US1894510A

US1894510A - Fuel injection system

Info

Publication number: US1894510A
Application number: US311512A
Authority: US
Inventors: Roy F Ensign
Original assignee: Ensign Carburetor Co
Current assignee: Ambac International Corp
Priority date: 1928-10-10
Filing date: 1928-10-10
Publication date: 1933-01-17
Anticipated expiration: 1950-01-17

Description

Jan. 17, R, ENSIGN I I 1,894,510

FUEL INJEcTI'oN SYSTEM Filed Oct. 10, 1928 3 Sheets-Sheet l Jan. 17,1933.

R. F. ENSIGN FUEL INJECTION SYSTEM 3 Shets-Sheet '2 Filed Oct. .10. 1928 2 5 WW 6 a c o .3 a r a a 6 Z in? m H a 5 x I 114 W J z a a I 6 0/ Q W W H b ,0 a 7 a I a 4 m a M 0, WW 4 J w 3 a E l :Z W Y L: a J 6 6 J J a 6 r J 5 3 J 6 8 2 8 Irilil wk 6 V 19M 7 A7 M V 9 6 v 0 7 0 0 G 172062? for. Fay F 27175494 Jan. 17, 1933. R, E 5 1,894,510 I FUEL INJECTION SYSTEM Filed Oct. 10, 1928 s Sheets-Sheet s E29 .9. v 35:. I I

Patented Jan. 17, 1933 UNITED STATES PAT NT OFFICE.

ROY F. ENSIGN, OF SOUTH PAS ADENA, CALIFORNIA, ASSIGNOR TO ENSIGN CARBURETOR 60., LTD., OF HUNTINGTON PARK, CALIFORNIA, A CORPORATION OF CALIFORNIA FUEL INJECTION sYsrnu Application filed October 10, 1928. Serial No. 311,512.

The present invention has to do generally with systems for supplying fuel to internal combustion engines, and relates more particularly to a fuel injection system for use in engines of this general type.

A primary purpose of the invention is to enable an engine equipped therewith to operate with greater power and efliciency than is obtainable by the use of the usual fuel supply systems. In order that the features embodied in the invention which bring about improved engine performance may be understood most clearly, mention is made at the outset of certain shortcomings of the usual fuel supply systems and how such disadvantages are overcome by the present system.

The most common systems for distributing fuel to the engine cylinders embody the use of a carbureter, wherein the fuel is drawn into the cylinders by virtue of a restriction in a passage through which fuel and air are drawn into the engine manifold. In addition to this restriction, however, numerous fuel delivery devices such as spray tubes and the like are necessarily placed in the path of the intake air, and as a result, loss of power to the engine is caused in decreasing its volumetric efliciency. Furthermore, the fuel contained in the mixture formed in a carbureter, though partially vaporized, is for the most art held in suspension in the air stream. Ks a result, when the mixture is drawn into the engine manifold and the velocity of flow reduced, the suspended fuel.

particles tend to separate from the air to a certain extent, and to deposit upon the walls of the manifold, thereby resulting in uneven distribution of fuel to the cylinders. In a carbureter system, the fuel used necessarilyj must be comparatively volatile; it being restricted to volatiles in that the heavier and cheaper grades of fuels are difficult to vaporize, to a sufficient extent to bring about their ignition and complete combustion in the engine cylinders.

In certain general types of injection systems, constant compression is maintained in the cylinders at all times, and the speed and ower of the engine controlled by the amount 0 of liquid fuel injected into the cylinders.

,fuel into the cylinders.

The quantity of fuel discharged generally is mechanically controlled by a pump arrangement actuated by the engine, the delivery from which depends upon the engine speed. This system of metering the fuel obviously is inferior to the air metering system of the carburetor toward maintaining the correct and most economical fuel and air mixtures.

In the present type of fuel injection system the flow of'intake air to the engine is entirely unrestricted by fuel delivery devices such as jet and spray tubes, in fact, a portion of the air is pumped into the cylinders. In addition, the fuel, in amount necessary for most eflicient engine performance at any speed 'or load, is evenly distributed and pumped through separate passage lines into each cylinder. Efficient operation is further gained by the present system in that the fuel is accurately metered in accordance with the amount of air used, and subsequently is injected under pressure and separately from the main air supply, directly into the engine sure, is sprayed into the cylinders and vaporized and atomized to such extent as to permit combustion of heavier grades of fuel than could be used by merely drawing the Since the fuel is pumped directly into the cylinders, separation and uneven distribution of fuel to the cylinders cannot Occur.

Inasmuch as the fuel is metered according to the amount of intake air used, and since the fuel is actually mixed with a quantity of air before injection into the cylinders, more accurate control andmore thorough admixture of fuel and air is effected thancan be accomplished by merely injecting, by the usual system, a quantity of fuel into the cylinders andcontrolling that quantity by some mechanical means actuated by the engine;

As will later be made apparent/the present system includes the desirable features of both t e carbureter and common injection systems,

and without the disadvantages mentioned above.

The above and numerous additional features of the present system will be most readily and clearly understood from the following detailed description of the invention, reference being made throughout the description to the annexed drawings, in which:

Figure 1 is a detailed view of the fuel injection system applied to an internal combustionengine, the various portions of the system being shown in section;

Fig. 2 is a vertical section through the pump and fuel reservoir taken on line 2-2 of Fig. 1;

Fig. 3 is a fragmentary and enlarged perspective view of the pump fuel chambers through section 33 of Fig. 1;

Fig. 4 is a horizontal section through the fuel reservoir on line 44 of Fig. 1;

'Fig. 5 is a section on line 5-5 of Fig. 1; Fig. 6 is a section on line 6-6 of Fig. 1; Fi 7 is a fragmentary side elevation of the alr controlled device as viewed in the direction of arrow A in Fig. 1;

Fig. 8 is a section on line 88 of Fig.1; and

Fig. 9 is a section'on line 9-9 of Fig. 8. Referring first to Fig. 1, an inlet air control device, generally indicated at T, is provided for re lating the flow of air to the engine mani' old M, passages 15 extending from the manifold to communicate one each with each of the engine cylinders C,one pas sage and one cylinder only being shown; In termittent fiow of air from passage 15 to the cylinder is controlled by the engine valve V. A liquid fuel reservoir R communicates with the air control device T in such a manner that the amount of fuel fed to the pump P from the reservoir at all times is proportioned or metered in accordance with the amount of air being taken into the engine. The fuel is discharged from the pump P and under pressure through lines 16 to the injector valves J, (of which there is one for each cylinder) from whence it is discharged into the engine cylinder.

With particular reference to the air control device T; a tube-shaped body portion 17 is joined to the engine manifold M as at 18, and is open at its upper end to provide an air inletI. As illustrated in Fig. 8, the body 17 is shaped at its side to provide a separate and auxiliary circular valve chamber 20 closed at its outer end by means of plug 21. The lower portion of the body has a cylindrical bore 17 (1 within which is a throttle valve 22, mounted upon a horizontally extending shaft 23, the latter being journaled in the body at 23a and in plug 21 at 21a as shown. The throttle valve 22 is actuated to control the flow of air through bore 17a by suitable connection (not shown) with arm 24, mounted on the end of the shaft 23. Intermediate the upper and 40a fitted into the cover bore 41.

lower ends of bore 17a isa'comparatively restricted portion or venturi 25, into the throat of which a passage 26 opens, the venturi serving in the usual manner to create depression through the passage.

Opening into the sides of the auxiliary valve chamber 20 is a pair of oppositely disposed

ports

28 and 29, the former communicating through passage or conduit 30, with the Venturi opening 26 and depression passage 32 leading to the depression chamber 33, and port 29 communicating with bore 17a of the inlet through passage 31 outside the venturi. An auxiliary valve 34 is mounted on shaft 23 in chamber 20, and is adapted, upon rotation of the shaft, to control the flow 0 air from passage 31 through the auxiliary valve chamber and into passage 30. It is seen that valve 34 is shaped to provide

arms

34a and 34?), the ends of which slidably engage the cylindrical wall of chamber 20, that portion of the valve between the arms being cut away as at 35 to permit the flow of air,

as indicated by the arrows in Fig. 9, from port 29 to port 28 in the position shown.

It may be noted at this time that the illustrated position of valve 34 corresponds to anintermediate position of adjustment of throttle valve 22, and that by moving valve 22 either to its open or closed position, port 28 is caused to be closed by the auxiliary valve ends 3411 or 346 respectively. Thus it is seen that during intermediate adjustments of throttle valve 22, by-pass of air from the inlet I to the depression line 32 is effected through passages 30 and 31 and the auxiliary valve chamber. However, at Wide open and closed positions of the throttle valve, the by-pass is closed and the full depression occurring at the throat of the venturi 25' is transmitted directly through line 32 to the depression chamber 33. As will later be seen, the purpose of the auxiliary valve arrangement is to modify the fuel metering, and it may be stated that other devices having similar operating characteristics may be used in the invention.

Reservoir R is mounted upon the cover 35 of the pump body 36, the walls 37 of the reservoir being formed integrally with cover 35 or in any other suitable manner. Mounted on the reservoir cover 38 is a cup 39 having a bore 39a defining the depression chamber 33, pipe 32 extending through the side of the cup as at 38a to open into the depression chamber. At one side in the bottom 38b of cup 39 is an opening 39?) communicating through the fluid passage 42 with an accelcrating well 40 formed by an inverted cup A restricted orifice or air bleed 40b is drilled in the top of cup 40, forming the accelerating well, the purpose of orifice 40?) being primarily to allow surging of the fuel in the accelerating well as will be described later.

pump P is As shown in Fig. 4, the float chamber 44 communicates with the depression chamber 33 by means of opening 45, liquid flow through this opening being adjustable by needle valve 46 mounted upon the reservoir wall 37 as at 47. Although the flow of fuel into reservoir 44 from a feed supply line 105 may be controlled by float 48 by numerous well known valve devices, I have shown, as typical, the float controlled valve G (see Fig. 2) wherein the feed flow to the reservoir 44 through orifice 106 and passage 107 is controlled by needle valve 108 resting on the float arm 109. The float is cut away as at 48a, see Fig. 4, in order to clear the accelerating well 40 and needle valve 46.

Within the depression chamber 33 is an inverted cup 50 depending from atubular stem 51 threaded through plug 54 in the upper end of bore 39a. Cup 50 is vertically adjustable by turning nut 51a on the end of stem 51. The vertical position of cup 50 1s such that its lower edge is below the liquid level L in the-fuel reservoir and normally below the liquid level in the depression chamber. Thus the skirt portion of the cup may be considered as forming a liquid seal between chamber 130, within the'cup, and the depression chamber 33, and by adjusting the cup vertically, the depth of the liquid seal may be varied as desired. 1

A tube 55. which serves essentially as a weir, s stationarily mounted in the bottom 38?) of cup 39, the weir being tightly fitted within bore 531) and extended downward into the upper end of pump actuating shaft 56, which will be more fully described at a later point. The weir is fitted into the upper end of the pump shaft with suflicient looseness to permit relative rotation of the latter. It will suffice to state at present that the fuel operated in timed relation with the engine and that the pump takes its suction of fuel and air through bore 57 drilled longitudinally within shaft 56 and communieating through weir 55 with chamber 130. Also it may be mentioned at this time that the depression in chamber 130 created by the pump suction may be greater, in accordance with the speed of the engine, than the depression in chamber 33 caused by the flow of air in the venturi past opening 26, and as a result the liquid level L in chamber 130 is caused to rise and the level L" in chamber 33 to fall. The upper end of weir 55 projects somewhat above the normal fuel level in chamber 130, but as the pump depression is applied to chamber 130, the fuel level rises, as mentioned, and the fuel overflows the weir and is delvered downward'through the bore 57 to the pump.

The fuel supply to chamber- 33 through orifice 45 is regulatedby needle valve 46, the

latter preferably being set so that the rate at which fuel which may "betaken into the depression chamber under the pressure head of the liquid in the reservoir is about that rate at which the engine takes fuel operating at highest speed. Under condition of acceleration or load increase when a maximum and still higher rate of fuel consumption occurs as the engine picks up speed or takes on load,

excess fuel as'may be required is rendered instantly available from the accelerating well 40. Fuel delivery from the accelerating well 40 occurs by way of passages 42 and 39b,

which preferably are less restricted than the valve controlled opening 45 so as to allow free flow from the accelerating well to the depression chamber, and thereby render the livery to the pump. That is, by making passages 42 and 39b of somewhat larger size than the effective opening 45, which is predetermined for high speed operation as mentioned, the fuel content of the accelerating well is rendered more quickly available for being taken into the depression chamber 33, than fuel taken directly from the float chamber through 45; and this will be especially true in case opening is made sufliciently large as to not restrict the air bleed into the well. As stated however, the rate of dumping of the accelerating well may be retarded, if desired, by making opening 40b sufliciently small that the air bleed into the well therethrough as suction is applied through chamber 33, will be so restricted as to cause the fuel in the well to be held back so that its flow from the well will be extended over a longer period.

I will now describe generally the procedure by which the fuel is metered in accordance with the amount of air flowing through the venturi 25 for delivery to the pump through bore 57 of shaft 56. Assuming first that the throttle valve 22 is-in its idling speed position, and with arm 34?) of the auxiliary valve 34 closing port 29, depression brought about by the flow of intake air past the throat of venturi 25 is transmitted directly to the depression chamber 33. The lower end 50?) of cup 50 is submerged somewhat below the liquid level L in the reservoir 44 in order that at idling speed and when the liquid level L in the depression chamber becomes lowered due to the rising of fuel in cup 50 and into tube 55, there 1s created an effective liquid head in reservoir 44 corresponding to the height between the normal reservoir level L and the level L of liquid in chamber 33. This added head s'serves to increase the 'fuel in the well instantly available for dethrough tube 55 in order to give a compara tively rich fuel mixture in the engine cylindens at idling speed. During idling speeds the liquid level L in the depression chamber mayor may not drop to the lower edge of cup 50, this being controllable by regulating thevertical position of the cup. Under either circumstance, a rich'fuel' mixture is delivered through the weir to the pump since in case the level L does drop to the lower edge of cup 50 and thereby permit some air to e drawn into chamber 130 from chamber 33, this amount of airowill be comparatively small and will not greatly dilute the fuel. As the engine speed increases, and assuming the upper end of the weir to be unrestricted, greater amounts of air will be drawn into chamber 130 beneath the lower edge of the cu due to the increase in pump suction. In

or er to prevent syphoning of the fuel through the weir, an orifice 50a is drilled in the top of cup 50, the size of this orifice necessarily being only suflicient to prevent such syphoning. Of course a small amount of air will be drawn in through the orifice and mixed with the fuel taken to the pump, although this air is more or less incidental to the main flow which occurs beneath-the cup. And in saying that the air taken into the cup chamber through orifice 50a is incidental to the main flow passing beneath the cup, I mean that the flow through 50a will be so restricted that it will not relieve the pressure differential between chambers 130 and 33, due

7 to the comparatively greater suction being applied to 130 from the pump than that transmitted to 33 from the venturi. In other words, the air bleed through 50a will prevent syphonin of the fuel over the weir but will not be su cient to equalize the pressures in chambers 130 and 33.

With the throttle valve 22 in an intermedi-- ate position as shown in Fig. 1, air is bypassed from the inlet I to line 32 as described, thereby lessening the depression in chamber 33 below that which wouldnormally result from the flow of air through the venturi at intermediate speeds. This correspondingly decreases the proportional amount of fuel discharged over tube 55 into the pump suction bore 57 although the actual amount is greater, with the result that at intermediate speed the engine is supplied with somewhat leaner mixture.

Should the engine be required to accelerate from idling to high speed, a load is imposed upon the engine in accordance with the acceleration required. Inasmuch as it is desirable that the engine, when under load, be supplied with a fuel mixture richer than that normally required, the amount of fuel necessary to take care of the accelerating load is made available through the accelerating or auxiliary Well 40. Therefore, upon sudden depression in chamber 33 due to wide opening of the throttle, the fuel in well 40 is drawn into tube 55 as described until the engine has attained its desired speed, after which the amount of fuel which would normally flow through opening 45 is suflicient to provide suitable mixture for the engine at high speed. It will be noted, in addition, that in the high speed position of throttle 22,

port 29 is again covered by the auxiliary valve arm 34a and the fuel mixture proportionately enrichened over that supplied during during acceleration. In other words the rate at which well 40 empties may be controlled by regulating the size of orifice 406. During high speeds and with the well exhausted of its contents, a comparatively small amount of air may enter the depression chamber by way opening 40?) and bubble up through the liquid in the depression chamber, this amlount of air being insufficient, though to appreciably affect the depression in said chamber communicated fromthe venturi.

Communication is established between the air inlet I and the space above the liquid level I L in the reservoir by means of a compensating line 60. By the provision of line 60, it will be seen that should an air filter or any other attachment be applied to inletI which would tend to cause a depression is compensated in that constant relative pressure conditions are maintained between the reservoir and the air inlet I regardless of obstructions to flow of the air before it enters the inlet. Also, as a safety measure, it will be seen that vapors from the fuel reservoir are kept within the system, that is, they are discharged into the intake air stream rather than to the atmosphere.

As shown'in Fig. 6, the pump body 36 is provided with a'plurality of vertically,eX- tending bores 61 containing pump plungers 62 and spaced symmetrically about shaft 56. A plunger 62 is provided for each cylinder of the engine, and although I have typically illustrated a pump for use with a four cylinder engine, it will be understood that the number of plungers may be increased or decreased to accommodate an engine having any number of cylinders. The plungers are provided with enlarged cylindrical heads 62a within correspondingly enlarged bores 61a, the plungers being urged upwardly by means of springs 63 contained with n bores 61a and around the pistons 62. Bores 61a open at their upper end into space S in the body, this space being closed at its lower end by means of the body partition 3605.

A flanged block 65 is fitted into the lower end of the body 36 in bore 360, shaft 56 being journaled in the block at 65a as well as in partition 36a at 66 and in the body cover at (36a. Confined between the flange 65b of block and the lower end of body 36 is a ring 67 oontainin ports 68, one each for each piston chamber 5', and controlled by check valves 70. The check valves'are contained within bores 71 in the block and ring 67, these bores opening into the fuel passages 72. It is seen that communication is established between chamber C and the fuel line 16, terminally communicating with passage 72 as at 16a, by way of ports 68, bore 71 and passage 72. As clearly shown in Figs. 3 and 6, the upper end of block 65 within the body bore 360 is shaped to provide a plurality of radial troughs 75, one for each of the pump plungers 62 and serving as fuel supply chambers for the pump chambers C. Each trough is seen to be formed by upwardly and outwardly extending crest portions 76 and down- Wardly inclined valleys 76a between the crests, body ports 78 being formed in the wall of bore 360 and establishing communication between the outer and lower end of troughs and the pump chamber C.

A conically shaped flange head 80 is rigidly mounted on shaft 56 and has slight clearance at its top and bottom from the body partition 36a and block- 65 as shown, and is spaced at 81 from the crests 76-0f troughs 75 to clear passages 82, which will later be described. A downwardly inclined distributor tube 83 extends through the head 80 in communication with the shaft bore 57 and pref-- erably projects slightly from the outer con-1 ical face of the head. Thus it is seen that by rotating shaft 56 by suitable drive means, from the engine, the distributor tube 83 is caused to rotate with shaft 56 and-to successively deliver fuel taken into bore 57 through the tubular weir 55, as previously described, to each of the trough chambers" 75. Inclined passages 82, extending betw en the plunger bores 61a and the clearance ace 81, are provided in order that should leakage of the fuel between the plungers 62 and their bores 61 take place during the compression stroke of the piston, and the fuel become forced into the upper bores 61a, it may then drain back into troughs 75 through the passages 82.

Within the upper portion of space S in the pump body 36 is a circular and inclined swash plate 85 adapted to bear on its lower face F against the upper end of the plunger heads 62a and to impart vertical reciprocatory motion to the plungers when shaft 56 is rotated. The swash plate is mounted on the eccentr c hub 86, positioned on the shaft by I means of set screw 87, and is confined between bearings 89 carried in the annular hearing rings 88 extending around the lower portion 86a of the hub. The bearing assembly and the swash plate are held in place on the hub by retention ring 90a mounted on the hub by means of set screws 90.

The lower face F of the swash plate and the upper ends of the plunger heads are pre-' successively forced downward on their compression stroke, and likewise are permitted successively to be urged upward by springs 63 on their suction stroke, all in sequence corresponding to the motion of the swash plate. In order to lubricate the swash plate and bearing assembly, the upper body space S may be permitted to communicate through openings 91 and 9101 with the vapor space in theengine crank case (not shown) to the end that oil vapors from the crank case pass through space S in sufficient amount to furnish the desired lubrication.

An injector valve J is mounted upon the engine head above cylinder C and, as will later be seen, serves to discharge fuel under pressure from line 16 into cylinder C. The

illustrated type of injector valve is merely typical of numerous devices of this general nature that may be used for injecting fuel into the cylinders, and therefore the invention is not to be considered as limited to the use of this particular form of injector valve. The valve is seen to have a body 92 threaded into the engine head H at 92a, there being formed in the body a pair of vertically extending co-axial bores 93 and 93a, the latter terminating at its lower end in an orifice O. The injector valve body has a horizontally extending bore 95 communicating at its inner end with bore 93 and at its outer endwith the fuel supply line 16 terminating in the body within bushing 94. Thus it is seen that the plunger compression chamber C communicates with the engine cylinder C by way of line 16, bores 93 and 93a and orifice O.

Confined between the cover 96 0f the injector valve and its body 92 is a flexible diaphragm 97, upon which is centrally mounteda head 98. A needle valve 99 is threaded in-, to the lower end of head 98 and depends therefrom through bores 93 and 93a to seat in the orifice O. The head ncl therefore the needle valve are urged do nward by means of spring 100 confined between the head and valve cover 96. It will be noted that the diaphragm, is spaced from the body and cover of the injector valve J in connection with the pump P. It willbe seen that due to the continuous distribution of fuel to the supply C. As the plunger 62 moves upward from its lowermost position, during which movement check valve 68 remains closed, suction is developed in chamber C, which, when the piston moves to sufficient height to uncover port 78, causes fuel and air, that is air supplemental to the main air feed, to be drawn through that port into the chamber. It will be noted that port 78 is open for a comparatively short time only. Upon downward movement of the plunger, the charge in chamber C is compressed causing check valve to be opened and thefuel, to be discharged under pressure into line 16. At an intermediate point in the plunger compression stroke the pressure developed in line 16 acting upon diaphragm 97 is sufficient to raise the needle valve 99 from its seat and to permit fuel to be discharged through orifice 0 into the engine cylinder. When the plunger has reached the end of its compression stroke, and a certain amount of depression has taken place in line 16 due to the discharge through orifice O, the pressure on the under side of diaphragm 97 becomes insuflicient to counteract the thrust of spring 100, and the needle valve 99 is therefore returned to its seating position to close the intake of fuel and supplemental air to the cylinder.

Plunger bores 61, and therefore the volume of plunger chamber C, may be of any suitable size, as in some instances it may bedesirable to pump considerable supplemental air into the engine cylinders by means of the fuel pump. The limiting factor is determining the size of the plunger chambers C is, of course, the power required to compress and inject large amounts of air with the fuel.

. It will be seen from the foregoing, that the point of initial fuel discharge into the engine cylinder is finally determined by the injector valve, that is, by regulating thetension ofspring 100 or of the diaphragm, the pressure that must be exerted on the under face of the diaphragm in order to unseat the needle valve may be predetermined. and may be caused to take place at substantially any intermediate point in the plunger compres-,

sion stroke. In a like manner. the point at which fuel intake to the engine cylinder is discontinued occurs when the plunger has reached the end of its stroke and when the pressure in line 16 attains a value corresponding to the adjustment of the injector valve.

Due to the fact that the discharge from the pump chambers is a compressible mixture composed of fuel and air, the injection of the mixture into the engine cylinders may be determined or timed according to pressure conditions. That is, the pressure of the mixture may be brought to suitable value for discharge into the engine cylinders at substantially any point of the piston stroke, and due to the pressure and compressibility of the charge, the period of discharge into the cylinder may be regulated as previously described.

As a typical means for driving the pump, I have provided a shaft 112 driven by the engine crank shaft 110 through gears 111 and 111a. Shaft 112 is drivingly connected to the pump shaft 56 by

gears

113 and 113a. Preferably, the driving arrangement is so geared that the pump shaft is driven at half the speed of the engine crank shaft. By proper adjustment and timing of the pump drive and the injector valve, discharge of fuel into the "cylinders may be maintained during substanmore or less dependent upon the particular engine used, and the conditions under which that engine is required to operate.

During operation of the invention as described, it is seen that as the engine speed increases, increasing amounts of fuel are sup plied by increasing the proportion of fuel to air taken into the plunger chambers C. That is, with passage 57 in the pump shaft 56 unrestricted, a constant volume of air is drawn into chambers C after the plungers have completed their suction stroke, and additional amounts of fuel are delivered to the chambers as acceleration takes place in accordance with the depression maintained in chamber 33 by virtue of the fuel metering system. Here we have a condition under which the actual quantities of fuel taken into the pump are metered in'the depression chamber as described, in accordance with the amount of air flowing to the engine through the venturi, and the fuel to air ratio of the mixture taken into the pump, is varied as the amount of metered fuel varies. It may be desirable under certain conditions, for the system to operate in such a manner that for all speeds of the engine, substantially constant and relatively rich mixtures of fuel and supplemental air will be discharged from the plunger chambers to the engine cylinders. Thus by controlling the amount of air drawn throughpassage 57 in accordance with the amount of fuel flowing therethrough, a mixture sufiiciently rich for accelerating pur poses may be held in the feed line 16 at all times. This is advantageous in that when it is desired to accelerate the engine speeds, there is instantly available for discharge into the cylinders a mixture sufficiently rich for achas no appreciable effect on the actual ratio of the main air supply flowing through the venturi, to fuel, since the quantity of fuel delivered to the pump is independent of the supplemental air mixed with it.

In order for the system to operate under these conditions, I have provided a needle valve 114 extending vertically through the bore of tubular stem 51 carrying the inverted adjustable cup 50, the needle valve being tapered at its lower end to project into the upper end of the tubular weir 55. As will later be seen the needle valve is vertically adjustable to control the passage of air to the plunger chambers by way of the pump shaft bore 57. A support 115 is carried on the upper face of plug 54, and a hub 116 is pivotally mounted upon the support,

the hub having angularly extending

arms

117 and 118, the former being pivotally joined at- 119 to the upper end of the needle valve. Arm 118 is pivotally connected at 120 to a rod 121 which, in turn, is pivotally joined at 122 of lever arm 123 rigidly mounted on the throttle valve shaft 23. The relative position of the throttle valve 22, lever arm 123 and needle valve 114 are such that when the throttle valve is in its idling speed position, the tapered end of the needle valve more or less closely approaches and restricts the upper end opening of the tubular weir, and when the throttle valve is in its open position needle valve 114' is raised inorder to permit free passage of air from the depression chamber into the plunger chambers.

Thus it will be seen that during idling speed in which the amount of fuel delivered to the pump is comparatively small, the air intake by way of the tubular weir is somewhat restricted due to the position of the needle valve. As the engine accelerates from idlingspeed, the depression in chamber 33 is increased due to the action of the venturi, and the amount of fuel delivered to the plunger correspondingly increased as previously described. Opening movement of the throttle valve, however, is accompanied by movement of lever arm 123 and the raising of the needle valve to permit increased flow of air to the plunger chamber, said flow of air bewith the increase of fuel delivery in such proportion that the ratio of fuel to air in the mixture fed to the pump remaining more or less constant. Due to the upward movement of the needle valve, this condition may prevail at all speeds including the maximum speed corresponding to the wide open position of the I throttle.

It will be seen from the foregoing that the fuel and air contained in feed line 16 is a relatively constant mix ure at all times irrespective of the operating speed or load, and that this mixture is of such richness as to provide sufficient fuel to provide for the acing correspondingly increased in accordance.

celerating load. It will be understood, of course, that the present system may operate with or without the auxiliary needle valve control, although in certain instances it may be desirable to embody in the system this auxilEary valve control.

As a general summary of the operation of the invention, it will be noted first that the fuel delivered to the pump or discharged to the engine is controlled in quantity by the air regulating device T, that is, the amount of fuel delivered to thepump at any one time is determined by the amount of air being taken into the engine, modified by the action of the auxiliary air control valve, and also by the position of the air inlet throttle. Then, although the fuel is proportioned in accordance with the flow of intake air, it is delivered to the engine cylinder entirely separate from the air. Furthermore, it will be apparent that by proper timing of the pump and injector valve with the engine, the engine may be operated under practically any compression, inasmuch as the pump and injector valve may be adjusted to deliver fuel to the engine cylinder during any portion of either or both the piston compression and suction strokes.

It will be understood the drawings and description are to be considered merely as illustrative of and not restrictive on the broader claims appended hereto, for various changes in design, structure and arrangement may be made Without departing from the spirit and scope of said claims.

I claim:

1. The method of supplying fuel to an internal combustion engine, that includes feeding air to the engine in accordance with its varying requirements, metering fuel proportionate to the amount of air being fed to the engine, and introducing such metered fuel to the engine independently of the said feed of air thereto.

2. The method of supplying a combustible air and fuel mixture to an internal combustion engine, that includes feeding air to the engine in accordance with its varying requirements, metering fuel proportionate to the amount of air being fed to the engine, and introducing such metered fuel together with supplemental air. to the engine independently of the main feed of air thereto.

3. The method of supplying a combustible air and fuel mixture to an internal combustion engine, that includes feeding air to the engine in accordance with its varying requirements, metering fuel proportionate to the amount of a r being fed to the engine, and

introducing such metered fuel together with supplemental air, to the engine independentlv of the main feed of air thereto. the proportion of supplemental air to fuel being maintained substantially constant.

4:. The method of supplying fuel (to an internal combustion engine, that includes feedingair to the engine in accordance with its varying requirements, metering fuel proportionate to the amount of air being fed to the engine, and injecting such metered fuel under pressure into the engine independently of the said feed of air thereto.

5. The method of supplying fuel to an internal combustion engme, that includes feeding air to the engine in accordance with its varying requirements, metering fuel proportionate to the amount of air being fed to the engine, and injecting such metered fuel into the engine in timed relation to the engine operation.

6. The method of supplying a combustible air and fuel mixture to an internal combustion engine, that .includes feeding air to the engine in accordance with its varying requirements, metering fuel proportionate to the amount of air being fed to the engine, and injecting such metered fuel together with supplemental air into the engine in timed relation to the engine operation.

7. The method of supplying a combustible air and fuel mixture to an internal combusti on engine, that includes feeding air to the engine in accordance with its varying requirements, metering fuel proportionate to the amount of air being fed to the engine,

and injecting such metered fuel'together with supplemental air into the engine in timed relation to the engine operation, the proportion of supplemental air to fuel being maintained substantially constant.

8. The method of supplying fuel to an internal combustion engine, that includes maintaining a restricted flow of air to the engine in accordance with its varying requirements, metering fuel proportionate to the amount of air being fed to the engine. by feeding and isolating the fuel by virtue of the varying depression caused by the air at its restricted point of flow, and introducing such metered fuel to the engine independently of the said air fed thereto.

9. The method of supplying a combustible air and fuel mixture to an internal combustion engine, that includes maintaining a restricted flow of air to the engine in accordance with its varying requirements, metering fuel proportionate to the amount of air being fed to the engine by feeding and isolating the fuel by virtue of the varying depression caused by the air at its restricted point of flow, and introducing such metered fuel together with supplemental air, to the engine independently of the main air supply fed thereto.

10. The method of supplying a combustible air and fuel mixture to an internal combustion engine, that includes maintaining a restricted flow of air to the engine in accordance with its varying requirements, metering fuel proportionate to the amount of air being fed to the engine by feeding and isolating the fuel by virtue of the varying depression caused by the air at its restricted point of flow, and introducing such metered fuel together with supplemental air, to the engine independently of the main air supply fed thereto, the proportion of supplemental air to fuel being maintained substantially constant.

11. The method of supplying fuel to an internal combustion engine, that includes maintaining a restricted flow of air to the engine in accordance with its varying requirements, metering fuel proportionate to the amount of air being fed to the engine by feeding and isolating the fuel by virtue of the varying depression caused by the air at its restricted point of flow, and pumping and injecting such metered fuel into the engine in timed relation to the engine operation.

12. The method of supplying a combustible air and fuel mixture to an internal combustion engine, that includes maintaining a restricted flow of air to the engine in accordance With its varying requirements, metering fuel proportionate to the amount of air being fed to the engine by feeding and isolating the fuel by virtue of the varying depression caused by the air at its restricted point of flow, and pumping and injecting such metered fuel together with supplemental air into the engine in timed relation to the engine operation.

13. The method of supplying a combustible air and fuel mixture to an internal combustion engine, that includes maintaining a restricted flow of air to the engine in accordance with its varying requirements, metering fuel proportionate to the amount of air being fed to the engine by feeding and isolating the fuel by virtue of the varying depression caused'by the air at its restricted point .of flow, and pumping and injecting such metered fuel together with supplemental air into the engine in timed relation to the en gine operation, the proportion of supplemental air to fuel being maintained substantial-ly constant.

14. The method of supplying fuel to an internal combustion engine, that includes maintaining a restricted flow of air to the engine in accordance with its varying requirements, metering fuel proportionate to the amount of air being fed to the engine by lifting and isolating the fuel by virtue of the varying depression caused by the air at its restricted point of flow, and pumping and the engine, and compressing fuel together with supplemental air and injecting such air and fuel into the engine. 16. The method of supplying a combustible air and fuel mixture to an internal combustion engine that includes periodically compressing air and fuel in timed relation to the engine operation, and admitting such air and fuel to the engine when its compression pressure reaches a certain predetermined value. e

17. In a charge feeding system for internal combustion engines, an air inlet having therein a restriction, a constant level fuel chamber, means actuated by the depression at the air passage restriction and operating to feed and isolate fuel from the constant level fuel chamber, and a fuel pump adapted to take fuel from the isolated fuel body and to introduce such fuel to the engine.

18. In a charge feeding system for internal combustion engines, an air inlet having therein a restriction, a constant level fuel chamber, means actuated by the depression at the air passage restriction and operating to feed and isolate fuel from the constant level chamber, and a fuel pump adapted to take fuel from the isolated fuel body together with a volume of supplemental air and to introduce the mixture of fuel and air to the engine independent 5 of the main air feed thereto.

19. In a charge feeding system for internal combustion engines, an air inlet having therein a restriction, a constant level fuel chamber, means actuated by the depression at the air passage restriction and operating to feed and isolate fuel from the constant level chamber, and a fuel pump adapted to take fuel from the isolated fuel body together with a volume of supplemental air and to introduce the mixture of fuel and air to the engine independent of the main air feed thereto, and means for maintaining substantially constant the proportion of supplemental air to fuel.

20. In a charge feeding system for internal combustion engmes, an a1r inlet having therein a restriction, a constant level fuel chamber, means actuated by the depression at the air passage restriction and operating to feed and isolate fuel from the constant level fuel chamber,'a fuel pump adapted to take fuel from the isolated fuel body, and means for conducting fuel from said pump to and injecting said fuel into the engine at a predetermined pressure.

21. In a charge feeding system for internal combustion engines, an air intake passage, a constant level fuel chamber, means for withdrawing and metering fuel from the constant level chamber controlled by the amount of air passing through the intake passage, and means independent of the intake passage to introduce such metered fuel to the engine.

22. In a charge feeding system for internal combustion engines, an air intake passage, a constant level fuel chamber, means for withdrawing and metering fuel from the constant level fuel chamber controlled by the amount of air passing through the intake passage, and means for forcibly injecting such metered fuel to the engine.

23. In a charge feeding system for internal combustion engines, an air intake passage, a constant level fuel chamber, means for withdrawing and metering fuel from the constant level chamber controlled by the amount of air passing through the intake passage, a pump operated in timed relation with the engine and taking fuel from metering means and means conducting the output of said pump to the engine.

24. In a charge feeding system for internal combustion engines, an air intake passage, a constant level fuel chamber, means for withdrawing and metering fuel from the constant level chamber controlled by the amount of air passing through the intake passage, a pump operated in timed relation with the engine and taking fuel from the metering means, and means conducting the output of said pump to and injecting it into the engine.

, 25. In a charge feeding system for internal combustion engines, an air intake passage having a restricted portion, a depression chamber communicating with said intake passage at the restricted portion, a constant level fuel chamber communicating with said depression chamber, a pump operated in timed relation with the engine and taking fuel from the depression chamber, and means conductin the output of said pump to and injecting it into the engine.

26. In a charge feeding system for internal combustion engines, an air intake passage having a-- restricted portion, a depression chamber communicating .with said intake passage at the restricted portion, a constant level fuel chamber communicating with said depression chamber, an accelerating well'in said fuel chamber communicating with the depression chamber, a pump operated in timed relation with the en ine and taking fuel from the depression cham er, and means conducting the output of said pump to and inj ecting it into the engine.

27. In a charge feeding system for internal combustion engines, an air intake passage havinga restricted portion, a depression chamber communicating with said intake passage at the restricted portion, a constant level fuel chamber communicating with said depression chamber, a pump operated in timed relation with the engine and taking fuel from the depression chamber, means in the depression chamber for lifting fuel therein for delivery to said pump, and means conducting the output of said pump to and injecting it into the englne.

28. In a charge feeding system for internal combustion engines, an air intake passage having a restricted portion, a throttle valve in the passage, a depression chamber communicating with said intake passage at the restricted portion, a constant level fuel chamber communicating with said depression chamber, a'pump operated in timed relation with the engine and taking fuel from the depression chamber, means in the depression chamber for feeding fuel and air to the pump, valve means in the depression cham-- ber for regulating the flow of fuel and air to the pump in accordance with the movement of said throttle, and means conducting the output of said pump to and injecting it into the engine. i

29. In a charge feeding system for internal combustion engines, an air intake passage having a restricted portion, a depression chamber communicating with said intake passage at the restricted portion, a constant level fuel chamber communicating with said depression chamber, a pump operated in timed relation with the engine and taking fuel from the depression chamber, a vertically extending inverted cup in the depression chamber having its lower edge submerged beneath the liquid level therein, a tubular weir communicating with said pump and extending through the bottom of said depression chamber and projecting above the liquid level within said cup, fuel being delivered to the pump by overflowing said weir, and

means conducting the output of said pump to and injecting it into the engine.

30. In a charge feeding system for internal combustion engines, an air intake passage having a restricted portion, a throttle valve in the passage, a depression chamber communicating with said intake passage at the restricted portion, a constant level fuel chamber communicating with said depression;

chamber, a pump operatedin timed relation with the engine and taking fuel from the depression chamber, a vertically extending inverted cup in the depression chamber having its lower edge submerged beneath the liquid level therein, a tubular weir communicating withsaid pump and extending through the bottom of said depression chamber and projecting above the liquid level within said cup, fuel being delivered to the pump by overflowing said weir, an auxiliary valve extending vertically within the cup and operatively connected to said throttle valve, said auxiliary valve being adapted to regulate the effective opening in the top of said weirin accordance with the throttle valve position, and means conducting the output of said pump to and injecting it into the engine.

31. In a charge feeding system for internal combustion engines, a constant level fuel chamber, a cover for said chamber, a cup mounted on the cover and extending downward below the fuel level in the fuel chamber, said cup defining a depression chamber,

depression chamber, a tubular Weir communicating with said pump and extending vertically through the bottom of said depression chamber and projecting above the liquid level within said inverted cup, fuel being delivered to the pump by overflowing said weir, and means conductng the output of said pump to and injecting it into the engine.

32. In a charge feeding system for internal combustion engines, a constant level fuel chamber, a cover for said chamber, a cup mounted on the cover and extending ward below the fuel level in the fuel chamber, said cup defining a depression chamber, a plug in the upper end of the cup, an open ing in said cup extending into the fuel chamber beneath the fuel level therein to permit fuel to flow into the depression chamber, an inverted, cup in the depression chamber hav ing its lower edge submerged beneath the liquid level therein and depending from a vertically adjustable stem threaded through said plug, an accelerating well, a passage communicating between the bottom ofisaid accelerating well and the depression chamber, and a tubular weir extending vertically through the bottom of said depression chamher and projecting above the liquid level within the first mentioned inverted cup, fuel in the depression chamber being adapted to downyond the venturi, a depression passage opening into said venturi at its throat, a by-pass conduit interconnecting said inlet and the depression passage, and means for closing said by-passconduit at open and closed positions of the throttle, the inlet and depression passage being in communication at intermediate positio ns of the throttle.

35. In a charge feeding system for internal combustion engines, a tubular air intake passage having an inlet, a venturi adjacent the inlet, a throttle valve in the passage beyond the venturi and mounted on a shaft extending diametrically across the passage, a separate and cylindrical valve chamber mounted on the side of the intake passage said shaft,"the auxiliary valve being shaped to provide a pair of arms for slidably engaging the cylindrical chamber wall on each side of one of said openings at an intermediate'position of the/throttle, said arms being adapted to close the last me'ntionedopening respectively when'the throttle valve is moved to open and closed positions.

36. In a charge feeding system for internal combustion engines, an air intake assage having an air inlet and a venturi in t e passage beyond the inlet, a depression chamber communicating with a constant level fuel chamber, a depression passage extending from said depression chamber and opening into the throat of the venturi, a pump operated in timed relation with the engine and taking fuel from the'engine, and means con ducting the out ut of said pump to and injecting it into t e engine. I

37 In a charge feeding system for internal combustion engines, an air "intake assage having an inlet, a venturi adjacent t e inlet and a throttle valve in the passage beyond the venturi, a depression chamber communicating with a constant level fuel chamber, a depression passage extending from said depression chamber and opening into thethroat of the venturi, a by-pass conduit interconnecting said inlet and the depression passage,

means for closing the by-pass conduit at open and closed positions of the throttle, a pump operated in timed relation with the engine and taking fuel from the depression chamber, and means conducting the output of said pump to and injecting it into the engine.

38. In a charge feeding system for internal combustion engines, an air intake passage having an inlet, a venturi adjacent the inlet and a throttle valve in the passage beyond the venturi, a depression chamber communicating with a constant level fuel chamber, a depression passage extending from said depression chamber and opening into the throat of the venturi, a by-pass conduit interconnecting said inlet and the depression passage,

means for closing the by-pass conduit at open and closed positions of the throttle, a conduit interconnecting said inlet with the constant level fuel chamber above the liquid level therein, a pump operated in timed relation with the en inc and taking fuel from the depression c amber, and means conducting the output of said pump to and injecting it into the engine.

In witness that I claim the fore oing I have hereunto subscribed my name tfiis 17th day of September, 1928.

ROYF. ENSIGN.