US1416858A - Carburetor - Google Patents

Description

F. C. MOCK.-

fCARBURETOR.

APPLICATION FILED Aue.24. I9II.

1 ,416,858, Patented May 23, 1922 "IHR- mi retenir carica..

FRANK C. MOCK, OF CHICAGO, ILLINOIS, ASSIGNOR T0 SROMBERG MOTORl DEVICES COMPANY, CHICAGO,v ILLINOIS,

A CORPORATION OF ILLINOIS.

CARBURETOR Lai-casas.

Specification of Letters Patent.

rat-@atea May 23,1922.

Application filed August 2 4, 1917 Serial No. 187,929.

T o all whom it may concern.' I i i Be it known that I, FRANK C. Mo'ox, a citizen of the United States, residing at Chicago, in the county of Cookand State of Illinois, have invented a certain new and useful Improvement inv Carburetors, of which the-following is a full, clear, concise, and exact description, reference being had to the accompanying drawings, forming a part of this specification. i

My invention relates to carburetors for internal combustion engines and is concerned particularly with that class of carburetors now commonly known as plaintube devices.l y

It is the object of my invention to provide a carburetor for the purpose referred to which, without varying the size ofthe air or valves, vbut rather by a compensating gasoline How, will supply to the engine at the various speeds and various loads', such as arel attained and assumed in automobile practice, a mixture with the most eicient proportions of air and fuel. My present invention has certain features of improvement, in structure and operation, over the device of my Patent No. 1,404,879, granted January 31, 1922, upon an application filed August25th, 1915. These features will be pointed out as this description proceeds and will be made the subject matter of the appended claims. i

This carburetor is of the same general type `as that shown in my co-pending application, Serial Number 188,896, filed August 30, 1917.

In the accompanying drawing the figure is a vertical axial sectional' view.

It will be seen that I provide the carbureting chamber 9 suitably formed in the casing 10, which provides a passagel from the airinlet 11 to the mixture outlet 12. f

A main Venturil tube 13 is setl in this passageway, a butterfly valve 14 being mounted in the air intake upon a rotary shaft 15, and a throttle valve 16 being mounted in the mixture outlet upon a rotary shaft 17. A flange 18 surrounds the mixture outlet and is adapted forv attachment to the manifold of an internal combustion engine.

A float chamber 19 is formed integrally with the casing 10, and needle valve mechanism 20, operated by a float 21, controls the entry of liquid fuel, such as gasoline, into `La plug 25. The sleeve the float chamber 19 by way of the pipe 22, the float thus maintaining a constant level at approximately the dot and dash line X X.

Between the float chamber 19 and the passageway through the casing 10 I provide a bore 23 in which sleeve member 24, having a threaded collar is threaded, as shown, and vwhich is closed at the bottom by means of member 24 has the axial passageway 26, through which the tube 27, arranged concentrically therewith, extends, this tube being set at the bottom in the plug 25 and extending upwardly with agsnug` fit into the reduced bore 28 above and in alignment with the bore 23. The sleeve member 24 is provided With the annular chamber 29 which, as will appear later', forms an accelerating well, the thimble beingr formed in two parts, namely, the tubular portion 24and jacket 25', in order that the structure may form a ready manufacturing proposition. At the top, as shown, the sleeve member is provided with the collar 30 which. has the oblique peripheral surface 31 wedged into contact with the conical bore which takes part in reducing the bore 23 to the bore 28. Between this conical bore and the bore 28 there is an intermediate bore 32,'

axial passageway 26. Small holes 39--39 are provided in the upper part of the tubular portion 24', whereby, as will be described, air may enter the axial passageway 26 from the atmospheric inlet 38', the size of which may -be determined by the passageway 39 in the screw plug 40. The screw plug 40 prevents the entry of foreign matter. It will also be seen that a passageway 41 admits air to the topof the annular chamber or accelerating well- 29, the passageway 41. being considerably smaller than the passageway 39. The air bleed through the hOleS 39 is one thing and the atmospheric inlet 41 to the well and through it is a separate thing and should be independently determined. It will now be clear that liquid fuel which is fed into the pocket 33 may be fed therefroml through the axial passageway 26, or through the passageways 37.-3'7, or through the tube 27, by way of the port 42 near the bottom thereof. The fuel which passes upwardly through the axial passageway 26 is the main fuel supply, and it will be seen that it goes to the bore 32 which has already been referred to, thence by way of the horizontal bore 43 to the annular groove 44 in the secondary Venturi t-ube'45, fuel jets 46-46 extending inwardly 'and radially from the annular groove 44 and being preferably distributed equi-distantly about the inner periphery. This secondary Venturi tube 45 is mounted in the main passageway in such a way that it terminates slightly above the most restricted portion of the .main Venturi tube, the most restricted portion of the secondary Venturi tube, approximately where the fuel is fed, therefore lying considerably farther down. This secondary Venturi tube is mounted in a spider 4T, through which the bore 43 extends, this spider spanning the air passage but leaving ample passage for air around it. It will benoted that the fuel jets 46-46 lie above the normal level of the gasoline.

The bore 28 which has already been referred to communicates at its top with a nozzle 48 in a plug 49 inserted in the casing 10 ata point in proximity to the closed posi- 'tion of the throttle valve, as will be pointed out. An air port 49 connects the carburething chamber 9 with the bore 28 and this connection is controlled by means of a needle valve 50 adjustable from the outside by means of the adjusting screw 51, a snapspring 52 being provided -to hold `this adjusting screw in any adjusted position.

The operation of the device is as follows:

When there is no suction in the carbureting chamber, or above the throttle 16, the

' gasoline stands, at a common level in the float chamber, the accelerating well and the' associated passageways. In starting, the response of the fuel depends upon the position in which the throttle is maintained when the engine is cranked, but it will suice as a general statement to say that gasoline goes to the engine from the nozzle 48 and also from the fuel jets 46-46. Since, collected fuel stands in the passageways lead- `ing to these nozzles when the device is idle,

there will be a desirable excess of fuel which is discharged upon starting, to compensate for the coolness of the engine cylin-,

ders, the lag in response of the gasoline, since the gasoline is heavier than air, and the excess of air.

In assuming now a .condition of idling, or very low running, the throttle is 'closed as far as it can be, in which position, as shown tional last named air, of course, goes to the engine with the mixture which comes from the nozzle 48. Under these conditions the reduction in pressure below the throttle is so slight that no suction is exerted upon the jets in the secondary Venturi tube. The adjusting screw 51 is set for the proper admission of air in order to secure the best mixture for idling and slow running, it being evident that this mixture may be determined independently of consideration as to higher running. In starting, particularly in cold weather, it may be desirable to choke the incoming air, and this is done by closing or nearly closing the butterfly valve 14, in the air inlet.

If it be now assumed that the throttle is gradually opened, it will be seen that the suction at the nozzle 48 decreases and the issue therefrom decreases correspondingly; at the same time the suction is increased below the throttle and the jets 46-46 come into play.

It will be remembered that up to this time the jets 46 have been practically inert, as

there has been insufficient influence to raise the level of the gasoline in the passageway toward the jets 46-46. As the throttle is opened, however, the suction becoming ef- 'part of the'tubular portion 24 is4 fed to the jets 46 as a supply additional to the regular supply for the `jets 46 up through the axial passageway 26. This increment` becomes exhausted promptly, however, and thereafter air is admitted through the apertures 39-39 into the passageway 26, leading into the gasoline supply to the jets. This air, taking the form of tiny bubbles, breaks up the gasoline discharge, frees it from the retarding action of surface tension at low suction, and regulates thegasoline flow so that it responds to the motor suction exactly 50 4bleeder opening 38 therein.

porary surcharging of the mixture with gasoline-upon acceleration, that is, at the beginnin of a period of increased suction. This desirability follows from the natural inertia of the fuel' from the main source,

and the lag with which the speed of fuel,

being heavier than air, follows the position of the throttle; ,it is also due tothe increased effort of the engine at that particular time. It is obvious that this extra l5 feed of gasoline should be merely temporary,

since', once the increased suction has become effective on the main source, the conditions are steady and lfurther additional gasoline would be excessive. The maximum gasoline iiow is determined at 34 and when the jets L6-46 are in action on the lower suctions, the gasoline is not drawn up as fast as it is supplied, or is drawn no faster than it is supplied, and the annular chamber 29, which has been referred to as an accelerating well,

Let it be assumed now that there is a sudden increase in suction that will draw asoline from the main feed through the axial passageway 26 rapidly; it will be attended by an additional charge of gasoline from the accelerating well, this charge of gasoline passing downwardly through the openings 37-37 or through the lower ones of the openings 38 the sides of the inner wall of the well 29, and joining the upward flow through 40 the passageway 26. Furthermore the size of this additional charge depends upon the amount lof increase and the regulation is due to the successive openings 38-38- For instance, when the suction reaches a point .f where itis not satisfied by the bleeder apertures 39-39 and fuel Howing' through the axial passageway 26, there will be a response of gasoline from the accelerating well to the extent of the fuel above the uppermost This uncovers that bleeder and if the two bleeders together with the fuel flowing satisfy the suction which has thus been attained, no further gasoline will issue from the accelerating well, except that which is drawn oi to maintain the level where it has been brought. In other words, then gasoline Hows' out as fast as it iiows in. On the other hand, if these two bleeders do not satisfy the suction,

i" more gasoline will go to the carbureting chamber until the next bleeder is uncovered,

, and then again the'test as to whether more gasoline is to go tothe carbureting chamber is whether or not the three bleeders complete satisfactionof thesuction. It will also be clear that, if the increased range of suction is maintained, the level in the accelerating well will be maintained at the point which was assumed when acceleration took place. Further vacceleration to a still higher range is merely a matter of further similar action, as has been explained. If the suction is decreased obviously the gasoline will rise by gravity due to the head in the yfloat chamber to balance the decreased suction, and a repeated acceleration meansmerely a repetition of the operation which has been set forth.

In `this particular construction I lead the regulated increment for acceleration directly into the main flow to the main jets and I do this by means of a concentric accelerating well through whichI air may pass in regulated quantities into the main flow. The result is simple and effective operation and a simple structure of good commercial form.

ll claim:

1. llnacarburetor, a casing forming a con stant level liquid fuel supply chamber and a carbureting Achamber side by side and a bore therebetween, said carbureting chamber having an air inlet and a mixture outlet, a throttle in said mixture outlet, a sleeve member in said `bpre forming a fuel passageway leading to said carbureting chamber and also forming an annular accelerating well about said passageway and connected therewith, means for the admission of air to the top of said accelerating well, a`fuel nozzle infproximity to said throttle, and a fuel tube passing through said sleeve member and leading to said nozzle, said constant level liquid fuel su ply chamber feeding said well and sald passageway and said fuel tube.

2. ln a carburetor, a casing forming a carbureting chamber having fuel and air inlets, and a mixture outlet, a throttle in said vmixture outlet, a passageway formed in the wall of said casing, the lower portion of 'said passageway being enlarged, a fuel supply chamber feeding into the enlarged portion of said passageway, atube disposed in said enlarged portion of said passageway, with its upper end rigidly fitted to andl feeding the upper portion of said passageway, a plug fitting in to the bottom of the enlarged portion of said passageway and clos- Vmg the same and-receiving the lower end ofdsaid tube, and afuel connection between said enlarged portion of said passageway and said tube.

In witness whereof, I hereunto subscribe my name this v21 day of August, A. D. 1917.

rattanl o. Moon.

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