacent to opening 11, and has a shoulder 17 which abuts the boss 14. A nut 18 threaded on sleeve 16, or any other suitable means, may I0 be employed-to lock the sleeve 16 rigidly in wall 6. Depending from the sleeve 16 and Apreferably integral therewith, is a dash-pot casing 19 having an open lower end 20, and having a circumferential shoulder 21 oppositely disposed with relation to shoulder 17. The casing 19 is externally threaded be ond the shoulder 21, as at 22. Adjacent the s eeve 16 and at the top of casing 19, there are a plurality of inlet ports 23 through which liquid fuel is supplied from the reservoir 2 to the dash-pot casing. Fitted in the sleeve 16 and freely reciprocable longitudinally thereof, is a valve stem 24, the upper end of which projects above sleeve 16 into air chamber 8, and the lower end of which projects below the said sleeve into the dash-pot casing or chamber 19. At its upper end 25 the stem 24 is fixed, as by threaded engagement, to the valve 13. Threaded, or otherwise secured on the lower end of stem 24, and within the dashpot chamber 19, is a piston 26 having a plu rality of passages 27 therethrough which are provided with upwardly opening check valves 28, preferably of the ball check type. The stem 24 is hollow, having a bore 29 which is constricted, as at 30, to provide a valve port 31, and said bore having communication at its upper end 25 with a fuel passage 32 in a nozzle plug 32u set in the valve stem 24, and 1f having a flaring upper end delivering into an outwardly flaring passage 32b through the valve 13. Suitable air vent passages 33 lead from the air chamber 8 through the valve 13 and around the nozzle 32a to the flaring opening 321. Depending from the valve 13 is an annular flange or skirt 34 which surrounds the sleeve 16.

The fuel reservoir 2, which is substantially cup-shaped, and preferably of sheet-metal, has a base 35 having a central aperture 36 whichlpermits the base 35 to surround the threaded end 22 of casing 19 and abut the shoulder 21. When so positioned, the reservoir 2 will have its rim 37 in engagement with the underside of the air chamber 8. An internally threaded cap 38 having threaded engagement with the end 22 of casing 19 serves to hold the reservoir rim against the air chamber 8 and the base 35 against the shouldeiI 21. A gasket 39 may be inserted between the cap 38 and base 35 to seal the unlon, and

another gasket 39a is employed to seal the,

joint between rim 37 of reservoir 2 and the chamber 8.

The cap 38 has a neck 40 which is both internally and externally threaded, and which is in the axi'al line of bore 29. Threaded into the neck 40 is a longitudinally adjustable supporting member 41 having a manual adjustment member, preferably 1n the form of a transverse rod or bar 42. At the inner or top end 43 of member 41, is fixed a valve 44, which may be in the form of a tapered needle or pin valve having a stem 45 which projects through an opening 46 in the piston 26. The valve 44 may be ad- 'justed relative to its port 31 by longitudinal movement of the screw support 41, to regulate flow of liquid fuel through the bore of the stem, the said fuel entering the bore through one or more ports 44". Surrounding the support 41 and externally threaded on neck 40 is a packing nut 47 carrying packing 48 to seal the dash-pot chamber 19.

Within the reservoir 2 is an annular float 49, preferably of hollow sheet-metal construction, having a hinge member 50 fixed thereto. The hinge member 50 has bearing eyelets 51 and an arcuate support 52. Carried by the side wall 7 is a cooperating hinge member 53 having eyelets 54 and which is the counterpart of member 50. A pin 55 is journaled in the eyelets 51, 54 to support the float 49 from wall 7 and to permit free movement of the float 49 in a vertical plane. Directly above the arcuate support 52, the side wall 7 of the air chamber 8 has a vertical internal passage 56 which opens into the inner end of a horizontal fuel supply inlet passage 57. Threaded into, or otherwise secured in the vertical passage 56, is a hollow cylindrical valve guide 58 having a valve seat 59, and vertically reciprocable in the guide 58 is a flat sided valve stem 60 having an attaching ring or loop 61 at its lower. end through which is loosely passed the arcuate support 52. At its upper end the valve stem 60 has a conical valve head 62 which is adapted to'engage the valve seat 59 to close the passages 56, 57. At the outer end of passage 57 the side wall 7 has an annular flange 63 which surrounds the passage 57. Threaded on the flange 63 is a cap 64 having an internal shoulder 65, between which and the end of flange 63 is clamped a filter screen 66, preferably of fine wire mesh. The cap 64 has a h ollow nipple 67 in the line of passage 57, which is externally threaded for union with a fuel supply line (not shown), and through which fuel is fed to the reservoir 2. In the Wall 7, preferably at a point below the passage 57, is an air bleed or vent 66a leading from the atmosphere to the fuel reservoir 2 above the liquid level therein, and having its inner end registering with a port or aperture 67 through the hinge member 53.

Supported on the air inlet element 3 and sealed thereto by suitable gaskets 68, 69-and cap screws 70, is the mixing chamber and throttle body member 4 having a flange 71 by which it may be attached to an engine intake manifold.` Adjacent the flange 71 is a threaded inlet opening 71a for connection witha vacuum tank whereby the desired subatmospheric pressure may be maintained in such tank. In the said member 4 is a throttle valve 72, preferably of the butterfly type, which is fixed by screw means 73 on a rotatable shaft 74 journaled in the sides of the chamber 4. One end 75 of shaft 74 extends through the wall of the chamber and carries an operating lever 76. A screw 78 threaded in lever 76 and kept in any fixed position by spring 77 determines the closed or idling position of throttle valve 72, said screw 78 striking against ange 71.

The wall 7 has a vertical boss 79 having a bore 80 extending longitudinally therethrough, said bore opening at its lower end into the fuel reservoir 2, and at its upper end to the atmosphere. Fitted within the bore 80 is a cylindrical tube or sleeve 81, the lower end of which dips into the reservoir 2 below the normal fuel level, and which terminates at its upper end substantially midway vof the height of the wall 52l of cup-shaped partition 5. The lower end of sleeve 81 has a disk member 82 fixed therein, as by threaded engagement, the disk member having a central calibrated orifice 83 for the admission of liquid fuel to sleeve 81 from reservoir 2. Within the top of the sleeve 81 is a plug 84 having a longitudinal axial bore 85 which at its lower end is enlarged and threaded, as at 86. The plug 84 has a pair of oppositely disposed fiat sides 84 which space it at diametrically opposite points from the wall of the sleeve 81 to form air ducts 84", 84b opening into the well sleeve 81', as is evident from Fig. 8. Transversely through the boss 79, the sleeve 81, the longitudinal axis of plug 84, and the wall 5*?, is a passageway 87 having its outer end closed by a screw plug 88 which projects through a side wall of sleeve 81 and into plug 84, and supports said sleeve and plug in the bore 80. The inner end of the passage 87 opens into the mixing chamber 4 (see Fig. 4). Above the passageway 87, and preferably in the same vertical plane, is a second passageway 89, the inner end of which opens into the mixing chamber 4 through the boss 79 and wall 5, said passage 89 being located above the upper end of the sleeve 81. The outer end of passageway 89 is sealed by a plug 90. Within the passageway 87 between the sleeve 81 and mixing chamber 4, is a plug 91 having a calibrated orifice 92. Depending from the plug 84 and within the sleeve 811, is a discharge tube 93, the upper end of which is threaded into the socket 86 in the'plug 84. The upper end of this tube 93 opens into the transverse passageway 87, while its lower end is open and terminates adjacent but above the disk member 82. Above the sleeve 81 and rotatably fitted in the bore 80, is a rotatable valve 94, the underside of which clears the upper ends of sleeve 81 and plug 84 and the upper end of which projects upward above the boss 7 9. The underside of the valve 94 has a transverse, openended passage 95 having an open lower side, one open end of which passage upon rotation of the valve 94, is adapted to communicate with the passageway or conduit 89. On the boss 79 is a lateral extension 96 through which is a passageway or air inlet 97, preferably in the same horizontal plane and at substantially rightangles to the passageway 89 and in a plane common to that of the passageway 95. The valve 94 has a stem 98 to which is fixed an operating lever 99 which seats upon the upper face of boss 79 and seals the valve 94 in the bore 80,and by which the valve may be rotated, one side edge 100, of said lever 99, being provided, as shown in Fig. 2, with a-stop having abutments 101 and 102. Surrounding the stem 98 above the lever 99, is a coil spring 103, one end 104 of which abuts'the carburetor body and the other end 105 of which is in engagement with the lever 99 to normally maintain the valve 94 in the position shown in Fig. 4 with abutment 101 of the lever contacting a fixed stop member 106. Overlying the coil spring 103 is one end of a leaf spring 107 having an aperture 107g by which it is passed onto the stem 98, the other end of spring 107 being fixed to the casing by a screw 108, which also secures the stop-piece 106 to the carburetor casing. This leaf spring holds the lever 99 on boss 79. Fixed on the carburetor casing 1 is a bracket 109 which supports a tube (not shown) through which an operating wire (also not shown) leads from some point within reach of the operator to the lever 99 for operation of the valve 94.

The operation of the carburetor is as follows: The tapered needle or pin valve 44 is preferably adjusted by the supporting member 41 so that port 31 is slightly open when the air valve 13 is closed, so as to permit suffcient liquid fuel to iow through the stem bore 29 and enter the mixing chamber 4 to combine with air admitted through ports 33 and 11 to provide a proper fuel mixture to allow the engine to run idle. As the throttle 72 is opened, the engine having been running idle, the subatmospheric pressure in the mixing chamber 4 will cause the valve 13 to be lifted further depending on the degree of throttle opening, and carry with it the stem 24, thus increasing the flow passage around the fuel valve 44. There is a slight clearance between the sides of the piston and the wall of the dash-pot chamber 19, so -that the movement of the valve 13 is controlled. The ball checks 28 permit the piston to sink and the valve 13 to close. The function of the dashpot and piston is to act as a vibrator dampener so that the air valve will not respond to every minute fluctuation of vacuum, which might result in objectionable hammering of the valve 13 upon its seat 12. The action of the main air and fuel inlets is the same as is found in the well-known Stewart type of carburetor, in which the air and fuel in the main mixture is proportioned to give maximum thermal efficiency, and need not be further described.

On starting the engine, the lever 99 is moved manually clockwise of Fig. 2 until the contact point 102 engages the stop 106. This will position the valve 94, as shown in Fig. 7, to close air inlet 97 and establish communication between tube 93 and discharge passage 89, so that solid liquid fuel alone will be drawn from the tube 93, where such fuel will divide, part going through passage- Way 87 to the mixing chamber, and the other part going through calibrated bore or port 85, passage 95, and conduit or passageway 89 to the mixing chamber 4. This is due to the fact that the valve 94 in position of Fig. 7, cuts oli' all air communication through air inlet 97 to the well, and opens the passageway 89 to the well, and the resulting charge is, in effect, a priming charge, as the solid fuel when mixed with'the air passing through the main mixing chamber supplies an overrich or sufficiently rich mixture to the engine for starting. As soon as the engine is running, the valve 94 is moved manually counterclock- Wise of Fig. 2 to the position substantially as shown in Fig. 6, which cuts off the passageway 89 and permits flow of solid liquid fuel in a relatively less quantity from tube 93 to enter the mixing chamber 4, but only Ithrough the calibrated orifice92, the air inlet passage 97 still being closed by valve 94.

Afl-

As the engine warms up, the solid liquid fuel supplied from well 81, which is additional at all times to that supplied by the main fuel nozzle 32, might cause the mixture fed to the engine to be too rich. To overcome this condition and cut down the amount of solid liquid fuel fed to the mixing chamber, the lever 99 is moved manually further in a countercloekwise direction, so that the valve 94 will be in some intermediate position to that shown in Figs. 5 and 6, and in this position the air passageway 97, 95 will be more or less open, admitting more or less air to the well 81 and passage 89 will be maintained closed. The amount of liquid fuel drawn into -the mixing chamber 4 through calibrated v orifice 92 will be in an inverse ratio to the 97, 95 to calibrated orifice 85 is insufficient to satisfy the suction created by the sub-atmospheric pressure in the mixing chamber 4, then the deficiency will be made up by liquid fuel drawn by the suction from the Well 81. Therefore, as the passage 97, 95 is opened by counterclockwise movement of lever 99, the

amount of liquid fuel drawn from well 81 into the mixing chamber will be decreased, due to admission of air through inlet passage 97. For normal running conditions the Valve 94 is returned by still further or continued counterc-lockwise movement until the abutment 101 engages the stop 106, when the valve 94 will be in the position shown in Figs. 2, 4, 5 and 8, passage 89 being closed and passages 87 and 97 opened. In this last position, air will enter through inlet passage 97 to passage 95, which is wide open, where it will divide, part passing through bore 85 and passageway 87 to the mixing chamber, and part passing down through the spaces or ducts 84a, 84b between the sides of the plug 84 and sleeve 81 into the latter. Due to the relative sizes of the passages 95, 97 and the calibrated orifice 92, the passages 95, 97 bcing of greater capacity than the orifice 92, the air pressure on the fuel in the well or sleeve 81 will be substantially atmospheric at normal power demands or part throttle, and no fuel will enter the mixing chamber 4 from the well 81,v this effect resulting because the air entering through 97, 95 and 85 is morel than sufficient to satisfy the suction through orifice 92. Under the conditions just stated, the fuel is not drawn from the Well because substantially atmospheric pressure is maintained in the horizontal bore of the plug 84, due to the fact that the air feed port 85 is larger than the calibrated orifice 92 in the passageway 87, and the suction in the mixing chamber 4 exerted at the orifice 92 is not sufficient to withdraw air from the space over the well at a greater rate than the air is supplied to said space through the port 85. It will be understood. that the areas' of the port 85 and orifice 92 are so proportioned that substantially atmospheric pressure will be maintained over the well, under the conditions just described, that is, during ordinary road speeds when the throttle is part open. When the throttle 72 is suddenly opened, however, there will be, momentarily, a higher vacuum in the mixing chamber 4 than at part throttle or normal running conditions, which higher vacuum will act to suck liquid fuel alone from the well 81 to the extent of the quantity contained in the well into the mixing chamber to supply the necessary rich mixture for acceleration. The momentarily higher vacuum mentioned causes li uid fuel to pass through the pas-v sage 87, cause the higher vacuum in the mixing chamber increases the suction effect at the orifice 92 and exhausts air from the bore 85 at a greater rate than air is supplied to said bore through the orifice 85, re-

sulting in a sub-atmospheric pressure in the `bore 85a. At this time while there is Subatmospheric pressure in the bore 85a, the pressure on top of the liquid in the well being atmospheric' because of the open ducts 84", 84" leading to the air inlet 97, liquid fuel will be instantly expelled from the tube 93 into said bore 85a, and thence pass through the orifice 92 into the mixing chamber. The body of liquid fuel is drawn so suddenly from the Well 81 into the space over the well, and thence into the mixing chamber 4, that momentarily the air bleed 85 ceases to function, or is sealed by the column of liquid fuel passing through the space over the well, port 92 and passage 97. If the higher; vacuum which accompanies wide open throttle or maximum power demands is maintained in the mixing chamber, then a mixture or emulsion of fuel from well 81 and air which passes through ports 84, 84h, and down around tube 93 'entering the bottom of tube 93 with fuel from orifice 83, will be fed to the mixing chamber through orifice 92, since the air entering through passageway 95 and calibrated orifice 85 will be insufiicient'to satisfy the demand at orifice 92, and the emulsion of air and fuel entering the bottom of tube 93, will be aspirated fronithe well 81 by the air entering at 85, which mixture will be constant in quantity per unit of time.

By the invention shown and described, it will be seen that I have provided -efiicient means whereby upon starting, solid liquid fuel will be admitted to the mixing chamber under such conditions that such fuel added to the main supply will afford a sufficiently rich mixture for starting, even though the supply of liquid fuel from the main jet would produce a mixture which would be relatively too lean. This result is under manual control of the operator, so that it may be produced or not, as desired. During a warming up period after starting, the lever 99 is permitted to move toward the position shown in Fig. 2, the valve 94 first moving to the position shown in Fig. 6, during which supplemental liquid fuel passes only through calibrated orifice 92 to enrich the normal flow through the carburetor. The valve 94 may pass quickly through this position or may be manually held at this position, if desired, until proper warming up of the engine is assured. During normal running, i. e., part throttle, the valve 94 is permitted to assume the position shown in Figs. 2 and 5, under which condition no fuel will be drawn from well 81. Should the throttle be opened wide for maximum power during normal running conditions, the increased suction through the carburetor body will first draw a charge of solid liquid fuel from the tube 93, to momentarily enrich the mixture, and then upon continued maximum power demand the air drawn through passage 97 and over top of tube 93, will aspirate the fuel and deliver a supplemental mixture thereof through calibrated orifice 92 into the mixing chamber.

By the expression solid fuel` as used herein, is meant liquid fuel which is not in the form of an emulsion with air,l or a mixture of fuel and air.

What I claim and desire to secure by Letters Patent of the United States is:

i. In a carburetor, a casing having a mixing chamber, main air and fuel inlets adapted to discharge into said mixing chamber, supplementary fuel and air supply means adapted to discharge into said mixing chamber, said fuel supply means comprising a well, a tube depending into said well and having communication with said chamber and said air supply means, said air supply7 means having communication with said well around said tube to admit air to the lower end of said tube, and a valve controlling communication with said well around said tube and controlling said supplementary fuel and air supply means, said valve having means which in one position of said valve will permit admission of solid liquid fuel through said supplementarv means to said mixing chamber and which in another position will permit admission of fuel and air through said supplementary means to said mixing chamber.

. 2. In a carburetor, a casing having a mixing chamber, main air and fuel inlets to said mixing chamber, a passageway opening into said mixing chamber, a fuel well, a tube depending into said well and opening into said passageway, means to supply air to said passageway and to said well around said tube to admit-air to the lower end of said tube, and a valve to control said air supply means and thereby regulate supply of air to said passageway and the space in said well fuel, or fuel and air, may be admitted through said passageway to said mixing chamber.

3. In a carburetor, a casing having a mixing chamber, main air and fuel inlets to said mixing chamber, a plurality of passageways leading to said mixing chamber independent- .ly of said main air and fuel inlets, means to supply fuel to said passageways, means to supply air to certain of said passageways, and a valve having means to cut off said air supply means, said valve having means to open one of said passageways when said valve means cuts off said air supply means.

4. In a carburetor, a casing, main fuel and air inlets to said casing, a fuel well,passage ways from said fuel Well int-o said casing and subject to suction effect of sub-atmospheric'pressure in said mixing chamber, certain of said passageways being calibrated and other of said passageways being unrestricted, an air inlet port, and valve means operable to establish communication between said air port, said well and said certain calibrated air inlets to said casing, a fuel reservoir, a

well having a calibrated inlet port communieating with said reservoir, outlet passageways from said well into said casing and subject to suction effect of sub-atmospheric pressure in said mixing chamber, one ofwhich passageways is calibrated, an air inlet port, and a valve device adapted to connect said air inlet port with said well and said calibrated passageway, and simultaneously cut off communication between another of said passageways and said well. V

6. In a carburetor, a casing, main fuel and air inlets to said casing, a fuel reservoir supplying fuel to said main fuel inlet, a well having a calibrated inlet port communicating with said reservoir, outlet passageways from said well into said casing and independent of said main inlets, one kof which outlet passageways is calibrated and another of which is uncalibrated, an air inlet port, a valve device including means to close said air inlet port and open communication between said uncalibrated passageway and said well, said valve device being adapted to connect said air inlet port with said well and said calibrated passageway.

7. A carburetor comprising a mixing chamber, main air and fuel inlets to said mixing chamber, a fuel well, passageways leading from said fuel well into the mixing chamber independently of said main air and fuel inlets, an air inlet adapted to communicate with said well, and valve means acting when in one position to close said second air inlet and establish communication between one of said passageways and said well, and acting when in another position to cut off communication between one of said passageways and the well and open communication between the second air inlet and the well whereby fuel from the well may be discharged through another passageway into the mixing chamber.

8. A carburetor comprising a mixing chamber, main air and fuel inlets to said mixing chamber, a fuel well, passageways leading from said fuel well into the mixing chamber independently of said main air and fuel inlets, an air inlet adapted to communicate with said well, and valve means acting when in one position to close said second air inlet and establish communication between one of said passageways and said well, and acting when in another position to cut off communication between said one passageway and the well and open communication between said second air inlet and the well whereby fuel from the well may be 'discharged through another of said passageways intothe mixing chamber, said valve means having an intermediate position whereby said second air inlet and one passageway are closed.

9. A carburetor comprising a mixing chamber, main air and fuel inlets to said mixing chamber, a fuel well, passageways leading from said fuel well into the mixing chamber independently of said main air and fuel inlets, one of said passageways being restricted, an air inlet adapted to communicate with said well, and valve means acting when in one position to close said second air inlet and establish communication through another of said passageways with said well, and acting wheny in another position to cut off communication between said other passageway and the well and open communication between said second air inlet and the well, whereby fuel from the well may be discharged through the restricted passageway into the mixing chamber.

10. A carburetor comprising a mixing chamber, main air and fuel inlets to said mixing chamber, a fuel well, passageways leading from' said fuel Well into the mixing chamber independently of said main air and fuel inlets, one of said passageways being restricted, an air inlet adapted to communicate with said Well, and valve means acting when in one position to close said second air inlet and establish communication through another of said passageways with said well, and

` acting when in another position to cut ofi' communication between said other passageway and the well and open communication between said second air inlet and the well, whereby fuel from the Well may be discharged through the restricted passageway into the mixing chamber, vsaid valve means having an intermediate position whereby said second air inlet and said other passageway are closed.

11. A carburetor comprising a mixing chamber, main air and fuel inlets to said mixing chamber, a fuel well, passageways leading from said fuel well into the mixing chamber independently of said main air and fuel inlets, one of said passageways being in constantcommunication with the fuel well, an air inlet adapted to communicate with said well, and valve means acting when in one position to close said second air inlet and establish communication through another of said passageways with said well, and acting when in another position to cut ofi' communication between said other passageway and the well and open communication between said second air inlet and the well whereby fuel from the lwell may be discharged through said constantly open passage into the mixing chamber.

12. A carburetor comprising a mixing chamber, main air and fuel inlets to said mixing chamber, a fuel Well, al passageway leading from said fuel well into said mixing chamber, said passageway being independent of said main air and fuel inlets, a calibration in said passageway and forming a chamber between said calibration and the communication between the passageway and said well, means to supply air to said second chamber, and a valve to control the supply of air to said second chamber to infiuence fuel How from said well whereby solid liquid fuel, or fuel and air, may be admitted through said passageway to said mixing chamber to modify the mixture supplied by said main fuel and air inlets.

13. In a carburetor, a casing having a mixing chamber, main air and fuel inlets to said mixing chamber, a fuel well, means to admit liquid fuel to said well, a discharge passageway from said well to said mixing chamber and subject to the suction effect of sub-atmospheric pressure in said mixing chamber, an air inlet leading to said well, and a valve operable to one posit-ion to close said discharge passageway and open said second air inlet, and operable to another position to close said second air inlet and said discharge passageway, and a second discharge passage leading from said well to said mixing chamber and acting to discharge fuel from said well when said first-named passageway is closed.

14. In a carburetor, a casing having a mixing chamber, main air and fuel inlets to said mixing chamber. a fuel well, means to admit liquid fuel to said well, a discharge passageway from said well to said mixing chamber, a second discharge passageway from said well to said mixing chamber, both of said passageways opening into said chamber above said m'ain inlets and being open to suction effect of sub-atmospheric pressure in said mixing chamber, an air inlet to said second passageway and said well, and a valve to control said second air inlet and control disido ies

4charge of fuel from said well through said passageways to the mixing chamber.

15. In a carburetor, a casing having a mixing chamber, main air and fuel inlets to said mixing chamber, a fuel well, means to admit liquid fuel to said well, a discharge passageway from said well to said mixing chamber, a second discharge passageway from said well to said mixing chamber, an air inlet leading to said well, and a valve to control said second air inlet and one of said passageways and operable to cut off the air supply through said second air inlet and subject both said passageways and said well to the suction of the mixing chamber whereby liquid fuel will be drawn from the well through both said passageways into the lnixing chamber.

16. In a carburetor, a casing having a mixing chamber, main air and fuel inlets to said chamber, a plurality of passageways independent of said main inlets and opening into said mixing chamber, said passageways being open to suction effect of sub-atmospheric pressure in said mixing chamber, means to supply liquid fuel to said passageways, means to supply air to certain of said passageways and said fuel supply means, and a valve dcvice including provisions serving when said valve device is in one position to open one of said passageways to establish communication between said liquid fuel supply means and the mixing chamber, and to cut off air supply through said means to supply air to said passageways and said fuel supply means, and when said valve device is in another position to close communication between one of said passageways and said liquid fuel supply means and admit air from said means to supply air to another of said passageways and said liquid fuel supply means.

17. A carburetor comprising a mixing chamber having a throttle controlled'outlet,

'main air and fuel inlets to said chamber.

valve means controlling said inlets. the position of said means being determined by the sub-atmospheric pressure in said chamber, the pressure decreasing as the throttle is moved toward full open position, a restricted passageway leading into said chamber and subject to the suction effect in the mixing chamber, a fuel well communicating with said passageway, an air inlet to said passageway and the well to place the well under substantially atmospheric pressure, said passageway and the opening from said air inlet to said passageway being so proportioned that the pressure in said chamber attending part open throttle will be ineffective to draw fuel from said well but lower sub-atmospheric pressure attending wider open throttle will draw a mixture of fuel and air from said passageway, a second passageway from said well to said chamber, and means controlling said second passageway and said second air inlet and operable to open said second passageway and close said second air inlet whereby a charge of liquid fuel will be'drawn from said well through both said passageways into said chamber, said means being also operable to close said second air inlet and said second passageway whereby liquid fuel will be drawn through said restricted passageway into said chamber, and said means being also operable to close said second passageway and open said second air inlet whereby air and fuel will be drawn through said restricted passageway at lower sub-atmospheric pressure in said chamber.

18. A carburetor comprising a mixing chamber having a throttle controlled outlet, main air and fuel inlets to said chamber, valve means controlling said inlets, the position of said means being determined by the sub-atmospheric pressure in said chamber, the pressure decreasing as the throttleis moved toward full open position, a restricted passageway leading into said chamber and subject to the suctionfect in the mixing chamber, a fuel well communicating with said passageway, an air inlet to said passageway andv the well tc place the well under substantially atmospheric pressure, said passageway and the opening from said air inlet to said passageway being so proportioned that the pressure in said chamber attending part open throttle will be ineffective to draw fuel from said well but lower sub-atmospheric pressure attending wider open throttle will draw a mixture of fuel and air from said passageway, a second passageway from said well to said chamber, and means controlling said second passageway and said second air inlet and operable to open said second passageway and close said second air inlet whereby a charge of liquid fuel will be drawn from said well through both said passageways into said chamber, said means being also operable to close said second air inlet and said second passageway whereby liquid fuel will be drawn through said restricted passageway into said chamber, and saidmeans being also operable to close said second passageway and open said second air inlet whereby at sudden lower sub-atmospheric pressure in said chamber liquid fuel will be drawn from said well through said restricted passageway and upon maintenance of lower sub-atmospheric pressure in said chamber air and fuel will be drawn through said restricted passageway.

In testimony whereof I have hereunto subi scribed my name.

WALTER H. WEBER.

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