US1722462A - Carburetor - Google Patents

Description

V. R. GAGE July 30, 1929.

CARBURETOR 2 Sheets-Sheet l Filed Jan. 15. 1923 BY M Y m E M11., M W0 m u T A w ,Q .C V

July 30, 1929. v. R. GAGE 1,722,462

CARBURETOR Filed Jan. 15, 1923 2 Sheets-Sheet 2 I l K INI/E/YTOR.

MC for /grjc g4 ATTORNEY Patented `luly 30, 1929..

VICTOR R. GAGE, F ITHACA, NEW YORK.

CABIBURETOR.

Application mea January 15, iena; serial No. 612,664.

This invention relates to carburetors and more particularly to the variety adapted for preparing and supplying liquid fuel for use, for example, with internal combustion motors, one object of the invention be1ng to provide a simple, and practical device of this character operating accurately as a meter for supplying fuel in quantities suitably and automatically proportioned with reference to the volume of air used by the motor.

Another object is the provision of an economical form of carburetor adapted to supply fuel to a motor in a finely and thoroughly subdivided or vaporized condition and to thereby eliminate the waste and other undesirable eiects accompanying the supply of the yfuel in a partially liquid or incompletely atomized form.

To thesev and other ends the invention. re-

sides in certain improvements and combinations of parts all as will hereinafter be more fully described, the novel features being pointed out in the claims at the end of the specification.

In the drawings: Figure 1 is a sectional elevation of a carburetor embodying the present invention;

Figure 2 is a sectional plan view of the same on the line 23---2a in Figure 1; Figure 3 is a sectional view on the line p a-S of Figure 2; i

Figure 4 is a sectional view on the line L1& 43 of Figure 1;

Figure 5 is a sectional elevation of a modified form of construction;

Figure 6 is a sectional plan view on the line 61-6a of Figure 5; and

Figure 7 is an enlarged sectional detail view on the line 7- of Figure 5;

Similar reference numerals throughout the several views indicate the same parts.

Referring to the drawings there is shown at 10, Figures 1 and 4, a main casing which may be conveniently formed as a metal casting comprising, preferably, a tubular portion 11 consisting of an air intake passage with an intake en'd 12 and an opposite end 13 for attachment to the engine manifold. Paralleling this passa e is an atomizing chamber 14 separated rom the intake passage by a wall 15 having spaced openings 16 and 17 therein providing communication be tween the chamber and passa e. Means are provided as hereafter descri ed for maintaining a chamber 14 filled with atomized or vaporized fuel and the air passage is supplied with devices for inducing a proportionate flow of air from the passage into the chamber through opening 16 and back to thepassage through opening 17 to carry the fuel into the air passage through the passage to form a combustible mixture.

Such How inducing devices may take various forms, one of which is shown in Figure 2 as embodied in a Venturi tube 18 having' a throat 19. The outer circumference of thev tube opposite this throat hasva channel 20 therein and a plurality of spaced openings 21 connect this channel with the interior of the throat, The tube is secured in the passage 11 as by means of a screw 22 with its circumferential channel 20 in communica tion with-the opening 17 from the atomizing chamber. It is apparent from this construction that as air is drawn through the passage 11 by the suction produced by the motor, the air pressure in the passage in advance of the Venturi tube, or, in other Words, opposite opening 16, becomes converted to a large extent into velocity at the throat of the Venturi tube, according to well known laws, so that the pressure at the opening 17 is reduced to a substantial degree below that existing at opening 16. This results in a proportional circulation or flow of part of the air passing through the intake passage through opening 16 into the chamber and out of the latter again through openings 21 into the intake passage, and thence to the motor, and the air in passing through the chamber picks up and carries with it to the motor the atomized or vaporized fuel with which the chamber is kept filled. Since the velocity of the air at the Venturi throat is proportional to the volume of air drawn through the passage 11 and since the force or pressure difference determining the quantity of the mixture ofair and fuel driven through the' openings 21 is proportional to the velocity of the air at the Venturi throat, the rate of flow of air through the atomizing chamber is proportional, neglecting the eects of friction, to the volume of air drawn through the intake passage; These parts may be so designed as to size, form and arrangementas to afford the desired ratio of air passing through the chamber and passage, respectively, so that the carburetor supplies to the motor quantities of fuel automatically proportioned to the volume of air required for ilo the different speeds and loads of the motor.

The means for atomizing or vaporizing the liquid fuel in chamber 14 may have various forms, such, for example, as comprises an opening 23 in the bottom of the latter about the per1phery of which the casing has secured thereto, as by means of screws 24', the flanged upper end of a fuel receptacle 25. Formed in one wall of the receptacle and communieating with the bottom of the latter is a duct 26 with which communicates a tube 27 extending upwardly through the main casin adjacent the center of one end of cham er 14 Terminating adjacent the open upper end of at the higher motor speeds.

this tube is a nozzle 28 extending through the end wall of the chamber substantially at right angles to the tube and having a pipe 29 for connection with an exterior source of air or other suitable gas under pressure, as, for example, an air pump or a reservoir. The atomizing gas in this embodiment is thus separate from the air current drawn from the atmosphere by the lowered pressure in the carburetor and it is preferred to employ an atomizing gas pressure greater than that of the atomizing chamber by an amount exceeding the differences in pressure developed in practice between the atmosphere and the interior of the carburetor. Asis well known the carburetor pressure varies widely and is least It is apparent from this construction that a jet of air discharged through nozzle 28 reduces the pressure in tube 27 so that the liquid is ejected from the tube and broken up into a finely divided condition and atomized and more or less vaporized by the air. By this means the atomizing chamber is maintained filled with a fog or mist of atomized fuel, the term` atomlzed being used herein 1n a broad sense' as inclusive of a condition in which the liquid is broken up into a fog or mist and vaporized more or less depending upon the properties of the fuel used, conditions of pressure, temperature and the like. Any fuel remaining in incompletely atomized or liquid form or condensed on the walls of the chamber, and any` excess which is first atomized and then condensed by reason of too great condensation of the atomized fuel. falls to the bottom of the chamber and is thereby returned to the source of supply hereafter described.

When the spraying means for the atomizing chamber is of the form described above it is preferred to provide means for automatically regulating the level of the liquid surface in receptacle 25, such means comprising the usual or any suitable float mechanism as, for example, the float indicated at 30 for raising weighted ends 31 of a pair of levers 31n of the well known variety. The inner ends of the levers (not shown) operate a spindle 32 moving longitudinally through a central opening in the float and carrying at its lower end a valve 33 controlling an opening 34 fitted with a nipple 35 for connection with a source of supply of fuel under gravitational or other pressure.

The air passage 11 is preferably controlled by the usual or any suitable throttle means such, for example, as the valve 36 which may be located at either the intake or discharge ends of the passage, or both, as desired. When a throttle is employed at the intake end of the passage the reduction of pressure in the passage and atomizing chamber serves to facilitate vaporization of the fuel. The circulating air for the atomizing chamber may, of course, be drawn directly from the outside instead of from the main passage as described above.

In Figures 5 to 7 there is shown a modified form of construction in which an intake passage 37 and an atomizing chamber 38 are somewhat diHerently arranged. The devices for inducing circulation of air from the passage to the chamber in this instance comprise an inlet opening 39 from the passa e to the chamber provided with a pitot tu e 40 opening against the incoming air and formed on a sleeve 40 fitted into the passage 37. At 41 is an opening from the chamber in spaced relation -with the inlet opening 39 and communicating with an arinular channel 42 formed in the walls of the intake passage. Sleeve 40 has a series of openings 43 spaced circumferentially and communicating with channel 42 and it is apparent from this construction that a circulation of air from the intake passage through the atomizing chamber is produced bearing a proportional relation to the volume of air drawn through the passage determined by the relative diameters of the passage and the pitot tube, as well understood in `the art. The intake passage is provided with one or more throttle valves as before and as indicated at 44.

The means for atomizing the fuel in this I modified construction comprises a spray nozzle of the usual or any suitable variety such as indicated at 45, Figure 7. This nozzle is adapted for connection with a source of liquid fuel under pressure supplied through the pipe 46 connected therewith, the nozzle comprising angularly arranged ducts 47 as shown for effectively breaking up the liquid into a fine mist and projecting the same into the atomizing chamber. The pressure on the fuel source may obviously be applied in various ways as, for example, by an air pump of any suitable variety, and such pressure is preferably greater than the differences developed in practice between the atmosphere and carburetor. Any liquid which may be incompletely atomized falls to the bottom of the chamber and is returned to the source of supply through the drainage connection 48 so that only the fog or vapor formed by the spray nozzle is carried through outlet 41 to the intake passage. In this modification the float chamber previously described may be dispensed with, more articularly if a throttle is located as shown etween the atomizing chamber and the motor. It is to be noted that the present apparatus does not employ the suction produced by the motor to pulverize the fuel, as commonly the practice in such apparatus, but uses instead for this purpose an independent pressure, such, for example, as an air pressure maintained by a pump, Which pressure is preferably greater than the pressure differences between the carburetor and the atmosphere. The maximum theoretical pressure difference between the atmosphere and the carburetor is that of one atmosphere corresponding to a perfect vacuum in the carburetor which, however, is never reached, but only approximated when the throttle is closed. When the trottle is open only a small port-ion of such pressure difference is available for atomization. Hence, in the usual carburetor construction pulverization of the fuel is not adequate at open throttle, and various heating and other devices are used in attempts to overcome the deficiencies. As the volatility of available fuel decreases such deficiencies increase. The present apparatus using external and separate pressure for pulverizing the fuel is free from this limitation.

Any imperfectly atomized liquid and that f condensed are returned to the source of supply` and there is thus eliminated the waste and other disadvantages of the carrying over of slugs of liquid into the intake passage and motor as in many carburetors `now in use. The operation of the carburetor has been described in connection with the description of its construction, and it is apparent that supply of fuel in quantities automatically controlled by the means described at the different speeds and loads of the motor so as to be proportional to the volume of air required. A carburetor is thus afforded which is not only economical of fuel with respect to the eicient preparation of the latter for combusa flow of air from the latter to and from said chamber for supplying fuel to said passafre in quantities proportional to the volume o air passing therethrough, the relative proportions of said chamber and said connections being such as to produce flow of low velocit-y within said chamber so as to supply only the thoroughly atomized fuel to said passage.

2. A carburetor comprising an air intake passage, an atomizing chamber substantially separate from said passage, fuel atomizing means within said chamber including a nozzle for connection with a source of air under pressure above that of the atmosphere, an exit opening leading from said atomizing chamber into said air intake passage, an inlet opening leading from said passage into said chamber at a point in advance of said exit opening for admitting air to said chamber in addition to the air entering through said nozzle, a valve in said passage in advance of said inlet openin for regulating the flow of air through sai passage and to said inlet opening, and a second valve in said passage beyond said exit opening for regulating the flow through the passage of mixed air and atomized fuel.

VICTOR R. GAGE.

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