US2098202A

US2098202A - Carburetor

Info

Publication number: US2098202A
Application number: US718800A
Authority: US
Inventors: Walter H Weber
Original assignee: Detroit Lubricator Co
Current assignee: Detroit Lubricator Co
Priority date: 1934-04-03
Filing date: 1934-04-03
Publication date: 1937-11-02
Anticipated expiration: 1954-11-02

Description

W. H. WEBER CARBURETOR Nov. 2, 1937.

2 Sheets-Sheet l INVENTOR whe@ hl: V2/(0u Filed April 5, 1954 am )du ATTORNEY Nov. 2, 1937. W, H WEBER 2,098,202

CARBURETOR Filed April 3, 19254 2 Sheets-Sheet 2 @Mam/KM MATTORNEY Patented Nov. 2, 1937 cAnBUnE'roR Walter H. Weber, Detroit, Mich., 'assignor to Detroit Lubricator Company, Detroit, vMich., a corporation oLMichigan Application April s, 1934, serial No. 718,800 l as claims; (ci. `zel-39) My invention relates to new and useful improvements -in carburetors for supplying-a mixture of fuel and air to an internal combustion engine.

An object of my invention is to provide a carburetor having automatic means responsive to temperature for controlling the ratio of fuelto air supplied by the carburetor to the engine.

Another object is to provide a carburetor -having means to supply the necessary rich fuel mixture for engine starting operation and which will act automatically to decrease the ratio,V of fuel to air supplied by the'carburetor when the engine has fired and is operating under its own power.

10 'Another object is to provide throttle by-pass means for supplying fuel mixture from the main air and fuel inlets to the engine whenthe throttle valve is in substantially closed position.

Another object is to provide thermostatic means for controlling the by-pass means and for controlling the fuel-air ratio supplied by the main air and .fuel inlets.

Another object is to provide a thermostat of novel construction for controlling the carburetor operation.

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, to be taken as a part of this specication, I have fully and clearly illustrated a preferred embodiment of my inventio`n, in which drawings- Figure 1 is a top plan view of a carburetor and the thermostatic control means of my invention;

Fig. 2 is a view of the carburetor in vertical central section, but with the thermostat and a portion of the inlet and exhaust manifolds in elevation;

Fig. 3 is a detail view in vertical central section,

showing the position of certain of the parts when .the engine has warmed up to normal running or containing an air inlet chamber 3 separated by a wall or partition 4 from a constant level fuel reservoir or chamber 5. The air inlet chamber 3 has a substantially horizontal air inlet 6 opening laterally thereinto and has a substantially rectangular outlet opening 1 in the top wall of the member 2. The reservoir 5 is provided with a fuel inlet connection 8 controlled by the usual oat operated valve mechanism 9 which serves to maintain the liquid level in the reservoir substantially at the line L-L, Fig. 2. Supported on the top wallof the air inlet member 2 there is a throttle body member IIJ having an internally rectangular lower portion I I which registers with and conforms to the opening 1. The members 2 and I0 are rigidly secured together in any suitable manner as by bolted cooperating flanges or the like, notvshown. The rectangular throttle .body portion II forms the lower or inlet part of the mixing chamber I2 having an outlet I3. Within the upper internally cylindrical part ofthe throttle body member I8 there is a throttle valve I4 of the disk or buttery type mounted on a shaft I5 journaled in the side walls of the member I8. One end of the shaft I5 projects through the`wall of member Ill and is provided with an operating lever I6. The reservoir 5 communicates through a port I1 in the wall 4 with the interior of a hollow housing member I 8 which extends upwardly from the bottom wall of member 2 within the air inlet chamber 3 and concentric with the mixing chamber I2. The housing member I8 contains av dash-pot chamber I9 within which there is a dash-pot piston 29 having a hollow stem or rod 2I which extends upwardv through the top wall of the chamber 20 and through a tubular guide sleeve 22 which extends upward from the top wall of the housing member; I8. The upper end portion of the rod 2| which extends above the upper end of the guide sleeve 22 has a nozzle head 23 rigidly fixed thereon. The bottom end of the housing I8 opens, as at 24, through the bottom wall of the member 2 and receives a closure plug 25 in which is adjustably mounted a tapered metering pin or fuel controlling valve 26. The piston rod 2| -has a longitudinally extending fuel passage 21 which opens downward through the bottom face of the piston 20 and which receives the metering pin 26, the passage being restricted at its inlet end, as at 28, to provide a fuel port cooperable with the metering pin 26. 'I'he upper end of the passage 21 is provided with a main fuel jet or orifice 29 which determines the maximum fuel iiow through the passage 21. Within the dash-pot chamber I9 there is a helical coil spring 30 which surrounds the rod 2| andvwhich is held under' compression between the top face of the piston of the nozzle member comprising stem 2l and head 23 relative to metering valve 2B. Positioned in the air outlet opening 1 adjacent the opposite sidewalls thereof transverse to inlet I, there are parallel shafts 3l supported at their opposite ends in the side walls of casing member 2. Journaled on the shafts il there are cooperable suction operated, upward opening valve members 32 which are substantially rectangular and which extend upward toward each other for cooperable edge engagement, as at I3. to substantially close communication between the air inlet chamber I and the mixing chamber I2. 'I'he valve membersl2 have their vertical side edges which are transverse to shafts. 3l in substantial engagement with their adjacent front and rear side faces of the rectangular portion Il lto prevent air now around the sides of the valve members. The nozzle head 23 extends into an aperture 34 through the meeting edges of the valve members 32. The cross-sectional area of the aperture I4 is slightly larger than the portion of the head 23 which extends thereinto so as to permit a minimum amount of air to pass from the chamber l to the chamber I2 around the discharge end of the nozzle member when the valve members are in closed position. Each of the valve members I2 is provided with an operating arm I5 projecting from its underface adjacent its supporting shaft 3l. The arms 35 extend toward each other and have their free ends engaged in a circumferential recess 3i formed in the nozzle head 23 so that the nozzle member and dash-pot piston 2U are operatively connected to the valve members for movement thereby. The dash-pot piston 20 and spring n act'jointly to resist upward opening movement of the valve members 32 in response to suction in the mixing chamber I 2 so that the desired ratio of fuel to air from the main inlets 29 and l will be maintained for normal operation. Journaled through a side wall of the throttle body portion II there is a loading lever 31 having one end 38 engageable with the top face of one of the valve members 32 so as to oppose opening movement of the valve members which are operatively connected together by their arm engagement with the nozzle head 23. The external end I9 of lever 31 is connected by a link or rod 4II to temperature responsive means 4I. In its preferred embodiment, the means 4I co'mprises a spiral coil bimetal thermostat which is rigidly supported intermediate its ends, as' at 42, by a post 43 which is preferably rigidly secured at one end in a wall of the exhaust manifold 44. 'Ihe post 4I may be slotted, as at 45, to receive one of the intermediate convolutions of the coil which may then be riveted, as at 46, or-otherwise secured in the slot. The link or rod 40 is connected, as at 41, to the end of the outer turn or convolution of the coil so that the resilience of the coil acts through the lever 31 to exert a spring load on the valve members I2 in accordance with temperature. The inner free end of the thermostat coil is secured, asat 48, to a shaft 49 having an operating arm or crank 5l ilxed thereon. The outer end portion of the shaft 49 between the lever 5I and the thermostat 4I is journaled in a bracket arm 50* which is rigidly secured, as at 50h, to the wall of the exhaust manifold 44. The arm 50 is provided with a connecting rod or link 5I for a purpose to be described.

The throttle body member I0 supports a housing I2 which projects externally 'from the side wall of member II. The housing 52 contains a vertically positioned, cylindrical valve chamber I3 in which a hollow valve member 54 is ntted and supported for rotary movement. The valve member has an operating, stemllfprojecting concentrically from' its4 upper end face through an aperture in the top wall of the housing l2. Rigidly secured on the external top end of the stem 54* there is a lever arm or crank B4'J which is pivotally secured, as at 54, to the end of the thermostat connecting rod Il. The valve member I4 is supported and held in chamber I3 by a screw Il which is threaded through the wall of the housing l2 and has its inner end projecting into a circumferential groove in the upper portion of the valve member I4. The bore of `the valve chamber I3 is in communication with the mixing chamber I2 by a by-pass inlet conduit 51 having its inlet end opening into the mixing chamber below or on the inlet side of the throttle plate I4 and preferably midway between the ends of the throttle shaft I I. The bore of chamber 53 is also in communication with the outlet I2 by means of a by-pass outlet conduit 5l opening into the outlet I3 onA the discharge side of the throttle valve I4 and preferably vertically above the inlet to conduit 51. The valve member 54 has an internal vertical fluid chamber II closed at its lower end by a hollow plug I0 having its upper inner. end open so that the interior of the plug forms the lower or inlet part of the chamber i.. The upper annular end face of the plug Il within chamber 59 is provided with an annular, rib or bead defining a valve seat Il. Within the upper or outlet portion of the chamber l59 there is a v valve 62 preferably a light circular plate or disk which is adapted to seat on the valve seat BI and to cut on communication between the lower and upper portions of the chamber il. I'he valve l2 is normally urged to its seat by a. helical coil spring positioned in the upper portion of the chamber i! and bearing at one end against the upper end wall of chamber 59 and at its other end on the top face of the valve disk l2. The valve member 54 has through its side-wall and the wall of plug 60 a by-pass inlet port 84 which opens into chamber 59 below or on the inlet side of the valve disk i2, the port 64 being movable into and out of registry with the outlet conduit 58 upon rotation of the valvemember 54. The side wall portion of the valve member 54 adjacent the port il serves as a valve to control the outlet conduit Il. The ports 84, are preferably of substantially the same flow area and are simultaneously movable out of communication with conduits 51, 5l respectively upon rotation of the valve member 54. The fuel reservoir 5 is open to atmosphere through an inlet passage I6 above the normal liquid level.

Within the reservoir I there is an atmospheric fuel well 61 having a calibrated fuel inlet port 6I through its side wall adjacent its lower end and supplied with fuel from the reservoir 5. Through the side wall of the well 01 above the normal liquid level and adjacentv its upper end, there is an air bleed port or inlet I! from the reservoir 5 so that the surface 'of the liquid in the well l1 is subjected to atmospheric pressure. 'I'he open top end of the well 61 is closed by a plug member 1l which extends through an aperture in the fuel reservoir cover member 1I. A supplemental fuel discharge tube 12 extends downward through the plug memberv 10 into the well 81 and has its bottom end which Vco is open terminating adjacent'the bottom wall of the well and above thel fuel inlet port 68. The tube 12 extends upward from the lreservoir 5 and has its upper end fitting tightly, as at 13, within the inlet end of a duct 14 in the wall of housing 52. The outlet .end 15 of duct 14 opens into the bore of chamber 53 above the plane of the valve seat 6I. Through the side wall of the valve member 54 there is a fuel port 16 which opens into chamber 59 above valve seat 6I and which is registerable with the duct outlet 15, preferably be-y ing positioned diametrically opposite the outlet port 65. The side wall portion of the valve member 54 adjacent the port 16 serves as a valve to control discharge from duct outlet 15 into the chamber 59. The open ended bore 11 of tube 12, the duct 14, and the outlet conduit 58 together provide a supplemental fuel supply conduit leading from the well 61 and discharging into the carburetor outlet I3, this conduit being controlled by the valve member 54. Rotation of the valve vmember 54 will close the duct outlet 15 during the rst part of its rotation and substantially vbefore the valve ports 64 and 65 have begun to move out of full registry with their respective conduits 51 and 58, see Fig. 5.

The operation of my carburetor is as follows: In the position of the parts shown in Figs. 1 and 2, the engine which is not running is cold so that the thermostatic means 4I has moved the valve member 54 to establish communication through the supplemental fuel supply conduit including the valve chamber 59 between the well 61 and the outlet I3 and to open the by-pass conduits51, 58 to the chamber 59 respectively below and above the closed valve 62 from the mixing chamber I 2 and to the outletIS respectively. The thermostatic means 4I has also pulled upward on rod 40 to resiliently urge the loading lever end 38 into engagement with the top face-of its closed valve member 32. If the engine is now cranked for starting with the throttle valve I4 in substantially closed warm engine idling position, the suction induced in the mixing chamber I2 beneath the throttle valve will ne substantially ineffecvtive to draw any fuel from the main fuel inlet 29.

However, this engine cranking suction will be transmitted through by-pass outlet 58, the open valve ports 65 and 16, duct 14 and tube core 11 to the fuel well 61 and will draw solid liquid fuel from the well into the outlet I3 whereit will mix with such air asv can pass through aperture 34 and around the edge of the substantially closed throttle valve for discharge to the engine -cylinders. The spring 63 holds the valve 62 closed at low or cold engine cranking speeds so that no air can pass to outlet I3 through the by-

pass passage

51, 59, 58. This exceedingly rich priming charge or mixture will continue to be supplied to the engine until the well 61 has been emptied to the level of the bottom inlet end of tube 12 unless prior thereto the engine starts running so that the suction in the outlet I3fand acting on closed valve 62 is sufficient to lift valve 62 against the force of spring 63 to open the by-pass passage around the throttle valve I4, so that the volume of mixture will be increased and the ratio of fuel to air will be decreased to`the proper ratio to maintain cold engine idling operation. When the well 61 is emptied to the bottom inlet end of tube 12, then the well will discharge an emulsion of fuel entering through port 68 and air entering through bleed'iport 69 -whether or not the engine has started running and until the duct outlet 15 is closed. As soon as the engine fires and is operating under its own power or the suction induced in chamber 59 reaches say two inches of 'mercury vacuum for which spring 63 is prefand air from aperture 34, the valve members 32 being held closed by the loading lever 31, will pass into chamber 59 through by-pass inlet 51 and mix in chamber 59 with the supplemental fuel from the well 61 to decrease the richness of the fuel charge supplied to the engine suiilciently to prevent stalling thereof. The thermostatic means 4 Il will respond quickly to engine operation as it is positioned closely adjacent the exhaust manifold and when the thermostat has warmed up to say sixty or seventy degrees F., the thermostat end 48 will have rotated sufficiently in a counterclockwise direction facing Fig. 2 to act through the rod 5I to turn valve member 54 to close duct outlet 15. This operation of the thermostat effects a gradual tapering olf of the quantity of supplemental fuel supplied from the well 61 with a consequent decreasing of the richness of the fuel mixture supplied to the engine. Simultaneously with the operation of valve member 54 by the thermostat to clcse duct outlet 15, the tension in the outer turns or convolutions of the thermostat coil will decrease, so that the valve members 32' can open more freely against the decreasing resilient force of the thermostat end 41 on lever 31 which will result in an increase in the quantity of air admitted to the mixing chamber from inlet 6 and a decrease in the ratio of fuel to air supplied to the mixing chamber 4I2 from air inlet 6 and fuel inlet 29 for a given mixing chamber suction. 'Ihe position of the by-pass control means when the thermostatic means has acted as above described is shown in. Figs. 4 and 5. As the temperature of the therinostatic means 4I increases due to Arunning of the engine, the thermfc-stat end 48 will continue its counterclockwise movement pushing on rod 5I and gradually rotating the valve member 54 to close the by-pass passage, as shown in Fig. 3. As the by-pass passage has its effective flow area gradually decreased, the quantity of fuel mixture from the main air and fuel inlet supplied to the engine will becrease until the engine reaches normal operating temperature, when the by-pass passage will be ccsed by rotation of valve member 54 so that the fuel mixture supplied to the engine will be only that passing around the edge of the substantially closed throttle valve I4. During the rotation of the valve member 54, the outer turns or convolutions of the thermostat coil will also be warming up, so that the tension of the thermostat end .41 on rod 40 and lever 31 will be gradually decreasing. The resilient spring load of thermostat end 41, will continue to be exerted on the closed valve members 32 aftervalve member 54 has been rotated to close the by-pass passage; but with a few degrees increase of temperature after the by-pass passage is closed, the thermostat end 41 will begin to move downwardand lift lever end 38 away from its valve member 32. If the throttle valve is opened while the Athermostat end 41 is acting through its lever 31 to resiliently load the valve members32 and oppose with piston 28 and spring 30' the opening movement of the suction responsive valve members mixing chamber I2 from the main fuel inlet 29 and air inlet 6 will be increased to provide a mixture which is richer in fuel than the normal operating mixture. As the valve members 32 swing outwardly away from each other in response to"`mixing chamberlsuction to open com munication between the air inlet chamber 3 and the mixing chamber I2, the arms 35 will lift the hollow rod 2| relative to the 'fuel metering pin 26 so that the be increased as the air admitted to the mixing chamber is increased. lThe resistance of thermostatic means 4I to opening movement of the valve members 32 in response to engine suction will be gradually decreased as the engine warms up so that the richness of the mixture from the main inlets will gradually decrease for any given mixing chamber suction. es

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

1. A carburetor of the character described, comprising a casing having a mixing chamber with main air and fuel inlets and a mixture outlet, valve 'means responsive to mixing chamber suction and controlling admission of air to said chamber, a thermostatically controlled supplemental fuel supply means operable to discharge fuel at sub-normal engine operating temperatures, a thermostatically controlled loading means for said valve means, said first-named and said second-named thermostatically controlled means acting simultaneously to regulate the ratio of fuel to air discharging from said outlet, the resistance exerted by said loading means decreasing upon' engine temperature increase as discharge from said supplemental means is decreased, and said loading means being so constructed as to resist opening movement of said valve means after discharge .ceases from said supplemental means.

2. A carburetor of the character described, comprising a casing having a mixing chamber with main air and fuel inlets and a mixture outlet, valve means responsive to mixing chamber suction and controlling admission of air to said chamber, means engageable with said valve means to resist opening movement thereof, a thermostat rigidly supported intermediate its ends,means operatively connectingione end of said thermostat to said resisting means, supplemental fuel supply means discharging into said outlet, a valve controlling said supplemental means, and means operatively connecting the other end of said thermostat to said last-mentioned valve. I

3. A carburetor of the character described, comprising a casing having a passageway therethrough with'main air and fuel inlets, a thermostat supported intermediate its ends, one end of said thermostat controlling the ratio of fuel and air supplied by said main inlets, and supplemental fuel supply means discharging into said passageway, the other endA of said thermostat controlling said supplemental means.

4. A carburetor of the character described, comprising a casing having a passageway therethrough with main air and fuel inlets, a throttle valve controlling the outlet from said passage- Way, said casing having a by-pass passage-around said throttle valve, a valve member controlling said passage, a suction responsive valve controlling said passage, and supplemental fuel supply means discharging into said passageway on the outlet side of said throttle valve, said valve member also controlling said supplemental means.

5. A carburetor of the character described, comprising a casing having a passageway therefuel supplied to the jet 29 will valve controlling the outlet from said passagef way, said-casing having a by-pass passage around said throttle,A valve, a valve member controlling said passage. a suction responsive valve controlling said passage, supplemental fuel supply means discharging into said passageway on the outlet side of said throttle valve, said valve member also controlling said supplemental means, and a thermostat controlling said valve member.

'7. A carburetor of the character described, comprising a casing having-'a passageway therey through with main air and fuel inlets and a mixture outlet, a throttle valve controlling said outlet, a fuel reservoir supplying `said fuel inlet, a fuel well open to atmosphere and supplied with fuel from said reservoir, a conduit leading from said well below4 the normal fuel level and discharging into said passageway on the outlet side of said throttle valve, a by-pass passage leading from and to said passageway around said throttle valve, a valve member controlling said passage and fuel flow through said conduit, said valve member acting to stop discharge through through said conduit prior to complete closure of said passage, and a suction responsive valve co'ntrolling flow through said passage.

8. A carburetor of the character described, comprising a casing having a passageway therethrough with main air and fuel inlets and a mixture outlet, a throttle valve controlling said outlet, a housing having a valve chamber, an inlet conduit to said chamber from said passageway on theinlet side of said throttle valve, an outlet conduit from said chamber to said passageway on the outlet side of said throttle valve, a suction responsive valve in said chamber and controlling flow from said inlet conduit to said outlet conduit, a fuel reservoir, a fuel supply conduit leading from said reservoir to said chamber on the outlet side of said suction responsive valve, and valve means in said chamber operable to close said fuel conduit and subsequently to cut off communication between said inlet conduit and said outlet conduit.

9. A carburetor of the character described, comprising a casing having a passageway therethrough with main air and fuel inlets and a mixture outlet, a throttle valve controlling said outlet, a housing having a chamber and supported externally by said casing adjacent said throttle valve, a conduit leading from said passageway on the inlet side of said throttle valve to said chamber, a conduit leading from said chamber to said passageway on th'e outlet side of said throttle valve, a hollow valve member in said chamber and having ports simultaneously'registerable with said conduits, a suction operated valve in said valve member and controlling flow from said inlet conduit to'said outlet conduit, a fuel supply conduit opening into said chamber, said valve memberhaving a port on the outlet side of said suction operated valve and registerable with said 'fuel conduit, and an atmospheric fuel well supplying said fuel conduit.

10. A carburetor of the character described,

5 comprising a casing having a passageway therethrough with an air inlet and a mixture outlet, means to supply fuel to said passageway, valve means responsive to engine suction and controlling ow through said passageway, an arm journaled in and extending through a wall of said casing and having a portion movable into the path of and engageable with said valve means to resist opening movement thereof, and temperature responsive means operable to move said arm into position to resist opening movement of said valvc means.

11. A carburetor of the character described, comprising a casing `having a passageway therethrough with main air and fuel inlets, a bimetal thermostat rigidly supported intermediate its ends, one end of said thermostat controlling the ratio of fuel and air supplied by said main inlets, and supplemental fuel supply means discharging into said passageway, the other end of said thermostat controlling said supplemental means.

12. A carburetor of the character described, comprising a casing having a passageway therethrough with an air inlet, fuel supply means discharging into said passageway, a valve controlling said fuel supply means, valve means responsive to engine suction and controlling said air inlet, and a thermostat responsive to engine temperature and supported intermediate its ends, one end of said thermostat cooperating with said valve means to regulate the admission of air to said passageway, the other end of saidfthermostat cooperating with and operable to regulate said fuel valve.

13. A carburetor of the character described,

comprising a casing having a passageway therethrough with main air and fuel inlets, a throttle valve controlling the outlet from said passageway, said casing having a by-pass passage around said throttle valve, a valve controlling said passage, a suction responsive valve controlling said passage, supplemental fuel supply means discharging into said passageway on the outlet side of said throttle valve, a valve controlling said supplemental means, and a bimetal thermostat rigidly supported intermediate its ends, one end of said thermostatA being operable to control said second-named-valve, the other end of said thermostat having operative connection to and for actuating said supplemental valve.

141 A carburetor of the character described,

comprising a casing having a passageway therethrough with main air and fuel inlets and a mixture outlet, means to regulate the air-fuel ratio supplied by said main inlets, a throttle valve controlling said outlet, a housing having a valve chamber, an inlet conduit to said chamber from said passageway on the inlet side of said throttle valve, an outlet conduit from said chamber to said passageway on the outlet side of said throttle valve, a suction responsive valve in said chamber and controlling flow from said inlet conduit to said outlet conduit, a fuel reservoir, a fuel supply conduit leading from said reservoir to said chamber on the outlet side of said suction responsive valve, valve means in said chamber operable to close said fuel conduit and subsequently to cut off communication between saidinlet conduit and said outlet conduit, and a thermostat responsive to ,engine temperature, means operatively connecting 75,.;Said thermostat and said ratio regulating means,

and means operatively connecting said thermostat and said last-named valve means.

15. A carburetor of the character described, comprisinga casing having a passageway-therethrough with main air and fuel inlets, a throttle L; valve controlling discharge of mixture from said passageway, said casing having a by-pass passage around said throttle valve, a suction responsive valve controlling flow throughisaid passage, a fuel supply conduit discharging into said passage n 1f; the outlet side of said suction-. valve, and val e means in said passage operable on movement to, close said conduit and subsequently to cut off* flow .through said passage.

16. A carburetor of the character described, 15 comprising a casing having a passageway therethrough with main air and fuel inlets and a mixture outlet, a throttle valve controlling said outlet, a housing having a chamber and supported externally by said casing adjacent said throttle 20 valve, a conduit leading from said passageway on the inlet side of said throttle valve to said chamber, a conduit leading from said chamber to said passageway on the outlet side of said throttle valve, a hollow valve member in said chamber and 25 having ports simultaneously registerable with said conduits, a suction operated valve in said valve member and controlling flow from said inlet conduit to said outlet conduit, a fuel supply conduit opening into said chamber, said valve mem- 30 ber having a port on the outlet side of said suction operated valve and registerable with said fuel conduit, and means to supply fuel to said main fuel inlet and to said fuel conduit.

17. A carburetor of the character described, 35 comprising a casing having a passageway therethrough with an air inlet, means to supply fuel to said passageway, a throttle valve in said passageway, said casing having a chamber and spaced ducts opening through said casing and communi- 4o catively connecting said chamber to said passageway on opposite sides of said throttle valve, a valve member in said chamber and operable to control flow through said chamber from and to said passageway around said throttle valve, and 45 means to supply fuel to said chamber for discharge through one of said ducts to said passageway, said valve member having a portion controlling admission of fuel from said last-named fuel supply means to said chamber. 50

18. A carburetor of the character described, comprising a casing having a passageway therethrough with an air inlet, means to supply fuel to said passageway, a throttle valve in said passageway, said casing having a chamber and ducts 55 communicatively connecting said chamber to said passageway on opposite sides of said throttle valve, a valve member in said chamber and operable to control flow through said chamber from and to said passageway around said throttle 60 valve, means to supply fuel to said chamber for discharge through one of said ducts to said passageway, said valve member having a portion controlling admission of fuel from said lastnamed fuel supply means to said cham-ber, and 65 temperature responsive means controlling said valve member. y

19.A)carburetor of the character described, comprising a casing having a passageway therethrough with an air inlet, means to supply fuel to 70 said passageway, a throttle valve in said passageway, said casing having a chamber and ducts communicatively connecting said chamber to said passageway on opposite sides of said throttle valve, a valve member in said chamber and operable to control ow through said chamber from and to said passageway around said throttle valve, means to supply fuel to said chamber for discharge through one of said ducts to said passageway, said valve member having a portion controlling admission of fuel from said lastnamed fuel supply means to said chamber, and temperature responsive means operable when cold to hold said valve member in position to maintain communication around said throttle valve through said chamber.

20. A carburetor of the character described, comprising a casing having a passageway therethrough with an air inlet, Ameans to supply fuel to said inlet, a liquid fuel reservoir supplying said means, a throttle valve controlling iiow through said passageway, said casing having a by-pass passage around said valve, said passage including intermediate its ends a chamber, a fuel ksupply conduit opening from said reservoir belo'w the liquid level therein and discharging into said chamber in spaced relationship to said passageway, and a valve member movable in said chamber, said valve member having one portion operable to close said conduit and having another portion spaced from said one portion and operable to close said passage.

21. A carburetor of the character described, comprising a casing having a passageway therethrough with an air inlet, means to supply fuel to said inlet, a throttle valve controlling flow through said passageway, said casing having a by-pass passage around said valve, said passage including a chamber, a fuel supply conduit discharging into said chamber, a valve member movable in said chamber, said valve member being operable to control discharge from said conduit to said passageway and to control flow through said passage, a valve controlling admission of air from said inlet to said passageway, and temperature responsive means controlling said air inlet valve and said valve member.-

22. A carburetor of the character described, comprising a casing having a passageway therethrough with main air and fuel inlets, a throttle valve controlling discharge of mixture from said passageway, said casing having a by-pass passage around said throttle valve, a suction responsive valve controlling flow through said passage, a fuel supply conduit discharging into said passage on the outlet side of said suction valve, and valve means controlling discharge from said conduit and being operable to cut of! flow through said passage.

2a. Ali. carburetor or the character amused.v

around said throttle valveand including a chamber, a valve member in said chamber having a passageway therethrough cooperable with and controlling said passage. a valve in and controlling said valveA member passageway and responsive to suction, and a conduit' for supplying fuel to said chamber, said valve member having a port operable to establish communication between said conduit and said chamber.

24. A carburetor of the character described, comprising a casing having a passageway therethrough with an air inlet, means to supply fuel to said passageway, a throttle valve in said passageway, said casing having a by-passl passage around said throttle valve and including a chamber, a valve member in said chamber having a passageway therethrough cooperable with and controlling said passage, a valve in and controlling said valve member passageway and responsive to suction, and a conduit for supplying fuel to said chamber, said valve member having a port opening into said chamber on the outlet side of said suction valve and registerable with said conduit.

25. A thermostatic carburetor control comprising a casing having a mixture passageway therethrough with air and fuel inlets, valve means controlling said air inlet, a throttle valve controlling the outlet from said passageway, a oonduit opening from and to said passageway around said throttle valve, means controlling ilow through said conduit, supplemental fuel supply means discharging into said passageway posterior to said throttle valve, means controlling said supplemental means, and temperature responsive means controlling said valve means, said conduit controlling means and said supplemental supply controlling means. said responsive means acting on decreasing temperature to resist with increasing force the opening movement of said valve means and simultaneously to move said conduit controlling means to establish flow through said conduit and also to move said supply controlling means to provide supplemental fuel discharge.

WALTER H. WEBER,