US1325689A - Carbureter - Google Patents

Description

dit

THUMAS W. BURR, F STNEHAM, MASSAHTIFETTS.

GARBURETER.

assenso,

.application ler November 28, 1917.

To all fwiom it may concern:

Be it known that l, THOMAS WV. BURR, a citizen of the United States, and a resident of Stoneham, county of Middlesex, and State of Massachusetts, have invented an improvement in Carbureters, of Which the following is a specification.

This invention relates to certain improvements in carbureters `of the type in which the lliquid fuel is `drawn up thereto from a low level tank', which is open to atmospheric pressure, by the suction action of the engine; and more particularly to certain. improve-J ments in a fuel feeding device of the type disclosed in my pending application, Serial No. 196,943, in which no auxiliary reservoir is employed, the supply pipe leading directly from the main tank to the carbureting chamber, so that it is practically dry at all times in that it, at no time, contains any sub-- stantial quantity of fuel in liquid form.

ln this device also, the liquid fue] supply pipe, which entends from the lowdevel tank, opens to the carbureting chamber at the ene gine side of the throttle, which. controls the air supply thereto, so that said pipe is open to the full suction action of the engine, and the discharge therefrom is controlled by a needle valve which is automatically. operated With the throttle in'predetermined proportion, so that the relative proportions of air and fuel are essentially maintained ander all conditions.,

The object of the present invention is prii marily to provide a simplified form of device having` the above characteristics, so 'that the cost of manufacture thereof may be reduced, as compared with prior devices for the purpose; and the danger of its getting out of order will be reduced to a minimum, and to accomplish this object Without impairment of eiiiciency, but with possible increase in efficiency.

I accomplish this object by means herein after described and illustrated in the accompanying' drawing. in which:

Figure l is a side elevation of fuel feeding device embodying my invention.

Fig. 2 is a plan vien7 thereof.

Fig. 3 is a sectional view on the line 3W?.

specification of Letters EPatent.

Patented lien.. ad., this.. Serial No. Rodda-.

Fig. d is a sectional View on the line fit-t Fig. l. Fig. 5 is a general view, illustrating the combinationn As shown in the drawing, the liquid vaporG lenig device, embodying the present invention, comprises a casing o oi cylindrical' form, having ears a at one end, adapted to connect the same directly to the intake manifold of the engine, and having its opposite end closed by a cap removably secured thereto. An air supply pipe c, of substantially smaller internal cross-sectional area than that of said casing, and which, in practice, is arranged so that the air passing therethrough will be heated, is connected to said casing at right angles; and a hollow cylindrical throttle valve al, closed at one end and open at the opposite end, and having` a port al in one side thereof, is disposed in said raising' with its closed end adjacent said cap 7), and so arranged that, when rotated, its port .may be brought into register withthe opening in the casing1 to Which. the air supply pipe c is connected. The head end of said. valve d is provided with a tubular stem e which extends through said cap if and is rotatable therein, and a nut j, having an operating; arm f extending therefrom, is mounted on the outer end of said stem and is locked in position thereon by a set screw g, or other suitable means, to provide means for controlling; said valve, the movements of which are limited. by fingers .e on said. arm, arranged to engage a stop lug e' on the cap l).

rllhe liquid fuel supply pipe j' is extendedV from the bottom of a suitably vented, low level, liquid' fue] supply tank it into said casing, at a point between the open end of the throttle valve and the end of the casing which is connected directly to the intalte manifold; the inner end of said pipe beingF extended beyond the longitudinal center of said casing, and having a nipple m mounted therein, the center line of its bore being coincident with the center line of the casing, liavinpr a side opening' connecting said bore with said supply pipe j. rlhe bore of said nipple, next the suction end of the casing, is preferably enlarged and Covered with a 'iti fine mesh screen m', as shown in Fig. 4,1and a shoulder m2 is formed in said bore between said enlargement and the point of connection of said supply pipe therewith. A tapering valve seat is formed in said shoulder; against which a needle valve a is adapted to seat, the stem of which is extended through and threaded in the stem?l of the throttle valve and through the bore of said nipple. 'Ifheouter end of the needle valve stern` is provided with a head 0, by means of which it may be conveniently adjusted, and a lock nut p is providedion said stem for locking the same in adjusted position. An inclined is formed on the' outer end of the head concentrically with cam-faced proJection b the needle valve stem, and a correspondingly inclined cam face is formed on the nut said 'faces being constantly held in Contact by a spring 'g surrounding the stem t and interposed between `the inner side of the cap b and the head end of` the valve In practice the vparts are so adJusted that lwhen they are in initial position, and one port and become mixed therewith. Under these conditions only suiiicient mixture will be supplied to run the engine 'without load. It will be understood that the exact initial adjustments of the valves will dependto a large extent on conditions, and that the relative extent of opening of the two valves, when in initial position, will be varied according to particular requirements.

A In the initial position of the throttle valve, its closed end is held at a suiiicient distance from the cap to permit the same to be axially moved toward said cap tor a distance equal to that which it is necessary to move the needle-valve axially, to. move the same from a position, in which it is seated, to its fully open position, so that when the arm f is movedto -pen the throttle valve, as its cam nut-f1 rides up on the cam projection b', the throttle valve will be moved axially toward said cap as itis rotated, and as the needle valve n is mounted iu the stem ot the throttle valve. it will be carried away from its seat by the throttle valve, as thelatter is opened; the relative arrangements of cams and valve ports being such that the volume of air, whichfmay bey drawn 'in through the port fl of; the throttle. and the volume of liquid whichwill be permitted to escape past the needle valve, will be in direct and Vconstant proportion ind all positions thereof. Then the valves are closed, the `opposite movements will take place, as will be obvious.

Itis essential to the successful operation of the above described device that the cross sectional area of the air inlet be lessthan'- that of the air suction chamber to which vthe engine is connected, so that the engine may act to A'reduce the air pressure in said chamber to a suiiicient extent in the completely open position of the throttle valve, to insure the discharge of liquid fuel into the mixing chamber in sufficient quantities to maintain the desiredl vproportions of air and fuel.

The device above described is not only of simple construction, but it isunlikely to et out of order, and it is adapted to be ad- Justed to meet widely diHering demands.

' I claim 1. A carbureter comprising a' casing having acarbureting chamberto which air and fuel are supplied, a cylindrical throttle valve mounted for axial movement in said casing and rotatable to vary the air supply to said chamber, a needle valve carried by said throttle valve in axial alinement therewith and arranged to be operated to vary the fuel supply to said chamber when moved axially, and means to cause simultaneous axial and rotational movements of said throttle valve, to operate saidneedle valve, and to cause simultaneous and corresponding control of the air and fuel supply to said chalnber.

Q. A carbureter comprising a casing having a. carbureting chamber to which air and fuel are supplied, a cylindrical throttle valve mounted for axial movement in said casing and rotatable to vary the air supply to said chamber, a needle valve carried by said throttle valve in axial alinement therewith and arranged to be operated to vary the 't'uel supply to said chamber when moved axially. means to cause sin'iultaneous axial and rotational movements,'of said throttle valve to operate said needle valve and simultaneously and eorre'spondiugly control the air and fuel supply to said chamber and means permitting axial adjustment of said needle valve. while said throttle valve, is

held against rotation, to varv the fuel supply relative to the air supply.

3. .i\ carburoter compr1slng a casing havrotationally to vary the air supply to said chamber, a spring arranged to move said throttle valve axially in one direction and a, cam for 'moving it in the opposite direction when the valve is rotated, to cause corresponding axial movements of seidv needle valve and simultaneous and corresponding control of the air and Jfuel' supply to said chamber.

In testimony whereof, I have signed my 10 name to this specification.

THOMAS W. BURR. Witness:

L. H. HARRIMAN.

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