US1300517A - Carbureter. - Google Patents

Description

P. S. TICE.

CARBURETER.

APPLICATIQN HLED 1uNE27. 1917.

Patented Apr. 15, 1919.

PEncIvAL s. TICE, on DETROIT, MICHIGAN.'

p CABBURETEB.

Specification of Letters Patent. Patented Apr, 15 '19] 9v Application led J' une 27, 1 917. Serial No. 177,176.

To all whom #may concern.'

Be it known that I, PERcIvAL citizen of the United States, residin troit, in the county of Wayne and S. TICE, a

at Detate of Michigan, have invented new and useful Improvements in Carbureters, of which the following is 4a specification, reference being had to the accompanying drawings, forming a part thereof.

The purpose of this invention is to provide an improved construction of a carbureter adapted to, yield more uniform and complete admixture of the air and liquid fuel. It consists in the elements vand features of construction shown and described, as indicated in the claims.

Figure 1 is a verticalsection axial with respect to the passages of a carbureter Aembodying this invention.

Fig. 2 is a section at. the line, 2 2, on Fig. 1.

Fig. 3 is a section at the line, 3 3, on Fi 1.

he carbureter illustrated in the drawings is shown as having conventional means, commonly called the float chamber, for maintaining app'roximately uniform level of liquid for supplying the mixing chamber. Such float chamber is shown at 1, having communication from the passage, 2, with the main air inlet passage, 3, of the carbureter, (controlled at its inlet by a throttle valve, and having communication from the lower part through a restricted or metering orifice, 5,'formed in the metering plug, 6, with the liquid fuel inlet passage, 7, formed in whatmay be termed the nozzle member, 8. Said nozzle member comprises an axially-apertured boss,8, projecting interiorly and exteriorly of the main air inlet passage, 3, and the. terminal member, 9, screwed into the upper end of said boss, 8, and projecting up into the main mixing chamber, 20. This mixing chamber is formed by means of a sleeve, 10, which depends from the wall of the narrowed upper portion, 11, of the pas- -sage leading to the engine intake, concentrically within the lower enlarged portion thereof, forming an annular pocket, 3, which is a continuation ofthe air inlet passage 3 above the lower end of said depending sleeve 10. 12 is a tubular member constituting an air jet inlet, hereinafter referred tol as the air jet member. It is screwed into the lower top through the.

4, of any desired type),

.engine is at rest.` 'the partial vacuum produced by the intake end of the boss, 8a, and rendered leak-tight at 1ts ]unct1on therewith by a gland, 15. At

the portion which extends above the threadand above the port, 16, of communication of the float chamber with the fuel inlet passage, 7 its exterior diameter is less than that of said fuel inlet passage so that an annular space isdeined between it and the wall of said fuel inlet passage, thus making said fuel inlet, passage annular. Near the upper end of the air jet member, 12, it is sharply constricted as shown at 17, the constriction extending for a short distance and the axial cavity of the air jet member being enlarged immediately beyond the constriction, forms an initial mixing' chamber, 18, for the air and fuel, the mixing being effected by means of lateral slits, 19, 19,- forming apertures leading from the air jet to the encompassing portion of the liquid fuel inlet passage below the upper end of the latter. The airA jet drawn in through the air jet member, 12, having its velocity greatly increased and its passage through the constriction, 17, and

expanding rapidly at its emergence beyond that constriction into the mixing chamber, 20, causes a relatively high vacuum to be produced immediately above the constriction-that is, at the level of the slits, so that the liquid fuel which is lifted in the fuel inlet passage as hereinafter more fully ex- .I

plained, to the margin of said slits is sucked over the margln through the slits transversely to the movement of the air jet and thoroughly broken up thereby in said initial mixing' chamber into which air from the main mixing chamber 20 is also drawn by the entrainment of said high velocity jet which emerges from the constriction 17. From this initial mixing chamber 18 the mixture emerges into the main mixing chamber 20 formed by the sleeve, 10, for further air admixture with the larger quantity of The entering through the main a1r inlet.

operation of the structure described, may be more fully stated as follows:

The well understood operation of the float in the lioat chamber, 1; maintains the liquid Ifuel at substantially the level of the lower end of the sleeve, 10, forming the main mixing chamber, as indicated by the dotted line, w-, and this isthe condition when the Upon starting the engine,

stroke of the engine in the intake passage operating to produce a higher degree of vacuum in the main Amixing chamber, than' -in the oat chamber causes the liquid fuel in' the annular liquid passage, 7, to

10 -liquid tending to rise above the level of said slitsin case vof higher suction. `The' same engine Suction while taking in the main supply of airV throughthe Imain air inlet, 3, causes an inrush through the air jet member, 12, of an air jet whose velocity is relatively high at its emergence from the constriction, 17,`V in the air jet passage, so that i. the higher degree of vacuum produced at that point draws the liquid fuel throughthe slits and atomizes it in the initial mixing cham- 'ber, 18, asV hereinabove stated.

The efficiency of the device for the purpose of producing a proper mixture at ally 'times is. largely dependent uponthe metering of the communication from the float chamber to thev liquid inletv passage, 7 that is, the restriction of that communication to .a diameter such with relation to the cross- Sectional area of the annular fluid inlet pas- Sage that the variation in vacuum to which' the liquid in that passage is exposed, in comparison with the vacuum operating on the liquidin the ioat chamber, shall not hasten the'flow of the liquid from the floatehamber more than proportionately to the flow of air through the main air inlet passage...-

I claim Y 1. In a carbureter, in combination with a main airinlet'passage, an air jet discharging 40 in the vmain air inlet. passage, a fuel inlet passage extending-'adjacent to the air jet passage, the air jet passage bein?,r constrict ed at a short distance back of its discharge. in the main air inlet passage, and laterally.

apertured immediately beyond the restriction for communication with the fuel inlet passage, said fuel inlet passage being extended a short distance beyond said aper- .tures and open at the end there-beyond for i communicatlon with themain "air inlet passage.

of June, 1917. 2. In a carbureter characterized as set out passage.

3. In a carbureter characterizedas set out in clalm 1, the air jet passage being enlarged beyond the construction thereof, forming a minor mixing chamber within the mixing chamber'which is formed by the main air 60 inlet passage,

. 4:. In a carbureter characterized as set out in claim 1, the lateral apertures of the air jet being` dimensioned f or admitting fuel .from lthe lfuel passage in thin relatively widey spread jets or spray.y

5. In a carbureter.characterized as set'out in claim 1 foregoing, the airjet passage being enlarged beyond the constriction thereof, forminga minor mixing chamber. within the mixing chamber which is formed by the 1 main air inlet passage, said minor .mixing chamber being of a less cross-sectional area than the portion of the-main mixing chamber which encompasses the air jet and fuel inlet passage at the plane of discharge therefrom.

6. In a carburetor, in combination with a mixing chamber, a liquid level governing chamber adjacent thereto, having a suction so connection from above the liquid levelbf said governing chamber leading to the mixing chamber, a liquid fuel passage from the lower part of the governing chamber into the mixing chamber, and a metering device in said passage for restricting the flow of liquid therethrough, a main air inlet pasv sage into the mixing chamber, an air 'jet discharging in said main air inlet passage,

the fuel passage from the level-governing chamber being adjacent tosaid air jet passage; the air jet passage being constricted a short distance back of its dischargein the main air inlet passage, and laterally apertured beyond the restriction for communication with said fuel passage, the latter being extended a short distance beyond said a'pertures and open at the end therebeyond `for communication with the main air inlet lpassage.

Intestimony whereof, I-have hereunto ,setv my hand at Chicago, Illinois, this 21st day rERorvAL y s. TICE.

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