US2381259A - Fuel pump - Google Patents

Description

vr"PMS/57,1945. 1 HIgE. col-FEY 2,381,259

' Y 'l y vFUEL PUMP Y f v Filed March 1B, 1942v f sheets-Sheet 4' f F, e

f -lNvENToR` l I RVEN E. COFFEY Wag" ATTORNEY l ments w t fi'j tiene; in..

y I' invention'relates to recinrocatins'pumps t l and lmore particularlytothletype orfuelpump Animate-mis,

outiiow for"dis`cha'rge stroke resiliently` actuated which renders the pump automatically" operable in proportionstothe demand forl fuel.-

The greater number ofprescnt da? Dumps Sed 'f inl automobile practice are mechanically" driven v 'from some rotating partfo'f the'niotor an'cl,there l I 1 motore; .-Itls'trile. hwe'vr, thattl'ioi'- the motorlis not'neoessarilyproper for controlling thespeedlof the pumpfor oiten-the 'speed is too,V

' great'. pumping.fuel ata'rate'which is no trequired resulting "in tiver-l'ieating'v ofv the pumped fuei-waheoneequent lose thereof by* The of a sults'lin ,automatically reducing the action of the` lpumpwhlenztheamount'of'i'uel delivered exceeds Y the., inquirmnts, sincefwhen the pressure `built: un in discharge line exceeds the spring pres-5 sure the pump no longer reciprocate. f How' f ever, to gain full advantage from the useof this type of pump it is important that sumcient capacityQbeavailable forgDeak requirements and v n pump having 'e' spring actuated over-owordischargefstroke re`- eipr'oeetmgpnitteieereeeecspacity.

poeitive1y actuated intake stroke which delivers y breaks the.arm orjupturesl'the di phrasing, Y

- Itis, therefore', afprimary object of the present e inventiongtoprovide a pump having yielding. in- -kk takeianddischarsinz stroke; andl having inaddi' tion,y second pump-controlled in its reciprocaltion in alternate with the rsi:v pump lnzin't'ak' -f present tune: Ause a, resiliently actuated discharge stroke and al.'

y -l however, cannot bel satisfactorily Vobtainedtrymerely increasingathe sizeof the re'- ns1-p blew` tothe diepnregrend actuating y-sti mi lischl'estrokes whereby a more nearlyiconstantflow 'may 'Dcmaintained s'zipeiik;l lrequire- 1118 alternately diaphragme in separate vimini Weichert., botnzbemefreeneeuy ated by mechanical means dependent'npon pp'. 5o/ l n respectively,. for receiving lportionsr yiii' the` pump; diaph'r'a'gms during the intake strokes ofthe' num ,and @horizontal-'chamber i2 f9r eccml f 'f wir it-Pump chamber# with theirmepnfegme positivelvtccnnected soestojspeee themr en une@ vervingl apart; "and 'springme'ang u, rec.;

one Dump chambaifl(asth te. f

fransen-nine. 435,242'351 -V humm hmm is eineu entnehmen It isv afurther obiectfto"VA provide a Dumpwith 'dual lpumpingdiiltl'ihragms-111avijng alever; mechanisn actuated: bythe engine for? transmitting` power to the springs actuating thediaphragms during both the intake `and dia-.charge strokes;V f

`It is afurther object-'to construct apump'hav-f.

ing dual pumping chambersja single inlet chamber in communication 'with both pump vchambers and :an outlet y"chamber in'V communication with-v both chambers and a pressure relief valve between the inlet and outlet'cha'mbers. I

A further'object of the invention is to provide a pumpin which'y thepossibility or the-actuating lmeans delivering a. sharp blow to theV pump dia- The above and otherobjects will appear more fully from the following 1detailedfdescription of the invention andrfrom the attached drawings, which forma part of this speciilcation and illustrate r :t preferred` embodiment ofthe invention.inurhich:` t

Fig; 1 is a diagrammaticside thereon'.

Fig. 2 isa 'sectional-vviewioifthe pum'pftaken substantially online yl--loflilez 1f Y Fis.:3 is a plan view ofthe pumpe.l Y j vIig.,4 is a; sectionalview of the inlet and outf-y -let chamberstelren substantIaIIyon-'line i Figs 5 y bodying two moditledfcrms of theinvention;

Asshown-inrie. 1,; thc-nump embodyins mv' `flnvention is vdesignatedgby numeral Lfand is shown for conveniencein explainingits operation 'as installed ai;v afuel pump in operative connec tion lwith' an internal combustion, engine -oi'the' typefgenerny used in. 'induetrxfniotog-vemelee, Vmotor' boats, air craft and the like end ,generallyindicated by numeral 2. `I'he pumpis to d'avvliuel froni'rthe fuel tank 3,'4 through conduit2 tand. force the 'fuel to thecarburetorl through To better understandthe inventionrei'erence is directecltoV Figs. 2,3- and 4-. -The hOUOwpump casting .all islsecured to yengine I` by bolts. (noty shown), The pump casting -is provided pwitha verticahcylindrical chamber Il terminating vat' the top and bottom in .annular recesses. and I4', y,

uiodating the pump :of the invention n v elevation `af-Le engine,with the improved fuelffpumpinplace,

epe je einleiten-elette: pempeem'.

The pump ,assembly a"4 compression chambers and the charging of one compression chamber starts when sumclent spring `pressure is. built up to 'move thediaphragm to pair of compression springs and 2l surrounding spacer rod I1 to exert an outward pressure sumciently to seal the diaphragme Il `and II against leakage between the backing washers 22 and 23, respectively. Springs 2l and 2l are of sufficient strength to'. eliminate the possibility' of the diaphragms I! and l! being moved` in' discharge the other compression chamber. With l this construction the' possibility of transmitting e sharp blow from the lever arm to the pump diawardly on rod l1 'by'iluid pressure built up inthe compression chambers, and at the same time having sumcient strength to transmit i'romtheV arm 36 the forces essential to'eifect dischargel from the compression chambers under -normal pressure. The outer portions` of the diaphragms function as gaskets between pump housing Il and the top and bottom 'castings yand 2l. re.-

screws 28. Top and bottom castings 24 and 2l are recessed tovform pump or compression cham? bers 21'and 2l andinclude passageways 2l` and 3l, respectively, which, V.in turn, are.incom-fi munication with 'the valved .inlet and. outlet chambers to be described later.

Solid pump lever 38 pivoted at II operating in the horizontal chamber I2i has one end Ila shaped to contact a revolvingfcamN of engine 2, while the other end ll is forked .anddepressed arm in constant contact with cam I1 while com-.

pressing spring 2l soras to discharge the pump chamber 28.

spectively, which are secured to the hoiisingby` -Passageways 29A and 30 are in communication T with the inlet chamber 44 and outlet chamber 4l` formed in the casting |4.-v Spring actuated valves. indicated at 4l, 41, 48 and 49 'are vso positioned as to control 'thedirection of fuel iiow from inlet chamber 44 to outlet chamber 4Ias diaphragme I5 and Il are actuated -to alternately chargeand discharge the pump chambers 21 and 2l.

An adjustable relief'valve indicated at ll is seated in a passageway between the inlet chamber .44 and-outlet chamber 45 by means oi'v a spring compressed between thevalve and a hol" lowA plug- 34 threadedly received in passageway I2"` for varying the pressure applied to ball check I3 wherebythe fluid' pressure in outlet chamber 4ll and compression chambers 21 and 2l maybe limited.

It' win b e applied alternately to springs 2l and 2l which will, in turni resilientlymove diaphragme lland il. ,The length of travel of arm Il -will be con,-

stant and dependent upon the throw o f cam 21, while the travelo! 'the diaphragms Il Land `II willvary in accordance with the pressure built' up in. the compression chambers n 21 and 2l. Therefore;- the pump `will discharge in accordance with tno yiemimdror met, within limits, irre spective'of the speed -of actuating lever 3l.' It is also evident that if, perchance,'pressure isI built up in chambers V21 and '2l to'a point'equal tothe` pressure exerted by springs "and 2| the dia-wy y bo evident from mooosoriptioo i-.nitt`r when cam l1 rocks ythi'pump arm, ,pressure will.

phragms will remain stationary until. the'pressure'A in the compression chambers is relieved. It will be further' evident that springs 2l 'and 2l apply a` gradually increasing `pressure on *the diaphragms toalternately charge and discharge the various operating parte willbe materially inlWhen the engine 2 is started.'cam'l1 actuates pump lever il for applying pressure to spring 2l and asthe pressure builds up. diaphragm Il is moved outwardly to discharge the fuel from chamber 21 through passageway 2l and past check valve 41 into outlet chamber 4l. Dure ing the discharge of fuel from chamber 21, diaphragm Il has moved with diaphragm Il causingfuel to be drawn from inlet chamber 44 past check valve 4i and' through passageway 3l into compression -chamber 2l. When cam 31 has moved pump lever Il, to the length of its stroke. spring 4| then starts rotatingpump lever 3l in the opposite directionthereby applying pres- -sureto spring 2|.causing diaphragms Il and Il to move in the opposite direction to discharge chamber'2l and 4charge chamber 21. `.Il` modification of the invention is in Fig. 5 which is identical with Fig. 2 with the .exceptiony of the lever'V arm and' compression spring 4| isellm'inated. `In 1113.5 a-pairoflcver arms 5l and Il, pivoted at l2li: have'their outer ends a andlia contacting opposite sides n! the engine cam 81a and their inner ends .lla and ,2lb

forming seats for'compression springs 20a and 2|a, respectively. By this construction, spring 4I in Fig.2 is eliminatedand springs-2.a and 21a lfunction to keep'the. rocker arms in constant 'contact with the engine cam 31a. I

Another modiiication of the invention is illustrated innig. 8,v showing a similar spring and lever Aarrangement .as in Fig. 2 `but acting'llpon a single diaphragm Ila which forms a movable wall for `two compression chambers 21av and 28a. Compression chamber 2Ia,v through which spacer rod Ila passes, is provided with a stumng box comprising sealing rings Il, backing Plates l., compression spring" andA plug", threaded intc the body casting.- Passageways vMit and 241iv leading from the 'compression chambers 21a and 22a communicate `with yvalved inlet and outlet chambers similar to those previouslyy described in Figs. 2. 3 and 4.

The `above is a full and clear disclosure of an? illustrative embodiment of my invention by which the above results and advantages'may be real ized and various modiiications of myvinvention may bec@ me apparent to those skilled in the art and the exclusiveuse of all modifications ascome within the scope of the-appended claims is antici- :mied-` l, `.Il pumping device for an internaly combustion engine comprising a pair of pump chamm bers, 'a diaphragm wall for each chamber. a rod forspacing said diaphragme an unvarying dis tance apart. a pairof spring elements surrounding (said rod forA exerting anoutward .pressure against said diaphragme. a lever having one end arranged for contacting a cam of the engine and the other end interposed between said spring elements to. transmit motionto one. spring ele-v ment for moving the diaphragmsto vdischarge one pump chamber, and :springn'ieans acting to keep said lever in constant contact with the cam pi' the kexigirle and motion to the other spring'elements alternately jcharge said 'pumpchambersyy n v n 3. Afueifpump comprisingja pair 'or pump chambers, wall means forv said chambers movable as a unit, an actuating stemprojecting from spring element for moving said' diaphragm to ydischarge the ,other pumpehamber.

Y' 2; A pumping device :oran internal combus' 'f i tion'engine comprising apainof pump chambers,-

a diaphragm-*wall for each :chamber-pa rod for "liL ifo

Ato charge dissaid wall means,'apair of opposed,':coi1ed, com# lpression springs embracingand connected at opposite ends to said stem, and a reciprocating lever having' an extremity gripped betweensaid springs and also embracing said stem for applying pumpingy movements to said wall means.

' IRVEN E.,COFFEY.

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