US1875713A - Carburetor - Google Patents

Description

Sept. 6, 1932. J, DUSEVOIR 1,875,713

CARBURETOR Filed June 24, 1929 2 Sheets-Sheet 2 INVEN TOR.

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A TTORNEYS.

atentecl Sept. 6, 1932 UNITED STATES PATENT OFFICE ULIUS DUSEVOIR, OF OAKLAND, CALIFORNIA, ASSIGNOR TO MOTIVE DEVICES, INC,

01 SAN FRANCISCO, CALIFORNIA,

A CORPORATION OF CALIFORNIA CARZBURETOR Application filed June 24, 1929. Serial No. 373,088.

This invention relates to carburetors, and specially to that type which-is used in conmotion with internal combustion engines, or instance on automobiles, airplanes etc.

The requirements of a good carburetor re that it shall:

1. Provide an exceedingly rich mixture )r starting when the engine is cold.

2. Provide. a fairly rich mixture for lling.

3. Provide a comparatively lean' mixture )r average running roads, regardless of 1e Sp eed of the engine.

4, rovide a fairly rich mixture for heavy ads, regardless of the speed of the engine.

5. Provide quick acceleration. 6. A carburetor should be provided wlth cans for atomizing or vaporizing the fuel finely as possible under all conditions of iced and load.

The object of the present invention is to anerally improve and simplify the conruction and operation of carburetors; to ."ovide a carburetor which is capable of perrming the conditions above specified; and lrther to provide a carburetor which is caible of automatically leaning or enriching le combustible mixture as the motor is subcted to varying running or load conditions. The carburetor is shown by way of illusation in the accompanying drawings, in

hich

Fig. 1 is a centraLvertical section of the' rburetor, Fig. 2 is a vertical section taken at rlghtigles to Fig. 1 on line II-II,

Fig. 3 is a diagrammatic view of the,

frburetor,

Fig. 4 is a cross section taken on line 7-IV Fig. 1,

Fig. 5 is a sectional detailed view of the r bleeder indicated at A, 5 Fig. 6 is a perspective view of the valve artion of the air bleeder. y I The carburetor as a whole consists of a ain housing, indicated at 2, the lower-e end "which is provided with the usual air let passage 3, the opposite end of the cariretor being provided with a flange 4 whereby it isfbolted to the intake manifold of an engine in the usual manner.

The main throttle valve, indicated at B, is secured on a'shaft 5, .and it is positioned near the outlet or upper end of the carburetor in the conventional manner. v

The shaft of the throttle valve is provided with a crank arm 6, and this is connected with a remote or dashboard control, not here illustrated.

By referring to Figs. 1, and 6 it will be noted that the shaft 5 of the throttle valve is extended, as indicated at A. It is provided with an annular passage 7 which remains in constant communication with an opening "(at in-the side of the housing. The member A, or the valve end of the shaft 5 is also provided with a central passage for the reception of a needle valve 8, and it is provided with two radial passages, such as shown at 7 b and 10a, the radial passage 7 I) being in communication with a central passage in the valve, and also with the annular passage 7 and the radial passage 10a, while the radial passage 10a may be moved intocommunication with a passage 10, hereinafter to be described.

Disposed below the valve A is a graphite plug, such as indicated at 9. This is held against the valve by spring-tension, so as to maintain a tight fit and prevent leaka e of air. The passage 10 extends downward y from the valve A, as shown in Fig. 1, and it connects with the intake end 11 of a multiple jet spray nozzle, generally indicated at C. The valve indicated at A will hereinafter be referred to as an automatic air bleeder, andits function will later be described.

The multiple jet spray nozzle consists of a tube 12- extending crosswise'of a Venturi passage, indicated at 12a. I

A needle valve 13 extends through the tube, and as one end of the tube is in communication with the passage 10,,and with The fuel passage 14 is directly connected 106 with the float chamber 15 of the carburetor, through a passage 14a.

By again referring to Fig. 1 ofthe drawings it will be noted that a series of collars or flanges 16 are formed on the exterior surface of the spray nozzle. These flanges are drilled horizontally, as indicated at 17 so as to communicate with the interior passages of the nozzle. When the carburetor is in operation the gasoline is sucked out of the openings 17 and as the collars terminate in knife-like edges 16, the gasoline is readily drawn off by the air stream. Experimental work has shown that this is important. For instance, a multiple jet spray nozzle, such as here shown, without the knife edge flanges was placed in a carburetor connected with an engine. The highest revolution obtained by the engine was 1700 R. P. M. When a multiple jet spray nozzle with knife like flanges, such as shown at 16, was applied, the revolutions were stepped up to 1800, proving that the gasollne would escape more readily from the knife-like flanges than from straight tubular orifices.

The carburetor-is provided with an auxiliary jet, such as generally indicated at D. This jet is best shown in Fig. 2. The auxil' iary jet is provided with a needle valve 18, so that the flow of gasoline from the discharge end of the jet may be regulated.

The discharge end of the jet terminates on the same level as the multiple jets from the spray nozzle C, and at one side thereof. The auxiliary jet is supplied with fuel through a passage 19, and this passage in turn connects Y with a starting and accelerating well, generally indicated at 20, this well being supplied with fuel through a passage 21 which is connected with the passage 14 which in turn supplies the main multiple jet spray nozzle 0. .The flow of fuel through the passage 21 into the well 20 is regulated by a needle valve 22.

The starting and accelerating well, which is best illustrated in Figs. 2 and 3, tapers from end to end so that it presents its largest area at the top. The function of a well of gradually reducing area will hereinafter be described.

Extending downwardly into the well, is a tube 23, which is perforated throughout its length, as indicated at 24, 25 and 26. A'fuel inlet opening 27 is formed in the bottom of the tube, and a needle valve 28 controls the amount of fuel admitted through the lower end. The fuel entering the tube 23 passes upwardly through a passage 29, and this terminates in a starting or idling jet, which is disposed above the throttle valve at the point indicated at E.

In actual operation, when starting amotor, particularly when it is cold, it is essential that an over rich mixture be supplied by the carburetor. This mixture is, in the present instance, sup lied by the starting or idling jet indicate at E (see Fig. 3) When starting the throttle valve is placed in a substantially closed position, and as the opening of the idling jet is above the throttle a high suction will be created and the fuel is sucked upwardly from the starting and accelerating well 20 through the assage. 29,'and as such is sprayed into the car uretor-at a point above the throttle, thereby producing an exceedingly rich mixture. The well presents a large area at the top, and a free flow of a comparatively large quantity of fuel is accordingly available.

As the engine gainsvmomentum the fuel level in the well 20 becomes lower and lower, and the openings 24, 25 and 26 are gradually opened. The mixture still remains rich, but it becomes leaner and leaner, first because the area of the well diminishes as the liquid level drops, and secondly because air will be admitted through the openings indicated at 24, 25 and 26, and by the time the well is empty the motor will become sufficiently heated to continue running. Hence there is supplied an over rich mixture for starting and this mixture is gradually leaned as the motor increases in speed, due to the tapered formation of the well, and due to the air admitted through the bleeding openings 24, 25 and 26 which are successively uncovered as the fuel level drops, the bleedingair being admitted through an opening 30.

It will now be assumed that the motor is started and is running. If it is desired to keel the motor running at idlin speed, fuel will be admitted to the tube 23 t rou h the lower needle valve control opening 2%. A fairl rich mixture will still be supplied as the only air admitted is that which enters througl the bleeding opening 30. On the other hand if it is desired to speed up the motor tht throttle valve B is slightly opened. The moment this is opened the vacuum or depres sion at the starting jet E is lowered to sucl an extent that it ceases to function. Hence the main multiple jet spray nozzle C and tht auxiliary jet D will now have to be depended upon to supply fuel to the incoming air.

The main multiple jet nozzle is supplier directly from the float chamber 15 by the pas sage 14, and the valve controlled opening 11 The air rushing by the knife-like flanges 16 o: the multiple jet nozzle produces a depressiol in the Venturi throat, and at the ends of th' discharge openings 17, thereby causing sufli cient suction to withdraw the fuel from th nozzle so that it will mix with the incoming air to produce a combustible mixture.

The multiple jet nozzle is designed to giv a rich mixture which is used only under cer tain conditions,,to wit, under heavy loads but it must give a comparatively lean mixtur during other conditions. It is for this reasm thatthe air bleeding valve, indicated at A. i

rovided. This air bleeder admits air downardly through the passage 10, and the air atering with the gasoline'through the open- 1g 11 produces a comparatively lean mixture air and gasoline are discharging from the iultiple jet nozzle, except under heavy loads, t which time the bleeder is automatically iut off by opening the throttle to full open osition.

From the foregoing it is apparent that the irburetor is provided with a starting jet E 'hich provides an over rich mixture for start- 1g; secondly, the starting jet is also utilized )r idling conditions; third, a main multiple at nozzle O is provided for delivering a lean ixture under most running conditions. This due to the fact that a graduateda-mount f air is admitted with gasoline delivered to 1e nozzles, and means are also provided for itting off the air supply when a richer mixlre is required, as when operating under full ad conditions.

The auxiliary nozzle D is designedto pro- .de a comparatively rich mixture when rapid )eed changes are encountered. That is, to ermit quick acceleration. At other times it ractically ceases to function. This will he tore fully explained. v

By referring to Fig. 3 it-will be noted that 1e fuel passage '14 is connected with a float lamber 15 by the passage 14a, this passage .aking an almost direct connection with the iultiple jet spray nozzle, so as to permit a ath of least resistance thereto. Passage 14 so supplies the passage 21', which in turn lpplies the well 20. Under actual operating nditions the path of least resistance is irough the passage 14, to the multiple jet vray nozzle, as more resistance is encountered hen the fuel is flowing through the passage L Furthermore, the flow of fuel through this assage is limited by the needle valve 22. Then the engine is standing the'well and all f the passages will fill up with gasoline, ance providing an ample supply of gasoline l the well for supplying the over rich mixlre to the starting jet E when starting the rotor. However, after the motor has started 1d the well becomes sufliciently empty there a comparatively small amount of fuel eniring through the needle valve 22. The jet is supplied from the well, and as the amount 5 gasoline entering is comparatively small, .t D will-normally supply a very lean mixlre. On the other hand, if the throttle aslme's th or 1 th opening, and the engine running comparatively slowly, the fuel vel in the well increases so that if the irottle valve is, quickly opened, sufficient iel is provided to permit quick acceleration. hat is, at high speeds the well is comparavely empty and the fuel jet D supplies a lean .ixture, at slowor almost idling speeds it Lpplies fuel or" a comparatively rich mixable in the well to supply fuel or a rich mixture, thus permitting quick acceleration.

When the engine is running under any speed whatsoever, and it is necessary to subject it it full load conditions, throttle valve B is completely opened. In that instance the air' supply through the passage 10 is completely cut off and as now no air enters the multiple jet nozzle O with the fuel, a rich mixture will be supplied for full load condiv tions, and if the speed of the engine is fairly low, the fairly rich mixture will also be supplied by the jet D.

On the other hand, if the engine is operating at high speed and full load, the jet D will be of comparatively little assistance as it would supply only a lean mixture as the well will be comparatively empty.

By referring to Figs. 1- and 6 it will be noted-that the radial passage 10a terminates in a grooved passage 106 formed in the exterior face of valve A, and that this passage tapers, as shown in Fig. 6, so as to present less, and less area. The groove 10b moves over the passage 10, and hence regulates the amount of bleeding air admitted. As the engine speed increases the fuel mixture should gradually become richer and richer, hence the reason for tapering the passage 10?) so as to gradually reduce the amount of bleeding air before it is cut off altogether when operating under full load.

By referring to Figs. 1 and 2 it will be noted that the air inlet passage 3 is arranged at one side of the carburetor housing, and that a trap chamber such as indicated at X is formed below the Venturi passage. It should also be noted that the interior surface of the carburetor is corrugated or grooved, as indicated at 41.

The formation of the well, and the corrugations are important, as under certain speed or load conditions, a certain amount of unvaporized fuel has a tendency to drop down- Wardly away from the spray nozzles. Any fuel thus lost, or any leakage fuel will, in this instance, collect in the corrugations and in the well, and as such will not escape. On the other hand, it will be picked up by the incoming air which enters at high velocity and as such will be evaporated and removedf-rom time to time.

This is particularly important when starting, as the overrich mixture of raw fuel entel-ing through the jet E has a tendency to leak by the throttle valve and down into the lower part of the carburetor. Such leakage fuel is picked up, evaporated and mixed with the incoming air, thereby aiding starting.

By properly shaping the groove 106 on valve A, it is possible to bring about practically any condition desired. That is, cari buretors are known to have what is'termed flat spots. Such flat spots may be remedied by properly shaping the groove, whereby air is supplied to the multiple jet fuel nozzle.

While certain features of the present invention are more or less specifically described, I Wish it understood that various changes maybe resorted to within the scope of the appended claims, similarly, that the materials and finishes of the several parts employed may be such as the manufacturer may decide, or varying conditions or uses may demand.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. In a carburetor a main fuel supplying jet, a combination starting and idling jet, a well in the carburetor to supply fuel to the starting and idling jet, the latter having fuel controlled communication with the well at different levels and said well having an air inlet at the top a common connection for supplying fuel to the main jet and the well, an accelerating jet having its discharge end located at the main jet, a connection between the accelerating jet and the bottom of the well whereby fuel is supplied, and a throttle valve interposed between the main jet and the starting and idling jet.

2. In a carburetor a main fuel supplying jet, a combination starting and idling jet, a well in the carburetor to supply fuel to the starting and idling jet, the latter having fuel controlled communication with the well at different levels and said well having an air in-, let at the top, a common connection for supplying fuel to the main jet and the well, an accelerating jet having its discharge end located at the main jet, a connection between the accelerating jet and the bottom of the well whereby fuel is supplied, a needle valve regulating the flow of fuel through the accelerating jet, and a throttle valve interposed between the main jet and the starting and idling 'et. J 3. In a carburetor a main fuel supplying jet, a combination starting and idling jet, a tapering vertically disposed well in the carburetor having its largest diameter at the top, a tube extending downwardly in the well, and terminating adjacent the bottom of the well, said tube having a plurality of interspaced perforations formed therein and one at the bottom of the tube, a connection between the upper end of the tube and the starting and idling jet, an air inlet in communication with the upper end of the well, and a common connozzle mounted therein, said nozzle compris nection supplying fuel to the main jet and the well.

4. In 'a carburetor a main fuel supplying jet, a combination starting and idling jet, a tapering vertically disposed well in the carburetor having its largest diameter at the top, a tube extendin downwardly in the well and terminating ad acent the bottom of the 7 well, said tube having a plurality of inter spaced perforations formed therein and om at the bottom of the tube, a. connection between the upper end of the tube and tlll starting and idling jet, an air inlet in com munication with the upper end of the well a common connection supplying fuel to th main jet and the well, an accelerating je' supplied with fuel from the well, and a nee dle valve regulating the supply of fuel U the well.

5. In a carburetor a main fuel supplying jet, a combination starting and idling jet a tapering vertically disposed well in th' carburetor having its largest diameter at th top, a tube extending downwardly in the wel and terminating adjacent the bottom of th well, said tube having a plurality of inter spaced perforations formed thereinand on at the bottom of the tube, a connection be tween the upper end of the tube and the start ing and idling jet, an air inlet in commu nication with the upper end of the well, common connection supplying fuel to th main jet and the well, and a throttle valv interposed between themain jet and the com bination starting and idling jet.

6. In a carburetor a main fuel supplying jet, a combination starting and idling jet, well in the carburetor to supply fuel to th starting and idling jet the latter having fue controlled communication with the well a different levels and said well having an ai inlet at the top, .a common connection sup plying fuel to the main jet and the well, throttle valve interposed between the mail jet and the combination starting and idlin; jet, means actuated by movement of the throt tle valve for admitting air to the main je during a predetermined range of movemen of the throttle valve, said means also adapte to shut off the supply of air tothe main je when theth'rottle reaches a substantially ful open position and an accelerating jet con nected with the well at the bottom thereo and having its discharge end located sub stantially in the plane of the main jet.

7. In a carburetor a rotatable throttl valve, a main fuel jet, means supplying fue to the jet, means for admitting air to the jet a valve directly connected to and carried b; and rotatable with the throttle valve to ope] or close an air duct through which air is sup plied to the jet, and a needle valve carried b; said valve whereby the flow of air tothe je may be regulated.

8. In a carburetor a Venturi passage, a fue 'the outer end of the orifice terminating in th peripheral edge of the lmife-like flange and formlng a fuel spray nozzle.

9. In a carburetor aVenturi assage, a multiple jet spray nozzle moun therein, said nozzle comprising a tube to which fuel is admitted, a lurahty of interspaced annular knife-like anges formed on the exterior surface of the tube and extending in the direction'of the current through the pasage, said tube havin a plurality of orifices formed in the outer efigesof the knife-like flanges, the

outer ends of the orifices terminating in the peripheral edges of the knife-like flanges and forming a plurality of spray nozzles.

10. In a carburetor a Venturi passage, as multiple jet spray nozzle mounted therein, said nozzle comprising a tube to which fuel is admitted, a lurali? of interspaced annular knife-like auges ormed on the exterior surface of the tube and extendin in thedirection of the current through e passage, said tube having a plurality of orifices formed in the outer edges of the knife-like flanges,

the outer ends of the orifices terminating in the peripheral edges of the knife-like flanges and forming a plurality of spray nozzles, and a needle valve regula the flow of fuel entering the tube and disc urging through the spray nozzles.

11. In a carburetor a Venturi tube, a fuel spray nozzle in said tube, a trap chamber formed below the Venturi tube, the walls of said chamber presenting a corrugated surface forming liquid holding gutters to collect unvaporized fuel escaping from the fuel nozzlc, and an air inlet connection at one side of the trap chamber to direct air against the corrugated surface and upwardly into and through the Venturi tube.

12. In a carburetor a Venturi tube, a fuel spray nozzle cooperating therewith, a trap chamber formed below the Venturi tube and having liquid holding gutters in the walls 7 of the trap chamber to collect unvaporized fuel escaping from the nozzle and an air inlet connection at one side of the trap chamber to direct air into the chamber so as to vaporize the fuel collected therein, and so as to direct the air upwardly through the Venturi tube.

JULIUS DUSEVOHL

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