US1224489A - Carbureter. - Google Patents

Description

y nonna n. norsrneisa, or ne. raver-rn, namens.

oannuanrnn.

Specification oi Letters Patent.

Patented May il, lltnli.

Application fi-lednguot 13,1935. Serial lo. $25,831.

fh all whom t may cio-neem.' f

le it known .that l, Hoeren N. Morsmenn, a citizen of the United States, residing at La Fayette, in the county of "Tippecanoe and State ofindiana', have invented a new useful improvement in Carbureters, oli which the following is a specification.

My inventionrelates to improvementslin y earbureters and my object is to provide a novel design of carbureter particularly suited for use on internal combustion engines which operate under considerable V.- riations of speed and load, such Jfor stancev as automobile origines. /The yCarburetion requirements of such engines are peculiarly difiicult in that the demand of the engine for gas is subject to the widest and most sudden iluctuatio'ns, and it is my primary purpose therefore to provide a carbureter of such construction as'to be capable of efficient action under these conditions.

ln Figure 1 of the accompanying drawing l have illustrated in longitudinal section a form of carburetor embodying the principles of my invention, and from this draw-v ing, in connection with the following description, it will be possible to fully comprehend, these principles and one Inode in which they may be applied in carrying the invention into eEect. Fig. 2 of the drawing illustrates a modified construction of the-valveloading mechanism.

The primary structural element of a carbureter embodyingmy invention consists of ar. air conduit or passageway member opening at one end to the outer atmosphere and the other end discharging into the intake passage oi' the engine. Such a conduit is illustrated in the drawing (Fig. 1) as a tubular casting 1, the end 2 of which is provided with a flange 3 by which attachment to the engine may be effected, While the opposite end l is provided in its upper face with an aperture 5 opening to the atmosphere. The tubular member 1 is preferably of Venturi-tube formas shown, consisting of a contracted throat'G with a relatively quick-tapered inlet portion leading from the end 4 and a relatively lon g-tapered outlet portionleadin to the end 2. The latter end is prefera ly cylindrical to coperate with an ordinary butterfly throttle valve 7, while the end 4 may be of boxlike form as shown, in order to provide a flat suri'ace surrounding the aperture 5.

'.lhe second structural element of my carring.

`a weight 12. mounted on a lever 13 which is pivoted at i4., ina suitable pivot bearbureter consists' of an automatically operating loaded valve controlling-theadmission of air to the' outer end of the air conduit or passageway-member. lathe embodiment of the invention which. l have illustrated, this valve consists vof a srrewthreaded cage or v seat-ring 8 which is mounted within .the

aperture and has a ange 9 resting on the dat upper face 'of the box-like end yl, and a puppet or mushroom valve 10 the head of which' normally seats against thefseat-ring 8 and the stem of which is` guided bya' hub carried upon the spider'arms 1l of the seat- 'lhe valve l0 is loaded by means of ingcarried by the seater-ing members` 8,' and has its opposite end forked to embrace the 4stem of the valve 10, the forked ends being slotted to en' age a pin 15y mounted on the valve. By t is construction the weighted lever'13 urges the valve toward' its seat with an approximately constant forca-so that in the operation of the carburetor the pressure' within the end l of the conduit 1 will at all times remain approximately 'the saine, e'. e., below atmospheric ypressure by an amount determined by the edective force exerted on the valve stem by the weighted lever 13.; rlhis force may readily be varied either by removing the weight 1Q and substitutingvga lighter or heavier piece therefor, or by adustlng the weight along .the lever 13,A which latter result may readily be et ected by screw-threading the end of the lever 13 and fixing theweight 12 thereon by adjustable nuts 16 as shown in the drawv ing, so that the constant sub-atmospheric pressure or vacuum maintained during normal operation 'of the carbureter in the chambered endl thereof may be 'accurately fixed to obtain the best results. A

In order to steady the action of the valve 1() it may be advisable under certain circumstances to apply dampening means thereto. Such means is shown in the drawing as a conventional dash-pot arrangement, the cylinder 17 being carried by arms 'formed on the seat-ring 8, and the piston comprising a disk 18 detachably mounted upon the eX- tended end of the valve stem.

In Fig. 2 lhave shown a modified construction of thevalve-loading means. ln this construction a pair of tension springs 30 are caught at their inner ends by a slotted connector 31 the slot of which embraces the valve stem, and are fastened to swivels 32 carried by adjustment screws 33 at their outer ends. The screws are mounted in blocks 34, which form corner members of a parallel linkage 35, the other pair ot' corner members (3G) having bores to receive the valve stem. The latter carries a nut 37 which contacts with the top corner member of the .parallel linkage. lt will be understood that as the valve opens under suction thel parallel linkage will be flattened out7 against the tension of the springs Ill), and that by reason ot the changing angle ot the links, which in et'- t'ect constitute opposed toggle-joints, the eft'ectivo load on the valve may be keptl almost constant throughout its range of movement. The value ot' the load may beadjusted by means of the screws 33, by increasing or. de creasing the normal-tension of the springs 30.

The third structural 'element of a carburetor embodying my invention consists of a relatively small air-intake conduit entering the large conduit l intermediate the length of the latter. and having free communication with the atmosphere at its outer end. ln the drawing this element is shown as a Venturi-tubc lll o't the same general construction and proportions as the large tube 1 and entering the latter at an angle of 45 to the axis tlu-reot'7 the discharge end of the tube 19 being slightly behind the throat.

The Vtom-th structural element of my carbureter consists of a fuel nozzle opening into the small Venturi-tube 19 intermediate its length. This nozzle is shown on the drawing at 20, entering' the tube 19 at an angle ot' 45 and terminating. in the same position with reference to the throat of the tube 19 as the discharge end of the latter occupies with reference to the throat of the tube 1. rlhe nozzle Q0 may be controlled as by'a needle-point valve 21 screwthreaded in the Wall of the conduit 1 and having a knurled adjustment head 22 accessible from the top of the carburetcr.

The last structural essential of my carbureter is a means for supplying fuel to the nozzle 20. Such means is shown as a constant-level float-controlled supply-chamber 22. The construction and operation ot' such devices is well known and forms no part of my invention. It need only be said therefore that the fuel supply is constantly maintained at a pre-determined level within the chamber 22j and it is immaterial to my invention what means be employed to this end, or what the level nl the fuel may be., so long' as itis not high enough to escape by gravitylrom the nozzle. aperture nor low enough `to require an inordinately great suction on vacuum to lift it to the nozzle aporture.`

llhe several structural elementsI 'it my car bureter having been arranged iu the manner described, andthe carburetor secu-red to the intake member oi' an internal combustion engine or like gas-consuming machine, it will function in the following manner.

lVhen the demand upon the carburetor for gas is at a minimum, as in the cranking or idling of an internal combustion engine, tlc 'valve 10 may remain seated .the entire supply entering through the tube l) or the valve 10 may open very slightly-to. admit a small quantity. of air. As the. air entering the tube 19 approaches the throat of the latter it will,l by reason ol its velocity, exert strong' aspirating eliiect upon the nozzle 0, and will draw the 'fuel up Within the 4trame and cause it to spray outward into the passing air stream7 whereby the latter becomes impregnated with the atomized or volatilized fuel and is rendered explosive or combustible. The mixture or carbureted air will issue from the tubo 19 and pass through the outlet end of the tube 1 and thence to the i, engine. The proportion ot fuel contained in the air may be regulated by adjusting the load upon the valve 10, whereby the vacuum within the carburetor may be varied, until the best results are obtained, such possibility of adjustment being particularly useful in internal combustion engines by reason of the fact that air leaks frequently exist around the valves and intake pipe, connections ,of the engine, which leaks may dilute the entering stream of carbureted air to such an extent that it becomes desirable to compensate for the dilution by initiall 'over-carbureting.

As t# e demand of the engine for gas rises substantially above this minimum value, the

g valve l0 will open further admitting a substantial quantity of air to the chamber Ll. This air in passing through the tube 1 will exert an aspirating ettect upon the discharge end of the tube 19 which is cumulative upon the static vacuum eliect, whereby the velocity ot the air passing inward through the latter will be increased, 'and by consequence the l .aspirating efect upon the nozzle 20W1ll be I' y increased, whereby an increasing percentage of fuel will be delivered from the nozzle, such increasing percentageor over-carburetion serving to compensate for the dilution effected by the air entering through the valver 10. y i

Asthe demand forges increases still fur ther the valve 10 will open still wider, the vacuum Within the chamber 4 being thereby maintained at its proper constant value, and the increased aspirating effect due to the higher velocity' through -the'tube 1 being relied 'upon to increase the effective dey livery7 of fuel from the nozzle 20 to compensate for the increased volume of dilutingv air, the needle valve being adjusted to obtain the best results. y

From the foregoing it will be seen that my carbureter is characterized by the "following principles of operation: First, may he dewaage@ lined as a constant vacuum instrument, in that the static or absolute vacuum Within the body thereof is designed to remain at an approximately constant value throughout the range of action, being so maintained by the loaded valve. (It will be understood of course that the same effective results may be obtained with various other forms of valves and loading means). Second, the increased eective fuel delivery which compensates for the diluting air is supplied by a cumulative aspirating effect of the tubes l and 19 and Wholly Without material change in the static or absolute vacuum.

`While l have particularly described a specific construction which I find Well adapted to perform the objects of my invention, it

is to be understood that this description is illustrative only and for the purpose of rendering my invention more clear, but l do not regard the invention as limited to the details of construction and arrangement shown, nor to any of them, except in so far as l have included them vWithin the terms of the following claim, in Which it is my intention to claim all novelty inherent in the device as broadly as is permissible in view of the prior art,l v

What l" claim is:

ln a carbureter and in combination, a relatively large Venturi-tube having its exit end adapted to be connected to an engine to be suppliedand having an air admission port in its entrance end, a constantly loaded automatically operating valve controlling 'the .i

admission of air through the said port, relatively small Venturi-tube having its entrance end open to the atmosphere and its exit end discharging into the said larger Venturi-tube at an angle to the axis thereof and at a point behind the throat of lthe saine, a fuel nozzle discharging into said smaller Venturi-tube at an angle to the axis thereoi and at a point behind the throat of the and a constant pressure means for supplying fuel to the said nozzle.

N. MGTSNGEL. .ln presence oi"- G Aviaire, l C, Tunesien.

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