US1419035A - And frank c - Google Patents

Description

l. M. FLANNERY AND F. C. DETTELBACH.

CARBURETOR.

APPLICATION FILED MMI. 1o, 1919.

PatentedJune 6, 1922..

UNITED STATES PATENT OFFICE.

JOHN M. FLANNERY, 0F DETROIT, MICHIGAN, AND FRANK C. DETTELBACH, OF CLEVELAND, OHIO, ASSIGNORS, BY MESNE ASSIGNMENTS, TO THE EAGLE CAR BURETER COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO.

CARBURETOR.

To all 'whom t may concern:

Be it known that we, (1) JOHN M. FLAN- Near and (2) F RANK C. Dn'r'rnLBAcrr, citizens of the United States, residing at 1) Detroit, (2) Cleveland, in the county of (l) Vayne, (2) Cuyahoga and State of (1) Michigan, (2) Ohio, have invented a certain new and useful Improvement in Garburetors, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings.

This invention relates to carburetors of the type employed for the production of an explosive mixture of air and hydro-carbon for the operation of an internal combustion engine as in automobiles, boats, airplanes, tractors, and stationary power plants. For illustrative purposes we have shown our improved carburetor in connection with an automobile engine owing to the particularly severe requirements flowing from the wide speed-range demanded and the necessity of large torque at low speeds. It will be understood however that neither in this nor in other details are we limited to the features of our drawing or specific description since the same is intended to be only interpretative of our generic idea rather than exhaustive of its specific application.

The objects of our invention are the provision of a carburetor which shall afford a rich mixture at low speed graduating uniformly to a comparatively lean mixture at high speed, whereby maximum torque is obtained under all conditions and with a minimum fuel consumption; the provision of a carburetor' which shall be proof against iiooding or choking; the provision of a carburetor of extremely simple construction; the provision of a carburetor which shall in some cases at least permit vacuum tanks or the like separate feeding devices to be dispensed with; while further objects and adm vantages of our invention will become apparent asthe description proceeds.

.in the drawings accompanying and forming a part of this application, we have, .for purposes of illustration but not of limitation, shown the construction and mode of operation of one practical embodiment .of our inventive idea. In these drawings Fig.

Specication of Letters Patent.

Patented June 6, 1922.

-Applcaticm filed March 10, 1919. Serial No. 281,766.

1 represents an automobile engine equipped with our improved carburetor; Fig. 2 is a vertical sectional view through the carburetor showing the throttle closed; Fig. 3 is a sectional view on the line 3--3 of Fig. 2; Fig. 4 is a view similar to Fig. 2 but showing the throttle in open position; Fig. 5 is a perspective view of the carburetor, the mixing chamber having been removed; and Fig. 6 is an enlarged detail sectional view of the nozzle.

Describing by reference characters the parts shown in the drawings, 1 represents thefloat chamber of our improved carburetor having projecting from its side the annular bracket 2 which is traversed by a hori zontal web 3. The top of the bracket 2 is formed with a seat 4 for the reception of the cylindrical mixing chamber 5, while the bottom of the same is formed with a seat 6 adapted for the reception of the inlet elbow 7, the parts 5 and 7 being secured in place by screws (not showr) engaging the ears 8, 8 of the bracket. arried by the web 3 is the fuel nozzle 10 which rises vertically into the axis of the mixing chamber and is preferably formed at its upper end with a laterally enlarged head terminating in a flat top wall 11 defined `by an annular slanting portion 12. The top 11 is also surmounted by an upright cylindrical :flange 13 forming a cup.

This nozzle is formed with a vertical axial fluid-passage 15 leading from the bottom of said cup to the interior of the web 3 where it joins the horizontal passage 16 leading to the iiuid chamber; and also with a plurality of branch passageways 17, 17 which open through the slanting portion 12 and join the main passage 15. Formed in the bottom surface of the web 3 is a chamber 18, wholly disconnected from the fuel ducts, but communicating with the bottom of the cup 13 by means of a plurality of narrow ducts 19 which are so arranged as to avoid all the fuel passageways, The chamber 18 communicates freely with the outer air by means of a pipe 20 which passes through the side of the elbow 7, and the throttle 21 is located in this elbow.

Mounted in the chamber 5 is a slidable n venturi 25, formed intermediate of its length with an inclined seating portion 26 adapted when in depressed position to engage the slanting portion 12 outside of its ports 17, and having above and below said seat the outwardly fiaring portions 27 and 28 respectively. The top of the chamber 5 is shown as flanged at 29 for attachment to the engine manifold 30 in the usual manner, and is also placed in open communication with the interior of the float chamber 21 by any suitable means such asthe pipe 31, the float chamber being otherwise hermetically sealed so that no air can enter the same. From the float chamber a fuel supply pipe 33 leads v`to the fuel tank 34 whichmay be disposed a nearer or greater distance as will hereafter be explained, andinside the float cliainbeiits a float 35 which cooperates with a valve 'rod'Bb to close the valve seat 37 with which the ypipe 33 communicates.

' The connection between thefioat and valve rod may be of any suitable or desired type but we have found the construction shown herein particularly advantageous, that is to Isay: the upper end of the rod 36` is threaded for the reception of an adjustable sleeve 10 which is provided at its lower end with a groove 4-1 receiving` the inner ends of levers 12 whose outer ends engage the float. The rod 3 6 also 'carries a jam lnut 48 which locks the Sleeve in position while permitting adjustment thereof to raise or lowerthe fuel level.A The sleeve and rod project upwardly through ahole in the top of the float chaniloer but are housed in a cap 45 which is herinetically screwed thereon. v

` The loperation of the device is follows: Thefloat is adjusted so as normally to cause the rod 36` "to 'close the fuel inlet when the li'quidlevel reaches the line a in Fig. 2. We will assume however that the float chamber is drainedr of liquid and that the tankis be low the level thereof,` the throttle 31 being closed'. Upon the cranking of the engine the first effect is to create a very `high vacuum in the carbureting chamber and manifold, frequently equivalent to 2O inches of mercury or 9 pounds per square inch below'atmospheric. This "vacuum is transmitted to the float chamber by the pipe 31 and serves immediat'ely to elevate a1 supply of fuel therein from the tank 34; and experience shows that not only does the fioat chamber become filled to the level a, but also to a higher level owing to the fact that the upward pressure ofthe fuel against the valve rod 36 overcomes the seating tendency produced by the float excepting upon a deeper submergence. This tendency is decreased by decreasing the size of the valve-seat aperture and by increasing the ratio of the levers 42. This action may be and sometimes is available as affording a measure of speed-compensation as will hereafter be explained, but need not be so used. In any case, however, it is imperative that the maximum level be lower than any of the nozzle ports.

The suction in the manifold sets up a rapid rush of air through the pipe 20 and ducts 19, which air, owing to the constrictive effect of the cup 13, aspirates fuel through the vertical duct 15, an d by a proper proportioning of those ducts produces a mixture of exactly the right coinposition for idling purposes. So long as the throttle 21 remains closed the sliding venturi remains .seated upon the nozzle top and the fuel jets 17 remain wholly inactive, lf now theI throt-` tle 21 be opened, the inrush of will lift the venturi to or towards the position shown in Fig. 4 (depending upon the amount of throttleopening) and the rush ofair past the ports 17 will aspirate fuel therethrough with the production of an explosive mixture at this point. The richness of this mixture will ydecrease with the opening of the throttle for three reasons: First, because with the increasing elevation of the venturi the distance between the nozzle and the portion 28 becomes gradually wider thereby decreasing the aspirating effect upon the ducts; second, because with the decrease of inanifoldsuction produced by the throttle opening the aspiration of air through the passageways 1.9 falls off or ceases; and'tliird, because with the decrease in suctionthe liquid level in the float chamber falls from ZJ toward a and thus decreases the flow tendency. lf the throttle be opened gradually these changes in mixture are substantially uniform; but if the throttle be opened suddenly, the excesv sive level in the fioat chamber tends to effect a priming action, giving a richer mixture for a few seconds and thus facilitating the accelerationof the motor:

As previously stated this variation in liquid level can be utilized as a part of the compensation if desired or it can be largelyv ignored By making the needle valve small and the lever ratio high, the liquid level ca n be kept within fairly narrow bounds, and vthis indeed is desirable in case the fuel is to be elevated from a tank 34 at any great depth or long distance. But in case the fuel reservoir is close at hand, the lever ratio and valve seat opening can be adjusted so as to afford a large variation in liquid level and hence of automatic compensation arising from this source. i j i lt will be understood that we do not confine ourselves to the elevation of fuel vfrom a tank placed beneath 'the carburetor, since it can equally well be fed from above; we do not restrict ourselves to the omission of a vacuum tank or other feeding devicegthe float valve and its adjuncts can take a great number of forms; the number of fuel ducts and air ducts in the nozzle can be varied;` other means than unassisted air pressure can be employed for moving the venturi; and numerous other changes of detail construe tion and arrangement can be made Within the scope of our invention Which is limited only by the prior art.

aving thus described our invention, What We claim is In a carburetor, in combination, an upright mixing chamber, a fuel nozzle therein having an enlargement, a slidable venturi in said chamber having a constricted portion adapted either to seat upon the enlargement of said nozzle and close the passage surrounding the same or to be elevated thereabove producing a variable passage, said nozzle being formed with a second air passage independent of the first passage, and with independent fuel ducts cooperating with the respective passages and means for controlling the flow of air through said first passage. y

In testimony whereof, We hereunto aHiX our signatures.

JOHN M. FLANNERY. FRANK C. DETTELBACH.

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