US1421790A - Carburetor - Google Patents

Description

H. V. LEAHY.

CABBURETOR.

APPLICATION iiLED APR. 14. 1919.

1 21,790. Patented Ju1 4, 1922.

3 SHEETS-SHEET a.

8 49 v V 3% a 3 wk) I net 0 UNITED STATES PATENT OFFICE.

HERBERT V. LEAHY, OF LOS ANGELES. CALIFORNIA, ASSIGNOR TO HERCULES CARBURETOR COMPANY, OF LOS ANGELES, CALIFORNIA, A CORPORATION OF CALIFORNIA.

C'ARBURETOR.

Specification of Letters Patent.

Patented July 4, 1922.

To all whomit may consent:

Be it known that I, Hrnnnn V. LEAHY, a citizen of the United States, residing at Los Angeles, in the county of Los Angeles and State of California, have invented a new and useful Carburetor, of which the following is a specification.

An object of this invention is to produce an intimate mixture of air and liquid fuel for use in internal combustion engines.

Another object is to produce a mixture of substantially the correct proportions of fuel and air at various degrees of throttle opening.

Another object is to provide a construction which will break up the fuel into a maxi mum number of minute particles and distribute said particles uniformly throughout the column of air passing through the carburetor.

Another object is to make provision for using either one of two different fuels, a lighter hydrocarbon and heavier hydrocarbon.

Another object is to provide a construction in which an air valve functions to admit a smaller volume of air to the space adja cent the nozzle orifice at lower engine speeds or power and to admit an auxiliary volume of air to the space adjacent the nozzle at higher engine speeds or power.

Another object is to make provision for spreading the fuel over a face of relatively large area exposed to a moving column of air so that the fuel will be readily absorbed by the air.

Other objects and advantages will appear in the subjoined detailed description.

The accompanying drawings illustrate the invention:

Figure l is a side elevation of a carburetor built in accordance with the provisions of this invention.

Fig. 2 is a plan section on line indicated by a' m Figs. 1 and 3.

Fig. 3 is a vertical mid section of the carburetor on a plane at right angles to the direction of sight in looking at Fig. 1.

Fig. 4 is a plan section on the irregular line indicated by mi0*, Fig. 3.

Fig. 5 is an enlarged fragmental vertical section of that portion of the carburetor on the right in Fig. 3.

Fig. 6 is an inverted plan section on the irregular line indicated by .u".r, Fig 5.

Fig. '7 is an inverted plan section on the irregular line indicated by ad-W, Fig 5.

Fig. 8 is a plan section on the line indicated by tb ill Fig 3.

Fig. 9 is a perspective view of the air nozzle shown in Figs. 3 and 5.

Fig. 10 is an elevation of the collar.

There is provided a float chamber 1 screwthreaded at its lower end into a base 2 which is provided with a chamber 3 communicating with the chamber 1. The base 2 is connected at one end by a nipple 1 and union 5 with the circular bottom 6 of a tubular mixing chamber indicated in general by the character 7 The bottom 6 is provided with a fuel duct 8 and said fuel duct communicates through the nipple at with one end of a duct 9 in thebase 2, the other end of said duct 9 communicating through a three-way valve plug 10 with the chamber 3 when said valve plug is in the position shown in Fig. 3. hen the valve plug 10 is turned to another position it affords communication between the duct 9 and a duct 11 which communicates with a coupling 12 connected with an elbow 13, said elbow being adapted to form a portion of a pipe line extending to a tank, not shown, containing relatively light fuel as, for example, gasoline.

Screw-threaded into the base 2 is a valve chamber 14 in which is a needle valve 15 to control a port 16 in said valve chamber, said valve chamber communicating with a coupling 17 connected with an elbow 18. the elbow 18 being adapted to form a portion of a pipe line to connect the carburetor to a suit able tank, not shown, containing heavier fuel such as, for instance, distillate or the like. The needle valve 15 is controlled by suitable means to regulate the level of fuel in the float chamber 1 and such means may be constructed as follows: The upper end of the needle valve 15 is adapted to be engaged by one end of a lever 19 pivoted at 20 in the chamher 3 of the base 2, the other end of said lever engaging an eye 21 which is screw-threaded onto the lower end of a stem 22. Surrounding the stem 22 is a float 23 which is prevented from rising relative to the stem 22 by an abutment 24; screw-threaded onto the stem 22, the opposite ends of the abutment 2 1 being guided in vertical ways 25 formed in the inner face of the peripheral wall of the chamber 1. and said ways extending longitudinally of the float chamber 1. Thus the abutment 24 is adjustable on the stem 22 so as to regulate the level at which the float 23 will cause closing of'the needle valve 15 to shut ofi the flow oi ltu'el into the chamber 3. The upper end of the stem 22 slides in the bore 26 of a stem guide 27 which is screw-thread ed into a hollow boss 27 on the top of the chamber 1. In axial alinement with the upper end of the stem 22 in the bore 26 is a push rod or tickler 28 having at its outer projectingend a head forming an abutment 29, there being a coil spring 30 between the abutment 29 and the guide 27 to tend to normally hold the tickler 28 out of engagement with the stem 22. When the abutment 29 is depressed against the pressure of the spring 30 it causes the tickler 28 to push downwardly on the stem 22 so as to operate the lever 19 to retract said lever from the needle valve 15 and allow said needle valve to be opened by the pressure of fuel in the port 16 so that the fuel will flow through the valve chamber ll into the chamber 8. By the means just described the operator can cause the level of fuel in the chamber 1. to rise above that predetermined by the float v The bottom 6 is provided with an annular shoulder 31 on which rests anair admission member 82 which is provided in its bottom with a circular opening to lit the bottom 6. The topiof the air admission member 32 is provided with a circular opening 34 to fit an annular shoulder 35 on the outside of the mixing chamber '7. The air admission member 32-surrounds the lower portion of the chamber '7. The air admission member is provided at one side with an inlet port 36, and it is clear that the member may be turned relative to the mixing chainher to various positions the advantage of this'being that the port 36 can thus be connected at various angles with a hot air tube, not shown, which may be connected with any suitable heater, not shown, tor heating the air entering the air admission member 32'. The port 36 is controlled by a butterfly valve 37 which never entirely closes said port, and the air admission member is provided between the valve 37 and outer end of the port 36 with openings 38 controlled by a rotary tubular valve 39 having openings 40 which may be brought into registration with the openings 38 by appropriate turning of the valve 39 to ad,- mit atmospheric air directly into the air admission member 32 so as to dilute the heated air entering the port 36. The valve 39 is provided with an operating member ll and the valve 3'7 is provided with an operating member 42 The portion of the mixing chamber 7 positioned inside of the air admission inembe 32 is provided with ports 4-3 near the lower end of the mixing chamber. Slidable in the mlxmg chamber 7 1s a suction-operated tubular air valve 4i which at its lower end forms a sleeve 45 of reduced diameter so as to form an annular passage &6 between the wall of the mixing chamber 7 and the periphery of the sleeve d5 adjacent the ports a3. The sleeve of the air valve substantially fits the outside of an annular flange a? of a collar d8 which is screw-threaded onto the lower endol a cylinder or tubular :tuel chamber l9, that in turn is screw-threaded onto an upwardly projecting boss of the bottom 6. The flange a? is provided with ports 51 which may be of V-shaped construction,

so as to be reduced downwardly.

The valve is provided with an inwardly extending annular shoulder 52 adapted to engage an maternal annular seat 53 on a irusto-conical or upwardly reduced air-discharge nozzle 54%. \Vhen the shoulder 52 engages the seat 53 it limits downward movement of the valve ti and when thus engaged the ports 51 in the flange 4:7 are almost, but not quite, closed by the air valve as clearly shown in Fig. 3. The air nozzle 5% is provided below the seat 53 with a port or ports 55 and said air nozzle screw-threaded onto an annular flange 56 of a cap 57 which closes the upper end of the fuel chamber 49 and also terms a nozzle base. Thus it is clear that when the valve 44 is in position to eng the seat 53, air in the interior of the valve let can only flow through the ports 55 into the bore of the air nozzle 54: and that when the valve 4L4: is raised, the air in the air valve it can liow through the ports 55 and also between the valve l4 and air nozzle 54 outside oi said air nozzle.

The cap 57 is provided with an opening 58 through which passes a chamber 59 of a valve 60 that is located at the upper end of the duct 8 to control said duct. The chamber 59 is provided with ports 61 to admit fuel from said chamber to the cylinder L9. The lower end of the chamber 59 is screwthreaded into a hollow plunger 62 adapted to work in the cylinder 49, the plunger and cylinder 49 functioning as a dashpot to retard and steady the valve 60 on the opening i'novement of said valve. The lower end of the chamber 59 is provided with a port or ports 63 to admit fuel from the bore of the plunger 62 to said chamben The plunger is guided by a cylindrical post 64 through which the duct 8 extends. said post being integral with the bottom 6. Fastened to the upper end of the chamber 59 is a rod 65 which passes through a bridge (36 termed on the upper end or the valve 441, the upper end of the rod being screw-threaded to receive a nut 67. The rod 65 and chamber 59 together term the stem of the valve 69. Screwthreaded on the rod (35 beneath the bridge 66 is a shoulder or collar 68 adapted, when the valve is down. to rest upon the upper end oi an upper hollow trusto-conical external nozzle member 69 which is provided with an internal shoulder 70 screw-threaded on the up per end of an internal tubular nozzle member 71, there being downwardly extending spaced feet 72 on the lower end of the nozzle member '71 adapted to rest on the upper flat face of an intermediate hollow frustoconical external nozzle member 73 so as to form an annular nozzle discharge orifice 74 between the nozzle members 69, 73. The lower end of the nozzle member '73 is provided with downwardly extending spaced feet 7 5 adapted to rest on the upper fiat face of the cap 57 so as to form an annular nozzle orifice 76 between the nozzle member 73 and cap 57. In the drawings the nozzle orifices T4, 7 6 are exaggerated in size for clearness of illustration and in actual practice said orifices will only be one or two thousandths of an inch in thickness.

The internal nozzle member 71 is provided with ports 77 and the chamber 59 is provided above the level of the cap 57 with a port or ports 78 so that fuel can flow from the chamber 59 through the ports '78 into the internal nozzle member 71, thence through the ports 77 into the upper and intermediate external nozzle members 69, T3 and thence through the nozzle orifices 74, 7 6 to the space between the external nozzle members and the air nozzle 54.

The mixing chamber 7 is provided with an outlet '79 which is controlled by a butterfly valve 80 operated by an arm 81.

In practice, the abutment 24 will be adjusted on the stem 22 to a position to allow the fuel to rise to a level preferably somewhat higher than the level of the nozzle orifice 76. Assuming that the inlet 36 is connected with a source of hot air supply, that the outlet 79 is connected with the intake manifold of an internal combustion engine,

that the elbow 13 is connected with a source of supply of a heavier hydrocarbon such as distillate, that the valve 10 has been turned to position to admit fuel from the fuel supply pipe to the duct 9 and to shut off the duct 9 from the chamber 3, and that the throttle valve 80 and valves 37, 39 are closed the carburetor operates as follows: The engine is cranked in the usual manner and the comparatively slight suction produced in the air nozzle 54 causes the gasoline to flow from the cylinder 49 through the ports 61 into the chamber 59, thence through the ports 78 into the nozzle member 71, thence through the ports T7 to the bores of the nozzle members 69, 73. and thence through the nozzle orifices to mix with the comparatively small amount of air admitted through the ports 51, the air valve 44 being in the position shown in Fig. 3 so that air will pass from the passage 46 beneath the lower end of the sleeve 45 and thence through the ports 51. The mixture of air and fuel will flow from the air nozzle 54 into the upper portion of the mixing chamber 7 and thence through the outlet 7 9 into the intake manifold of the engine where ignition of the charges will take place in a manner well understood in the art pertaining to internal combustion engines. After the engine'has run a short time on the mixture of air and gasoline so as to heat the engine, the valve 10 will be turned to the position shown in Fig. 3 so as to admit the lower grade of fuel to the duct 9 and said fuel will pass to the chamber 59 through the duct 8, plunger 62 and ports 63. From the chamber 59 the lower grade of fuel discharges the same as described for the gasoline.

To enable the engine to deliver higher speed or power, the valve 87 will be opened to admit more air into the air admission chamber 32 and the throttle valve 80 will be opened to the desired amount so as to increase the degree of vacuum in the mixing chamber 7. The increased degree of vacuum raises the air valve 44 so as to admit a greater flow of air from the chamber 31 through the ports 51 to the interior of the air valve. This raising of the air valve also causes raising of the rod 65 to cause a greater degree of opening of the valve 60 thus allowing fuel to flow from the duct 8 into the bore of the plunger 62, thence through the ports 63 to the bore of the stem 59, thence through the ports 78 into the internal nozzle member 71, thence through the ports 77 to the bores of the external nozzle members 69, 73, thence through the nozzle orifices 74, 76 into the annular space between the external nozzle members and air nozzle 54. It is clear that the air admitted through the ports 55 sweeps over the peripheral faces of the nozzle members 69, 73 so as to spread the fuel issuing from the nozzle orifices over the peripheral faces of the external nozzle members in order that the column of air will readily absorb the fuel and thus break it up into exceedingly small particles to insure the making of an intimate mixture of the fuel and air. The carburetor may be adjusted for the desired proportions of fuel and air by turning the nut 67 so as to adjust the beginning of opening movement of the valve 60 relative to the degree of opening of the air valve 44. If the throttle valve 80 be opened suddenly to a relatively great degree the air valve 44 and fuel valve 60 will not move immediately to corresponding open position since the fluid above the plunger 62 retards upward movement of said plunger. The plunger 62 does not fit snugly in the chamber 49, there being sufficient space between the plunger and chamber 49 to allow the fuel in the chamber 49 to pass slowly from above the plunger to beneath it. If, however, the throttle valve 80 be closed suddenly the air valve 44 and fuel valve 60 Will function to quickly reduce the supply of air and fuel because the plunger 62 is not materially retarded in its downward movement, owing to the provision of means to -quickly relieve the pressure beneath the plunger. To provide for the plunger 62 falling quickly, the plunger is provided with a valve chamber 82 communicating with the space above the plunger through a port 83 and communicating with the space beneath the plunger through port 84. The port 84; is controlled by a ball valve 85 in the valve chamber 82. Thus when the plunger is drawn upward the valve 85 remains closed so that the fuel above the plunger offers resistance to the upward movement of the plunger. When the plunger falls the pressure of the fluid below the plunger operates to raise the ball valve 85 so that the i'luid beneath the plunger can rapidly escape through the port 84: into the valve chamber 82, thence through the port 83 into the space above the plunger.

When the throttle is opened but slightly and the air valve 44 is closed upon the seat 53, the air will flow from the air valve only through the ports 55 into the air nozzle 54: so that all of the air will sweep through the air nozzle in close proximity to the nozzle orifices 74, 7 6 and spread the fuel in a thin film over the upwardly and inwardly slanting faces of the nozzle members 69, C and thus provide for quick vaporization of the fuel: Then the throttle is opened wider to cause lifting of the air valve the air not only flows from the air valve into the air nozzle, as before, but also flows as an auxiliary supply from the air valve through the annular gap then existing between the air valve seat 53 and air nozzle shoulder 52, so that the mixture is decreased in richness or, in other words, the ratio of fuel to air is decreased though the volumes of both fuel and air are increased. Thus have provided means to discharge an initial supply of air close to the nozzle when the air valve is in one position and to discharge an auxiliary supply of air above the nozzle when the valve is in another position. Also it is clear that the one air valve as controls both the initial and auxiliary supplies of air to the mixing chamber.

In order to prime the carburetor, that is to say, to cause a flow of fuel from the nozzle orifices Tel, 76, the base 6 is provided with an orifice S6 in which is positioned a priming pin 8'? that is in alinement with the lower edge of the air valve iaso that an upwarr push on the pin 87 will raise the air valve and consequently cause opening movement of the fuel valve 60. it is understood that to effect such priming the tank, not shown, for supplying the fuel to the carburetor will be positioned above the level of the nozzle orifices 74:, 76 or that pressure will be produced' on said fuel by other suitable means lt is to be noted that the nut 67 and collar air valve l l and valve stem 59, 65 since the collar 68 is shiftable in the perforation 88 of the bridge.

I claim:

In a carburetor, the combination of a tubular member closed at its lower end and provided with port, a; tubular air valve slidably fitting in the tubular member for controlling the air admitted by the port and having a shoulder, a nozzle inside of the valve, an air tube surrounding the nozzle and having its upper portion spaced therefrom and having a port communicating with the interior of the valve and provided above the level of its port with a seat for engagement with the shoulder, and a valve to con.- lrol the flow of "fuel through the nozzle, said fuel valve beingoperatively connected with the air valve.

2. in a carburetor, the combination of a tool member, a nozzle mounted on the upper end of the fuel chamber, a post extending into the fuel chamber and having a. fuel duct, a valve to control the fuel duct and )rojccting into the nozzle, and a chambered stem for the valve having a port communieating with the fuel chamber and another port communicating with the interior of the nozzle.

3. ln carburetor, the combination of a fuel chamber, a nozzle mounted on the upper end of the fuel chamber, a post extending into the fuel chamber and having a fuel duct, a valve to control the fuel duct and projecting into the nozzle, a chambered stem for the valve having a port communicating with the fuel chamber and another port communicating with the interior of the nozzle, and a hollow plunger in the fuel chamber surrotmding the post and connected with the valve, the plunger being provided. with means to allow the passage of fuel. therethrough on its down stroke and to prevent the passage of fuel therethrough on its up stroke.

Signed at Los Angeles, California, this 8th day of April, 1919.

HER-BERT V. LEAHY. lVitnesses Grouse H. HILEs, EDGAR M. Hironcoon.

o8 constitute a loose connection betweenthe-

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