US1629327A - Internal-combustion engine - Google Patents

Description

1927. G. w. WALDO INTERNAL COMBUST [ON May 17 ENGINE Filed Feb. 26, 1921 3 Sheets-Sheet l ay 17 G. w. WALDO INTERNAL COMBUSTION ENGINE Filed Feb. 26. 1921 s sheets-sheet 2 yWf/wamtoz %1 VCOMMMW j wfg: f5

May 17 1927. 1,629,327

c.:1 w. WALDO INTERNAL COMBUSTION ENGINE Filed Feb. 26. 1921 E Sheets-Sheet 3 Patented May 17, 192-7.

UNITED STATES PATENT orifice.

GEORGE. WAIVDO, OF BROOKLYN, NEW YORK.

m'rmzunnfconmusnoir Enormi.

nppnmpn mea February ze, wei. semi No. 448,034.

This application is a continuation in part 6 of my copending application Serial. No.

298,895, tiled May 22, 1919 .which has been merged herewith.

i ll) The action of four-'cycle internal combustion engines of the types at.' present in use, in which gnsolene sind kindred fuels 're hurned, does not permit ot. themaximum* economy of fuel -hecuiise the mixture of air and fuel cannot, after ignitioz., he properly expanded within thc available spnc within' the cylinders. This is due to the friet that the entire cylinder spiicc'is filledwith the fuel mixture ut atmospheric pressure before, compression und ignition tolte, place. Such :i quantity of eas after compression :ind ignition requires a. much larger space in which to expand ciiicicntly, und the iuteoclin'ngre of volume, due to movemcntAofYtlie-'pistom must alsouhe an eilicientproportiori A'of the mitural and unrestricted rute of loirpnnsion of the gras, otherwise e large proportion of the expansive. power of the gas is deliveredI :is :i dead blow upon the piston and a large percentage of the heat 'energy of thegas .is expended in` heating the cylinder walls.

Most earliureters and mixingdevices in use at the present time depend upon thenc- (ioii of :i current of air passed across u smiill jet .supplied with fuel from a small constant level reservoir usual-ly located in such a. mannei- :is to furnish u: slifvht head to assist the issue ot" fuel from the ,iet which is controlled hy some torni of needle valve. The amount rt liquid which issues from the jet depends upon the opening of the needle Valve and the suction action of the nir curi-cnt Iover thel iet. After issuing: twin the jet'. the liquid is carried along und mixed with the air current. becoming!` more or lessvaporizecl according to the `grrside of fuel used and the temperatures obtaining.

It an exceptionally volatile liquid fuel is used iu ncarburetor or other mixing device, it willhe found that-.a fairly close regulation can he obtained iii supplying siiitable. quantitiesot fuel for the formation of a dry vapor within the air current passing through the carburetor into the engine. It .should he notedt however. that the formation of rgipofi ikes place within the air' during itsfpssugeinto the engine. It is doubtfuL-if any yapor is formed in the carluiiieter itself. It the proper quantity of fuel. is'imectedinto the air current,.a. dry vapor mixture will be formed, which, if of-Slili cient quentitybwill constitute an ex lesive p iindcicient mixture for ,usewithin t e en-A eine. Since n. dry vapor cannot be condensed under conditions met in tggis engine practice as to temperature and'piessure changes, it'

follows that such e, mixture willundergo compression withoiit liqucfaction of any of. the fuel content.

Consider1 now, the lower grades of fuel passinfr'through :i carburetor oi' other mixin;y device. It iS found that it is Very diflicult. even if :it all possible, to obtain a.' dry vapor mixture for use in the engine.1 'lliis is due to tho lower vapor pressure of the. fuel at atmospheric temperature and prirsule and to the inadequate meiiiis of the eurburetcr for' injcctiirg` tlie fuel into the eiineurrent in proper quantity.

Various v plans havelieen pro osed for obviuting this rlitliculty. such :is

the jetoi.' spray into fine particles.-

eatiiifftlie carburetor from the exhaust manifold. or'lireakin'ii ri Spell; methods, however, there-is no 'postvef way of assuring the production of a dry vapor because there is no ineens of asce'rtaining that the particular fuel has. beenl supplied at a suflicient temperatureto le.

n iziin in vapor toi-in in the original quantity throughout the compressionstroltegof the. particular engine. That this 'condition exists is horne, out h v the fqrinatieno'f earhon deposits in all gnsoleue and kindred .en- Y rines regardless of the most ,careful .ea'roi'lf roter adjustment. such format-ion being undouhtedly due .to combustion of fuel in Aliquid vinstead of in vapor or gaseous forni".

It appears from the foregoing` considera- IIE tionsthat internal 'combustion engines oft-he types et present in use requireradlcal departui-e, notvonly as to the means of ex# paridingrn heated gus, but as to earhu'r'eters' and mixing devices, :ind also 'as to the methods-of' forming the 'vapors in order that the existence of a 'd nitely assured at all times. Particularly is this the euse on account' of the low vapor tensions of present day .liquid fuels at the intake pressures and temperatures obtaining in practice.' I have found that it is pos`v 'sible to reduce the pressure'of the air. within the cylinders of an internal combustion en ,eine to such a intthat if a. given quenvapoi" will be de tity of fuel be injected, onadmitted liq' uid form. in suspension, the vapor pressure .of the fuel 'willallowa dry vapor mixture vot air and fuel to be formed, provided the result which, after combustion, can he most;

` efficiently expanded within t-he engine.. This reduction of pressnre'nnay heohtaiued hy expanding a given quantity of zur :dune or air with fuel iii-liquid suspension. within -the cylinder of the engine. or within a sultable auxiliary cylinder, te u pressure .out able for mixture with the particular fuel to be used. Preferably the fuel slumld he injected when the greatest. reduction ol air pressure obtains und where movement of thcl piston may be utilized for metering, that is, at the cn'd of the intake stroke. The greater the reduction in alii' pressure, the more rapidly will the particular quant-ity of fuel projected into the cylinder, or present in suspension in the air, become dr)- Vllpnl.

lt. is accordinfcglj,r an object of' thc present invention to provide a cylinder space wherein a moet cllieient rate of change ot volume may he possible und in whirh theheated gus may he expanded'. to or slightly below utmospheric pressure. Irl-accordance with the invention, this isaccomplished by closing the intake'vali'e during a certain proportion ofthe intake stroke of the piston so that only that quantity of air willenter the cylinder which, when compressed and heated by the fuel combustion, will be capable of the most eiicient expansion rate. The-heated gas should he expanded to a point somewhath elow the pressure ot the atmosphere in order that air muv headluitted to the evlinder )ust lu'evxous .lo and' durn'ig the more i ment ot' the piston on its explosion stroke past. a )ort having communication with thc atnmsplmre through a suitable valve. The air thus enteringl the. cylinder is transferred to the clearance spare of the engine by the piston on its exhaust or scnveluginer stroke,

thus permitting a much more eliicient condition of clearance space than would otherwise obtain.

the present invention, being' entirely aecom- :plislu-d by t' l\en|o\enient of the piston on its scavenging stroke. and in no sense by thel exec-.ls ot' pres-:ure obtaining within the c \lluder when thelexhaust valve is Opened.

la considering the action which oecurs during' the exhaust stroke oil'lzhe4 en inc, it will he seen that the gases discharge from 'the cylinder which were originated from a partial vacuum will immediatel)r cool to ntlnospheric teiuperatureand hence to tht` original pressure of the partial vacuum, the gases Within the cylinder thereby tending always to c'zpand and cool lo the initial pressure und temperature of the. partial vacuum from which they originated, or to the original volume at atmospheric )resent-e and telnp'erature. ThusI u stroke which, in the usual coustlluflitul lt-internal vtuullnstion :plugjiru-:i` is au idle strelen against a 1s [uws-nre. hue. in the rut-filoo|` thmpre ent invention` been conve-rtm1,iuto :i power :,ttrokc` with the result that the engine may be considered tu have two 'power strokes-a major one duc to the combustion of the fuel,` and a minor one due to the cflect of the air pressure acting upon the exterior of the piston Iagainst; a partial vacuum within .the cylinder, which has a tendency to exist' throughout the entire exhaust stroke.

The present invention is not, however, confined to a noiseless engine or to one in which the gas is expanded to the limitsrc fcrred to above, hut it also provides for the augmentation of the vaporizing tendenciosI of various more or loss volntile'liquid fuelslrv providing a construction wherein a suitable partial vacuum is provided for vapori/,ing fuel to the extent that the fuel muv bef-injected directlyinto the 4c linder an vapor-ized Without special provision for preheating and in uantities 'desirable for an'ctlicient conibustlon, auch as 10W grade gasolene, kerosene, ale'ohol .or 'other similar fuels, by merely injecting u. suitable quantity into the cylinder during an part of the intake stroke, the amount; o liquid injected being regulated by the piston movement past a port, hence by the. width of the port, or by the piston movement during the time Iwhen injection of'fueltakes place, and by timing the movement of fuel to the spraying device so that just the proper amount of fuel is` admitted 'by both means which will give thel proper quantity of`dry vapor necessary for the amount of airwithin the cylinder. This timing is accomplished by the change of level of a fuel reservoir 'or by the air pressure upon the` surface of the fuel within the reservoir, or by both means` By spraying .fuel into a lpartial racuuni obtain' a d fuel vapor which readily uuxcs wlth he'air in the cylinder and cannot he condensed to liquid forni while undergoing' compression and other presqures., l Y

'l-he invention also provides an internal combustion engine. iu which the com resson may he varied in accordancewith titl'erent operating renditions due` 'for instance, to the kind or guide of fuel employed or the atmospheric pressure eristinr, hut for any particular condition will remain constant so loi@ as the condition doesnot change.

Other objects and advantages of the invenf llt) tionlwill appear more clearly from a description 'of a preferred embodiment as shown `in the accompanying drawings in which Fi 1 isan., elevation in' section of one cylin er of an'engine constructcd'in accord-V ance with' the invention,

Fig- 2 Ais a sectional view nt the cylinder taken at,'right angles to F ig. 1,

Fig. 3'is 'a sectional view of the tuel rcservor,

Fig. 4 is a'seetional -view of the fuel v Figs. '5, 6 and 7. are diagrammatic `views showing the position of theparts at the beginning, an 'intermediate point and the end, respectively, of theintake stroke,

.Fig.' 8 shows the @position of `the parts shortly after the 4beginning of the .compres-V l sion stroke,

Figi 9 shows the` position "of the parts at the beginning of the working stmke,

Fig. 10 shows the positio'nof the parts near `the termination of the working Stroke, and

Fig. 11 -shows their position shortly after the beginning ot the exhaust stroke.

Referring to the drawings in which simillar reference characters denote similar parts throughout. the several views, 2O is one of the -cylinders of the engine, which is mounted upon a suitable base 21 which also serves as a portion of the crank case, Athe latter being completed by means of a member-22 attached to the bottom of the base.; Within the cylinderis a piston 23 providedwith suitable packing ,rings-24 and connected by means ofa rod 25 with a crank 26 attached to a crank shaft- 2T which is mounted'in suitable bearings at the end of the crank case.'

The cylinder is'surrounded by outer walls '28 forming a chamber within which, it desired, a cooling-liquid may .circulate in accordance with the usual construction of internal comv bustion engines,' or the engine may be air cooled instead. The cylinderhead 29 is also provided .with an 'outer wall 30 forming-a chamber within which cooling liquid may circulate. Incase the clearance space at the top t vthe cylinder is todgreat, as may be 'the case if the invention is 'a' plied to engines of ordinary .'rlesign, a mem er 3l of suitable shape may be immovably attached to the inside of the cylinder head to till up 'the central portion ot the clearance space leaving an' annular chamber 32. This-chamber is provided at one s ide with a port 33 which is closed b v a valve 34 the stem'35 of which is normally drawn down by vmeans of a spring 36 and .is provided at. its lower end with airoller37 or the like resting upon a cam 38 on a cam-shaft 39 carrying a gear 40 meshing with a gear 41 on the crank shaft27. The valve 34 may be' roviderll vwith a detachable member 42 by w 'ch the free space within the chamber 32 above the valve may be altered by the substitution ot members of diti'crent volumes in case it. should be desired to alter an' engine-to accom lish the cycle herein described. The inta te port 33 communicates with a chamber 43 having a valve 44 between it and-a conduit 45 lending to the external atmosphere or to an intake manifold and )revided with a throttle valve -46 if desirec. The stein 47 of the valve 44 is surrounded by a spring 48-which normally holds the valve on its seat. In order to limit'thc upward movement of the valve and thus restrict the opening betweenthe chamber 43 and-the conduit 45, there is provided anndjusting screw 49 adapted to be engaged by the upper end'of the valve stem 47 when the valve vided with a detachable member 55. by

which the free space above the valve may -be altered: Itwill be understood that the valve stem 53 is extended and providcd'a't its lower end with a roller adapted to 'cngage a cam driven from th e crank shaft'.A the arrangement being similar to that'shown in connection with the intake valve.'

The cylinder is vprovided with a snitahlo spark plug 56. preferably placediahove ilu` intake valve 34. and. if desired. a priming devi'ce 57 of an appropriate construction may be placed `above the exhaust -valvi- ."rl'.v

or in any other suitable position.

The cylinder 2O is provided with a 'port 58 at the inner end of a passage 5f! having communication-with the 'external at|nosphere through a valve 60. the stern (il of which is provided with n.' roller G2 hearing upon a cam 63 on a cam shaft (i4 which murries a gear 65 meshing with a gear on .the crank shaft 27, such. for instance. :1s-the gear 41. The stem of the, exhaust valve may conveniently be Opcratedfrom the cam shaft 64. The lower portion of this stem, its roller and actuating-cam do notan-)pear in Fig. 1, but the roller and cam are shown in the diagrammatic views Figs.

Extending into the chamber 55) 'and terminating near the port 58 is a nozz'lett preferably inclined at a slight angleandhaving the construction shown most clearly 5 to ll,l

in Fig. 4. This nozzle comprises a casing 67 having a pointed inner end. lVithimthc outer casing is 'a Atube 68 having an extenmay be controlled.

from the pipe i into the tank 74 is ron- {rollt-d h r a. valve 7G adapted to be operated l| a (lout 77 to maintain asuhstantiall)` couslant level of liquid within the tank. The main tank is provided with an air veut 78 of any suit-able construction. Associated with the main tank 74 is an auxiliary taak 79 liaving: conimunicntion with the main tank through Aports 80 adapted to be closed hy a valve 8l controlled hy a spriiugr S2, 'lhe top of the auxiliary tank is provided with an extension 83 within which is a valve S4 normall)y held oil' of its sont ,by a spring S5. 'lhe top of extension S3 is open to the atmosphere through a port. which is controlled by a valve S6 connected to a hell-crank lever 87 adapted to .be operated hy a (.ontrollingr rod 8S. 'lhe auxiliary tank is also provided with a .Quitahle check vulve 89 which allows the escape of air from the tank, but prevents it from lowingrnto the tank.

The cylinder 20 is also provided with a relief port 90 (sce Fig. 2) located at e suit;- ahIe distancehelow the top of the cylinder for a purpose which will hereinafter appear. 'lhe ieliet )ort is provided with a valve 91 held normally against its seatby means of a. sprintY 92 surrounding: its stem. Cooperating. with the outer end of the stem 93 is a.

cam 94 upon the en d of a handle 95 which is connected to the outerend of the stem of a rotary valve 96 in o. conduit 97 communieating with the relief port. The parts are so arranged that under normal conditionswith the valve' 96 closed thel cam 94 will `hold the valve 91 locked on its seat, but it. the handle.

, downward movement of the piston on its intake stroke will draw air inte thel cylinder through thc manually controlled throttle valve 16, conduit 45', adgustzible throtthng valve 4l which is lifted hy the air entering the cylinder, chamber 43, and. port 3:3. When the piston 23 has` completed approximately one third of its downward movenunt on the intake stroke, the intake valrell. will have completed its opeuingaud closincr movement and the parts will he in the positionsl @uhstantiall'v as slm-wn in his'. i. Further movement of the piston.dnwnlivard will permit the air prcviousliv drawn'l into tlul lvliudrr lo expand. 'lhis expalxsiou will continue until the parts are-ilupositiou sullstantiallv as shown in Fig. 7. The air will then have heen expanded to the illmit of the cylinder volume provided n ndas tal" as possible with the parts shown. A partial vacuum will therefore exist within the cvlinder at this time.`

At the instant when port 58 is uncovered by piston 23 on its downward movement.' a flow of fuel may take place from auxiliary tank 79 through pipe 73, and nozzle casingY 67 into the cylinder` since full or any part of full atmospheric pressure may he .caused to olitain in the air space over the liquid in tank 79 hy admitting air or restrictingr the admission of air through manually controllod valve 86. The valve S4. is held open' by its spring Slito permit entrance of air to the auxiliary tank. Air at atmospheric pressure will also enter the cylinder through Slt anjet tube'68, the amount of this air being controlled hy needle valve 7 Since lioth air and fuel must enter the cylinder-through the same port the fuel entering the cylinder. if in liquid condition, will he in the form vot fine spray. However, it' is possible that. the fuel, dueto its vapor pressure will become va orized directly atythe needle valve and wi l be drawn into the c\,linde r as fuel vapor mix'od with air at the `end of the air jet 68.

From tho foregoing it will be readily seenthat a `mixture of air' and liquid fuelslnay,

l or of air and fuel 'vapor or, assuming jet 68 to be eliminated, liquid fuel alone'orw fuel vapor alone may enter the lcylinder al: any particular time or during all "of the time that the port-58 is uncovered by the piston,

-and that an)7 liquid fuel entering the cylin vder will, due to its vapor pressure.' become vaporized and will mix with the air in the cylinder in direct proportion to the pressure of the nir and the particular vapor pressure o'f the fuel. It will also he seen` considering: the proportion of fuel to air for cllicicnt combustible mixtures. that if the fuel sup:

will he obtained within the cylinder. which cannot. he condensed under any pressure to which it, may he'suhjectcdwhile in the cylinder. v I, l

Referring to Fig. 4 and assuming a liquid level as shown, it will bc seen that in order to reach the needle valve 70 of nozzle G6 the liquid will have t9 travel a definite ldis lll lill

plv is suitably regulated a drv fuel vapor -the fuel in main tank 74, thus permitting "e, or by suction from auxiliary tank 9, will4 tions that :my movement of liquid out ofl tance lthrough pipe V73 and that for a given pressure ou the surface of the liquid in the tank 7 9, the liquid will accomplish the travel to the'needle valve 70 in -u proportionate length of time. If the volume `o -the air space over the surface of theliquid 1s properly proportioned and theair permitted to means.A In des ning the fuel System @011- V-Siderution should 73 and to the location of tank 79 sotha be given to' the size of pe trzivcl and'umount o'f movement 0f liquid out, of the tank willause s, change of volume of the space over .the liquid in the tank such as will give a sensitive control du@ t0 the change -m uir pressure in this space cuu'sed by the chungo of volume due to the movement of tbeliquid outof .thei'tnnk.

The flow of fuel 'from the 'supply tank through 'the i e 75 tqthe main tank of the reservoir w' e controlled by float vulve 76. The check valve 81 is held .open normally by spring 82, the force of which is just suliicient to overcome the liquid head of normal passage of liquid for a proper quantity in auxiliary tnnlr''t).` Any considerable flow of liquid such as might be caused by uir pressure ou thesurfalee of the liquid in tank result'in closing the check valve 81 and sto ping wmmuncation between the two. Tie

nuxiliaizY tank is provided with an air space above t eliquid which is of' such proport'he tank will result lnconsiderable change of volumeof this space. Air is admitted freely to the main'tank 74 by means of pipe 78 so as to permit li uid to flow freely in und out of this taik; Air is admitted to the uur `iliary tank 4 79b through the munuully controlled vulve 86"loceted in tlieentrance'to the uir space, The check valve 84 is n or- :nelly held oli-"of its seat by light spring tension suflicientv to hold the valve open under-normal conditions to permit the passage of uir admitted throu h valve 85, but in ease 'f u sudden clumge ofgliquid How out ,of tan-k 7i), suclrns might be caused b slowingl down of the engine speed duc to amorinul conditions, the pressure of air entering through vulve 85"\vill'cause the cheek valve to close and thus automatically restrict the pressure exerted onithe top of the fuel, such pressure being due primarily to the partial vacuum obtaining. within the cylinder. Air muy escape from tank T9 by means of check vulve 89. Such cseul'ie of nir necessary in order that normal liquid level muy be established in tank 79. Assuming valve 86"to I have'been previousml opened to admit nir pressure to thista and change 'of liquidv level caused therein, and vthen closed for regulating urposes, it will be seen that the;

original vo ume of air in the, tank has been increased and the liquidscould not reestab lish vits former level'when relieved from the suction of the jet, unless means were provided for the escape of air previously admitted to the tank. Thisis accomplished through the check valve 89 should the valve 86 have been closed after admitting air.

Considering new the subsequent operation of the engine, the piston A23 will move upward on decompression stroke, and just as` its upper edge coincides with the upper ed e of the port 58, as shown in Fig'. 8, or at suc other suitable time as 'practice may demonstrate to be' most eilicient, 4vulve 60 will be opened by its stem 61 hnvingbeen lftediby com Such openingfof valve' 60 will continue for en interval sufficient to establish atmospheric ressure in chamber 59, thus AStopping furt er flow of fuel through nozzle 66, since no difference of pressure will then obtain between chamber 59 and the nir space in auxilio tank 79. Or under eertuin operating con itions, supposing valve 86 remained closed, un excess of pressure will exist in chamber 59 und such excess pressure will act to force thejiquid back down pipe 73 until normal level 'obtuins in tank 79 and pressure equilibrium is established between chamber 59 and air space ixpthis tank. Continuing upward on itscompressin stroke -tlre piston will com ress the mixture of a'ir and fuel in to the -earunce space provided by -annular chamber 32, which -is proportioned to give suitable compression to theA quantities of air und fuel which huvepreviously entered the cylinder. Air will have been supplied through 'intake port'33, and

also 'through port 58 frohifchamber 59 in limited amount, while fuel willhave been sup lied by nozzle GG. Ignition takes place in t e usual manner from s arl: lng 56 and may be suitably controlled y either advancing or rctardng the spark in the usual munner. Since a partial vacuum of considerable degree exists within thecylinder at the end of the intake stroke, the compression may be vulve in open position from the Ytime of opening previously described in connection with the fuel intake. Just before aga-inuncoverine port 58 the burned or exploded mixture w l have expanded to or slightly 'below atmospheric pressure so that when port58is uncoi'ered on thi.` stroke (see Fig. l0), vnlvc (io being held open by en ni G3, nir ntiit- .niospherie pressure will. ruler the cylinder, such entrunce of nir continuing duriu f the further movement of the piston to its ower demi center. Upon reaching its lower dead conter cum 63 will hin-e operated to close vulve ('ll und exhaust vulve will be opened by cum (2l. Fig. l1 represents` the position of the ports just after thel exhaust. slrolee has hvgnn. Upward movement o f; the piston'will expel the products of' eoinliustioirfrom the cylinder and transfer the uir previously nd'- niitted through vn ve 60 and port 58 tothe clearance space, thus leaving the lattei; in n hotter condition for the next intake stroke. The exhaust stroke of the engine amounts to u minor power stroke since -the exhaustrgas ns'dschiu'gcd is immediately cooled to. ntinoeplieric teinperuture :uid Ithus substantially to the pressiireof the partial vacuum obtaining jwithinthe cylinder at the 'endof the intake strokel the whole exhaust stroke heingnccomplshed with the aid of nir pres sure noting outlie/bottoni of' 'the piston from the crunk lcurse which is open to the atnios- 'phere through u port Q8. Thus the exhauststroke, which in ordinary engines is en idle stroke against n buck pressure, is .in this Vengine converted into n minor power stroke,l

with'eoiisequent advantages of operation.

Afteiwthe exhaust .stroke luis been completed,'tl1e`piston )asses over its upper dead center point vand the parts :wein occupy the position shown in Fig. 5 at tiie beginning of the next intake stroke:

With an' engineI designed 'for operation with different' grades and kinds of fuel, it 'is desirable to change the compression pressure making it greater or less according to the tuel' used. Referring to Fig. 1, the iidjustable throtbling valvel permits. of the I above to n certain extent by 'adust'ing the stop 49 so that the amount of opening of vulve 44 will permit 'a predetermined amount of aiuto enter the en 'ne on isintiike stroke, the stop 49 being :i )usted according to the compression desired for the particular fuel to be used. Howet'er, the usefof this valve to ether with the cut ott' point of the iutii'ke wre 34 must be co-ordinated in the engine design so :is not to endanger the degree of.

vncnum required for properly vziperizng: the fuel to he used und for expanding the gus in the cylinder ilfter ignition and rron'ibustion. It is nlsodesiriihle to vary the compression according to the utinosifiherie pressure obtaining, so that en engine may operutc :it full efficiency :it high nltitudes where u considerable reduction in uln'iosplieric iressure is encountered. '"I"l|f"`ii djustable tiirotV .tling vulve permits of this i'u the i'nzinner :is :ibove described for -fuels of different grades.

pressure. li'ith the engine herein' embodied',-

vnrinton in speed is accomplishedby regir 46' eibrmannally or autel lut-ing the amount of fuel supplied and nd- Y -jnsting the ignition point accordingly by advancing or retnrding the vsiiinel thus vnrying the combustion or e thil object being to suppy im amount ot' fuel mplilired by the particular load und to adjust e ignition to give the maximum combustion pressure for the nmountof fuel use d. Since the compression pressure-reA ninms the same at ull engineepeeds, n very desirable condition is obtain in. this eug ine, d ue to the tact that a maximum etliriencyis thus obtained for :1li engine speeds.

If im engine Aof the kind. described were stopped with the piston 23 in the position f" shown in 'Fin'. 7,' a1r would enter the cylinder through the nir jet tube (i8, or leiilc pest thepiston rings, until the' pf'irtial vacuum within the cylinder was destroyed. To st rt the engine under the above 'condition would require considerable power,v for the piston 23 would immediately commerce to compress air from atmospheric pressure, und since the clearunce space is proportioned for the coinpression of a much smaller volm-ne of nir nt lesion pressuresntniospheric pressure, the lefltn't requiredto complete 4compression or toA turn the engine overini'ght recpiire power 1n excess of, that required for t 'operation Ais ns folloivszuponfstnrtling'the ruggine. handle 95 willbe turnedtW-.open

ie ordinary starting olf-gifs' engines: l`o'lobviateitlus diiculty, the coin-y vnlve fifi nudreleuse stern 9), thus permitting l .vulve J1 t0 hejopened b the pressure-within.

the cylinder due "to t ie moi-ement of tlie pistoirjroin ther'position shown in' Fig. 7'. i

.\r iwjll therefreescnpe frmnthe cylinder through port 90,'eondu'it Slnnndfvnlves to the nti'nljisphere-.- After the engine has taken.

up itsxeycleythevnlve'lil be' closed' by inoi'einentrof handle 95, ein .ntf the" salue time' the stem viil Abe locked do'wnto to aid the spring ,prevent further opening of valve 9i. #Exten 1*,eiaageav f .shoivfn'fit will'be understood that addi-- tional nozz es. may be 'potid`ed,some or all of .which may be usedaccording to. the de 'mande upon the engine. These nozzles-'moy be supplied from a oominon fuel-reservoir or fromY separate reseri'oirs. The en 'ne may consist of any desirednumber of cy in vided withy a' movable piston ivith a comfor su plying 'a mixture ders, the several valves ofnvhic'h will .be

operated in tim'ed relationy in accordance with the usual arrangements for th1spurpose. While in the embodiment 'of the in' vention shown and described a special form of fuel system has beenqused, it will be understood that a carburetor ma be-,used of fue and air througthc inlet port/in the usuel manner, but with distinct advantages as to vaporiz ingthe fuel and without les'sening the other advantagesof the invention. It will also .he understood that various-other changes may be made in the details of construction I of the 4engine without depirtng from the principle. of the invention as defined in the appended claims.

. I claim: n

The method of charging a cylinder prohustilrle mixture which consists in supplying nir to the cylinder during'a portion of the stroke of the piston, maintaining the cylinder out of lcommunication with the air sup lycluring substantially the remainderv of't fe-.strlke of the piston topermit the air4 inthel cylinder toexpand to` a pressure .below' that ot the suppl and at the end ofthe stroke injecting liqui fuel into the cylinder and.vaporizinpl it therein by the elect of the low pressure in the cylinder.

- 2. Themethod of charging a cylinder provided with a movable piston with a com- .l \l. st-il)le mixturewvhich consists in supply-,lv ing air t0 the cylinder during substantially onethird of the stroke of the piston, lnain taining the cylinder outot communication with the air supply during substantially the remainder of the stroke f the piston -to` permit the air in .the cylinder to expand to.

apressure below that of the supply audit the end of the stroke of the piston injecting liquid fuel into the cylinder and vaporizng it therein bv the eifectof the low pressure in the cylinder, y

3. The method of operating a four-cycle internal'combustion engine which consists in supplying 'air to the cylinder during a portioufof the intake strokeof the piston, .mainraining the cylinder out of comi'nunication, with the atmosphere .during substantiallyiheremaindcr of the intake stroke to permit the air therein to expand to a pressure below that of the supply, 'njecting liquid furl into the cylinder and vaporizirngr 1t therein at thc'cnll of the intake stroke h v the effect of the low pressure in the. cylinder. compressing and igniting the charge of air and cylinder at th termi- 'vaporizingfuel'an'd supplying' ar-at'natlnos phei-xc' pressure tothe nation of theovorking stroke-to'aid v'nidisl ffzharging the .1'nft`xluetr1l of combustion thererom. 4. The method of operating a four-cycle internal cpmbustiou engine 'which consists. V1n supplying air to the c linder during a l portion of the intake stro 'e' of the piston, maintaining the cylinder out of communication with the atmosphere 4during substanf tially the remainder of the intake stroke to permit the air therein. to expand to'a pressure below that of the supply, injecting liquid fuel into the' cylinder and vaporzing it therein atthe end of the intake stroke by the eiectp the low pressure inthe cylinder, compressing and igniting the charge of air and vaporizcd fuel and cooling the exhaust products of combustion to reduce their pres- 3 sure below that` of the atmosphere in order that external pressure may be etl'ective upon cylinder to expand to a pressure below 'that 'of the supply und at the endof the stroke ofy the piston -injecting a liquid intothe cylinderl and .vaporlzing it therein hy the effect of thelow ressure n the cylinder. s

A6. The meth' of charging` a cylinder with a combustible mixture which consists' in supplying a predetermined quantity of air-to the cylinder, increasing the free space. n'thin the cylinder while maintaining it out of'communication with the air supply to permit the air inthe E vlinlder izo-expand to a' .pressure less than that of `the snpgly and supplying liquid fuel tothecylin er and vaporiziug it h5' the low pressure therein. '2'. In an engine, the combination of' a' cylinder provided with an intake. port oorn-- g municating with a sourcef supplyza piston in the cylinder, means` for malntaining the cylinder ont of communication"\\th the source of nir supplyby closure of the rt -after the piston has performed'a. parte im. der to expand, during the remainder o the -intake stroke to a pressure lessv than that of intake stroke to permit the air in the the air supply and means whereby at the" end of the intake stroke liquid fuel" 111;; llie' "suppli'ed'to the cylinder and vapori? the effect of the low pressure'in thecylinder.

8. in an engine, the -comhination .of n cylinder provided with an intake port communicating with a source of air supply, u piston in the cylinder, means .for maintaining thc cylinder ont of communicationnfith 13? the source of air supply by elosiire of the intake port when thepistou has performed sulistantially one third ol lsiutake stroke to permit the air in the cylinder to expand during the remainder oi' the intake stroke to a pressure. less than that ol tlic atmosphere and means. whereby at the end ol' the intake stioke-fnel univ he supplied to the cylinder and yaporized hy the etlect of the low pressure in the cylinder.

t). l'u a four-eyele internal coinlinstion'eniifiue. the eoinliinatioii of a cylinder proi'ided with a fuel supply port and an inlet. port communicating with a source olE air supply, :i :stou'in t ie cylinder adapted to uncover thea@1 nel supply port when it approalelies the end'ol the stroke. nieansilor opening the inletport at the beginning of tlieiliiitake slrolal and l'or closing it when the piston has performed a pait ol': such stroke to maintain the cylinder out of communication witlrtlte source of air supply 'to permit tlic air in the. cylinder to expand during the remainder of the stroke to a pressure less than that of the atiuosphere and means for supplying liquid fuel to the cylinder through the fuel supply port and raporizing it by the dif- 4l'erence in pressure between the interior and exterior of the cylinder. y

10. In a four-cycle internal combustion engine, the combination of a cylinderprovided with an inlet port, an exhaust port, and a fuel supply port. a piston adapted to uncover the supply `port when it approaches the end ot' its stroke, nieans'fbr opening the inlet port at the beginning ot the intake stroke and i'or closing` it when the piston has performed a part of its stroke to permit the air in the cylinder to expand during the remainder of the stroke. n'ieans for supplying liquid f-iel to the cylinder through tlrefuel snpplyport and raporiziug it liy the dit'erence in pressure between the interior and exterior of t-l'ie cylinder, means forl opening the' exhaust port 4attlie beginning of the exhans stroke, and means whereby air may be admitted to the cylinder through the supply port when it is uncovered by the piston on its workin;r stroke 5to aid-'in driving out the products of combustion during the followin;r exhaust stroke.

ll. In a fouiyeycle internal combustion engine. the combination of a cylinderpr0- vided with an inlet port'ancla fuel supply port. :i piston adapted to uncover-the supply. poi-,t w ien it approaches the:A end o't its stroke. means for opening the inlet port at the lieginning of. the intake stroke and for closing it when the piston lilas performed a part of its stroke to permit:l theair in the cylinder to expand during th remainder of the stroke. means for injecting.r fuel into the cylinder through the fuel supply port by the difference m pressure between the inte rior and the exterior of the cylinder, and

vsure in the cylinder.

ineans for eipializingtlie pressure upon the luel :i'lter the piston luis closed the fuel supply port. on its compression stroke.

l2. lii a l'onr-eyrle internal combustion 'en ine`- the eoinliiiiation of a cylinder proridi-.d with an inlet port communicating "nieiiuiinder'ol' lsueli stroke to a pressure less than that ot' the source of supply, an ad- ]ustahle automatic valve for controlling the admission ot air from the source of supply4 lo the inlet'. port and ineaiis whereby at the end of the intake stroke fuel may he supplied to the cylinder and vaporized by the i-ll'ect of the low pressure in the cylinder.

iii. In a four-cycle internal Acombustion engine, the. con'ibination ofga cylinder provided willi' an inlet port communicating with a source of air supply, a. valve forl the port, a piston in the cylinder, means for opening the valve at the beginning of the intake stroke and for ,closing it after the pi :tonlias performed a part of such stroke to maintain the cylinder out of communication with the source of air supply to ermit the air in the cylinder to expand uring the remainder of such stroke to a, pres# .sure less than that of the source of supply, an adjustable 'automatic valve for controlling the admission of air from 'the source of supply to the inlet port and manually controlled means for determining the amount of air supplied to the automatic val-ve and means whereby at the end of the intake stroke fuel may lie supplied Ato the cylinder and vaporized hv the effect of the low pres- 14. In an internal combustion engine, ,the combination of a 'ylinder provided with an inlet: port. an 'exianst port` a relief port and a fuel supply port.- avalve fdr the reliet" poi-L means for locking the ielief valve in closed position, a piston adapted to uncover the supply port whenl it approaches the end of its stroke. 4means for opening the inlet port at the beginning of the intake lstrolteand for closingr it when the piston luis peidorined-a part of tliisstroke to per-.-

mit the air `ni the cylinder to expand during rinrrnniiuder of the stroke. and means for drawiiifr't'uel into the cylinder at the terminatiou'of the intake' strok'e by the suction elleet of. the low pressure therein.

1.7. In an internal combustion. engine, the

combination of a cylinder provided with a relietport. a valve for the relief port, u. conduit eominunicatiner ,with the relief port, a valve in the conduit, and means for simulthe air to 'expand w a pesure considerably below that of the atmosphre and p the space in ccmmunicecen with s. source o fuel supply in order 'tha'fue my be sul plied to the spacend *la :ized by the effeet of the low preseure fwen.

23. The cycle .of operation o am ini'c'nul combustion; engine comprising a'n. inlet stroke (lm/lng the initial riad of whlclaair is. admlttedlio the cyln er of the engine from a eoureof -eupply and there'fter a1- lowed bo expendio a precisare less than-thi?.

mams? of the source of su Pl; during the vremain` der of the s'troke w is performed-without' communication with the'souroe of au ply and at the 'termmton of which -fuel 1s supplied to and va a com essun stroke, a wor ng stroke and an e ust stroke at an early criod of which air is su p'led to the cylih er to aid in driving out t e products o'f combustion.

In testlmony whereof I aix my si aturc.

1' A GEORGE W.

porud in the 'cylinder i 'by the elfect 'of thefreduced easure therein,

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