US1838675A - Carburetor - Google Patents

Description

F. H. HEITGER Dec. 29, 1931.

2 Sheets-Sheet 1 N N w 3 m m r QN KN m WN Dec. 29, 1931 Y F. H. HEITGEIR I 1,838,675

CARBURETOR Filed March 3, 1928 2 Sheets$heet 2 Patented Dec. 29, 1931 UNITED STATES FRANK H. HEITGEB, OF FLINT, HIOHIGAR cannuan'ron' Application filed. March 3, 1928. Serial No. 258,738.

This invention relates to certain new and useful improvements in carburetors and more particularly to carburetors for internal com bustion engines used in connection with motor vehicles and the like where the speed is variable, varying from a minimum speed to a high speed and where it is required to feed fuel to a carburetor posterior of the throttle in the carbureting passage for theminimum 0 or idling speed and to augment the fuel feed posterior of thethrottle as the throttle is opened some and before the main feed comes into action fully.

Another object of my invention ,is to provide a carburetor with a novel construction of idling device wherein air is bled into one of the idling openings from the other opening anterior of the throttle at a certain throttle opening to dilute the mixture after it becomes the richest'and about the time the main nozzle starts to feed.

A still further object of my invention is to provide a carburetor with a novel construction of throttle valve wherein I am able to control the idling and transfer openings so as to produce a proper mixture for idling and transfer. W

Other and further objects and advantages of the invention willbe hereinafter set forth ap ended claims.

11 the drawings, Figure 1 is a vertical section through a carburetor constructed in accordance with my invention, partly in elevation;

Figure 2 is a detail side elevation showing the stop for preventing the throttle from being distorted; V I

Figure 3 is a detail section showing the lip of the throttle when in closed positlon over one of the idling openings;

Figure 4 is a detail vertical section showing the throttle slightly open;

Figure 5 is a similar view with the throttle moved opened-to a greater extent;

Figure 6 is a :detail section showing a modified form of throttle; and

Figure 7 is a detail section showing still another modified form of throttle.

In the embodiment of my invention as and the novel features thereof defined by the shown, I'have illustrated what is known in the trade as a vplain tube type of carburetor comprising a body A having a carbureting passage B terminating at its upper end in an outlet B and at its lowertend in a lateral air 56 inlet-B provided with a choker valve B for controlling the admission of air thereto in the usual manner;- 7 Arranged in the carbureting passage is a Venturi tube l'into which extends a main 60 fuel nozzle 2 which is in communication with a main fuel passage 3 extending from a float bowl 4 which is of the ordinary construction now in eneral use on carburetors, the 'flow of fuel rom the bowl being controlledby a removable plug 5 having a calibrated orifice for allowing the maximum amount of fuel to pass therethrough.

An auxiliary fuel passage 6 is formed in one wall of the carbureting passage and in the embodiment of my invention as shown, is

supplied with fuel from an auxiliary reservoir 7 extending from the mainfuel passage 3. The lower end of the auxiliary, fuel passage 6 is enlarged toreceive the upper end of the reservoir which is provided with a restricted outlet 8 subjected to' suction and is adapted to feed fuel to the auxiliary pas;

" sage 6 at substantially closed throttle *position and to fed air to the main fuel passage 3 as the throttle is moved into open position substantially as described in the patent issued to Guthrie, December 5, 1916, No. 1,207,029. While I have shown the auxiliary fuel passage ,6 supplied with fuel from an auxiliary reservoir, I do not wish to limit myself to any particular means of supplying fuel thereto, as I am aware that the same can be supplied with fuel from any source of supply, such as a well or directly from the fuel bowl without departing'from the spirit of my invention which will be hereinafter fullydescribed.

L The auxiliary fuel passage 6 terminatesv at its upper end in an annular'chamber 9 formed by the end of a screw plug 10 working in a threaded bore formed in the wall of the carburetor as clearly shown. The annular chamber 9 is provided with superposed on- ' fic es 11 and 12 forming fuel jets for idling 1 0 and transfer these openings communicating with the carbureting passage B of the carburetor for supplying a fuel mixture thereto as will be later described. The passage 6 is provided with an air port 13 controlled by a screw 14 of the ordinary construction now in general use on carburetors.

Extending transversely through the carburetor passage B slightly below the orifices 11 and'12 is a throttle valve shaft 15 carrying a butterflytype of throttle valve 16 having a on an angle and practically closes the carbureting passage B and the orifice 11.

In order'to prevent the throttle valve from being sprungor strained, I provide the operating arm 8 carried by the throttle valve shaft 8 with spaced projections 19 and 20 arranged between a fixed stop 21 on the body of the carburetor. The projections and stops are so disposed that the throttle closes with a slight tension as the usual adjusting means are dispensed with and by having a slight clearance between the stop and projections, the throttle is allowed to close tightl and yet be prevented from being injured y being turned too far in closing or opening movement.

The throttle valve may be stamped or otherwise fprmed with a lip or projection on it or the lip or projection may be a separate member attached thereto, therefore'I do not wish to limit myself to any particular manner of forming the throttle valve so long as it serves the purpose of closing one of the orifices from the idling or auxiliary passage.

In order to supply the proper amount of air for idling when the throttle is in closed position or substantially closed position, I preferably provide the wall of the carbureting passage B opposite the orifices 11 and 12 in alignment with the lower edge of the throttle valve, with an opening 22 controlled by a screw 23 so as to allow a small amount of air to by pass through the opening 22 around the edge of the throttle from anterior to posterior of the throttle so as to mix with the fuel mlxture being delivered to the carburetlng passage from orifice 12 when the throttle is closed and to supply air for the fuel mixture from orifice 11 when the throttle is slightly open. In Figure 1 of the drawings 1 have shown the throttle in full lines in closed position so mixture for idlin and prevent fuel collection on that side w en throttle is closed tight.

In Figure 4 I have shown the throttle valve slightly opened so as to artiall uncover the orifice 11 so that it disc arges uel posterior of the-throttle in addition to the orifice 12 in 'order to produce an explosive mixture when mixed with the air that is by passed around the edge of the throttle so that the engine to which the carburetor is attached, will idle properly with partly open throttle.

In Figure 5 I have shown the throttle opened to a greater extentor in other words, the third stage of the throttle opening position in which position the throttle is above the opening 11 and in which position the orifice 11 instead of feeding fuel directly into the space posterior of the throttle, feeds air or a very lean mixture from anterior throttle to the orifice 12 so as to weaken the rich posterior throttle feed as by this time the main nozzle 2 commences to discharge some fuel which is fed posterior of the throttle around the edge of the throttle and the fuel mixture is formed by the two feeds 5 and 2 in order to produce a proper explosive mixture.

The reversal of flow in 11 is due to the fact that at this stage'll is in a region of lesssection than orifice 12, the suction on 12 dominating over that on 11;

This action also occurs at orifice 8 at a further stage or more opening of the throttle for the reason that as the throttle is further opened, the suction on main fuel nozzle 2' dominates over that of 8 and the auxiliary reservoir will start to empty causing a surplus discharge temporarily from 2 and finally 7 will empty entlrely and air will now enter 7 by way of 8 and be discharged along with fuel from 2, after which the calibrated opening 5 alone su lies fuel from the bowl 4, the latter part of this construction being shown in the above referred to patent showing a reversal of How in order to dilute the mixture being delivered from the main fuel nozzle.

WVhile I have shown and described such a construction, I am full aware that the particular construction 0 throttle valve can be used in connection with various other constructions of auxiliary fuel feeds whether the fuel is fed directly from a bowl or from a well or from any, source of supply and Ihave'only described this one particular construction illustrating a carburetor which has been constructed in accordance with my invention.

In the modification shown in Figure 6, I show a throttle valve 25 mounted on a shaft 26 having a thickened portion 27 for closing the orifice 11 extending from the chamber 9 of'the fuel passage 6 so when the throttle is in closed position, the fuel delivered to the passage 6 will be discharged from the orifice 12 in a similar manner described. In this idling passage and construction instead of employing means for by passing air around the edge of the throttle so as to supply the proper amount of air for idling, I provide the throttle valve with a calibrated passage 28 through which air is adapted 'to pass from the anterior to the posterior side of the throttle.

In the modification shown in Figure 7, I

show'a throttle valve 29 mounted on a shaft 30 having a depending lip or projection 31.

for'closing the orifice 11, said valve being provided; with an opening 32 calibrated for supplying the proper amount of air for idling and in this construction like the other constructions previously described, the fuel passage .6 feeds a fuel mixture to the chamber 9 from which it is discharged by the orifice 12 whenthe throttle is in closed position.

While I have shown certain details of construction of a carburetor, I 'do not wish to limit myself to these details as my invention consists mainly in providing an idling device for a carburetor in which an idling passage has at least two openings but can be more, one or more of which is normally closed by a throttle valve in connection with means for supplying anterior of the throttle additional air for mixing with the fuel delivered from one of these passages.

In'the operation of ed as herein shown and described when used in connection with an internal combustioii engine on amot-or vehicle, 'when the'engine is started by the usual operation, by choking-the air inlet through the medium of the choker valve in order to produce a rich discharge of fuel from the nozzle 2 with throttle valve open or substantially open position in ord di to obtain the proper suction on 2 after the motor has been started, the throttle valve is then closed and as it is very advantageous to obtain a rich mixture for idling, the fuel mixture is discharged through the 'orifice v12 posterior 6f the throttle, the desired mixture being obtained by. adjusting screw 14 so as to admit the proper air to the fuel passage.

When the throttle is in closed position, the suction onthe constricted outlet of the reservoir 7 -feeds liquid fuel to the passage 6' and there is air fed to 6 at the same time around the upper end of the reservoir or nozzle.

After the idling speed arid mixture are prop;

erly delivered and the throttle is v slightly open, the projection 17 on the throttle 16 uncovers the orifice 11 and it discharges fuel -which passes posterior of the throttle between the face of the projection and the wall of the carburetor bore as shown in Figure 4 of the'drawings. As the throttle is moved open to a greater extent, it reaches a point where the orifice 11 feeds air or a lean mixture'to the orifice -12- from below the throttle which dilutes the mixture discharged from 12 from what it was-previously discharging a carburetor construct} which is desirable for thereason that at this time the main fuel nozzle 2 begins to feed fuel as the throttle is moved into such a posi-' tion that the main fuel nozzle is subjected to suction.

From the foregoing description it will be seen that I first feed the needed idling mixture when the throttle is in closed position from the orifice 12, the proper amount of air being supplied by beingby passed around the edge of the throttle or through an opening formed therein and as the throttle is further opened, the mixture is augmented posterior of the throttle by fuel delivered from the orifice 11 and upon further opening of the throttle, the main nozzle begins to dis charge and the orifice 11 feeds air or a very lean mixture to 12 diluting-the same about ther opened, fuel discharges from 2 and the suction on 2 will dominate over the suction on the nozzle 8 and there will be a reversal of flow in the reservoir so that air will be fed into the fuel passage 3 in order to .dilute the mixture delivered by the main fuel nozzle. In the specification I have used the term transfer to mean the interval or degree of throttle opening, where a single fixed idling feed of proper mixture would be too lean to carry the motor before the main jet started to feed and as throttle is slightly opened; otherwise during this time the mixture wouldbe too lean from the idle feed alone.

While I have shown certain means for forming the passageways and throttle in producinga carburetor with an idling device, I do not wish to limit myself to the forming of these parts integral with the carburetor as separate passages or conduits might be attached to the carburetor in order to produce an idling passage without departing from the spirit of my invention.

What I claim is: 1. The combination with a carburetor, of a carbureting passage having an air inlet, and an outlet adapted to be connected to an internal combustion engine, a main fuel feed discharging into said carbureting passage, an auxiliary fuel passage having spaced superosed openings communicating with said carureting passage, said auxiliary passage being provided with a valve controlled air inlet, and a throttle valve mounted 'in said carbureting passage for closing said passage and provided with means for closing the loweropening of said auxiliary passage, the upper opening of said auxiliary passage being in constant communication with the carbureting passage to the engine side of the throttle lower opening first feeds fuel posterior of the throttle and then air from said carbureting passage to the upper" opening of said auxiliary passage as the throttle valve is moved into open position.

2. The.combination with a carburetor, of a'carbureting passage having an air inlet and a main fuel feed discharging into said passage, an auxiliary passage having superosed openings communicating with said carureting passage, said auxiliary'passage being provided with a valve controlled air inlet, a throttle valve mounted in the outlet to move into open position on the superposed openings sidein the direction of travel of the fuel and air assing through said carbureting passage, said closing the lower opening of said auxiliary passage and so positioned in respect to said openings that the lower opening first feeds fuel posterior of said throttle valve and then air from said carbureting passage to the upper opening of said auxiliary fuel passage.

3. The combination witha carburetor, of a carbureting passage, a fuel feed discharging into'said passage, an auxiliary fuel passage having superposed openings communieating with said carbureting passage, said auxiliary assage being rovided with a valve controlled air inlet, a t rottle valve mounted to move into open position on the superposed openings side in the direction of travel of the fuel and air passing throughsaid passage, said throttle valve having-means for closing the lower opening of said auxiliary passage, means for feeding air from anterior to posterior of throttle independent of throttle opening, the upper opening of said auxiliary passage being in constant communication with the carbureting passage to the engine side of the throttle valve.

' 4. The combination with a carburetor, of a carbureting passage, a main fuel feed discharging into said passage, an auxiliar. fuel passage terminating in a chamber, sai auxiliary passage being provided with a valve controlled air inlet,,said chamber being in communication with the carbureting passage through superposed openings adapted to progressively feed fuel as the throttle is opened, a throttle valve mounted in said carbureting passage for closing the lower opening of said superposed openlngs and adapted to move from closed position to open position on the superposed o enings side in the direction of travel of t e air and fuel passing through said carbureting assage, said carburetor passage having a y-pas's extending around said throttle valve distinctfrom the superposed openings for feeding air only during idle speed.

5. The combination with a carburetor, of-a carbureting passage, a main fuel feed discharging into said passage,- an auxiliary fuel passage terminating in outlet means to said carbureting passage comprising superposed throttle valve having means for' openings, to progressively feed fuel, said auxiliary passage being provided with avalve controlled air inlet, a throttle valve mounted in said carbureting passage for closing the lower opening of said superposed openings and adapted to mqve from closed position to open position on the superposed openings side in the direction of travel of the air and fuel passing through said carbureting passage, said carburetor passage having a bypass extending around said throttle valve, and means for adjusting the area of said by-pass.

6. The combination with a carburetor, of a carbureting passage, a main fuel feed discharging into said passage, an auxiliary fuel passage terminating in outlet means to said carbureting passage comprising superposed openings to progressively feed fuel, said auxiliary passage being providedwith a valve controlled air inlet, a throttle valve mounted in said carbureting passage for closing the lower opening of said super-posed openings and adapted to move from closed osition to open position on the superpose openings side in the direction of travel of the air and fuel passing through said carbureting passage, said carbureting passage having a bypass extending around said throttle valve for feeding air only from anterior to posterior of said valve during idling and means for adj usting the area of said by-pass.

7. The combination with a carburetor, of a carbureting passage having an air inlet, and an outlet adapted to be connected to an internal combustion engine, a main fuel feed discharging into said carbureting passage, an auxiliary fuel passage having spaced superposed openings communicating with said carbureting'passage, said auxiliary passage being provided with a valve controlled air inlet', a throttle valve mounted in saidcarbureting passage for closing the same and provided with a member closing the lower opening of said superposed openings, the upper opening of said auxiliary passage be ing in constant communication with the carbureting passage to the engine side of the throttle valve, said throttle 'valve being mounted to move into open position on the superposed openings side in the direction of travel of fuel and air passing through said carbureting passage to allow the lower opening of the auxiliary passage to first feed fuel posterior of throttle and then air from said carbureting passage to the upper open: in of said auxiliary passage.

Tn testimony whereof I hereunto afiix my

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