US1779803A - Carburetor for internal-combustion engines - Google Patents

Description

Oct. 28, 1930. .A. DROGO CARBURETOR FOR INTERNAL COMBUSTION ENGINES Filed Feb. 20. 1922 Fig.8.

115s Fig.1.

I 1. Fun 5 5 2 a 4 5 2 uJ 2 1 R m .9 8 w 5 I 7 fi 7 1 2, 6 J 1 e r nvvcwme Ava-MEN 019060 ZTTORNEYS Patented Oct. 28, 1930 PATENT OFFIC AUBELIEN DROGO, OF PARIS, FRANCE GABB'UBETOR FOR INTERNAL-COMBUSTION ENGINES Application filed February 20, 1922, Serial No. 538,033, and in France February 28, 1921.

The object of the invention is to provide a carburetor free of the capillary phenomena connected with the usual atomizing nozzle and capable of supplying proper explosive mixtures with both heavy and light distillates.

This invention will be best understood from a consideration of the following detailed description, reference being had tmthe accompanying drawing.

Inthe drawings:

Figure 1 is a lon 'tudinal vertical section of the carburetor ta on along the line 1-1 of Figure 3.

Figure 2 is a fragmentary vertical section taken along the line 2-2 of Figure 3.

Figure 3 is a horizontal sectiontaken along the line 33 of Figure 1.

Figure 4 is a fragmentary vertical section taken along the line 4-4 of Figure 3.

Figure 5 is a fragmentary horizontal section taken along the line 55 of Figure 4.

Fig. 6 is a diagrammatic view of the entire carburetor particularly illustratin the relative arrangement and location of t e various passages and connections.

Referring more particularly to the drawings, 1 designates a float chamber of the carburetor which includes a float 2 of any ap- 3 proved construction. The float chamber has a cover 2" at its upper end in which is formed the upper end 3 of a passage which is in communication with a Pitot tube 4, the free end of said tube opening at the mouth of the air intake 6 of the carburetor, with the end 5 being located in the direction of the flow of the air to said motor.

The float chamber 1 is connected by a passa e Z with a suction well 8 which is provided with a plug 9 having a properly diminished aperture 10. O enmg above the plug is an end 11 of a fuel intake conduit 12 projecting into a distributor pipe 13 which is connected either directly or through convenient tubes with the inlet passage 14 of the motor. The inlet passage 14 is in communication with air intake 6, the suction being regulated in the said intake by a throttle valve 16 which is controlled throu h a cam member 20 59 actuated by a shaft 21. 'I he shaft is operated in any approved manner through connections 1with the usual throttle control of an automo- In the opening of the intake 6 is arranged the endof a tube 17 which I describe as an up-stream Pitot tube, the said end being directed in an inverse position to the end 5 of the Pitot tube 4 and the said tube 17 through a passage 17 a and a passage 24 in the cover 2 connects the opening ofthe intake 6 with the upper part of the well 8 which is provided for feeding the liquid fuel.

The foregoing assembly is diagrammatically illustrated in Figure 6 and functions in the following Way:-When the motor is at rest, the end of suction tube 12 is slightly submerged in the fuel contained in suction well I take tube 6. The pressure in the float chamber and in the suction well will, therefore, be nearly equal, and fuel will flowfrom float chamber to suction Well by the action of gravity. The diameter of the aperture in plug 11, and the level of' liquid in the float of fuel intake conduit 12 is neither completelysubmerged in, nor entirely above the level suction well 18 and, since aperture 10 in plug 11 limits the rate of flow by gravity of fuel from the float chamber to the suction well, it becomes 'necessary to provide supplemental means for accelerating the rate of plished by the upstream and downstream Pitot tubes 4 and 17 The increased velocity of the air flowing into air intake conduit 6 reacting on the oppositely directed Pitot tubes, creates a pressure differential in float owof fuel through aperturelO 1n proportion to the increasing speed of the motor. This is accomchamber are adjusted so that the extremity the nozzle of an ordinary carburetor.

chamber 1 and suction well 8 which has the effect of forcing fuel into the suction well at a rate which is a function of the velocity of the air passing through said air intake tube. The Pitot-tubesfunction,therefore,to maintain the liquid in suction well 8 at the same level as at idling speed i. e. so that the end of suction tube 12 is neither submerged in, nor above the level of, the liquid in the suction well. From the foregoing, it is evident that the suction tube will aspirate an emulsion of fuel and air through extremity 11 throughout the range of motor speeds. The suction tube thus replaces, and is in a rough'way equivalent to, It will be noted however, that no capillary phenomena are involved in its operation as is the case with the usual suction nozzle, and as a consequence, none of the usual difficulties at starting and idling speeds are encountered.

Should, for any reason, the level of the float chamber 1 be maintained constant the liquid will flow through the plug 10 with a speed which is proportional to the speed of the air in the suction pipe 6 at the plane passing across the orifice of said pipe. It is possible, when the motor is running slowly, to have the proportion increased by taking the fuel from the level 7Y lower than the level 7 Y thus having a supplemental charge equal to the depression due to the suction of air at the orifice of the pipe 6. This effect is a trifle at high speeds but it is very noticeable at low speeds as well as when starting the motor. In this manner the starting of the motor is made easier.

The Pitot tube 4 is connected through a passage 22 with passage 3 which is formed in the cover 2 A short passage 23 extends downwardly from the passage 3 and opens into the top of the well or float chamber 1 and above the level of the liquid. A valve 26 in the passage 27 which opens into the intake 6 adjacent the valve 16 forms a by-pass from the passage 22 to the intake 6.

The distributor 13 has a perforated end or rose 13 which is adapted to be disposed within the valve chamber of the internal combustion engine for further breaking up the fuel and air before it enters the engine. It will be appreciated that while I have shown one tube 13 any number may be employed which may be required for the purpose.

It may happen that owing to the special arrangement of the motor it may be possible to directly bring to the valve chamber the emulsion of liquid fuel and air. In this instance the suction pipe 12 will open directly into the pipe 6 at a convenient point between the throttle 16 and the motor. In this construction the valve 26 will be opened for placing the passage 3 directly in communication with the intake 6 at a point adjacent the valve 16 and through the passage 27.

What I claim is:

1. A carburetor comprising in combination an air intake conduit, a valve controlling said conduit, 2. well having an opening in the wall thereof communicating with the atmosphere, a fuel conveying system including a passageway having one extremity communicating with said well and the other extremity communicating with said air intake conduit, said passageway being separate from, and independent of, said opening in the wall of the well, a fuel reservoir communicating with said well through an orifice of predetermined dimensions and means operable to vary the flow of fuel through said orifice in accordance with variations of the velocity of the air flowing into the air intake conduit.

2. A carburetor comprising in combination an air intake conduit, a valve controlling said conduit, a suction well having an opening in the wall thereof communicating with the atmosphere, a suction conduit having one extremity terminating inside the suction well and another extremity in communication with the air intake conduit, said suction conduit being separate from, and inde endent of, the opening in the wall ofthe suction well, an enclosed fuel supply chamber communicating with said suction well, and means including a Pitot tube for varying the pressure in said fuel supply chamber in accordance with variations of the velocity of the air flowing into the air intake conduit.v

3. A carburetor comprising in combination an air intake conduit, a valve controlling said conduit, an enclosed suction Well, a suction conduit having one extremity terminating inside the suction well and having another extremity in communication with the air intake conduit, a fuel supply chamber communicating with said suction well, and means including a Pitot tube for varying the pressure in the upper part of the suction well in accordance with variations of the velocity of the air flowing into the air intake conduit.

4. A carburetor comprising in combination an air intake conduit, a valve controlling said conduit, a suction well, a constant level chamber communicating with said suction well through an orifice of predetermined dimensions. a suction conduit having one extremity in communication with the air intake conduit and having another extremity terminating inside the suction well, an upstream Pitot tube positioned in the air intake conduit and extending to the upper part of the constant level chamber,'and a downstream Pitot tube positioned in the air intake conduit and extending to the upper part of the suction well.

5. A carburetor comprising in combination an air intake conduit, a valve controlling said conduit, a well having an opening in the wall thereof communicating with the atmosphere, a suction conduit having one extremity terminating inside the Well and having another extremity communicating with the air intake conduit at a point situated downstreamward with relation to said valve, said suction conduit being independent of the opening in the wall of said well, and a fuel reservoir communicating with said well through an orifice of predetermined dimensions.

6. A carburetor as defined in claim 5 in combination with means including a Pitot tube for varying the rate of flow of fuel through said orifice in accordance with variations of the velocity of the air flowing into the air intake conduit.

In testimony I have hereunto set my hand at Paris, France, this 3d day of'February, 1922.

AURELIEN DROGO.

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