US1631716A - Carburetor - Google Patents

Description

1,631,716 June 7, 1927. F. BAVEREY CARBURETOR Filed Dec. 27. 1920 2 sheets-snee*- 1 N 1 1,631,716 Jlme 7 1927 4 F. BAVERE'Y GARBURETOR Filed Dec. 27, 1926 2 sheets-sheet 2 vw. wml

S14/uml T01,

M 63H01 new] Patented June 7, 1927.

UNITED STATES PATENT OFFICE.

FRANCOIS BAVER'EY, 0F LYON, FRANCE, ASSIGNOR T0 SOCIETE DU CARBURATEUR ZENITH, F LYON, FRANCE, A `COIR'POIRA'IION 0F FRANCE.

CABBURETOR.

Application led December 27, 1920, Serial No. 433,477, and in France October 24, 1919.

The present invention relates broadly to charge forming devices, and more particularly to carburetors for sup lying combustible charges to internal com ustion engines.

An important object of the present invention is to provide a carburetor of the multiple Venturi type having the inner venturi adapted to receive an emulsion and of a construction preventing the necessity of a gasolene correction for rich spots such as ordinarily result from multiple Venturi constructions.

Still a further object of the invention is to provide a carburetor having fuel admission to the inner venturi in substantially the plane of the fuel level in the constant level chamber.

The foregoing and other objects, together with their attendant advantages, will be apparentas the invention becomes better understood, by reference to the accompanying 'specification and drawings forming a part thereof, it being premised that changes may be made in the various details and the manner of kopera-tion, within the scope of the appended claims without departing from the spirit of the invention.

Figure 1 is a vertical sectional view, partly broken away, of a vertical carburetor em. bodying the present invention;

Figure 2 is a sectional view on the line II-II of Figure 1;

Figure 3 is a top plan view, partly 1n horizontal section, of a horizontal carburetor embodying the present invention; and

Figure 4 is a transverse sectional View on the line IV-IV of Fig. 3.

Referring more particularly to the'form of invention illustrated in Figures 1 and 2, there is shown a carburetor embodying' the usual constant level chamber 2 and the carbureting chamber 3 having a throttle 4. Entering the constant level chamber below the fuel level therein, is a channel 5 adapted to supply fuel to the vertical channel 6.

Intersecting the vertical channel 6, below the fuel level, is a passageway 7 having the outer end thereof closed by a cap plug 8 and the inner end controlled by a screw plug 9 having a calibrated orifice 10 therein communieating With the lower portion of an atmospheric well 11 formed in the carburetor casing.

Also intersecting the vertical channel 6, f

and preferably located at the level of the Iuel in the constant level chamber, is a second passageway 12 having the outer end thereof closed by a cap plug 13 and the inner end communicating through a calibrated opening 14 in the screw plug 15 with the atmospheric well 11.

The upper end of the atmospheric wellv tube and the inner wall of the well. Formed on the tube 18, at some point intermediate the calibrated openings 10 and 14, is a bead 21 which partially closes the annular space for a purpose hereinafter more fully pointed out. The interior of the tube '18 communicates with the atmosphere throug a suitable port 22.

Extending within the tube 18 is a second tube 24 carried by the plug 25 and provided with a calibrated opening 26 at its lower end communicating with the atmospheric well 11. The plug is preferably hollow and is provided with a series of transverse openings 27. Certain of these openings communicate with a secondary air inlet 2S con. trolled by a suitable valve 29, while other or the openings communicate with a passage 30 formed in the wall of the carbureting chamber and terminating adjacent the throttle 4 for forming a slow speed feed device, as is well understood in the art.

Within the carbureting chamber 3 is the usual venturi 31 havinor its lower end open to the atmosphere. xtending below the lower end of the venturi is a fuel supply therefor which may comprise a hollow casting 32" having a fuel passage 33 leadino thereto and adapted to communicate with7 the atmospheric weil 11 above the annular bead 21 and substantially at the levell of the fuel in the constant level chamber. Supported by the casting 32 is an ejection venturi 34 and a diffusion venturi 35.

It has heretofore been found that double Venturi carburetors of the general construction herein disclosed produce rich spots in the gasolene feed when the throttle is at substantially its intermediate position. Such rich spots have required a supplemental gasolene correction in order to prevent the feeding of an excess of fuel at such times. In the present carburetor, the inner venturi, herein referred to as the ejection venturi, is of such construction as to automatically proportion the fuel supplied at all times in such manner that a supplemental fuel correction is unnecessary. According to the invention, the ej cction venturi 34 has its converging inlet extending from an intermediate portion having a cross section S, while the diverging outlet extends from a portion having a cross section S. This construction provides an abrupt change in cross sectional area intermediate the converging inlet portion and the divergin' outlet portion equivalent to S lminus Sg At this point are located a series of openings 36 communicating at their outer ends with the annular collecting chamber 37 formed by the casting 32 and the ejection venturi. Experiments have shown that it is desirable to locate the openings 36 at a point approximately 4 mm. above the level of the fuel in the annular chamber 37. The ejection venturi in turn discharges into the diffusion venturi 35 at substantially the region of maximum velocity therein. Experiments have demonstrated that with a multiple Venturi carburetor of the character herein shown having an abrupt change in area in the inner venturi immediately below the point of fuel admission thereto, the cross section S4 of the diffusion venturi minus the cross section S5 at the discharge end of the ejection venturi should be substantially equal to one and one-half times the cross section S. While this relationship may vary under certain conditions, advantageous results are not produced where the difference between the cross sections S4 and S5 is less than the cross section S or'more than twice this cross section. In order to produce theI best results, it is also -desirable that the combined area of the openings 36 should equal the zontal carburetor corresponding to parts in the vertical carburetor hereinbefore described in detail are designated by the saine reference characters with a prime affixed thereto, with the except-ion of the areas of the, various venturis1 which are designated in the same manner as in Figure 1. In this carburetor the ejection venturi 34 is illustrated as formed with a fuel admission slot 36 extending partially around the saine, as clearly disclosed in Figure 4. The ends of this slot preferably terminate substantially 5 mm. above the level of the fuel in the annular collecting chamber 37', although this exact location may be slightly changed if desired.

The inlet to the carbureting chamber is illustrated as provided with a. sheet metal cup 38 having screen covered openings 39 therein for the admission of air.

In operation, the suction of the motor, intensified by the combination of Venturi tubes, is transmitted through holes 36 or slot 36 to the channel 33 or 33 and hence to the fuel orifice 14 or k14. It is also transmitted past the bead 21 or 21 to the annular space outside of the tube 18 or 18. The inside of theJ tube 18 or 18 is open to the atmosphere through the openings 22 'or 22. Due to this atmospheric communication, the fuel which has accumulated in the well 11 or 11 while the motor was at rest, can be sucked up, its place being taken by the air entering at 22 or 22". When this amount of fuel has been sucked up, additional fuel continues to flow throughthe orifice 10 or 10 and is sucked upwardly between the tube 18 or 18 and the well 11 or 11 past the bead 21 or 21. The orifice 14 or 14 being above bead 21 or 21 is subjected to the full force of the suction obtaining -in channel 33 or 33. The orifice 10 or 10, on the other hand, each opening as it does below the contracted an nulus left by said bead is shielded from the full suction. The two fuel feeds therefore follow entirely different laws and their combination is such that a constant proportion of gasoline to air can be obtained as is now well understood by those skilled in the art. This operation is due to the tendency of a suction operated feed to enrichen as the constant flow per unit of time feed leansout under increased suction, and vice versa.

Due to the location of the channel 33 at substantially the level of the fuel in the constant level chamber, and to the location of the openings 36 or the slot 36 but a slight distance above this fuel level, the fuel does not have to be lifted any appreciable distance by the engine suction, and -therefore is more readily available for use by the carburetor. This feature is highly desirable from a standpoint of acceleration.

The advantages of the present invention result from the means for preventing the formation of rich spots during the operation of the carburetor, and to the relative cross sectional areas of the respective parts.

Further advantages arise from the means for partially cutting off one of the calibrated fuel feeds from the engine suction and positioning thev other calibratedopening and the fuel supply for the inner venturi at substantially the same level as the level of the fuel in the constant level chamber.

I claim:

1. A carburetor, comprising a carbureting chamber, a constant level chamber, an atmospheric well, a plurality of fuel feeds for said well from said constant level chamber, a tube in said well, means restricting the suction exerted on one of said feeds by said carbureting chamber, and means in said carbureting chamber receiving fuel from said well, substantially as described.

2. A carburetor, comprising a carbureting chamber, a constant level chamber, an atmospheric well, a plurality of fuel feeds from said constant level chamber to said well, a tub-e in said well, means on said tube restricting the suction exerted on one of said feeds by said carbureting chamber, and means in said carbureting chamber receiving fuel from said well, substantially as described.

3. A carburetor, comprising a carbureting chamber, and means for feeding fuel thereto, said means comprising a constant level chamber, an atomspheric well, a plurality of fuel feeds between said constant level chamber and said well, and'means in said well for restricting the suction exerted on one of said feeds bythe carbureting chamber,-

substantially as described.

4. A carburetor, comprising a carbureting chamber, a constant level chamber, an atmospheric well, a plurality of calibrated fuel feeds from said constant level chamber to saidwell, a tube in said wellan enlargement on said tube restricting the suction exerted on one of said feeds by said carbureting chamber, and means in said carbureting chamber receiving fuel from said well, sub'- stantially as described.

5. A carburetor, comprising a carbureting chamber, a constant level chamber, an atmospheric well, a plurality of calibrated fuel feeds from said constant level chamber to said well, a perforated tube in said well, an enlargement on said tube restricting the suction exerted on one of said feeds by said carbureting chamber, and means in said carbureting chamber receiving fuel from said well, substantially as described.

6. A carburetor, comprising a carbureting chamber, a constant level chamber, an atmospheric well, a calibrated fuel feed connecting said constant level chamber and said well below the fuel level, a second fuel feed connecting said constant level chamber and said well at substantially the level of the fuel in said constant level chamber, and means in said carbureting chamber for receiving fuel from said well, substantially as described.

7 A carburetor, comprising a carbureting chamber, a constant level chamber, van atmospheric well, a calibrated fuel feed connecting said constant level chamber and said well below the fuel level, a second fuel feed connecting said constant level chamber and said well at substantially the level of the fuel in said constant level chamber, means in said carbureting chamber for receiving fuel from lsaid well, and means in said atmospheric Well restricting the suction exerted by said carbureting chamber on said first mentioned fuel feed, substantially as described.

8. A carburetor, comprising a carbureting chamber, a constant level chamber, an atmospheric well, a plurality of fuel feeds from said constant level chamber to said well, means, in said well restricting the suction exerted on one of`said feeds by said carbureting chamber, means in said carbureting chamber receiving fuel from said well and a' supply channel for said last mentioned means, said channel being located at substantially the level of the fuel in said constant level chamber and above said restricting means, substantially as described.

9. A carburetor, comprising a carbureting chamber, a constant level chamber, a well, a plurality of fuel feeds from said constant level chamber to said well, a tube in said well having a communication with the atmosphere, means formed on said tube intermediate said fuel feeds for restricting the suction exerted on one of said feeds by said carbureting chamber, and means in said carbureting chamber receiving fuel from said well, substantially as described.

10. A carburetor, comprising a carbureting chamber, a constant level chamber, a well, a plurality of fuel feeds from said constant level chamber to said well, a tube in said well having a communication with the atmosphere, means formed on said tube intermediate said fuel'feeds -for restricting the suction exerted on one of said feeds by said carbureting chamber, and a low speed feed communicating with said well, substantially asl described.

11. A carburetor, comprising a carbureting` chamber, a constant level chamber, a well, a plurality of fuel feeds yfrom said constant level chamber to said well, a tube in said well having a` communication with the atmosphere, means formed on said tube intermediate said fuel feeds for restricting the suction exerted on one of said feeds by said carbureting chamber, a low speed feed communicating with said well, and an air supply for said low speed feed, substantially coincident with the normal fuel level in the as described. f constant level chamber for normally receiv- 10 12. In a carburetor, al venturi having a ing fuel and feeding the same from the confuel collecting chamber therearound, there stant level chamber to said fuel collecting 5 being means for vfeeding {fuel from said chamber, substantially as described.

chamber to the interior of the venturi, Va In testimony whereof I have hereunto set constant level chamber, and horizontally exmy hand;

tending means having its axis substantially FRAN QOIS BAVEREY.

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