US1594682A - Carburetor - Google Patents

Description

w. MOR-TON GARBURETOR Filed July v11, 1921 Aug. 3 1926.

Ving drawing Pianta; aug. 13,1926.

rUNITED 'STATES' N 1,594,682 PATENT OFFICE.- Y

wurm. xonrom or wnrnson, ournmo, msm.

OABBURETOB.

Application filed luly` 11,

im. serial z 0. 483,699.

This invention 'relxites to charge forming flows through a passage '3 into the. bottom devices and more particularly to carburetors for internal combustion engines.

It is an object of the invention to provide a device which will successfully handle present day low grade fuels and which require a better breaking up or finer division, thus permitting a closer and freer combination with air at the time of 'atomization to form highly combustible charges which will produce even llame propagation and consequent even pressure uponthe engine piston,- eliminatin to agreat extent knocks produced by irregular combustion.

The invention consists in supplying the ingoing air with the necessary quantity of fuel for low engine speeds and in preparing the fuel for thorough combination with the ingoing air so that itvwill be carriedintoV the engine in complete combustible form at.` all engine speeds.

The invention` also consists in providing improved and eiiicient means for controlling the mixture by admitting air into the fuel passa" e prior to atomization and regulating this air inlet. l

Further, the invention consists in novel means for increasing the air velocity through the restricted portions of a venturi into which fuel .is introduced to lprovide easy starting.

With the foregoing and other ends in View, the invention consists in certain other new and useful features in the construction, arrangement and combination of parts, all as hereinafter more fully described, reference beinghad to the accompanying drawinin which--v 4 e igure 1 is a -transverse vertical section through a device illustrative of the' invention; y' Fig. 2 is a horizontal section of the same substantially upon theline X-X of Fig. 1;

Fig. 3 is a; sectional detail of the upper portion of a venturi; .i l

Fig. 4 is a detail of the member shown in 3 and in end'elevation, and

Fi Fig'. 5 is a sectional -detail of a lower Ven" turi member. i v

The carburetor shown in the accompany-A and illustrativeof the inven- "tion, comprlses the usual and common oat' chamber 1 containing a suitable oat 2 with any suitable means operated b theloat for controlling the admission o fuel to the chamber. From the oat chamber the fuel.

of a suitable chamber or well 4-formed in the b ody of the carburetor between the .chamber 1 and the' main air passage 5 in the body which extends upwardly through an extension 6 of the body, which extension is dapted to be connected kto 'the lower end of an engine intake manifold (not shown).

vVlr'ithin the'lower -end of the well 4 is a suitable opening 7 which, during engine operation, controls the flow of fuel from the float chamber intothe well and extending downwardwithin the well from the upper end thereof is a tube 8 with its lewe-rend adjacent to andspaced from the jet opening 7. A small air inlet opening 9 1s provided l at the upper end of the well 4 to admit air into this well, and if found desirable, this air inlet 9 my beprovided with any suitable ineans (not shown) for controllingflthe size`of the inlet or it may be made of a fixed size to be determined upon when the carburetorn is built.

From `the upper end of the tube 8, a pa'ssage 10 extends laterally within .the body and opens into an annular passage or chamber 20 yformed in a Venturi body, which, f

venturi is indicated as a whole at 12, said venturi comprising an upper member 13, shown in Figs. 3 and 4, and a lower member 14, shown in Fig. 5. These members are set within the bore ofthe extension 6 of the body and together form a Venturi restriction within the main airpassage leading to the engine.

ladapted to seat upon a shoulder of the bore and hbld the venturi securely 1n place therein." This member 14: is also formed member 13 to form a very narrow annular passage, vertically 'disposed and communieating with the opening 17. At the outer side of the Bange' 1-9 andbetween it and the body of the carburetor is formed an annular chamber or passage A20 which surrounds the ange 19 and consequently, extends around The lower member vis formed with an annular outwardly extending flange 05 with an upwardly extendinglannular rib 16 loo the venturi opposite the outlet or discharge s ot 17. with the discharge slot through a series of notches 19" formed in the lower edge of the flange 19, as shown in Fig. 3. With lthis arrangement a very narrow annular outlet opening for the fuel is provided in the restricted portion of the venturi and this' outlet is in communication with the annular chamber surrounding the venturi, through a restricted and tortuous passage at the outlet of which the fuel is taken up by the inrushing air. The fuel will lose its inertia in large degree during flow to the outlet through the tortuous and restricted passage because of such restriction and upon passing from the outlet into the ingoing air stream, it will be finely divided and picked up by the currentof air moving at high velocity through the Venturi tube, as distinguished from entering 'the air stream un'der pressure and with velocity, and therefore to a greater or4 lesser extent, in the form of a solid stream. f

At the side of the venturi op osite that at which the passage 10 is locate is an/outlet 21 controlled in any suitable manner as by au adjustable needle valve 22, and this outlet communicates with a small vertical passage 23 formed in the extension 6 and extending upward' past the throttle valve 24 which is located in the bore of this extension. A small outlet passage 25 leads from the passage 23 into the main passage or bore of the extension 6 just above or beyond the throttle valve and thus an idling passage is provided communicating with the chamber 20 and extending past the venturi and the' throttle valve so that when the engine is idling and the throttle is closed, as shown' in Fig. 1, just suliicient fuel will be drawn through this passage to keep the engine running.

As fuel is drawn through the idling passage, the chamber 20 is supplied with fuel from the tube 8 within the well 4 and therefore a quant-ity of fuel is maintained with- 'in the chamber 20 adjacent the main or annular outlet slot 17 so that uponthe opening of the throttle, fuel will be at once available forv the main annular discharge, the direction of flow from the chamber being simply changed from out throughthe idling passage to the main annular outlet. Fuel will therefore be supplied through the main outlet of the venturi immediately upon opening of the throttle and the engine-will therefore have a quick pick up. To prevent too much fuel being drawn through the idling passage when the throttle is closed, this passage is controlled by the needle valve 22 which may be adjusted -to vary the iiow.

Itwill be noted that the normal fuel level v u inthe fioat chamber and consequently in the.

well 4, is considerably below the annular This chamber 20 communicatesl specifically limited in main outlet opening17. This arrangement is provided to prevent flooding through the main outlet opening during idling and at low engine speeds. At high en 'ne speeds or upon increase of speed, the' uel will be gradually drawn from the well 4 through the tube 8 until the well is emptied. When the well is empty, air will be drawn in carburetor having a jet nozzle located in" the center of the venturi, to give a rich mix' ture at high engine' speeds. This is corrected in the present construction by admitting air into the fuel supply prior to its -entrance through the annular and restricted discharge opening, `and this arrangement also provides efficient means for regulating the amount of fuel at high engine speeds. By limiting the amount of air which may enter the well through the orifice 9, the

amount of fuel which' willbe consumed at various engine speeds, may be regulated, as for instance, should no air be permitted to enter the well, the fuel outlet at all speeds will be directly under the influence of the suction produced in the venturi, and by varying the amount of air entering the well, the strength of the mixture may be controlled.

To provide for easy starting of the engine, a tubular choke member 26 having a closed and tapered upper end 27 is provided within a suitable bearing in the lower part of the carburetor body and this choke member is moved vertically endwise by means of a link and lever connection, indicated at 28, to project its upper tapered end into the r'estricted portion of the venturi, further restricting the passage at the point where the main fuel outlet 17 opens into it, and thus the strong suction and higher air flow created thereby at the discharge will give a strong mixture for starting purposes.

While the construction shown in the ac.

detail, it will be understood that changes may be made therein without departing from the spirit of the invention, and 1 do not, therefore, limit myself to the particular construction or arrangement, except aS certain of the appended claims.

Having thus fully described my invention, what I claim is 1. In a device of the charact 4r described having a mainair passage, a enturi -restriction 1n said passage comprising an upper and a lower member inserted 1n the passage with a restricted space between the adjacent end surfaces of said members to form an annular fuel outlet opening into the main air passage, said members together forming an annular fuel chamber communieating with the outlet and one of said members havngan annular flange extending into said annular chamber and `providing a restriction between said outlet and chamber.

2. In a device of the character described having a main air passage, a Venturi restriction in said passage comprising an uper and a lower member, said lower member liaving an upwardly extending annular rib with its upper face spaced from 'the adjacent lower `face of the upper member to provide a horizontally disposed annular outlet passage opening through the venturi into the main air passage, said annular rib also forming at the outer side thereof an annular chamber surrounding the venturi, and an annular flange `on the upper member extending downward into the annular chamber and spaced a restricted distance from the outer vertical face of said rib on the lower member to provide a restriction between the annular chamber and the annular outle passage WALTER MORT( )N

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