US1165087A - Carbureter. - Google Patents

Description

W. M. FULTON.

CARBURETER.

APPLICATION FILED MAR. 31, I913.

N NN N Witness UNITED STATES PATENT OFFICE.

WESTON M. FULTON, OF KNOXVILLE, TENNESSEE, ASSIGNOR TO THE FULTON COMPANY, OF KNOXVILLE, TENNESSEE, A CORPORATION OF MAINE.

" cannunn'rnn.

I Specification of Letters Patent.

Patented Dec. 21, 1915.

Application filed March 31, 1913. Serial No. 757,887.

To all whom it may concern Be it known that I, WEs'roN-M. FULTON,

of Knoxville, Tennessee, have invented a" approximately the maximum explosive effeet may be automatically maintained.

A further object of my invention is to dispense with manual regulation of the fuel supply and thereby relieve the operator of the inconvenience and annoyance of an act which heretofore has required considerable attention and to economize the use of fuel while at all times securing the maximum or approximately the maximum amount of energy from the explosive mixture.

These and other objects will be fully explained in the detailed description.

Heretofore carburetors for engines have usually depended on manual adjustments ferregulating the relative quantities of air and vapor delivered by the carbureter. For various reasons manual adjustments are objectionable. Owing to the varying demands made upon the carbureter by the engine; adjustments must be frequent. This demands considerable attention and is inconvenient and annoying to the operator. Accurate regulation of the proportions of air and vapor is essential to secure the best working results. Too large proportion of vapor causes! waste of fuel and cylinder troubles.

Too small a proportion causes weak explosions and sometimes stopping of the engine.

My invention overcomes the above objections and secures the objects herein stated by providing a carburetor with temperature controlled means for automatically regulating the supply of fuel to the carburetor, whereby any predetermined proportion of air and fuel vapor may be maintained in the explosive mixture delivered by the carbureter.

Heretofore air has been supplied to the carburetor either at variable temperature or at constant temperature. My invention is applicable to either case, and in applying my invention I provide a thermosensitive element subject both to the temperature of the air entering the carbureter and also to the variable temperature of the mixture of air and fuel vapor in the carbureter and by means of this element, control the supply of fuel to the carbureter. Thus the explosive mixture of air and vapor is made constant in composition by automatically maintaining a constant difference of temperature between the incoming air and-the outgoing mixture of air and fuel vapor.

In order that the invention may be readily imderstood, certain mechanical expressions of the inventive idea involved are shown in the accompanying drawings which are designed merely as illustrations to assist the description of the invention and not as defining the limits thereof.

In the drawings :Figure 1 is a central, vertical sectional View with interior parts in elevation showing a carburetor provided with my improvements. Fig. 2 is a perspective' detail view, and Fig. 3 is'a side elevational detail view.

Referring to Fig. 1, there is illustrated a carbureter having a float chamber 1, supplied with liquid fuel through supply pipe 2. An annular float 3 maintains the liquid in the chamber 1 at a predetermined level by controlling the liquid fuel supply entering through pipe 2 by means of a needle valve 5 connected through securing means. I to the I float by a lever 6 pivoted at 7. Through the float chamber 1 is an air pas- .sage 8 open to an air supply conduit 9 and vide three tubular castings: a casting 14 ported; and a top casting 16 provided with a flange air inlet connection 17 and a flanged outlet connection 18. The several sections of castings 14,15 and 16, when assembled, are secured together by flanges and bolts in the usual manner. For the purpose of supporting the thermosensitive elements,

to be described, semi-circular bearings or supports 19, 19 are formed in the wall of casting 15 and correspondingly shaped caps 20, 20, are formed in the wall of casting 16. In Fig. 1, two suchsupports are shown. I

Referring to Fig. 1, I have shown two similar thermosensitive elements 21,22, preferably of the construction shown and described in my U. S. Patents 729,926, 729,- 927 and 760,443. The opposite end walls of each vessel are non-flexible and are pro- Vided with hubs 23, 24, centrally located. Hubs 24 are adapted to fit in supports 19, 19, and are provided with threaded extensions 25, 25, for receiving fastening nuts 26, 26. To facilitate the application of the nuts,

a slot 27 is cut in the threaded end of each.

hub 24. The movable ends of the vessels 21,

' 22 are connected by a rod 28 which is'adapted to be screwed into threaded sockets in hubs 23,- 23. The connecting rod 28 worksthe air supply conduit 9, and is provided with annular shoulders 30 between which is held the forked end of one arm31 of a bell-crank lever, the companion arm 32 of which is also forked and pivotally supports the valve stem 33 carrying needle valve 13. The valve 13 is preferably provided with a slender guide pin 34 for centering the valve on its seat. Lugs 35, Fig. 2, formed on the casting 15 contain a knife-edge pivot 36 which is received in a slotted opening in the elbow of the bell-crank lever and forms an anti-friction fulcrum for thelever. The arm 31 is provided with knife-edge pivots 37 onwhich bear the forked ends of a springpressed adjusting rod 38. This rod has a shoulder 39 against which a spring 40 is pressed by means of a thumb-screw 41 work ing in a threaded opening in the wall of the casting 15 and bearing on an adjusting plate 42. The spring is preferably housed in a recess 43 formed in the wall. Openings 44 and .45 are provided in the casting 16 for receiving thermometers when the carbureter is adjusted and are afterward closed by screw plugs 46 and 47 when the adjustment is com- I pleted.

The casting 16 may be'and sometimes is provided with a spring pressed valve 48 normally closing a passage between the atmos- 'phere and the space in the mixing chamber and is adapted to admit air and relieve any material difference of pressure in the mixing chamber and the air conduit which latter is open to the atmosphere.

By reason of the peculiar design of the castings, the parts are readily assembled. In casting 14, the float 3 and its parts are secured. Casting 15 is then placed on casting 14 and secured thereto by clamping bolts 49. Bell crank-lever 31, 32 with its valve 13 and adjusting rod 38 are positioned in casting 15. The two thermostatic elements 21 and 22 having previously been connected by red 28 are placed with their hubs 24 resting in the semi-circular bearings 19, 19, and with the portion of rod 28 between shoulders 30 resting in the forked end of lever arm 31.

cured to section 15 bybolts 49'.

In describing the operation of the carbureter, the parts are assumed to have been assembled in the manner described and that the discharge end of the same is connected to an internal combustion engine through a suitable connection.

Adjusting the carbureter: The liquid fuel is admitted to the float chamber 1 and maintained at proper level by float 3 acting on needle valve 5 which has been properly adjusted for this purpose. The throttle valve 11 is set partly open and the engine is started, thermometers having previously been introduced through openings 44 and 45. -The engine creates a draft of air through conduit 9 in the direction of the arrows, past the spray nozzle 12, throughthe mixing chamber 10 and past the throttle valve 11. Thermosensitive element 21 is thus subjected to the temperature of'the incoming air and thermosensitive element 22 to the temperature of the mixture of vapor and air in the mixing chamber 10. In the act of spraying the volatile liquid fuel into'the current of air, the vaporizationresulting abstracts heat from the air in a manner well understood, and lowers the temperature of the mixture.

The thermosensitive elements 21 and 22 are therefore subjected to different temperatures I while the engine is in operation. This difference of temperature between the incom-,

ing. air and the mixture of air and vapor passing. through the mixing chamber,,de-'

pends upon the relative quantity of air and liquid fuel vaporized into the air and is a measure of the ratio of the quantity of vapor to that of the air in the mixing chamber. Thereforea gaseous mixture of practically any predetermined composition may be maintained in the mixing chamber by keep ing a constant difference of temperaturefbes- 1 tween the incoming air and the outgoing mixture of air and vapor. It has heretofore been determined that between certain limiting proportions air and inflammable gases and vapors produce explosive mixtures .which burn with completecombustion. "It

' ence taken.

is, therefore, only necessary to determine by experiment the difference in temperature- Which'must exist between the incoming air and the out-going mixture for a given explosive combination of air and vapor and then to maintain as near as practicable this difference of temperature by means of the thermostatic control device. This is accomplished in the following manner: The engine being in operation, a current of air and vapor passes through the apparatus. Previous tests have indicated for example that a satisfactory explosive mixture of air and gasolene is obtained when there is a diflerence of about 14 C. between the incoming air and out-going mixture. The temperatures of the incoming air and the air and vapor mixture are noted on the two thermometers above referred to and their differ- Should this difference be less than the one selected for standardizing the carbureter the temperature of the mixture in the carbureter is evidently too high and therefore more fuel needs to be sprayed into the chamber to increase the difierence. Thumb-screw 4:1 is therefore turned in a direction to compress spring 40 and thrust lever arm 31 to the left to overcome somewhat the force exerted by the expansion of vessel 21 on vessel 22. This opens needle valve 13 and permits increase spraying and evaporation of the fuel into the mixing chamber thereby reducing the temperature of the mixture or air and vapor. When the predetermined difference of temperatures is secured, the device will maintain this difference, whatever may be the temperature of the incoming air, and therefore maintain constant the composition of the explosive mixture. The thermometers are removed and the plugs 46, 47 are inserted to close the openings. It is now evident if throttle valve 11 is open wider so as to create a greater de mand on the carbureter, causinga morerapid flow of air through the same, the amount of liquid fuel passing valve 13, just previous to the opening of the throttle valve, will not be sufli'cient to bring this increased amount of air up to the proper content of combustible vapor. The result is that the temperature of the mixture passing thermosensitive element 22 rises while that passing element 21 remains constant. This'causes element 22 and spring 40 to overcome the expansion force of element 21, thereby thrusting rod 28 to the left as viewed in Fig. 1, rocking lever arm 31 to the left and lifting needle valve 13 to admit more fuel to the mixing chamber. This action continues until'the content of vapor again reaches normal when the balance is restored between the opposing forces and the predetermined difference of temperature between the incoming air and out going mixture is restored. Owing to the multiplicity of corrugations in the thermo- 'response to such variations.

through the carbureter. The reverse movement of the throttle 11 to reduce the demand on the carbureter causes element 21 to overcome the combined action of element 22 and spring 40, and thereby, reduce the supply of the drawings to substantially equal that of the mixing chamber, while the mouth of the air conduit is somewhat restricted in size where it opens to the atmosphere above element 21. Hence any vacuum which may form in the carbureter will exist to an equal degree around both elements 21,22.

It is to be understood that I do not desire to be limited to any particular form or size of thermostat nor to the particular location of the connections between the same and the fuel supply valve as the lattermay be exterhal to the air conduit.

What I claim is v 1. In a carbureter, a conduit for conducting air subject to fluctuations of flow, means delivering vaporizable liquid fuel into said incoming air and outgoing mixture of air and vapor and adapted to control said supply means whereby the proportion of vapor to air delivered by the carbureter is maintained constant under varying demands on the carbureter.

2. In a carbureter,a conduit for conduct: ing air subject to fluctuations of flow, means delivering vaporizable liquid fuel into said conduit, thermosensitive means operable by the difference in temperature between the incoming air and outgoing mixture of air and vapor and adapted to control said supply means, and means for regulating said thermosensitive means whereby a predetermined proportion of vapor and air is delivered by the carbureter under varying demands on the carbureter.

3. In combination, a carbureter provided with a mixing chamber, an airinduction conduit, and liquid fuel supply means, thermosensitive means exposed to the air in said conduit and to the contents of the mixing chamber for automatically regulating said supply for maintaining a constant composition of the explosive mixture.

5. In combination, a carbureter provided with a mixing chamber, an air supply conduit and liquidzfuel supply means, and thermostatic elements one of which is exposed to the incoming air and one exposed to the 'contents of said mixing chamber, non-flexible connections between said elements, means operated by the differential movements of said elements to regulate the fuel supply and adjusting means for said last-named means whereby a predetermined proportion of air and fuel is maintained in the fuel mixture.

6. In combination, a carbureter provided with liquid fuel supply means and having an air supply conduit and a valved dis charge conduit for connecting with an -engine cylinder, a collapsible and expansible vessel in said air conduit and a collapsible and expansible vessel in said discharge conduit, a non-flexible connection between said vessels and connecting means between said vessels and supply means for automatically regulating said supply means and to control the composition of the explosive mixture delivered by said carbureter to the engine.

7. In combination, a conduit open to the atmosphere at one end and adapted to open into a combustion chamber at the opposite end, liquid fuel supply means delivering into the conduit intermediate its ends, thermostatic elements one of which is exposed to the incoming air and one exposed to the outgoing air and vapor mixture, a connection between the movable ends of said thermostatic elements, means transmitting the movements of said connection to control the fuel supply means and adjustable resilient means acting in opposition to one of said elements.

8. In combination, a conduit open to the atmosphere at one end and adapted to open into a combustion chamber at the opposite end, a valve controlled spray nozzle opening into said conduit delivering vaporizable fuel therein, thermostatic elements one of which is exposed to the incoming air and one to the outgoing air and vapor mixture, means connected to the movable ends of said thermostatic elements and to said valve and adapted to transmit the resultant movement of said elements to said valve for regulating the supply of fuel to said conduit and to maintain a constant composition of the air and vapor mixture.

9. In combination, a conduit open; to the atmosphere at oneend and adapted f'tq en into a-combustion' chamber at the opposite end, a valve controlled spray nozzle vopening into said conduit delivering vaporizable fuel therein, thermostatic elements one of which is exposed to the incoming air and one to the out-going air and vapor mixture, means connected to the movable ends of said thermostatic elements and to said valve and 10. In combination, a carbureter, liquid fuel supply means for the same and thermosensitive means subject to changes of temperature of the fluid passing through' said carbureter associated with said supply means and other means associated with the said thermosensitive means and supply means for adjusting said devices tojautomatically maintain a predetermined composition of the explosive mixture as discharged from the carbureter.

. 11. In combination, a carbureter provided with a mixing chamber, anair induction conduit and valve-controlled liquid fuel supply. means, thermosensitive means exposed to the air in said conduit and-to the .contents of said mixing chamber and having connections with said valve means, and means for ad ustlng said devices whereby a predetermined composition of the explosive mixture is maintained as discharged from said carbureter. I

12. A carbureter comprising a casing in three separable sections in form of a U- shaped conduit, an. annular fuel supply chamber in the base section surrounding one leg of the conduit and having a valve-controlled spray nozzle opening into said conduit, a collapsible and expansible vessel having one end supported by a hub in a semicircular bearing formed in the top of the means for introducing vaporizable liquid into said conduit, and thermosensitive mea'ns operatedby the difference in temperature between said gas supply and said mixture wall of the intermediate section and means of gas and vapor and controlling said liquid supply to maintain a constant gas and vapor in said mixture.

14:. In a device for mixing the vapor of a liquid with a gas, means for introducing proportion of Vaporizable liquid into a stream of gas and In testimony whereof I have signed this thermosensitive means actuated by the difspecification in the presence of two subference in temperature between said gas scribing Witnesses.

and mixture for automatically controlling WESTON M. FULTON. 5 the liquid supply as the flow of said stream Witnesses:

varies to maintain the relative proportions HINES S. MCCOY,

of gas and vapor in the mixture. I C. H. BROWN, Jr.

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