US1721209A - Force-feed charge-forming device - Google Patents

Description

Julylqwzs] H CUTLER 1.721,209

l l FORCE FEED CHARGE FRMING DEVICE l Filednec. 27 1925 4 sheets-sheet 1 lign- July 16, 1929; H. H. c-UTLER FORCE FEED CHARGE FORMING DEVICE I Filed Dec. 27, 1923 4 Sheets-Sheet 2 -July 16, 1929.

H. H. CUTLER FoRcE.FEED CHARGE FORMING'DEVWIGE Fild Dc. 27', 1925 '4 Sheets-'Sheet 5,

Patented July 16, 19,29..

v UNITED smiias HENRY H. CUTLER, 0F BROOKLINE, MA's'sACH-SETTS.

FORCE-FEED 'cHARGE-FoRMINeDEvicE.

imputation filednecember 27,1223. serial No. 682,962.

The object of my invention is to'produce a force-feed charge-forming device that will deliver to the intake manifold an exceedingly intimate mixture of air and fuel in a correct and uniform proportion, and surround each minute particle of fuel withsufficient air to make it possible to produce, when fired, complete combustion or CO2, which is a harmless, non-poisonous gas.

This I accomplish chiefly by forcing the liquid fuel under pressure 1around the pef riphery f a comparatively large valvelifted only a few thousandths of an inch from its seat. For example, this distance in a one inch carburetor may be about .O02 of an inch. The style of carburetor which has gone almost into universal use sucks' the fuel around the surface of a needle valve lifted from its seat a distance frequently of 1/50 or .02 of an inch, thus delivering` the fuel to the mixing chamber in the shape of globules averaging .02 in diameter, or one thousand times the volume of drops .O02 inches in diameter obtained in my invention.

It has been ascertained experimentally that the large drops of liquid fuel produced in most carburetors hold to their globular form with great tenacity. Y

This means that only the outside circumference oflthese comparativelylarge dropsof liquid fuel come in contact `with the air from which they may derive sufficient oxygen to form CO2 gas when fired, the inside or greater part of these globules not coming in direct contact with the air, cannot Obtain su'ff icient oxygen to form CO2, with the result that the exhaust gases of 'all gasoline engines universally used for propelling automobiles, emit CO gas with the exhaust, which is highly poisonous, besides causing a great loss in the eflioiency of the engine.

The drawings submittedare made full size for a so called one inch carburetor and while this design may be used in connection with an engine having any number of cylinders,

' it is better, and especially adapted fora four cylinder engine.

Fig. l is a top plan view of a complete charge-forming device embodying my invention Fig. 2 is a vertical cross section through the middle of a complete charge-forming device on line 2-2 of Fig. 1;

Fig, 3 .is a vertical cross's'ection through the middle taken at right angle to Fig. 2 on line 3 3 thereof;

Fig. 4 is a horizontal section on line 21e-4 of Fig. 2;

' Fig. 7 is a horizontal section on line 7-7 of-Fig. 2;

Fig. 8 is a top plan view of the steering post and control levers of an automobile; A YF 1g. 9 is a horizontal section on Vline 9-"9 of Fig. 2. Fig. 16 is an elevation partly insection of the Vfront or number one cylinder of a four cylinder, four'cycle engine, having the socalled T head, and showing applicants charge-forming device attached -thereto.-

VMy charge-formingdevice consists of a main casting 10, cylindrical in shape, tapering gradually towards the top, and provided there with a flange 11 adapted to be bolted to the intake manifold of the engine. Two projecting. lugs 12, 12, serve to hold the outside bearing casting 13 tothe bowl 10 by means of four screws 14, 14. VThe cylinder Vor bowl 10 is turned out smooth inside at 15, 15 'and 16, 16 and a bottom casting 17 is turned up to 'fit tightlyin the ybottom of the bowl 10 to whichl itis fastened by the screws 18,.Fig.l 4.

The' bottom `casting V17 has a downward projecting lug 19 which is connectedwith -fthe outside bearing casting 13 bya .metal bar 20'which serves to, holdthe castings 10 and 13 rigidly together.

The inside -of the bottom :casting 17 Lis l turned out to fit a steel cylinder 21, whichis threaded on the inside and heldin place by the set screw 22. Screwed -into this cylinder 21 isa large distributing valve 23 which takes the place of the needle valve inmost cari buretors. This valve 23is )ground yaccurately on to a seat formed in the bottom casting 17, and isthen partially unscrewedsufheiently to lift lit fromits seat a few-thousandths of an inch. The distributing valve 23 is fastened with screws 24 to a double conical casting 25. Underneath the valve 23 is a small cylindrical reservoir26, designed to lhold a small amountof the liquid fuel.

AThree 'circular openings 27, Figs. 2and 4, vare 'cast through the top of the bottom casting 17, which openings connect with va kpassageway 28 which can-be opened and closed to any desired amount bymeans o'f the'butl terfly valve 29 operated by the crank 30.

Another conical casting 31 is also inserted inside the bowl 10, so as tofkeep the area of the air passageway the same from the time the air enters through the butterfly valve' 29 until it reaches the intake manifold through the circular opening 29 in the flange 11. It is thus seen that the suction of the en-y gine will draw the air through the butterfly valve 29, into the 'passageway 28, thence through the arc-shaped openings 27, and will finally. enter the mixing chamber 32 as a hollow cylinder of air with a very thin wall, shown in the drawings as 3/16 of anV inch and tapering toy 3/32 near the top of the mixingy chamber. Y

The liquid fuel enters the reservoir 26 through two holes 33, 33, drilled through the bowl 10V and bottom casting 17, after these/.two castings have been screwed together. i Y

The fuel is'forced into the reservoir 26 Y and thence by the valve 23 into the mixing chamber 32 by means of a pair of plunger pumps 34, 34, whose stroke is varied according to the load on the engine. y

The pump plungers are driven by a walking beam 35, fastened rigidly to a long hub casting 36, free to'turn on the shaft 37,

i which is supported ateach end by the bowl 10 andthe outside bearing casting 13 .respectively. Connecting rods 38, 38 connect the pump plungers and walkingbeam. The hub ycasting 36 has a slotted arm 39 projecting at right angles. A square steel block 40 slides freely in this slot, and is held by a pin 4l, on which it is free to oscillate. r1`hc other end of the pin 41 is fastened rigidly to a forked lever 42 by means of the nuts 43, but

can be slid up and down in the slot 44, and thereby adjusted so as to varyover a wide range the-swing of the walking beam 35 and stroke ofthe plungers 34.

The forked lever 42-is rigidly secured to av hub 45, free to oscillate on a pin 46, 'and is 'ven a pendulum movement by means of the disc 47, Figs. 2 and 6, which is fastened by a pin 48 to a shaft 49 driven from the engine shaft at preferably the same speed by means -of the sprocket wheels`50, 50 and chain 50.

n The eccentric disc 47 is shown in the drawings as occupying a concentric position with the driving shaft 49, in which position the rotation of the shaft 49 will not cause the i' forked lever 42 to oscillate and there will be `no movement of the walking beam 35 or pump plungers v34.

vThe mechanical center' of the disc 47, however, can be moved away from the center Y of the driving shaft 49 by means of the cylincentric 51. A slot 52, the same thickness as the pin 48, is milled nearly through the cylinder 51, and then its open end may be closed up with the electric pencilA or otherwise. This cylinder 51 while free to slide on the shaft 49, is compelled to rotate with it, without changing its relative angular position, by means of the pin 48.

It is now seen that as the cylinder 51 is slid along the shaft 49, it will force the niechanical center of the disc 47 farther and farther away from the center of the shaft 49, thereby increasing its eccentricity and setting up a pendulum movement of the forked lever 42 and starting the desired de gree of motion of the walking beamA 35 and pump plungers 34.

The movement of the cylinder 51 is controlled by the carriage 53V which also slides freely on the shaft 49 as well as 'on the bar 20 which it embraces from rotation. y

The carriage 53 is fastened to a sliding rod 54 which may be connected with the throttle lever of an automobile by means of the usual system of rods and levers, thus giving' the operator complete control ofthe amount of fuel fed to` the engine.l Y

The fuel supply enters kthe intake valve chambers of the two plunger pumps at 62 andk which holds it whence it is drawn through the inlet valves Y 63 into the pumpbarrel, thence through the outlet valve 65, passage 33, reservoir 26, around the circumference of the distributing valve 23 into the mixing chamber 32, which it enters in the shape of an extremely thin hollow cone, with walls` only a few thou'- sandths of an inch thick. Here it is met by a hollow cylinder of air with also avery thin wall, so that the extremely small globules of fuel become thoroughly mixed with the air before being brought together in a solid stream at the neck of the carburetor when the complete mixture enters the intakemanifoldof the engine. l

ln order to adjust the degree of opening of the distributing valve 23, a number of holes 25 are first drilledand tapped, close together in the side of theV conical casting 25; the y valve 23 is then unscrewed from its seat the desired amount and a threaded rod 55 is pushed up through a slot 55 (Fig. 8) in the bottom of the bowl l0, and then screwedinto the proper hole in the cone 25. The? end yof the rod 55 is then attached to a spring V56 which is fastened at 57and tends to, as shown in the drawings, open the valve23 still wider, but is prevented from doing thisby'the trie angular piece 58 (Fig. 9) against which it presses. Since the triangular piece 58 is fastened by the screws 59 to the slidingl carriage 53, it will. now be plain that as the carriage 53 is moved back and forth, the cone 25'and valve 23 will be made to oscillate back and forth and thus detach any grain of dust or foreign 'matter that mightotherwise tend to stop up a portionof the very narrow passage between the valve 23 and its seat. Y

' The inlet valves 63are shown mechanically operated lby means of thesbell cranks. 68, (Fig. 3) pivoted at 69, operated by valve tappets 70, driven by the cam 7l, pinned tothe driving shaft 49. A minute air chamber 75 is drilled into the top Aprojection of the distributing valve 23 and communicates with the reservoir 26 by the passage 75. The volume of this air chamber can be regulated by the long screw 76. s f

An electrical heatinff coil 77 surrounds this upward projection of the 'valve 23 with its insulated lead 77 connected with an insulated binding post 7 8 in the neck of the carburetor bowl 10. The top and bottom of the valve 23 are also shown faced with micaA 78 in order to help throw the heat derived from the heating coil towards the circumference of the valve 23 where it warms more or less the fuel being forced between this valve 23 and its seat.

In all four cylinder four cycle, combustion engines there is a steady pulsating suction action in the intake manifold varying from practically nothing toa maximum when one of the engines pistons starts on' its intake stroke until it reaches about the middle of the stroke. The velocity andamount of air being drawn into the intake manifold varies accordingly as does also the amount of fuel sucked in by the air rushing through the ordinary type of carburetor.

In order to duplicate this necessary action I drive the two pumps shown at the same speed as the engine and also synchronize the movement of the plungers with the pistons of the engine. Thus when anengine piston starts on its suction stroke one of the twov pumps starts on its'delivery stroke, and thus automatically Vincreases the amount of fuel pumped in precisely the same proportion and timeftliat the amount ofair is increased thereby keeping constant the percentage of air and fuel during all portions of the suc.-`

tion stroke of the engine. In aDiesel engine the pumps force in fuel during the power stroke, vand stop Vthis action long before thel engine pistonV reachesthe end of its power stroke and consequently do not operate in synchronism with the engine pistons.

It is now evident that my charge-forming device produces not only anexceedingly intimate mixture of air and fuel, but also breaks up the fuel into exceedingly small globules constituting a genuine mist. Y It also supplies electrical heat at the proper place tov assist this mist in becoming a gas before it is fired, and furthermore,` when used in connection with a four cylinder engine, keeps an abso.

lutely constant percentage of mixture during all portions of arsuction stroke of th-e engine. The resulting effect 1s the complete combustonfof the fue1ntofGG-a nompoisonousgas.

Itis furthermore practical to voperate-an ordinary vengine over Wide 'ranges ofload at constant compression by varying the: stroke of thepumps and consequently the amount of fuel supplied, without cutting down the supply ofair, as is done in the Diesel engine.. f To lever 79, and connect the throttle leven-8()k to the sliding carriage 53, thus 4,giving the* operator complete control of both the air and fuel supply.v .Y f i Fig. 8 shows a slight changein 'the' con# struction of the throttleI lever, in order-to compel the operator to change thecompression when vthe engine is idling or running under very light loads, the rack 8,1 of the lever V79 being attached to and movable with the'lever 80, so that by moving the lever 80,\the `lever 79 also is moved, and the butterfly valve 28 f operated simultaneously with tlielcarriage 53. l/Vhen my charge-forming `device is used on a ,stationary engine running` at c'onstar'ijt speed under the control `of algover'nor, it is only necessary to connectV the governor rod with the sliding carriage vrod 54, adjust lthe butterfly valveV 29 in a permanent position and run the engi-ne v`under constantcompres-A sion.

nio

Before the 'chargeformingdeviceis put to work it is necessary to press open .both the' inlet valve '63 andthe air relief valve^67 ony each pump. The fuel will then flow inj through they inlet valve 63 and drive out allthe air through tleair relief valve 67 thus completely filling. ther valve chamber and L no It is furthermore necessary to'make.the-I area of the opening of the ydistributor valve 23 a trifle smaller than the area of the plungerv pump cylinder with the liquid-fuel.

34, in order-to accumulatea slightpressurein the reservoir 26 `and Vthus eause'the fuel `'to spray entirely around the' circumference off the distributor valve 23. This ipress'ure s will cause avery small amount of'fuel to backfu'p into` the air reservoir 75 which willVtlien be'A i forced lout'by the compressedjair afterv the plunger has finished its delivery stroke.

Now since the flow of liquid-fuel is 'apt to be sluggish in getting Astarted into the pump when its plungerstarts on its suction stroke, I may set thepumpplu'ngers'slightly in advance of the engine pistons and regulate thexsize of the air reservoir 75 with the screw 7 6, to compensate for the'rinerti'a effect of the liquid fuer f I VThe fop .part ef Fig. l.ic :Sh-Oase terrien lac section-through themiddle of the first cylinder ofa four cylinderV engine. VThe engine piston 93 is shown at top dead center with the connecting rod 91 vertical, theintake valve 94 aboutcto open andthe exhaust valve 95 aboutI to close, so that the piston 93 is about to start into the cylinder on its suction stroke. The crank shaft 85, crank pin 90 and the piston pin 92 are consequently approximately in line, as shown.

My ycharge-forming device is shown bolted to the intake manifold 96 of the engine by means of the flange 97 in the usualmanner. The shaft 49 of my charge-forming device is shown extended so as to reach to the front part Y of the engine. The shaft 49 of my charge-forming device is rotatedat precisely the same speed as the crank shaft 85 of the engine. The two eccentrics 47 and 51 rotated by the shaft 49 and fully illustrated and described -in .the specification and drawings are drawn so as to'throw the rocking forked lever 42 toits extreme position, thereby tilting the walking beam 35 to its extreme position softhat the pump plunger 34 will have entirely completed vits delivery stroke and pump plunger 34 will he just about to start f on its delivery stroke.,-

Assuming that the engine is ruiming and firing l, 3, 4,2, the intake valve of No. 2 cylinder will vnow be nearly wide open and the air will .be .still rushing through this valve, although the piston in No. 2 cylinder will have fully completed its suction stroke. rlhe fuel pump34 has also entirely completed its delivery stroke but during this actionlit has compressed the air in air chamber 7 5- (Figq2) underneath the distributingjvalve 23, thereby causing Vfuel to be forced through saidfvalve 23 into vthe mixing chamber 32, therebysupplying fuel to mix with the air now rushing into No. 2 cylinder.

vNow, as the piston 93 in No. lk cylinder starts in von its suction stroke, the'pump plunger 31 of my charge-formingl device starts to deliver fuel underneath the distributing valve 23 and also to help maintain the pressure ofthe air inthe air chamber 75. A

supply of fuel isv thus ensured to mix with the air at all times during the operation of the engine. The chief advantage claimed'in usingmy charge-forming device over the usual form ofsuction-type carburetor is that by using mechanicalpower to force the fuel around the periphery of my distributing p valve 23, it becomes practical to hold this valve 23 adistance of only one or two thousandths of an .inch from its seat, thereby forcibly breaking up the fuel into a mist containing drops of fuel very much smaller than is possible when using only the suction pull of the engine cylinder, as is now the usual custom in all commercial types of carburetor.

The advantage of breaking up the fuel into extremelyy vfine mist is well understood byall those skilled in the art of designing' car'- buretors. Heavy grades of fuel not capable of self-evaporating into a gas may also be used with my charge-forming device. It is evident that in the ydesign submitted in the drawings and` specification unlessv the valve 23 is lifted an extremely `small distance from its seat the fuel from the pumps 34, 34 will iow freely through and by the valve 23,'so that little or no compressed air will be stored up in the air chamber 75. Such an adjustment would not only defeat the chief object of my invention, but would cause an intermittent supplyy of fuel to be delivered to the engine, thereby failing to keep up the proper p-roportion of air and fuel which is the sole function of all practical carburetors.

l In adapting my invention to a six cylinder engine I set the plungers so they will start to pump when the demand forfuel is at a minimum, and by enlarging theair reservoir 7 5 still further, utilize the accumulated pressure in' the air reservoir to supply fuel when neither pump is delivering. This arrangement however only approximates the requirements of the engine, and in order to make my charge-'forming device ideal for a six cylinder engine there should be three pumps set 1200 l. VA force-feed charge-forming device for supplying fuel to an internal combustion engine comprising in combination a fuel feed pump, said pump operating in synchronism with thepower piston of the internal Vcombustion engine to which said device is attached and being so timed that the delivery stroke thereof begins and'ends simultaneously with the beginiviingv and ending of the engine'suction stroke, a reservoir containing a small amount of fuelrelative to the capacity of said pump and subjected to the pressure of' a conlined gas, and a distributor valve spaced such a small distance from its seat as to oppose the flow of fuel forced through said valve by vsaid pump and thereby cause the fuel to beV llO so timed that the delivery stroke of each of said pumps begins and ends with the beginning and ending of the suction stroke of the corresponding power piston, a fuel reservoir of relatively small capacity communicating with said pumps and a valve for said reservoir spaced a relatively short distance from its seat.

3. The combination with an internal combustion engine having a power piston, of a fuel pump driven in mechanical synchronism with said power piston and being so timed that the delivery stroke of said pump begins and ends with the beginning and ending of the suction stroke of said power piston, a fuel` l reservoir, a valve for sald reservolr, the area stroke of said pump, and to deliver the same .y

after the completion of said delivery stroke. In testimony whereof, I have hereunto subscribed my name this 21st day of December, 1923. i i

HENRY H. CUTLER.

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