US1626813A - Liquid-fuel combustion apparatus - Google Patents

Description

May 3,1927. 1,626,813

, J. GOOD LIQUID FUEL COMBUSTION APPARATUS Filed June 21 1920' 4 Sheets-Sheet 1 8 v .gn

W5 whom y J. soon LIQUID FUEL COMBUSTION APPARATUS Filed June 1. 1920 4 Sheets-Sheet 2 May 3, 1927. I 1,626,813

J. GOOD- LIQUID FUEL COMBUSTION APPARATUS Filed Ju ne 21. 1920 4 Sheets-Sheet s 33 N 5 h I T. l M I: 5 I f III May a, 1927. 1,626,813

J. GOOD LIQUID FUELL COMBUSTION APPARATUS Filed June 21. 1920" 4 Sheets-Sheet 4 (9 8 j? I in 1 42 K 2 I l 5 :71. z i f is' al 4 n Patented May 3, 1927.

UNITED STATES PATENT OFFICE.

JOHN GOOD, OF GARDEN CITY, NEW YORK, ASSIGNOR TO GOOD INVENTIONS 60., OF

- NEW YORK, N.'Y., A CORPORATION 01:" NEW YORK.

LIQUID-FUEL COMBUSTION APPARATUS.

Application filed June 21,

The invention relates to liquid fuel burn-- ers, and more particularly suction-operated and spark-ignited burners, used for vaporiz-ing and perfecting the charge mlxtures of internal combustion engines and conslsts in certain developments of the Combustion method" set forth in my prior application Serial No. 222,557, filed March 15, 1918, and in the application thereof to engine uses, although not limited thereto as will be later made apparent.- According to said method related flows of liquid fuel and air bearing. the relative proportions of an explosive mixture are formed into mixture portions which are relativelyrich in fuel and lean in fuel, respectively, these mixture portlons being rapidly brought together in the zone of 19;- nition and combustion to produce flame. By this method of combining fuel and air, it is possible to produce non-explosive but very rapid-combustion although the fuel and air may be within the proportion limits of explosive mixtures, as used for example In internal combustion engines. Such proportions are difficult to burn non-explosively so as to give a steady flame, without popping, especially in confined passages.

According to this invention, substantially the aforesaid method is carried out in a simple tray and the rich and lean mixtures are formed out of a flow of previously measured fuel and air by the control of such flow while in transit to the ignition space and said flow is produced by a pressure difference established between the entrance and outlet of the burner mechanism which will be herein treated as caused by the suc tion effect created in thein-take of an internal combustion engine. By producing the rich and lean portions in this way the burner apparatus is materially simplified and reduced in size and thereby particularly adapted for compact organization with a carburetor 'and moreover, the ,desired rate. of combustion is attained by very moderate pressure differences or suction effects such as obtain in carburetors, which specially adapt the invention for operation under .the conditions present in automotive engines.

In the accompanying drawings, Figure 1 represents a suction burner-carburetor combination illustrating one manner of carrying out the invention.

1920. ,SerialNo, 390,354.

Figure 2 is a modification of Fig. 1

Figure 3 illustrates difi'er'ent means of separating the flow into. the rich and lean mixtures;

Figure 4 being a detail of the means for measuring the fuel and air supplies;

Figure 5 is a modification of the separatmeans of latter having the usual float-controlled or and constant-level liquid-receptacle 3 throttle 4 for controllingthe mixture flow through the intake. passage to the engine. The suction effect present in said passage when the engine is in rotation, either by the operation of a starting agency or by its own combustion, is transmitted to the burner and serves to operate itas presently explained,

the flame or burner products being drawn into the intake passage along with the normal charge mixture vaporizing the latter and thus helping the engine start in cold weather as well -as improving its operation underrunning conditions. Thesuction con nectionjto the burner in the present case is through the small holes in the wall of the intake passage which holes represent the burner outlet and are marked 5 in this fig- 'ure, but the apparatus may be connected in other ways and with other devices adapted to maintain an equivalent pressure difference between its entrance and outlet ends, as will later be apparent.

The burner inFig. 1, comprises a' casing 6 provided with an air entrance 7 in the form of-an open Venturi tube and with a fuel nozzle 8 having its orifice centered in the throat part of the tube, and supplied with fuel by a. tube 9 from the liquid reeptacle 3. The

suction in theburner produces, coincident- 1y, an inward flow of air throu h the entrance 7 and an inward sprayof iquid fuel from the nozzle 8. The burner contains an inner cylindrical distributing 'shell 10, the

interior of which is in communication with the burner outlet 5 and forms the combustion space of the burner. This shell is provided with a funnel shaped deflector entrance 11 protruding more or less into the inner end of the Venturi tube 7 and having such shape and location that some of the air and a large part of the liquid spray is drawn into it, the remaining spray and air being drawn around the. exterior of the deflector through the annular space between the shell and casing and through the mixing and dis tributing holes 12 near its outlet end. The fueland air entering by way of the deflector entrance 11 constitute a relatively rich mixture, and that entering by way of holes 13, a

relatively lean mixture. The total proportions of air and fuel arriving in the combustion space in this way are determined by the corelation of the fuel entrance 8 and the air entrance 7 and these entrances, or their connected appurtenances, are designed or adjusted to measure and deliver proportions which will produce efiicient and clean combustion inside the mechanism, under all the circumstance of use. The lean mixture joins the rich mixture inside the shell or mixing lot space and there the resulting mixture is ignited and then combustibly combined, resulting inflame or flame products passing through the burner outlet to the engine. The combustion is continuous in the sense that it is not explosive in character, and it is also particularly efficient for producing a very rapid development of heat because of the preliminary partial mixture of the fuel and air. Since the object in all combustion processes is to combine all of the atoms of fuel with appropriate atoms of oxygen as quickly as possible, it is plain that by first mixing some of the fuel with what would otherwise constitute the combustion supportmg air of the burner, the combination referred to is already partly effected before the combustion zone is reached and the eventual combination constituting combustion is therefore completed with greater promptness than would otherwise be the.

case. The nonexplosive character of such combustion occurs from. the absence of any homogeneous mixture of explosive proportions through which flame can propagate with explosive velocity; neither the rich nor the lean have such proportions. Ignition is obtained by a spark-plug screwed into the main casing with its igniting end or sparkgap in the path of the relatively rich mixture, this position being preferred because if the said mixture is sufficiently rich, ignition may be obtained without resorting to the expedient of initially increasing the fuel de livery when the 'device is first set in action.

The degree of richness of the rich mixture is obviously controlled in this form of the mvention, by the shape and position of the de fleetion and guiding entrance but the reliability of ignition is improved especially in cold weather, if the initial fuel delivery is also momentarily increased, when the device amcter than the lower part and when the burner is idle the liquid level stands in this upper part about as indicated by the dotted line. The lower end of the fuel tube is closed and the fuel enters it by way of the series of fine holes bored in its side in different vertical positions. \Vhen the burner is started, the suction effect on the nozzle 8 draws off the liquid in the upper part of the Well, at first quite rapidly, due to the short lift, until the level falls to the narrower part and at some point in the latter it finds a constant height at the level of one of the lateral holes and according to the particular degree of suction acting on the burner. The copious delivery occurring while the level is falling makes the mixture condition in the burner combustion space momentarily overrich, so that ignition is readily and reliably attained by spark under all conditions. After the level reaches the narrow part of the well the fuel delivery occurs at that rate which makes the proportions of the burner mixture suitable ency of air-induced liquid flow through small orifices to grow overrich on increasing delivery and keeping the burner proportions constant. This compensating method of fuel delivery enables the burner to operate properly at different rates of combustion, that is to say, to deliver flame or flame products in variable amounts to the intake passage coinc-idently with variation in the operation of the engine. 7

It will be understood that the spark-plug llh is connected to some appropriate source of current as, for example, to the distributor head of the engmes ignition system, or a magneto or otherwise. so that when the engine is started the burner will be ignited automatically, and also that the burner and carburetor may be structurally combined or built together if desired so as to constitute but a single unit.

In Fig. 2. the means for forming rich and lean mixtures is substantially the same as in i an Fig. 1, but in this case the funnel-sha ed separating or deflecting and uiding mem er is used without the distri uting shell, its rim being held by screws and spacers at a distance from the casing end wall so that the lean mixture enters the combustion space around the edge of the deflector and nearer to the entrance end of said space than in the preceding figure. The rich mixture enters through the deflector as before, and the spark-gap or heat source of the igniter is located in its path. Both the lean and rich mixtures enter the combustion space down- \vardlyv and transversely to the main or longitudinal axis thereof, so that the resulting flame or burning mixture is required to turn a corner before reaching the outlet holes. This has the effect of further hastening the mixing effect, results in a shorter and hotter flame and correspondingly permits the use of a smaller structure for a given heating effect. It is specially efiicacious for these purposes when used for combustibly combininglean and rich mixtures, for reasons which will already be apparent, but it is not limited to use therewith. The burner outlet inthis case is similar to that in Fig. 1 and its'several holes 16 open into the intake passage 17 of the carburetor 18 which appears in the background in this figure, 19 being its throttle and 20 its float-controlled liquid receptacle.

Fuel for the burner nozzle 8 is taken directly from this receptacle by thetube 21 controlled by needlevalve 22 and compensation is afforded by interposing a springseated valve in the air path to the burner, which valve has the same effect as the compensating well and tube of the preceding figure, but does not of itself provide the initially rich effect to facilitate ignition. This valve is constituted by. a reed 23 screwed over a hole in a cap screwed to the burner air entrance. and its mode of action on the fuel delivery is by its control of the suction effect inside the burner as will be, obvious. I have ascertained that this type of valve is particularly accurate in maintaining correct fuel proportions and it is of course cheap to construct and-apply. It will, of course, be understood that the total proportions of the mixture in the burner may be made initially rich for facilitating ignition when starting, if desired, either by momentarily restricting the air entrance or .by any other means.

Figure 3 illustrates an alternate way of. separating the measured supply of fuel and air. into rich and lean mixtures and as ap- )lied to the same general combination of burner and carburetor as shown in Fig. 2.

In this case the n'ieasured portions of fuel liquid and air are drawn by a mixture tube 24 from a well tube 25in the carburetor receptacle 20 (see Fig. 4) and from an an entrance 26 controlled by a reed valve 27 the same as that just described. The Well tube and valve are corelated so-that the proportions taken by the tube 24 are for example, those which will, give complete combustion in the burner and they are also compensated so that such proportions are maintained substantially constant for all rates of combustion. The liquid fuel and air so drawn in by tube 24 are of course more or less mixed in transit through it, and are discharged by its orifice 28 against a wire mesh screen 29 which ,lIltCH-QILQS between said orifice and the combustion space. This screen and the space above it are of such relative dimensions with respect to the diameter of the orifice that the spot on the screen which receives the direct impingement of the discharge passes a relatively large amount of fuel through it forming a relatively rich mixture proceeding from the opposite side to the combustion space. The said spot and rich mixture path are central of the screen in this case and the spark-gap I of the igniter is also centralized thereto so W that it intercepts the rich mixture. The rest of the discharge from .the orifice 28 passes through the surrounding or remoter portions of the screen and forms a relatively lean mixture proceeding from the opposite side of the screento the combustion space. Thus the separating efl'ect already described is produced in this form by the coordination of a screen with a mixture discharge orifice. It will be apparent that a clean demarcation between the rich and lean portions is obtained by making the nozzle 28 consider.- ably narrower than the width of the screen and locating it fairly close to the latter; un le;:s these requirements are observed, the tendency of the screen is to produce a homogeneous mixture which is to be avoided, especially as, the proportions are generally within the explosive limits, A relatively coarse mesh screen say about 40 to (50 mesh to the, inch is preferred, but other types of reticulated barriers may be used for directing and guiding the flow to produce or accentuate the separation of the rich and lean mixture portions at the place of ignition.

Fig. 5 illustrates another method of producing themixture discharge against a separating screen or barrier and with the same efi'ect. In this case the fuel spray nozzle 30, is mounted directly opposite the screen and has a spear-head point or tip occupying an air passage formed in thefitt-ng 31. The air isv drawn in from atmosphere through this passage, under thesuction effect in the burner and liquid fuel issues into it from the small holes in the nozzle just back of its spear-head point, producing a, centralized spray impinging on the screen and giving a rich mixture on the p-- posite side in the line of the spark gap and a lean mixture around the margin of the screen. The screen in this case is vertical. The air passage is provided with air cooling fins 32 to aid in keeping the nozzle-below the vaporizing temperature of the liquid and the latter is supplied to the nozzle by a tube 33 which may be assumed to be connected to a compensating well like the tube 9 in Fig. 1.

Fig. 6 shows the same type of burner and mixture producing means wherein the fuel tube 33 is connected in the usual way to the lioat receptacle of the carburetor and under the control of a regulating needle valve 34. The burner air in this form is admitted through an entrance passage under the control of a reed valve 36, which acts in the same manner as the corresponding valve in Fig. 4 to maintain predetermined or constant proportions of the fuel and air admitted to the burner. The cor-elation of this burner to the carburetor is described below.

In Fig. 7 the mixture of air, admitted at the hole 37, and fuel admitted through. the compensating fuel well 13 as above described, is conducted by a mixture tube38 and discharged through its orifice 39 against a screen 29 as in preceding figures but in this case the tube 38 is looped and most of the liquid therein, after first impinging on the outer wall of the curve under the centrifugal effect, thereafter flows along the inner wall of the curve and issues from the nozzle 39 on the loop side. or the right hand side in the figure, and impinging on the screen directly opposite that side of the orifice makes a relatively rich mixture stream in the line of .the spark-gap, while the learn mixture passes through the screen on the left hand side. Otherwise the action of this burner is the same as already described. Upon ignition the lean and rich mixtures combine rapidly but non-explosively and the flame or flame products proceed through the outlet holes to the intake passage 1 with the effect above explained. It will be apparent in this form that the screen merely transm ts and perfects the separated mixture portions already partly separated in transit to the burner, and likewise that other means for so t'ansmitting or guiding the mixtures may take its place.

In Fig. 8 a mixture of previously measured proportions is produced from a liquid jet derived from a compensating well 13 as a1- rcady described and from air admitted from atmosphere by the hole 40. This mixture is drawn through a nozzlell directly into the combustion space of the burner and transversely to its main axis, or to the general direction of flow therethrough, so that the liquid particles therein, particularly the heavier particles by reason of their inertia, impinge against the opposite wa'll while the finer particles and much of the air are drawn more or less directly from the nozzle in the direction of the burner outlet. The impinging heavy particles produce a rich mixture flowing along the opposite wall and over the spark-plug terminals while the finer particies form alean mixture flowing along the other side, and both mixtures are promptly combined under combustion though sutiicicntly separate from each other at the ignition point to permit ignition without explosion. The production of lean and rich mixtures in this case occurs by the effect of the inertia of the liquid under a sutiicient entrance velocity and by the general shape and dimensions of the combustion space, which islonge'r than wide, but it will be plain that other shapes and different dimensions may be utilized to cause a directing and guiding surface to produce a sufficient separation to secure the results referred to. The total mixture proportions are made initially rich in fuel in this case by the use of the compensating well having a wider diameter at its upper end as in Fig. l.

The formation of rich and lean mixtures by the inertia effect above described is effective and specially desirable for avoiding explosive ignition when the total proportions are those of an explosive mixture, but it is i also usefully employed when the aggregate proportions of the rich and lean mixtures is too rich to explode (if homogeneously mixed or not separated). Fig. 9 illustrates a manner of use under this special condition. Here the liquid fuel is drawn in by fuel tube 42 and nozzle 43 and air by the reed-valvecontrolled air entrance 44-, the latter serving to maintain aproper compensation. This mixture is delivered by the mixture nozzle 45, transversely to the combustion space so as to form a rich mixture stream along the bottom wall and across the spark-gap and a leaner mixture near the corner 46, but the aggregate of the proportions of both mixtures is not in this case suited for the character of combustion desired for which reason more air is admitted to the two mixtures, while in the act of combustion. This auxiliary air enters by way of a ring of holes 47 direct from atmosphere. It will be quite apparent that auxlliary air could also be a-dn'iitted in like manner to some of the other forms above described, if the aggregate proportions of the lean and rich mixtures were correspondingly modified and it is not a departure from the principles above set forth if more than two streams of mixtures of different proportions be admitted and combustibly combined in the burner, and even, though one of the streams should be air without fuel, as in the case just men-' tioned.

It will be apparent that the manner of connecting the burners above described to s referablysmaller than the one on the car uretor side. This form of burner connection has speclal advantages quite independent of the specific character of burner itself and is herein independently claimed.

The rate of combustion and the range of engine operation through which the burner operates, depend upon the suction transmitted to it and that again depends on the size of the burner outlet. The double outlet on opposite sides of the throttle transmits suflicient suction .through the smaller hole or from inside the throttle when the latter is closed or partly closed; to enable the burner to start when the engine is being cranked,= as well as later when it picks up, and is idling and also provides enough suction through the larger, outside outlet to' keep the burner going when the throttle is opened wider and the intake suction has therefore diminished. In other words, the said arrangement has the effect of providing a large outlet when the intake suction is low and a smaller one when it is higher, and thereby assures an adequate or a desired lrange for the operation of the burner,,quite as though the movement of the throttle effected a mechanical variation of the cross .area of the burner outlet, and without'disturbin the "action of the engine.

In t e case of carburetors provided with chokers, as indicated at in Fi 1, it is apparent that the full force of t t suction would be transmitted to the burner if the engine should be cranked with the. choker closed and tliat it might result in type as that already described but of greater tension. I

Such a. suction-limiting air'vent may also be incorporated in the burner itself as shown for example in Fig. 6, where a similar reed valve 52is mounted in the wall of the entrance35', outside of the compensating reed valve 36 already described. In this particular form of carburetor burnercombination the carburetor proper is supplid with a" choker '53 andthe burner air entrance is provided with an individual choker 54 and intake justment by the pull rod 55. The effect of both chokers is to. increase the suction so as to make the mixtures produced in carburetor and burner respectively, temporarily overrich, as when startin a very cold engine on heavy fuel, but the increase of the suction in the burner is limited by the valve 52 which is normally closed but opens on an excessive suction. The flame from .the

burner is thus certain to be available for vaporizing the carburetor mixture even under mistreatment of the latter.

- I claim:

1. The method of non-explosively burning liquid fuel which consists in causing a pressure difference between the entrance and outlet passages of a combustion space to produce a flow of liquid fuel-and air in predetermined measured proportions directing and guiding said flow so-that it forms itself into flows of relatively rich and relatively lean mixtures of fuel and air, igniting the rich flow by an igniter intercepting the same, and combustibly combining said mixtures in said space.

2. The method of non-explosively burning liquid fuels which consists 1n causing a pressure diflierence between the entrance and outlet passages of a combustion space to produce a flow ofliquid fuel spray and air in measured proportions, directing and uiding said flow so that it forms itself into ows of relatively rich and relatively lean mixtures-of fuel and air, the aggregate proportions of which are those of an explosive mixture, initiating combustion by a spark in the rich flow, and non-explosively combining said rich and lean mixtures in said space.

3* The method of non-explosively burning liquidfuels which consists in causing a pressure difference between the entrance and outlet of a combustion space to produce a flow of liquid fuel and air, making said flow initially overrich in fuel and later-less rich,

directing and guiding said flow so that it forms itself into flows of relatively rich and relatively lean mixture portions, 1 mtmg the same during the initial rich perio and then 'mixing and combustibly combining said mixtures in said space during the ensuing period when the proportions are less rich.

4. The method of non-explosively burnlng liquid fuels which consists in transmitting suction to a combustion space, admitting li uid fuel and air thereto under the suction eii ect, forming thereof relatively rich and relatively lean mixtures and combustibly combining said mixtures 1n said space.

5. The method of producing hot fuel mixture for use in internal combustion engines, which consistsin transmitting the suction effect of the engine intake to a combustion space, admitting liquid fuel and air thereto under said effect, forming thereof relatlvely rich and relatively lean mixtures, combos tibly and non-explosively combining said mixtures in said space, and passing the combustion products into said intake.

6. The method of producing heated fuei mixture for internal combustion engines which consists in utilizing the suction effect of the engine intake to cause a suction flow of air and liquid fuel into a combustion space, making the total proportions thereof initially overrich and later less rich forming thereof relatively rich and relatively lean mixtures and igniting the same during the initial period thereof and continuing the combustible combination of the mixtures in said space, and coincidently passing the coinbustion products into said intake.

T. The method of burning liquid fuels which consists in directing a mixture tlo .v of liquid fuel spray and air against the wall of a combustion space so as to cause the larger liquid particles to travel in a predetermined path and form a relatively rich mixture flow, the rest of the fuel forming a relatively lean mixure flow in an adjacent path, igniting said rich flow by an igniter located in the path thereof and combustibly combining said portions within said space.

8. The method of producing heated fuel mixture for internal combustion engines which consists in transmitting suction from the engine intake to a combustion space, ad-

mitting liquid fuel and air thereto in predetermined proportions, directing said flow against an interior surface in said space and thereby causing the same to separate into rich and lean portions, igniting said portions while separated, combustibly combining them in said space, and passin the combustion products to the engine inta e.

9. The method of roducing heated fuel mixture for internal combustion engines, which consists in causing a variable suction of the engine intake to cause a variable mixture flow of liquid fuel and air into a combustion space, maintaining substantially constant proportions of the fuel and air in said mixture throughout the variation in the rate of said flow, abruptly changing the flow direction of the mixture within the space and thereby causing the same to separate into rich and lean mixture portions, igniting said ortions in their separate condltion by an igniter intercepting the rich mixture, and combustibly and non-explosively combining said portions within the space.

10. A liquid fuel burner comprising means for creating a mixture flow of liquid fuel and air, a deflector surface intercepting the flow and forming the'same into relat1vely rich and lean mixture portions, an igniter located in the path of the rich mixture, and a surrounding burner wall enclosing the paths of said rich and lean portions and the igniter and also forming a mixing space for said portions after ignition.

11. A liquid fuel burner comprising an ignition and mixing space, means for crr :ting a mixture flow of liquid fuel and air entering said space transversely to the longitudinal axis or general direction of flow therein, means whereby said entering mixture is caused to separate into relatively rich and lean mixture portions and an ignitcr in the path of the rich mixture.

12. A suction-operated liquid fuel burner comprising a combustion space connected with a suction passage, means for admitting liquid fuel and air thereto by the etl'ect of said suction and means for forming relatively rich and lean mixtures of said fuel and air for combustible combination in said space.

13. A suction-operated liquid fuel burner comprising a combustion space connected to a suction passage, means for admitting liquid fuel and air-thereto by the effect of said suction, means for forming relatively rich and lean mixtures of said fuel and air for combustible combination in said space and an igniter in the space in the path of the rich mixture.

14. A suction-operated liquid fuel burner comprising a combustion space connected to a suction passage, means for admitting liquid fuel and air thereto by the effect of said suction, means for maintaining substantially constant proportions of said fuel and air throughout variation of the suction elfect, means for producing relatively rich and relatively lean mixtures of said fuel and air, and an igniter, said space being adapted to mix said mixtures following ignition.

15. Means for producing heated fuel mixture for internal combustion engines comprising in combination a carburettor and a burner both operated by the intake suction and the burner having means for producing and combustibly combining relatively rich and lean mixture flows, and an outlet through which the flame or flame products reach the fuel supplied by, the carburettor.

16. Means'for producing heated fuel mixture for internal combustion engines comprising a carburettor having a choker and a suction-operated burner connected to the intake passage between the engine and the choker, and a valved air vent operating automatically to limit the degree of suction transmitted to the burner when the choker is closed.

17. Means for producing heated fuel mixture for internal combustion engines comprising in combination with the intake passage anda throttle therein, a burner having its outlet connected to said intake on opposite sides of the throttle.

18. Means for producing heated fuel mixture for internal combustion engines comprising the combination with an intake passage including a carburettor and a throttle,

of a suction-operated burner connected to the intake by plural outlets, one being on the engine side of the throttle when in its restricted position and anotheron the carbu rettor side of the throttle.

19. Means for producing heated fuel mixture for internal combustion engines comprising the combination with an intake passage and throttle, a suction-operated burnerrect its mixture transversely-tothe axis of said space.

22. The combination with an engine intake having a carbureter, said carbureter comprising a liquid jet and air entrance arranged for makinga spray mixture containing fuel in liquid state, a throttle for said carbureter, and a choker device functioning independently of the position of the throttle scribed, comprising a chamber of'greater length than breadth having an outlet for combustion prorfiucts at one end and means for admitting ixed liquid fuel and air at the other end and containing an igniter, said fuel admitting means being disposed to dispecification.

for restricting the air entrance so as to increase'the suction effect acting on said liquid jet and thereby enrichen said spray mixture, a suction-operated burner connected to the suction intake, said burner comprising means operated by suction to produce a mix- 1 a ture of fuel and air and an electric igniter for said mixture, and means for automatically venting 'air into said intake when the operation of said choker device increases the suction therein above the predetermined limit.

In testimony whereof, I have signed this JOHN GOOD.

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