US1799434A - Engine-operated fuel pump - Google Patents

Description

April 7, 1931. w. H. Muzzv 1,799,434

ENGINE OPERATED FUEL PUMP Filed May 5, 1929 accumulated water.

Patented Apr. 7, i931 UNITED STATES PATENT OFFICE WILLIAM BI.l MUZZY, OF EVANSTON,

y ILLINOIS, AssIGNOn'IO STEWART-'WARNER Con- POIIATION, on CHICAGO, ILLINOIS, A CORPORATION or VIRGINIA ENGIE-OPERAIED FUEL PUMP Application led May 3,

The p urpose of this invention is to provide an improved construction of an enginevoperated pump for supplying the carbureter of an internal combustion engine,

the .im-

and in another part ing the fuel supply,-'relieving it of solid sedimentary material and water,-without liability to embarrassing .the operation by the accumulation of the'sedimentary solids or Water, particularly by the freezing of the It consists in the elements and features of construction shown and described as indicated in the claims.

In the drawings: y

Figure l is a vertical section of a fuel pumping apparatus containingthe invention. Y Figure 2 is a portion of thei same showing the parts' at a different position.

Figure 3 is a view similar to Figure 2 showing a third position of the parts.. l

Figure 4 is a different portion of Figure 1 on an enlarged scale.

Figure 5 is a detail mediate-lever in the pumping member operating connection.

Referring to the-first mentioned part of the inventions-The lpump shown in the drawings is designed in view of certain defects and embarrassments encountered in the operation of 4apparatus for'like purpose in common use, and to overcome and avoid these defects and embarrassments," cer-tain of which. arise .from the stiffness ofthe diaphragmdesirably employed Ias a pumping member. lt has been found ,in devices of this character in which a 'flexible' diaphragm is employed under the impulse o a feeding spring and with a positive movement imparted tothe diaphragm inthe 'opposite or suction movement bv the engine of the car, that at high speeds the diaphragm, though arranged tobe actuated positively in one direction by any means, cannot be made to react quickly enough in the opposite directionfto follow the cam in the idle .phase of the ycam cycle; and consequently, after a few cycles at high plan view of an inerconstruction speed, the diaphragm 1s i929. serial No. 360,018.

found to be barely moving, and only pulsating the fuel content from the fuel source Without lifting the fuel to any suiiicient extent for supplying the carbureter, even under the conditlons of least fuel requirement. .The main spring for devices ofthis sort must be'fairly flexible and-not too strong, or

the pressure produced will be .l much more than desirable for meeting the engine requirements. Such spring 1s of' course limited in respect to the rapidity with which it may force the diaphragm in fuel feeding direcfuel feeding movetion, especially as this ment is resisted by the fuel being fe which is being forced through comparatively small ports and chambers against a pressure which increases up to the limit for meeting the engine requlrements. 4 4 For this reason, at high engine speeds the diaphragm in its reaction under the reaction ofy the main spring lags behind the movement of the positively actuating means driven byl the engine, which, in the active phase lof the operating cam or other engine part, moves with the speed corresponding tol the speed of the engine shaft. This lagging of the diaphragm increases with the speed.

In pumps of this character the pump, space above the diaphragm must be very, small,

because the movement of the diaphragm for veryV slight; and for this reason the 'pumping member in the present construction a diaphragm', must make a comparatively full stroke in order to act efliciently for suction. While strokes shorter than the the feeding movement, correspondingly short strokes in theopposite direction will producing suction is fnot .develop suction sullicient to draw gasoline into the pump chamber from the fuel source.

This inefficiency increases with the shortnessof the stroke, until the stroke finally only agitates the fuel without lifting the fuel in the intake passage from the fuel source.v The full stroke ofthe diaphragm for suction is therefore desirable,v notwithstanding certain advantages of the so-called short stroke. The object of the present invention is to of the intake passagev full strokes will impel the fuel in yon the casing (not shown), which the shaft, 21, pertains.

phase of the cam. Said lever is fulcrumed at 31 inthe chamber, 30, of the pumpcasing member, 30, which is arranged to be mounted o f the engine to The lever, 22,

at'the end opposite that which is engaged by the cam, 20, is connected by a link, 33, witha second lever, 3 4, pivoted tothe upper end of said link intermediate the ends of said second lever, which is connected at the end portion toward the fulcrum, 31, of the first lever with the end of the diaphragm stem, 35.. The ump casing member, 30, has a second chamer, 36, partitioned from the chamber, 30a,

the partition, 37 being formed with a central boss, 38, through which fthe piston stem, 35,

extends, and in which itobtains guidance for the diaphragm' strokes.

The chamber, 36, is partitioned by the diaphragm, 40, from the pumping chamber proper, 51, which is formed as a recess in the lunder side of the casing member, 50, bounded by a flange, 52, which is mated with a flange, 32, which terminates the casing member, 30,k and bounds the chamber,`36. f

The casing member, 50, has fuel intake passage, 53, in which at 54 there is seen the intake valve, and the discharge passage, 55,

in' which at 56 there is valve.

The main pump spring,6`0, islocated in the chamber, 36, encompassing the, boss, 38 stopped at its lower end-on the partition,- 37, and reacting at its upper end on the diaphragm, 40, for giving-the latter its feeding stroke. p

A spring, 7,0, is provided-seated at its lower end in a-pocket, 71, formed for that purpose in thev bottom' plate, 72, of the casing chamber, 30a, and reacting upwardly on the inner' arm, 22, of the lever, 22. i

In the chamber, 30', there is suspended on a pivot, 61, afulcrum bar, 6 1, so named because, as hereinafter described, at certainl stages of the operation itaffords a fulcrum for the lever, 34, which at another stage is fulcrumed at the opposite end where it is connected to the diaphragm stem. v

This -fulcrum bar is arranged to depend transversely with respect to the lever, 34, and there is provided a spi-ing, 65, re-acting beseen the discharge 1, atl which position the left hand end of the lever," 34, rests upon an abrupt or horizontal shoulder, 63, formed by a notch in the right hand edge of the fulcrum ba`r,;he upper edge lof the notch'being sloped obliquely for a purpose hereinafter described.

Upon considering the construction as thus far described it may be understood that the main spring,60, operates by its reaction from compression which it receives from the `connections with the engine cam, 20, for giving the diaphragml its feeding stroke; and that at the normal position of the parts in the idle phase ofthe cam with the engine at rest, the diaphragm is at the extreme limit of its fuel feeding stroke, as seen in `Figure 1. And upon further consideration it may be understood that the .rotation ofthe cam to the climax of its active phase causes the lever, 22, to pull the lever, 34, by means of the link, 33, downwardly while said lever, 34, is fulcrumed at the lodgement of its left hand end on the abrupt shoulder, 63, of the notch in the fucrum bar, 61. And on full consid'- eration it may be understood that upon inability of the main spring, 60, to react quickly enough to thrust the diaphragm fully back to the position seen in Figure 1 during the idlev phase of the cam cycle, the reaction of the spring, 70, on the inner arm, 22, of the'lever,

, 22, forcing that end of the lever upward, and

through the link, 33, forcing upward the lever, 34,. at its left hand end, will causethe latter to fulcrum at its pivotal connectiony with the vdiaphragm stem, 35, and swing upwardly atits left hand end. y

And upon-further consideration it may be understood that upon the recurrence of the active phase of the cam cycle, .the lever, 34, being no'vi7 o' its fulcrum -on the shoulder, 63, of the fulcrum bar, 61must be pulled down onto that fulcrum before the diaphragm will derive any actuationfin the direction of its suction or intake stroke, and will thus derive only so much actuation as will compensate for the reaction 1which loccurred in the brief interval ofthe idle phase of the cam; thus it will be retracted to the limit of the suction stroke, compressing the spring, 60, to the limit; so that itwill alwa s react at its maximum resilient capacity or its fuel feeding stroke whether that lstroke be shorter vor longer.

ln theyconstruction shown, the operation above indicated is somewhat modified by`detail features which will now be more particularly described.

rlhe left hand end ofthe lever, 34, is formed to present upwardly an'- inclined or beveled terminal, which, as shown, is made by a right angle fold at the'end which' was rst lcut sloping at an angle'of. about 45, and 4 the fulcrum bar, 61, formed at theedge toward the left hand bevel'of thelever,34, ywith the notch bounded as above mentioned at its lower'side by the 'abrupt shoulder, 63, anfd at the upper side by the sloping shoulder, 64,. forms the under side of a cam nose, 67, which overhangs the abrupt shoulder, 63, and projects somewhat beyond that shoulder toward engine',1 at rest with the cam at-the middle point of its idle phase, the left hand end of the lever, 34, is lodged, as stated, on they abrupt horizontal shoulder,-63, of the fulcrum bar, 61, and comes the fulcrum of the lever, 34,`as above described, when the cam rotating throughits active-phase through the link,`f33, causes the lever, 22, to pull downwardly on the'lever, 34, and retract' the diaphragm against the rev action of the main spring, 60, thus giving the diaphragm' its suction strokev as above described.

While the cam isl rotating slowly and up to.

some limit of speed dependent uponl the resiliency and ystiffness of thespring, 60, and the resistance of the column of fuel in the fuel line' from the pump to the carbureter, the spring will react Vfor giving the diaphragm its feeding strokevrapidly enough to keep the lever, 22, following thel cam in the idle phase of the cam cycle; and thereby the diaphragm will have its full intake or suction stroke.

But when the speed of the cam passes thecertain limit indicated, the Spring, 60, cannot react-rapidly enough to keep the lever, 22,on the ,cam in the idle phase; and the spring, 70, reacting on the lever, 22, for causing it4 to Afollow the cam, and in so doing thrusting the link, 33', against the lever, 34, while the right hand 'end of the latter connected to the low position from which the main spring has not at times retracted, will lift the left 4hand end v'of the lever, 34, 0E the shoulder, 63. p

And when this occurs after the cam speed has become so great that the diaphragrnis very slightly retracted by the spring,'60, in the idle phase of the cam cycle, the beveled end of the lever, 34, will be swung up past the cam nose, 67, forcing back the fulcrum bar ,against the-reaction of the spring, 65, and snap in above the 'nose in the recess, 67, of

that -shoulder accordingly bediaphragml stem still at thev the edgeof the fulcrum bar, when in the completioniof the active phase of the cam cycle, the lever, 34, is pulled down by the link, 33. And the slope of the edge of the fulcrum bar against which the end of the lever, 34, is`

then resting being too easy to cause it to serveas a fulcrum for the lever, the end of the lever llodged'thereon will merely co-operate camwise with said slope and swing the 'fulcrum bar back, while the end of the lever which thus movedpositively by the positive action of the engine cam in its' active phase at high speedlof rotation, will be swept down past the f lc'rum shoulder, 6,3, and accordinglyfor l cko-f afulcrum for .the lever, 34, the diap ragm will derive no actuationfrom its revolutiony of the cam, but will continue its feeding stroke under the reaction of the spring, 60, which it was unable to finish in the too-short interval between the active phases of the cam cycle.

AThis sortof operation will beprep'eated through several revolutions of the cam when the speed is very high' until the diaphragm has made its full feeding stroke land is holding the lever, 34, in the position seen in full line in Figure'l at anidle phase of the cam, so that as the cam moves into its active phase and gives the lever, 34., its .positivedown pull by means of the link, 33, the lever, 34, is found fulcrumed on the shoulder, 63, so that the actuation which it receives serves to give the diaphragm again a full suction stroke against the reaction-of thespring, 60.

-Thus vit' may be understood that the construction results inthe diaphragm receiving a full suction stroke as often only as it can react fully therefrom, and being skipped as to actuation for suction in all the revolutions o f the cam between those of which it can thus take advantage for deriving a full stroke.

The second part of this invention relates to the construction shown in enlarged view in Figure 2 and willnow be described. i

The fuel reaches the intake'valve54, by way of a fuel receiving chamber or fuel and sediment trap formed by a glass bowl, 75,

mounted on the under side of an extension,

50", of the casing member, 5 6, and held in' place .detachablvy by a wire loop, 76, arranged to be tightened by-any convenient means, as

the customary eccentric, 77, havingan oper l ating handle, 55'. For rendering the junction between the bowl and the'casing suitably tight, a gasket, 79, is interposed, as shown, between the top` flange of theM bowl and 4the seat provided for it on the under side of the casing extension, 50".

The fuel line indicated at81 from the `fuel source or main fuel supplytank, not shown, is connected as seen at 82 for delivering fuel into the 'fuel and sediment trap chamber,

80,'-at thecto'p of the latter. The fuel passes out of the chamber, 80', toward the intake valve, 54, by way of a vertical pipe, 83, screwed into the passage, 84, which leads to the valve, 54C; and a filtering screen, 85, enc'mpassing the pipe, 83, and having bottom webs obstructing the. entrance, 86, of, said pipe, serve to exclude sedimentary limpurities and water from the pipe and thereby from the pumpingchamber.

For the further purpose of excluding from thepipe, 83, and causing to be trapped and retained in the trap chamber any water which may be mixed with the fuel as .it comes from the fuel source,'ther'e isprovided a hood, as shown at 88, made of chamois'or.

like material which is to amlarge degree impervious to water and not impervious to gasoline, said hood having its bottom web covering the bottom web of the screen and .extending from said bottom web up around the screen to a level higher than any expected accumulation. of. water.

Diaphragm 'pumps at present are subject to mis-operation in starting after the engine has been lstanding for some time, as over night in the garage, because the charge in the pump tends to leak back into the main feed pipepast the valves, and allows air to enter the pump chamber and the pipe' connecting the pump and the carbureter.

Some of this air passes through the fabric of the diaphragm; someleaks in the pipe joints, and some air and gas leaks back out of the carbureter; The gas in the main feed pipe is of course seeking to return t0 the main feed tank and this exerts a backward pull on the gas in the bottom chamber` and the pipe therefrom to the carbureter and the carbureter fuel chamber.

When the pump is now started lat slow speed, it simply alternately expands and compresses the air inthe chamber and does not elevate gas from the back tank for some time. It is particularly noticeable when the diaphragm is cold and stiff after the car has been standing in a cold garage over night.

One object ofthe present invention is to overcome this difficulty and utilize the gasoline that isftrapped in the-fuel and sedimenttrap bowl, 80, to form a priming charge that may be readily drawn into the pump chainber by the slow motion of the pump, and start the engine, so that the speed'may be increased and the gasoline fed to the pump 'from' the main tank.

This gasoline will be 'readily drawn into the pump chamber even-though theA gasoline in thev main fuel line from the tank tothe pump is not at once lifted, because the air in the top of the trap chamber, 80, will expand to permit the feeding.- The gasoline in the trap chamber cannot be drawn back into themain fuel line extending to the tank because there is no siphon action backward out of the bowl. The construction shown and herein- 'of the engine by the starter or by the crank,

produces a partial vacuum in that chamber, causing fuel to be drawn through the fuel supply line leading from the main tank. Amd upon consideration of the structure and the operation as indicated, it will be seen that the pipe, 83, will not be emptied at any time in the operation so far as to unseal its lower endA port, 86, except for the instant when, by

reason of leaky valves' and the enginebeing stopped with the car standing much inclined downwardly, the pipe, 83, might vbe emptied by siphoning; whereupon the lowering of the liquid in that pipe to the intake port, 86, would cause the siphon to be broken and the air to bubble upthrough the liquid and occupy. the upper part of thetrap chamber, causing the liquid to subside in the trap chamber and rise in the pipe, 83,`to.a balancing point, from which it will be lifted when they engine land umpare started by the starter or by cran ing, with the effect above stated of immediately filling the trap cham- `berthe remainder of its depth, except as to a limitedspace at the upper part, wherein, except forq some preventing means, theair which bubbledup throughthe liquid when the siphon was broken would be trapped. It isdesirable for insuring steady pumping action while the engine is running, that the entire fuel line from the main tank to the pump intake should be filled with liquid; and to insure such f condition, notwithstanding the trapping of air in the manner described, there is desirably provided so near the upper end of the pipe, 88, as to be substantially at the top of the cavity of the trap chamber, a small air vent and suction port, 87, through which the engine suction ,operates 'for completing the exhaustion of the aii' from the trap cham- `ber and fuel intakepassage after the intake port, 86, is sealed. The size of this port being vabout that'of a` No. 72 drill, is not sufficient to lll@ this structure may be noted as comprising the following :-(a) that 'the 'pump is automatically primed or self-priming; (b) Athat the fuel supply for priming the pum also for primingthe carbureter; c) that this priming supply is available, notwithstanding the same trap chamber serves also for accumulating wateran'd sediment separated by means of. that chamber from the fuel; (d) that thesefunctions o f the trap chamber and connections are-not defeated by 'the freezing of the. water which may be-ac cumulated in the bottom of the trap chamber to any depth liable to occur; (e) that the value of the capacity -ofthe trap chamber for these purposes is available,notwithstand ing the trapping of air iii-the upper part of the chamber whichv results unavoidably from' )the entrance port to the pipe, 83, either when the ,engineis-runmng normally or when it is'operated by starter or by cranking; (2)l the provision of a limitedinlet a short dis-w tance above the bottom inlet; (3) vthe provplurielle tyre,

vthe rapidity `with which t .vibrated necessitates, construction providin vision of a filter' screen enclosing said pi 83, including the bottom'inlet thereofye the revision by which 'the .air is taken by suction from the top through the vent port, 87.. The tra chamber being of transparent material, ma es it serve as an'indicator of-the condition of the fuel supply, Whether failing or choked by the sediment or water. `The importance of providing'in some manr` ner for a substantial fuel supply'immediately adjacent-the pumping apparatus, sup lementing theV main supply of the relatively istant main tank when the pumpis of the dia-- maybe ly accentuated by the fact. that in thisltype ofpump employed with yhi e diaphragm is for a very short stroke; and'since the liqui body in'the fuel supply line is necessarily moved intermittently'by the suction strokes and tends to stand atrest in the interval between suctionstrokes, its movement must be restarted against its inertiaat'each suction stroke', and the Stroke being, as above noticed, 'very short, affords too little time .for

overcoming lthe inertia of the long. liquidbody extending back to the main tank. The provision of the near-bysupply content in the trap chamber isidesigned tomeet this dificulty. p v

It should accordingly be understood that servesl understood to` be greatl h speed engines the invention not limited to the specific details of' construction described, although cer tain of these details are claimed as constituting preferable means for serving the purpose stated, but thedet'ails may be modified and departed from in many respects v vithout departure from the invention as directed to the purpose indicated.

, 1 claim: 1. An apparatus for. supplying fuel to thel carbureter of an internal combustion engine comprising a casing having a pumping chamber with a iexible diaphragm constituting the pumpingv member and a main spring reacting on the diaphragm: for giving itl its fuel impelling '-movement;l.engineo'perated intake movement, comprising. a one-way` active camgJ main lever fulcrumed in the casing havingA an arm exposed to actuation by the cam in the active phase of the cam cycle; a

second spring reacting on the lever for causing it to 4follow the cam in the 'idle phase- 2. I-n the construction defined claim 1, the engine-operated connections inclu'dinga dlaphragm stem tolwhich the intermediate lever is connected at the end of said inter- *mediate leverl opposite that at .which it is to leave the fulcrum, and a link the main lever to the intermediate the latter intermediate its permitted connecting lever ata point in said end.

3. An apparatus for supplying fuel to the' connections forgiving the diaphragm its fuel ios carburetor ofaninternal combustion engine y' comprising a .casing havin i chamberl with a flexible diap ragm constituting'the pumping member; a main spring reacting on the diaphragm in the direction for giving it its fuel impelling movement; a

hragm; a fulcrum, yelementi in lthe casing a'ving an' abutment lodgement in the movement with freedom of the lever toleave saidfulcrum in thev reverse movementV of the diaphragm,

carbureter of an internal combustion engine comprising a casing having a pumping a pumping lever operatively connected with the diaon which said lever is l -arranged to lodgefor fulcruming at its said y i of the lever in the fuelintake movement of the diaphragm,-

and engine operated connections v arranl ed to. actuate said lever positively 1n.

chamber with a flexible diaphragm 'constituting the pumping member, and a Ina-in spring reacting on 'the diaphragm forgiving it its fuel lmpelling movement; engineoplerated connections for giving the dia- P ragm its full intake movement compris-v ,1n an actuator having alternate Aactive and id e phases in its cycle, said connections be`l l ing arranged to give the diaphragm said intake movement positively-.in the activ-'e phase of the actuator cycle, and spring means for causing the'actuated part tofollow said actuator in its idle phase', said connections comprisin a lever operatively connected with the laphr'agm, land a fulcrum for said 1ever, said parts being arranged to permit the lever to leavesaid fulcrum in the movev ment for followin the idle hase of the actuator and for avoi ing said ulcrum in its reo.

turn in the succeeding active phase; whereby the diaphragm derives a succeeding positive v actuation for its fuel intake movement only ,A after it has had time to complete a fuel imttf.

crum member to carry the fulcrum out of the, path of the levers return movement; Wherey some 7m handat'chicago,I11n0is,this 26th day pellingA movement under the reaction'of the main springv from a preceding positive actuation.

5. The'construction defined in claim 3, the fulcrum element being a bar mounted movably in the casing, a spring reacting on said bar for holding 1t in position for affording fulcrumto the lever', the lever and said bar being co-operatively formed for adapting the leverto displace the bar in the movement lodgement.

' '6. In the construction defined in claim 3, the fulcrum member bein movably mounted andyieldingly held positioned for the lodge- .ment of the lever on the fulcrum abutment, and having a cam projection spaced from the abutment in the dlre'ction from the latter. in

of the lever for leaving its, said'fulcrum which -the lever moves-in leaving said ful-l lcrum abutment, fulcrum member being arranged to co-operate with the lever-in said movement of the latter for movingthe fulsaid return movement when exceeding redeterminedspeed carries-the lever beyond thefabutment fof-defeating the fulcrumingA ofthe lever. 4

In testimony whereof, I'have hereunto set o April, 1929. y

l WILLIAMy H. MUzzY.

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