US1265515A

US1265515A - Carbureter.

Info

Publication number: US1265515A
Application number: US83215714A
Authority: US
Inventors: Charles L Rayfield
Original assignee: Individual
Current assignee: Individual
Priority date: 1914-04-16
Filing date: 1914-04-16
Publication date: 1918-05-07
Anticipated expiration: 1935-05-07

Description

C. L. RAYFIELD.

CARBURETER.

APPLICATION FILED APR- 16, I914.

Pawn May 7,1918.

2 SHEETS-SHEET l- G- L. RAKFIELD.

CARBURETER.

APPLICATION FILED APR. w. 1914.

w -..i|i y 7, 1918.

, .II/JIJIJI mi lillllltlll vvhf v llll " ans nn' r rent CHARLES L. RAYFIELD, OF CHICAGO, ILLINOIS.

CARBURETER.

To all whom, it may concern:

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

This invention relates to a carbureter of that class set forth in my prior application for patent Serial No. 789,730, filed September 15th, 1913, in which the parts are compactly arranged and involves a number of new principles of operation to insure a proper mixture for the engine at all speeds effecting an economy in fuel.

It is an object of this invention to construct a carbureter capable of instantly adjusting itself to sudden variations in load and in particular acting to supply'a rich mixture to the engine when the throttle is suddenly thrown into wlde open position whereby the engine may pick up in instant construct a carbureter wherein an intermeresponse to the movement of the throttle.

It is also an object of this invention to construct a carbureter wherein a sudden opening of the throttle resulting in a quick movement of the automatic air inlet valve, acts to force a charge of gasolene under pressure'into the carbureting chamber.

vIt is also an object of this invention to construct a carbureter. wherein a sudden opening of the throttle valve resulting in a sudden movement of the air inlet valve due to the draft of the engine, acts to increase the area of opening around a fuel valve and also to force a charge of fuel under pressure into the carbureting chamber of the device.

It is also an object of this invention to construet a carbureter in which a contracted valve member surrounds the point of admis sion of fuel to utilize a Venturi effect in drawing the fuel into the carbureting chamber.

It is also an object of this invention to construct a carbureter whereby movement of the automatic air inlet valve is transmitted to an intermediate valve member in the carbureting chamber, a part of which surrounds Specification of Letters Patent.

Patented May 7, 1918.

Application filed April 16, 1914. Serial No. 832,157.

the needle valve and acts to increase the area of discharge for the fuel from the needle valve.

It is also an object of this invention to construct a carbureter wherein an opening movement of the automatic air inlet valve of the engine is transmitted to an intermediate valve disposed in the carbureting chamber of the device, which in turn acts to increase the area of discharge from the fuel valve, and furthermore is connected to transmit movement to a piston in a dash pot chamber whereby a charge of fuel under pressure is pumped forcibly into'the carburet'ing chamber of the carbureter.

It is also an object of this invention to construct a carbureter provided with an intermediate valve in the carbureting chamber connected to be moved by movement of the automatic air inlet valve of the carbureter and with dash pot means acting to force a charge of fuel into the carburet-ing chamber with a sudden movement of said valves, and also acting to prevent fluttering of said valves with sudden successions of changes in the draft to the engine.

It is also an object of this invention to diate valve is mounted in the carbureting chamber and is actuatable partly by draft and partly by a positive connection with an automatic air inlet valve to cause opening of said intermediate valve with opening of said air valve.

It is also an object of this invention to construct a carbureter with an intermediate valve in the carbureting chamber thereof connected to vary the area of discharge leading from the needle valve by movement of said intermediate valve, and also connected to dash pot mechanism which prevents fluttering of said intermediate valve and as well, with a sudden movement thereof, serves to pump a charge of fuel under pressure into the carbureting chamber of the carbureter.

It is also an object of this invention to construct a stationary needle valve adjustably mounted to permit the proper setting thereof and-with a spring impelled tickler mechanism for increasing the opening of the needle "alve upon starting the motor.

It is furthermore an object of this invention to construct a carbureter wherein a spring impelled automatic air inlet valve is positively connected with an intermediate valve which is mounted co-axially around an adjustable stationary needle valve, and acts with movement to increase the outlet area for the fuel into the carbureting chamber flowing from said needle valve.

It is finally an object of this invention to construct a earbureter simple in operation and compactly assembled, adapting it to be used on practically any type of motor.

The invention (in a preferred form) is illustrated in the drawings and hereinafter more fully described.

In the drawings:

Figure 1 is a central vertical section taken through a carbureter showing the assembly of the parts.

Fig. 2 is a top plan view thereof. Fig. 3 is a section taken on line 3-3 of I Fig. 1.

Fig. 4 is a section taken on line 4-4; of Fig. 1, with parts omitted.

Fig. 5 is a sectional detail of the needle valve and its mounting.

Fig. 6 is a' detail of the needle valve adjusting means.

As shown in the drawings:

The carburetor embraces a float chamber 1, integral with which on one side thereof is formed a casing 2, affording a carbureting chamber. A partition or floor 3, extends through said carbureting chamber casing and opening thereabove through the side of said casing is an air inlet 4, into which an air inlet pipe 5, may be connected. Bolted upon the upper side of said float chamber and carbureting chambercasing is another casing 6, apertured to communicate with said carbureting chamber and provided with a partition 7 affording a closure for the float chamber.

A dash ,pot chamber 8, is formed on the lower end of he carbureting chamber easing 2, beneath the partition 3, and threaded therein is a plug 9, which is apertured to receive an elongated adjusting nut 10, supporting a part ofthe needle valve mechanism comprising a hollow needle valve seat 11.

Threaded on the lower apertured end of the float chamber 1, is a tubular member 12, which is provided with an inlet 13, for a fuel supply pipe. A plug 14, is threaded into the lower apertured end of said member 12, and fitted through said plug 14, is a pin 15, which, at its upper end, is provided with a plurality of passages 16, and is pointed to engage in and hold a circular screen supporting element 17, upwardly. Threaded on said supporting element 17, is a screen cage 18, which bears upwardly against the lower end of said float casing 1, and has a screen 19, fastened therearound. The purpose of this type of assembly is to permit the screening means for the fuel to be taken out and cleaned by merely unscrewing the plug 14, and of course adjustments may be made after the plug 1%, has been set in place by a rotation of the supporting pin 15.

The passages 16, are for the purpose of permitting an easy flow of fuel through and around the entire chamber afforded by the tubular element 12. Mounted within the carbureting chamber 2, is a double. conical intermediate valve 20, which is restricted at the point 21, thus providing a Venturi tube for the flow of air entering through the inlet pipe 5, and passing through the carbureting chamber. A hollow stem 22, extends axially through said intermediate valve 20, and is integrally connected thereto by a spider 23, at the upper end of said stem and valve. A disk 24, is also integral with said stem 22, and is spaced above the spider for a purpose hereinafter-pointed out. A sleeve 25, is threaded into said partition .3, at the bottom of said carbureting chamber, to afford a guide through which said hollow stem 22, slides, and secured on the lower end of said stem is a piston 26, which moves insaid dash pot chamber 8. An aperture 27 is provided near the lower end of said Valve seat 11, in order to admit fuel thereto from said dash pot chamber 8. Apertures 28, communicate through the side walls of said hollow stem 22, directly beneath an interiorly restricted portion 28, which, when the valve stem 22, is in its lowest position, rests tightly upon said seat member 11, but when said hollow stem 22, is elevated, permits a flow of fuel through said passages 28, into the interior of said stem.

A passage 29, is provided to communicate between the dash pot chamber 8, and the float chamber 1, to admit a supply of fuel to the dash pot chamber at all times. The upper end of said sleeve 25, is increased in diameter and coacts with the restricted portion of said intermediate valve 20, when the same is in its lowest position, to substantially close the passage therethrough. A plurality of apertures 30, are provided in said hollow stem 22, the majority of which are inclosed by said sleeve 25, when the stem is in its lowest position, but with an elevation of the stem and intermediate valve 20, therewith, not only is the passage for air opened up through the interior of said intermediate valve 20, as the same diraws away from the sleeve 25,'but also a greater number of the apertures 30, in said stem are withdrawn from within said sleeve 25, to increase the area for discharge of the fuel, which flows upwardly through the stem 22, entering the same at said passages 28, as

well as through the needle valve member 11.-

with the carbureting chamber and intermediate valve, is a bushing 31-, having a cam 32, forming the upper surface thereof. A lever33, complementally recessed to engage over said cam surface 32, is mounted upon said bushing and-held rotatably in position thereon by a sleeve 34, engaging around the boss on the casing and said lever 33. The sleeve is held rigidly in position by means of a set screw 35, which also engages through and into the bushing 31, to also hold the latter from movement.

Threaded through said lever 33, and extending downwardly and axially through said bushing 31, is an elongated tubular member 36, which is provided with a fluted head 37, at its upper end to permit adjustment thereof in said lever 33. A detent 38, is also provided, mounted on said lever 33, and bears against said fluted adjusting head 37, to hold said tubular member in any desired adjustment. A plug 39, is threaded into the upper end of said head 37, to aiford a stop for one end of a coiled helical spring 40, contained within said tubular member. At its lower end said tubular member 36, is restricted to receive adjustably therethrough a needle valve stem 41, with a ball 42, on the upper end thereof to hold the same movably within said tubular member, said spring 40, acting to impel the needle valve downwardly at all times with the ball engaged in said restricted lower end of the tubular element. A nut or washer 43, is secured upon the exterior lower end of said tubular element 36, and affords a stop for a coiled spring 44, which at its, upper end projects within said bushing 31, and bears thereagainst to hold said lever 33, and elementmounted therein downwardly in position.- The lower end of the stem 41-, is-re stricted and tapered to aflord a needle valve closure 45, adapted to project into the tubular seat member '11, to control the quantity of fuel flowing therefrom. The tubular member 36, which carries the needle valve being adjustable in said lever 33, permits.

the needle valve to be set into any stationary position desired, but when it is desired to start the engine to permit a rich inflow of fuel through the carbureter, the lever 33, is actuated, causing the same to be elevated by the interaction of the cam surfaces, thus lifting the tubular member 36, and needle valve therewith.

A tubular member 46, is threaded into the partition 7, co-axially communicating into the float chamber 1, to receive slidably therein a stem 47, on which is slidably mounted a spun copper float 48. The lower end of said stem 47, is ground to a point 49, forming a needle valve which projects into a sleeve member 50, threaded co-axially into the lower end of said float chamber 1, thus affording a guide for said stem and float in gay,

their movement and at the same time with an upward movement of said stem 47 admitting a flow of fuel into the float feed chamber 1.

Downwardly projecting lugs 51, are formed on the under side of said partition 7 in said float chamber 1, and pivotally mounted ineach thereof are weighted levers 52, the outer ends of which rest upon the float 48, and the inner ends of which engage in a grooved collar 53, rigidly secured upon said stem 47. It is apparent therefore that when the level of the fuel within the float chamber drops, the float moves downwardly by gravity and the outer end of the weighted levers moving therewith, the inner end of said levers 52, engaged in said collar 53, elevate the same and the stem 47 therewith, thus admitting more fuel into the float chamber by opening the needle valve 49.

An air inlet valve 54, is slidably mounted upon the upper end of said stem 46, and is normally held in closed position against an adjustable threaded inlet 55, by means of a coiled spring 56, which is wound about said stem 46, and at its lower end bears against a boss on said partition 7. A spring impelled detent 57, is mounted on the casing 6, and bears against the fluted surface of said inlet 55, to hold the same in any desired adjusted position, whereby the spring tension on said inlet valve 54, may be varied as desired.

A pivot shaft 58, extends through the casing 6, and journaled thereon is a lever 59, one end of which is provided with a yoke 60, which engages around the spring 56, and upwardly beneath'said valve 54, and the other end of which is provided with a yoke 61, which engages beneath said disk 24, above said spider 23, on said intermediate valve in the carbureting chamber of the carbureter.

It is readily apparent therefore that with a sudden draft through the carburetor, as when the throttle valveis quickly opened, the air inlet valve 54, will be depressed, and by means of the lever 59, will eause an elevation of the intermediate valve 20. The sudden actuation thereof causes an augmentation of pressure within the dash pot chamber 8, by the piston 26, forcing the fuel into'the hollow stem 22, through the passages 28, and thence upwardly and outwardly through the outlet ports 30, into the carbureting chamber.

" A butterfly throttle valve 62, is mounted end of said lever 64, and is adapted to contact said stop to limit the movement of the butterfly valve 62, as desired. An attaching flange 67, is formed integrally with the eas- 5 ing 6, beyond the throttle valve 62', to permit attachment of the carbureter to the intake valve 20, within the carbureting chamber the hollow stem 22, is elevated therewith, thus causing an augmentation of pressure within the dash pot chamber 8, and a flow of fuel takes place therefrom through said hollow stem 22, upwardly through the same and out through the apertures 30, into the carbureting chamber, and passes to the manifold of the engine, forming a part of a very rich mixture necessary in accelerating the speed of the engine. It is apparent, by reference to Fig. 1, that when the tubular valve stem 22, is elevated that the fuel ports or passages 30, are successively withdrawn from the sleeve 25, thus increasin the area through which the fuel may be discharged into the carbureting chamber. When the intermediate valve 20, is in its lowest position, that is seating upon the casing 2, the passage around the needle valve element 11, within said tubular stem 22, is closed by the restricted portion 28, of said tubular element 22, and consequently all the fuel admitted to the carbureter for use, flows upwardlythrough the valve element 11. The amount of fuel flowing is dependent upon the adjustment of the needle valve closure 45.

When the intermediate valve 20, moves upwardly, the air not only flows around the exterior thereof into the casing 6, but inasmuch as the restricted portion 21, moves away from the enlarged upper end of the sleeve 25, the area of assage through the interior of said valve e ement 20, is greatly increased, so that the quantity of air ad mitted is augmented proportionate to the area of the fuel discharge or to the amount of fuel admitted into the carbureting chamber. It is obvious that the intermediate valve 20, due to draft created through the carbureter, may move upwardly, causing the yoked end 60, of the lever 59, to move downwardly without causing an opening of the automatic inlet valve 54, providing the spring 56' is under sufficient initial stress. 60 However, the automatic inlet valve 54, can not possibly open without transmitting such movement to the intermediate valve 20.

The carbureting chamber of the carbureter may receive a charge of fuel by actuating the lever 33, which causes an elevation of the valve stem 41, and needle valve 45, upon which the spider 23, of said intermediate valve 20, is slidably mounted, and this rich supply of fuel is desirable in starting the engine. The adjustment of the needle valve does not change with changes in operation of the carbureter, but is determined by the setting of the head 37.

I am aware that various details of construction may be varied through a wide range without departing from the principles of this invention. I therefore do not purpose limiting the patent granted otherwise than necessitated by the prior art.

I claim as my invention: 0

1. In a carburetera float chamber, a carbureting chamber adjacent thereto, a movable Venturi valve mounted in said carbureting chamber, a dash pot connected therewith to prevent fluttering thereof, a passage com- 5 I municating with said dash pot and said float chamber to admit a flow of fuelv into said dash pot, an automatic air valve disposed above said float chamber, and connections between said a1r valve and said Venturi 9 valve to cause a movement of the latter with movement of the former.

2. In a device of the class described a float chamber, a carbureting and mixing chamber arranged adjacent thereto, a Venturi valve mounted in said carbureting chamber, a a hollow valve stem connected with said Venturi valve, a piston mounted on the lower end of said stem, a dash pot containing a supply of fuel in which said piston moves, apertures in said hollow valve stem adapted to permit a flow of fuel through said stem and into the carbureting chamber, a needle valve mounted within said hollow stem, and an automatic air valve mounted on said carbureter and operatively connected with said Venturi valve to cause actuation of the latter with movement of the former.

3. In a device of.the class described a carbureter comprising a float chamber, a 1 0 carbureting chamber, a Venturi valve movable in said carbureting chamber, an automatic air valve mounted in said carbureter, and operatively connected to operate said Venturi valve'when said air valve is moved, 5 a hollow stem connected with said Ven turi valve, and a needle fuel supply valve mounted within said hollow stem to admit a flow of fuel into said stem and thence into the carbureting'chamber of the carbureter. 12

4. In a device of the class described a float chamber, a float therein controlling the supply of fuel thereto, a carbureting chamber adjacent said float chamber, a dash pot chamber mounted beneath said carbureting 125 chamber and communicating with said float chamber, a valve mounted Within said carbureting chamber, a piston in said dash pot chamber connected with said valve, passages leading from said dash pot chamber 130 a dash-pot associated with said fuel inlet adapted to regulate the closing movement of said fuel inlet means.

16. In a carbureter of the class described a carbureting chamber, adjustable fuel inlet means therefor, a main airinlet, a normally closed auxiliary air inlet valve, a normally closed supplemental air inlet mechanism associated with said auxiliary air inlet valve adapted to open said supplemental air inlet mechanism and enlarge the opening of said main air inlet and fuel inlet means by the opening movement of said auxiliary air inlet valve, and a dash pot adapted to retard the opening movement of said auxiliary air valve as well as retard the opening and closing of said main air inlet, supplemental air inlet mechanism, and fuel inlet means.

17. In a device of the class described a carbureting chamber, fuel inlet means, an air inlet valve, mechanism associated with said air inlet valve adapted to be actuated by the opening movement thereof to enlarge said fuel inlet means, and a dash-pot adapt.- ed to retard the opening movement of said air inlet valve and the opening and closing of said fuel inlet means.

18. In a carbureter a fuel valve, means tending to close said fuel valve, means for retarding the movement of said fuel valve, an auxiliary air valve, means connecting said auxiliary air valve and said fuel valve whereby the opening of said auxiliary air valve opens said fuel valve, but permits an independent closing movement of said auxiliary air valve.

19. In a carbureter a .fuel inlet valve, an air inlet valve, means adapted to open said fuel inlet valve when actuated by the opening movement of said air inlet valve, and means adapted to retard the closing of said fuel inlet valve while permitting a free closing movement of said air inlet valve.

20. In a carbureter of the class described, a float chamber, a carbureting chamber, a fuel inlet means to admit fuel into said carbureting chamber, mechanism for opening and closing said fuel inlet means, a spring resisted air inlet valve disposed at one side of said carbureting chamber and operatively connected with said mechanism to move the same to open said fuel inlet means coincidently with an opening movement of said air inlet valve, and a dash pot mechanism receiving fuel into one end thereof and connected for operation by opening movements of said air inlet valve to force fuel outwardly at the other end thereof under pressure in excess of normal through said fuel inlet means as the same is opened.

21. In a carbureter of the class described, a float feed chamber, a carbureting chamber, a dash pot chamber forming a part of the carbureter and at one of its ends in communication With said float feed chamber, a

fuel inlet adapted to admit fuel into the carbureting chamber and communicating with the other end of said dash pot chamber, means varying the opening of said fuel inlet means, and a piston in said dash pot chamber connected for operation with movement of said fuelinlet means to force fuel under pressure therethrough as the same opens.

22. In a carbureter of the class described, a float feed chamber, a carbureting chamber, a fuel valve adapted to admit fuel into the carbureting chamber, a Venturi tube around said fuel inlet valve, an air inlet admitting fuel around the exterior and through the interior of said Venturi tube, a spring resisted air valve, a dash pot chamber on said carbureter, a passage leading thereinto from said float feed chamber at one end of said dash pot chamber, a piston in said dash pot" chamber, and operative connections between said air inlet valve, said piston and said fuel valve whereby, as said air valve is opened, the piston is moved'in the dash pot coincident with an opening movement of the fuel valve to force fuel under pressure outwardly through said fuel valve.

23. In a carbureter of the class described, the combination with a carbureting chamber, a float feed chamber, a fuel valve to admit fuel into the carbureting chamber, a Venturi tube surrounding said fuel valve, an air inlet adapted to admit air around and into said Venturi tube, a dash pot, a piston therein. and connections between said piston and said fuel'valve whereby when the piston is actuated to force fuel through the fuel valve the fuel. valve opens coincidently with the movement of the piston.

24. In a carbureter of the class described, a carbureting chamber, a float feed chamber, a dash potassociated with the carbureter, a piston in said dash pot, a passage for admitting fuel into said dash pot from said float feed chamber on one side of said piston, a fuel valve in the carbureting chamber. means permitting passage of fuel from said dash pot into said fuel valve for ejection therethrough under pressure when said piston is moved in said dash pot chamber, and a Venturi tube around said fuel valve constructed to permit a flow of air around the exterior and through the interior thereof to be carbureted by the fuel introduced through said fuel valve.

25. In a carbureter of the class described, a fuel valve normally partly open tr admit fuel therethrough, a piston movable with the fuel valve adapted to pump fuel through said valve as the valve opens, means operated by the suction of the engine to automatically open said fuel valve and operate the piston, and an air inlet for the carbureter.

26. In a carbureter of the class described, a float feed chamber, a dash pot chamber, a

into said carbureting chamber whereby with the opening movement of the valve therein fuel is forced into said carbureting chamber under pressure, an air inlet valve disposed at one side of said carbureting chamber, and operative connections between said carbureting chamber valve and said air inlet valve.

5. In a device of the class described carbureting chamber, a Venturi valve mounted therein, a hollow stem connected to move therewith, a needle valve surrounded by said hollow stem to admit fuel into said stem, and a plurality of fuel ports in said stem leading into said carbureting chamber, part .of which are normally closed when said valve is seated but successively brought into open position to increase thearea for the flow of fuel from said needle valve into the carbureting chamber as said carbureting chamber valve is opened.

6, In a device of the class described, fuel supply means, a spring resisted air inlet valve connected thereto to positively open said fuel supply means correspondingly with said air valve, and mechanism interconnected for movement with said air valve in a direction opposite thereto to force fuel imder pressure through said fuel supply means as the same is opened.

7. In a carbureter of the class described, adjustable fuel inlet means adapted to be opened and closed, an automatic air inlet mechanism, a dash pot at one of its ends in communication with said fuel inlet means and containing fuel therein, a fuel inlet at the other end of said dash pot, a piston in said dash pot connected for operation by said automatic air inlet mechanism, and connections between said automatic air inlet mechanism and said piston whereby said fuel inlet means is opened when said mechanism opens whereby fuel is forced from said dash pot under pressure through said fuel inlet means.

8. In a device of the class described an automatic air inlet valve, fuel supply means, lever connections between said valve and said means to cause an opening of the latter with an opening of the former, mechanism for-returning said valve to closed position, and dash pot means associated with said fuel supply means toretard a closing movement thereof independently of said air valve.

9. In a carbureter of the class described, a spring resisted auxiliary air valve, a fuel supply nozzle disposed to receive air passed therearound admitted into the carbureter, a float valve chamber affording a source of supply of fuel for said fuel nozzle, a dash pot in communication with said float valve chamber, a piston mounted in said dash pot and operatively connected for operation by said auxiliary air valve, and communication between said fuel nozzle and said dash pot whereby fuel admitted into the dash pot on one side of said piston is forced therefrom on the other side thereof through said fuel nozzle tocarburet the air flowing 1 therearound.

'10. In a carbureter, means adjusting the flow of fuel therein, an automatic airinlet 11. In a device of the class described, a

carbureting chamber, fuel inlet means directed thereinto, a main air inlet at the lower end of said chamber, an auxiliary air inlet valve at one side of said chamber, and a supplemental air inlet valve within the carbureting chamberadapted to be regulated by the opening movement of the auxiliary air inlet valve.

12. In a device of the class described a carbureting chamber, fuel inlet means there for, anormally open main inlet, an auxiliary inlet valve, a normally closed supplemental air inlet, and means associated with the auxiliary air valve adapted to increase the size of the main air inlet and to open said supplemental air inlet by the opening movement of said auxiliary air inlet valve.

13. In a carbureter of the class described a carbureting chamber, fuel inlet means therefor, a normally open main air inlet, an auxiliary air inlet valve, mechanism associated with said auxiliary air inlet valve adapted to regulate the size of the opening of the main air inlet as the auxiliary air inlet valve is opened, and means independent of said auxiliary air inlet valveadapted to regulate the return of the main air inlet to normal during and following the return of the auxiliary air inlet valve to its normal closed position.

14:. A carbureter of the class described comprising a carbureting chamber, movable fuel inlet means therefor, a main air inlet, an auxiliary air inlet valve, mechanism associated with said auxiliary air inlet valve adapted to regulate the opening movement of said fuel inlet as said auxiliary air inlet valve is opened; and means independent of said auxiliary air inlet valve and associated mechanism adapted to retard the return of said fuel inlet means to normal after the opening thereof has been enlarged by the openin of the air inlet valve.

15. n a carbureter of the class described a carbureting chamber, movable fuel inlet piston therein, means affording communication between said float feed chamber and said dash pot chamber on one side of said piston, an outlet from the dash pot chamber on the other side of said piston, a fuel inlet means communicating with said outlet from the dash pot chamber adapted to receive fuel ejected therethrough under pressure when said piston is moved in said dash pot chamher, a Venturi tube surrounding said fuel means, an air inlet for admitting fuel through the interior of and around the exterior of said Venturi tube for passage through the carburetor, and an automatic air valve connected to said fuel inlet means to open the same correspondingly with opening movements of said air inlet valve.

27. In a carburetor of the class described, a earbureting chamber, a float feed chamber, a dash pot chamber in communication with said float feed chamber, a piston movably mounted in said dash pot chamber, a fuel inlet means to admit fuel/into the carburet ing chamber from said dash pot chamber under pressure when said piston is moved therein, an air inlet valve, operative connections between the same and said piston whereby said piston is operated to force fuel under pressure through said fuel inlet means when said valve is operated, and means for admitting air around said fuel inlet'means for carburation and passage through the carbureter independently of the opening of said air inlet valve.

28. In a carbureter of the class described,

an air inlet valve, and means for retarding the opening movement of said air inlet valve and permitting free closing movement thereof by disengagement from said retarding means.

29. In a carbureter of the class described, an air inlet valve, resilient means for resisting the opening movement of said valve, and means for retarding the opening movement of said valve operating topermit free return of said valve under the stress of said resilient means toward closed position by disengagement from said retarding means.

30. In a carburetor of the class described, an air inlet valve, means operating normally to resist the opening movement thereof and to normally hold said valve in closed position, and mechanism for retarding the opening of said valve co-acting with said means for the purpose, but by disengagement of said valve from said mechanism to permit said valve to return freely toward closed position under the impulse-of said means.

31. In a carbureter of the class described, an air inlet valve, a spring normally resisting opening movement thereof and operating to close said valve, a dash pot chamber, a piston operating in said dz. 'h pot, and connections between said piston and said air inlet valve whereby movement of the piston in the dash pot serves to retard opening movement of the air valve, but said air valve is permitted to return freely to closed position under the stress of its spring independently of said piston in the dash pot.

In a carbureter of the class described, an air inlet valve, means resisting opening movement thereof, and a dash pot and piston operatively associated with said valve to retard opening movements thereof, and permitting free release toward closed position of said valve under the stress of said spring independent of. movement of the piston in said dash pot.

33. In a carbureter of the class described, fuel inlet means, a source of fuel supply, a dash pot chamber having one end thereof in communication with said fuel inlet means and supplying fuel to the inlet means, the other end of said dash pot chamber having communication with said fuel supply, and an air inlet valve interconnected with said fuel inlet means, said air inlet valve movable in one direction to open said fuel inlet means in an opposite direction.

34, In a carb'urcter of'the class described, a source of fuel supply, a dash pot chamber communicating at one of its ends with said source of fuel supply, fuel inlet means, a piston in said dash pot, said. fuel inlet means communicating with said dash pot on the opposite side of said piston from said communication with said source of fuel supply, an air inlet valve, and means connecting said air inlet valve, said piston and said fuel inlet means whereby movement of said air inlet valve in one direction imposes a movement in an opposite direction upon said piston and serves further to open said. fuel inlet means.

In testimony whereof I have hereunto subscribed my name in the presence of two suh-- scribing witnesses.

CHARLES it. RAYFIELD.

Witnesses:

CHARLES l V. Harms, n, FRANK K. Henson.