US2664864A - Engine head - Google Patents

Description

Jan. 5, 1954 R. P. ERNEST 2,664,864

ENGINE HEAD Filed Aug. 3l, 1950 4 Sheets-Sheet lA l N VEN TOR. aer? F E7/776152Z,

R. P. ERNEST Jan. 5, 1954 ENGINE HEAD 4 Sheets-Sheet 2 Filed Aug. 5l, 1950 R. P. ERNEST Jan. 5, 1954 ENGINE HEAD 4 Sheets-Sheet 3 Filed Aug. 5l, 1950 R. P. ERNEST 2,664,864

ENGINE HEAD 4 Sheets-Sheet 4 Jan. 5, 1954 Filed Aug-, 31, 195o Patented Jan. 5, 1954 ENGINE HEAD Robert P. Ernest, Wayne, Mich., assignor to Kaiser-Frazer Corporation, Willow Run, Mich.,

a corporation of Nevada Application August 31, 1950, Serial No. 182,571

14 Claims.

This invention relates to internal-combustion engines and more particularly to engine or cylinder heads therefor, wherein a fuel mixture is to be distributed to a plurality of cylinders in an economical and eiiicient manner.

In conventional internal-combustion engines it has been customary in the p-ast to attempt t provide means for supplying air-fuel mixture to the cylinders in such fashion that eflicient performance is achieved at high speeds, and at the saine time the distribution is sufliciently equalized at low speeds to prevent erratic or inefficient performance when the engine is idling or Warming up. In the conventional rake or gallery types of intake manifolds it has been customary, in order to keep the fuel in a proper state of suspension for distribution to the cylinders, to limit the cross-sectional area of the distributor section of the manifold so that especially at idling speeds sumcient velocity is maintained to prevent en-v trained liquid particles from dropping out of the mixture. As alternatives to this expedient, or supplemental thereto, the mixture must be made sufficiently rich, and of sufficiently high intake temperature, so that the cylinder or cylinders il' make the mixture too rich for the other cylinders,

decreasing the economy of performance. In order to overcome these disadvantages it has been proposed to provide multiple manifolding in the form of branches which extend from each intake port to, or nearly to, the riser. However, this design still has the inherent disadvantage of greatly differing passage lengths from the carburetor to the various cylinders, thus making it diflicult to achieve proper distribution without use of the aforementioned expedients.

It is, therefore, an object of present invention to provide a system for supplying the air-fuel mixture to an internal-combustion engine which will achieve equalized distribution of the mixture to various cylinders. and which will keep the fuel in suspension at lower manifold velocities. In association with this object it is Within the contemplation of this invention to provide a system which can use a leaner mixture, especially at idling speeds and which because lof .the even a greatly improved output and economy of operation.

It is a further object to provide a fuel supply system as described, which will result in a high volumetric efficiency and in which by elimination of the conventional gallery or distributor, relatively large fuel intake passages may be employed without a decrease in the efficiency of distribution at idling speeds.

It is also an object to provide a construction as described above which by eliminating the conventional application of heat to the manifold, can supply a fuel mixture to an internal-combustion engine at relatively low intake temperatures, thus resulting in a denser change and a concurrent high mean effective pressure, but which nevertheless has means for eiiiciently distributing and vaporizing heavy fuel fractions which collect in the intake system.

It is another kobject to provide an internalcombustion engine having a novel fuel supply system which can be fabricated at a greatly decreased cost by eliminating the necessity of casting an intake manifold, and in Which the fuel supply system may be cast integrally with the cylinder head.

Other objects and advantages of the invention Will become apparent upon consideration of the present disclosure in its entirety.

The essential features of the invention which achieve the above described objects comprise an internal combustion engine which entirely eliminates the conventional intake manifold gallery or distributor carrying the fuel mixture from av single carburetor, and substitutes therefor a pair of spaced-apart mixture distributing chambers supplied by a pair of positively linked complete carburetors, each chamber having connected thereto a plurality of relatively short radial pas-v sages leading to the intake ports of one half rof the cylinders. These passages are so designed that they are, as far as is geometrically possible, of substantially equal length, and each preferably has a section of Venturi shape. The distributing chambers are unheated by the exhaust system, but the end of each passage adjacent its corresponding port is preferably provided with an inclined dam which is heated directly from the combustion chamber for insuring completeV vaporization. In a modified form of the invention means are provided for insuring equalization of the intake pressures, as well as equal distribution, of.. theV heavy fuel fractions, and a novel exhaust arrangement is provided to cooperate with the intake system.

In the figures:

Fig. 1 is a top plan view of a cylinder head embodying the features of my invention, the view 5 being partly cross-sectioned for clarity;

Fig. 2 is a bottom plan view of part of the cylinder head Fig. 3 is :a cross-sectional' view taken along the line 3 3 of Fig. 1, and showing one of the intake 10 passages;

Fig. 4 is a perspective view of an internal come.. bustion engine embodying the cylinder head` shown in Figs. 1 to 3;

Fig. 5 is a top plan view, par-tlylin cross-section .15

of a cylinder head with a modified intake structure, and having a modiiied exhaust systemint gral therewith;

Fig. 6 is an end view of the cylinder head'slfxowne*2 otherwise :conventional design, .and :constituant-.2.5

by f. standard l methods. .using :conventional: mater-1 rials.: It may be:sta-tedrthat:altl'xouglrrthe:prirr ciple or.' the;vinvention:isszapplicablef to other; types` :1; of -pcxweneplants-athe inventionrt is.'1;particularlyadapted for use with four-stroke:xzyciegrfsixecyla -30 index; in-linefenginesp: andi is:` vfurther designed to -be.offespecial advantage'fin engines-:Where:- in the exhaustmanifold iwould ordinarily. beadiseg posed r opposite atheiintake systemr.; The cylinder:-

head is, :provided with' a: water iconnection; I 0,: 35

whichrleadsfto, awaterfjacket: I I surrounding.Y the/combustion chambersr Valve`=stem supportsr. I2 .',andro'cker-'arm supports I 3 areaprovided -on 1 theupperfvportion. offthe head; In; the embodi-vment illustrated in Figs. 1 to 4, the-cylinder head:40

is designed to-faccommodate'eJ rake :.typef-of.: exhaust. manifold. (not shown)Y which isconnected to exhaustuportsmM-by.f.means offexhaust pas-ff sages vI5... Bolt .holes eI 6 -are providedfat spaeedf.

intervals alongv therl cylinder headififor f attache` (A4- ingait to the engineblock, andf-asrisy besta-.scene in Figs. 2 and 3 the lower surfacepf -the :head1:v is providedwith combustionchambersfl'l.-

The i fuel. supply system fcomprisesf. a @pairy c of imixture distributing-.chambers AIL-onf .theesidal Wall. of..the.: cylinder4 vhead opposite ,-.theffexhaust manifold.. These chambers are. ofsubstantially identical V-inwardlyflared v: shape,:.and. lar-,e .dise posedin spacedrelation:- on itheside. .of the'fhead,

each .chamber beine. F'Dr eferably. v cast. Vintegrally ..55

with.. 4the .head.fand adj acent.. `a group J,of -three -1 cylinders. For illustrative. purposes,v eaclrchamber4 .is,.shown as. adapted to receive thereabove a carburetor ofthe downdraft .,type, although..

the invention is equally` applicableto other types .o

of Vcarburetors. For this' purpose; a flange I9 is provided at the" upper end ongeachJ chamber; having- -bolt holes to' which=a carburetor' 21' may' be attacheduas shcwmin YFig". 4.; Each ofitlr'ese" carburetorsfis complete initselfgand theyfareboth adapted-to be simultaneously'controlled by=the= accelerator: pedal,v .the -carburetors Avlbeing-zvposi-4 tivelyuconnnected by. adjustableflinkage means 1 22 :forl this-purpose. Airsupply: connections=23flv andffil'elfsllpplv connectionsftzrlead torthei-car-i 70 buretors,-these connections-.being preferablyi fedi' byA common sourcesg ofgair.; and fuel. respectively'. l It fwilt. thusifbe .rseem that eacha chamber:` -I 8f. lisf` independentlyf'g'supplied Iwitlr:airs-:airefuelz.:` lmix'- tureffromi its?corresponding-searbmetmw;andiv that-75 there can be no mixture flow from the carburetor on one side of the engine to the chamber on the opposite side. It will also be observed that no portion of either chamber I8 is directly supplied with heat from any source, especially from the exhaust system as would be customary in conventional intake systems.

Asstatedpreviously therchambersY I8 are eacht adjacent. afgroup of threecylinde'rs; and the arrangement is preferably such that the line ofisymmetry of the chamber is substantially a1igned.-with the centerline of the middle cylinder'of the group. For example, the chamber Ilshownwin'y Fig. 2.is1;substantially aligned with :thefcentral'combustion chamber I1 of the three supplied" by' thatchamber. Each chamber I8 has leadingtherefrom a group of three intake passages 251" These' passages are in a generally radlalarrangement with the passage 25a lead- 0 ing to the outer cylinder of each group and the passase..25c..leading5to .'each: inner.. cylinder.- be

ingdisposedr .on either. 4fside-of passage 25h leadf ing.to.1the-centercylixiden as will-be seen espef cially in Fig;.1. The passages` are of a substan .tially uniform length within..the geometrical; limitseof. design. .andV .eachpassage leads to .an' intakawalve .port .26.. For .this l.purpose the .inf take valve portsare preferably ,soarranged .that the..ports..for -.the..outer. cylinders Y. of f eachx group are. adjacent the v-centralcylinderxasseen inA Fig. 2, sosthat..passages:'25a.and=25e lie about 30v on either-:sideof .passage 25h.. The latter: passage is so designedasto be-curvedthroughout agreater portion. of.. .its length than .either of passages j,25a..and,25e,thus..giving.;it atotal length and resistance nearly equal. .to .thatl .offrits flanking passages.. The inner .surfaces of .passages 25.-are

preferably. .smooth and -..their cross-sectionalarea decreases to. aA narrow section .N exaggerated in `the .figures for..purposes.of. clarity) and lthen increases .,uniformly., toward .the-valve -ports for a predetermined..distanceVbecoming constant.

thereafter, thus providing-a Venturi effect iin the outer portions..of. the` passages... The-design of the Apassages is such that Lthe Venturi eiect v D in each passage will." result .in.uniform.velocities of the mixture in allthe passagea.

As isbest seen in Fig'.,.3, the floorof each. passage 25'is substantially horizontalV outwardly .f of its combustion chamber, .theinner end 4of eachv U passage; adjacent the valv'eport .26.- beingproe vided with an'upwardlyinclined-iloor portionll forming a dam for the collection andQvaporizaf. tion'. of liquid particles'of 'the heavier fractions which.dr.op out. of'the mixture. It will benoted thatzithe 'position of. dam 2l. lis .such .that it. is.

directly at tli'eA source of heat, .namely Y, combustion"'chamber I1.,. so that. fuel collecting.- the. chamber .or the passage. will. fl'wfup. against the- Adam .(o'r to theright. as seen. iniFig. 3). andbe. quicklyvaporizedby rthe .heatedsurface.

In.operation,..airfuel-mxture .Willbe supplied by carburators. 2 I. .to .chambers I8v and .will flow fromleachchambenintofpassages-.Za It will bcI` observed that due to tha-arrangement off'theY passagesvrelativemto chamber I8 av substantially equal famounta of mix-ture Iwill new. into each tof i' passages 25u',.-25bl,- and. 25e. SinceA the` passages areoffsubstantially; equailength 'and have approximately gidenticali- 'heat' balances relative to ther'cylinderdieaiithez type'of' mixture` arriving at eacheintalciport 26' will 'be' lvery nearlyY the sameand.'.because7 of thefrelatively short pathVv which-the: -mixture travels 1 to" arrive at each cyl; inder;;:there v'wilt.be#little:iopportunity for set-v tling out of the entrained particles. Any fuel which does collect in the chamber passages will be vaporized upon reaching dam 2`I at the end of the passages. It is thus possible to design passages 25 of relatively large cross-sectional areas, to decrease the mixture temperature so as to achieve high output, volumetric efciency and B. M. E. P. and low speciiic fuel consumption.

Table A below illustrates in tabular form the results achieved in testing the novel engine head installed in a stock six-cylinder in-line engine, the results being compared with equivalent ngures using the conventional manifold together It will be observed from the above results that by use of the intake system described above vastly improved results are obtained both in the power output and in the operating eniciency of va standard engine.

Figs. 5 to 7 illustrate a modified embodiment of the engine head having an intake system essentially the same as that of Figs. 1 to 4 but having several additional features designed to improve still further the results achieved by that intake system. As one of said features, each of the mixture distributing chambers I8 in Figs. 5 to 7 are provided with a pair of ridges 3| and 32 which are aligned respectively with the junctures 33 and 34 of the intake passages 25. These ridges rise from the oor of each chamber I8 a short distance and extend from the outer wall of the chamber, diverging inwardly toward the passages. The purposes of ridges 3| and 32 is to distribute equally the heavy fuel fractions which may settle out in chambers I8 before reaching the passages 25. It will be seen that liquid fuel droplets which settle on any part of the floor of chamber I8 will be held by ridges 3| and 32 in the i area in which they settle, and since the settling tends to be distributed evenly over the chamber, each of passages a, 25b and 25C will receive substantially equal amounts of liquid fuel. This construction is especially advantageous when the engine is operating on an incline from the horizontal, since it will be obvious that without ridges 3| and 32 the liquid fuel would tend to flow toward the lowermost point of chamber i8, thus being fed unequally to the three passages 25.

The modification of Figs. 5 to 7 is further vprovided with a tubular aperture 35 within side wall 36 which extends between and connects the two mixture distributing chambers I8. The function of this tubular passage 35 is to equalize the intake depressions between the two halves of the engine, especially at idling speeds. For this purpose the cross-sectional area of passage 35 is sufciently small to prevent substantial now of mixture between the two chambers I8, but at the same time to permit theslight now' necessary to equalize'minor differences -in pressure which mayy occur, thus increasing the smoothness of operation of the engine.

The modification of Figs. 5 to 7 is further provided with a novel form of exhaust system which is adapted to cooperate with the manifold system described above. This system comprises two separate groups of passages, each leading from three adjacent exhaust ports. The passages 31a, 31h and 31o in each group extend in converging fashion from their corresponding exhaust ports I4 and lead into two spaced-apart exhaust chambers 38 on the side of the engine head opposite rmixture distributing chambers I8. As best seen in Figs. 6 and 7, the exhaust passages are upwardly and outwardly inclined, and the chambers 38 are provided with inclined anges 39 adapted to be secured to the remainder of the exhaust system by such means as a common header (not shown). It will be observed that due to the streamlined nature of passages 31 ideal flow conditions will be allowed resulting in a minimum back pressure and a minimum of residual gases in the combustion chamber. Due to the converging nature of the passages and the inwardly ared shape of chambers 38 it is possible to cast the exhaust system integrally with the head without danger of cracking the casting. Since each chamber 38 draws exhaust from. only three adjacent cylinders, the problem of reverse ow in the exhaust system is eliminated if the conventional ring orders are used. The system also has the advantage of eliminating the conventional gasket between the exhaust manifold and the head, thus obviating the usual problem of a blown or otherwise damaged gasket due to expansion of the exhaust manifold under operating conditions.

It will be obvious that other modifications of the invention could be constructed embodying some but not all of the features shown in Figures 5 to 7. For example, a modication containing the tubular aperture 35 between the distributing chambers but having a conventional exhaust system would be possible. f

I claim:

1. An intake system for a multicylinder internal-combustion engine or the like, comprising a plurality. of mixture distributing chambers in longitudinally spaced relation on the engine head, each of said distributing chambers .being disposed substantially opposite the midpoint of a group of intake ports, means for mounting a carburetor on each of said distributing chambers to supply an air-fuel mixture thereto, and a plurality of passagesof nearly equal length within said engine head and extending from each of said distributing chambers in generally radial relation, each of said passages connecting a distributing chamber with one of the intake ports in its corresponding group.

2. An intake system for a multicylinder internal-combustion engine or the like comprising a plurality of mixture distributing chambers in longitudinally spaced relation on the engine head, each of said distributing chambers being disposed substantially opposite the midpoint of a group of intake ports, a plurality of passages of nearly equal length within said engine head and` extending from each of said distributing chambers in generally radial relation, and means for connecting an independent carburetor to each of said distributing chambers.

3. In an engine head for a multicylinder internal-combustion engine, an intake system comprising a plurality of mixture distributing chambersinIiongitudinailyfspaxzedirelationomonefsidece* of said engine head, said distributingtchambers:1:: being-lof inwardiyilaredshap, a plualityiofinsatake' portsffeach'r ofsai'dv distributingvfchaniberszf .i beingldisposedfisubstantially opposite :vthefzmid-.g 5v poirrtfof a groupof rintake-fportsandsa plurality of passages o't 'nearlyLequal lengthewithin :said'en gine'rhe'adl' 'and'iextendingl .from"'eachfoftsaid r dis tributingli chambers finilgenerailyaradial relation', zz. each'fofsaid passages oonnectmgza distributing .10 chamber with one of 'theintake ports inits fcorrespcnding'igroup; wherebyfeach ofasaididistrib-f: utingichambers i distributes '-J the mixture s only. tito' its own?grouplofrintakeerports.:

4. iAniintakefsystem toria six-cylinder internal:Y Nv15 combustion'en'gine'comprisingra pair of mixture; Tf distributing chambers:inlongitudinaliy::'space relation? on ithelfen'ginehead,y -each'iofisaididist'rib utingchambers being disposed substantiallyop positea' grcuipiofl threea'dj scent".cylinders;l means:i 20'.; for mountingv a earburetori'onfieach.'ofcsaid: dis1-z.- tributing chamberslto supply. lan .air-fuel-fmixture i f I theretopandthreerpassages pffnearly'equallength' f' extendinglradially fromreachroffsai'ddistributing i; chamberswitliinisaid ngineiheadyeachz of said] 225.A passages. connecting a distributingichamberwith fi one otitlie intake'ports-'iniits correspondingqgroupi 5. '.Inraninginemheadifor a'inulticylinderfinaz ternalcombustion enginlanrintake'systemcorn-a1 prisinga.pluralityofmixturerdistributingrcham; --30 bersPinlongitudinallyspaced:relation; on'. one'fsideffr of saidcenginehead; a mluralit'y of'. combustion -f's chamberstin saidzffhead, .ea'c'hof said distributing.- chambers beings-disposed substantiallyfopposite the midpoint;'ofta-grouproftadjacent:combustion35` chambeislandt a plurality off passageso'f nearly". equal length within said engine head and extend-"f: ing fromfiealchm said urlistiibiitingichambers':in:A generally'. :radial relationg each of-:saidrxpassages connecting. a distributingwhamberi with' .onerof '.40' the rcombustionchambersfrin itslcorrespondingf: groupgs'whereby each.' of'ssaid 'distributing'eham.- bers-distributes ethernixturefonlyLto its own group of combustion chambers.

6. In an intake system for an internalz-comr-v 45 bustionengina plurality ofrmixturezdistributing. chambers; in'rspacedleapart 'irelationz cn'said- `en-A l y gine; .each of* `said.fchan'ibers being `.adja'cent':'a groupiofzintake portsfaacarburetori operatively f connected 'toveach'` of 'said chambers," :passages 50- leadingv from"e`achi:of 'saidf'chambers 'to leach'cf'f: the intake 'i portsfin" its adjacent rgroup,I .Wl'ierebyl eachiof saidicarburetorswill only supply itscore' responding group 'of'ports;fandf ay tubularcony nection "between said chambers; said connection g5' being. 'of fsuicient' sizel f t'ozallow :equalization -of1 pressures within saidfchamberstwhile :preventing substantial mixturet-ow therebetween.;

7. :In ef-head'ffor .an internalcombustionJen`'''V` gine, a plurality of intake ports;"asplurality"of 30; mixturef= distributing: chambers ein" .f'spacedt-apartxi relation? on :said` engine; ieaclr foff. ysaid :chambers being:V adjacent-'fa group: ofrintake'ports, passagesffA`A of nearlylequal length leading=from"eachofsaid@ chambers tov'each-of the'intakeiportsin'itsv adja- YV'65 cent' groupfand a connection-betweenfsaid:champ: bersfsaid: :connection beings of 'sufficient size: to f alloivequalization .of pressures-within said .cham-'cxf bers l .while preventing substantially-.mixture -flow i therebetween.` 70

8.-iIn a headior-an internal-combustionffen.- gine, a plurality of intake.ports,.a :plurality of. mixture. distributingcharnbers in; longitudinally spaced..relationonifone side wallfot said head, f, passagesiwithin said-head-and leading-ingeneral- 75 1y radialrelation:fromfeachofsaid chambers-:tov:

eachso! thecintake: portsfof :its ".'adj acont Sgroupy;

and :a connectionz=betweemsaid i chambers-'.-withinr said y'side' wall, saidzconnection.; being ofsutcient:

size toallowequalization'offpressures within saidz-.e

chambers"while i. preventing: substantial z-mixturer-'e flow therebetween;` f

9. AIrran tenginen he'adfiffor a multicylinderintermal-combustion engine, an intake system corn-.:- prisinga plurality'of 'mixturedistributing cham#- bers in-`-lorxgitudiriallyrzspaeed'frelation on" one side f of said"V engine: ahead; i fa' plurality'z'of :combustion'nii i in saidhead, a plurality of mixture distributing chambers in spaced-apart relation on said head, a plurality of exhaust passages in said head, each of said distributing. chambers 'being remote'from. r said1exhaust-zpassages andsubstantially opposite the mid-'point of 'a'group of adjacent combustion chambersand .a pluralityfof'. passages extending within said head from each of said distributing' chambersxto the :combustion chambersA in its Lcor responding group; fthei'oorf offeach of said passages :being substantiallyi horizontal outwardly. of

its combustion chamber anda-:upwardlyE inclinedf v adjacent' its `combustion:chamber;l ,f

11. In a cylinder-head foran-internalcombus tion vvengine,"an intake. system .comprising a plurality of'intake ports,^'a plurality#ofaspacedapart i mixture: distributing'*chambers-onrsaid fhead, -each chamberbeing'adjacenta groupfof :intake ports f andthaving asubStantially flatfiloorpa plurality v of passages1;leadingirom' eachy of 1 said-` chambers in generallylradial'.relationftofthe intake'ports in its corresponding grouppand ridgescnfthe -ioor of'. said:chamber:insubstantialalignment with juncI turer.off=adjacent:passagespy whereby :liquid .fuel collecting; on said floor .twill :be rguided intosaid paSSageSz 12; Inwa'cylinderffhead -forra sixt-cylinder inter nal combustion engine; six intake ports,4 a pair ofr mixture: `distributing :chambers: infspacedfapart- I relation on'cone .sida/of V'saidheadl@each -orsaidl chambers '.befing: v4 of inwardly: :aredshape/:andl l adjacent-the midpointof a group'of threeintakeportsf-threepassagesl leading `from each of said chambers vtoeach' 'ofthe intake-'ports inits corresponding group;v said? passages being. of Anearlyv equal-.length-fand': extending ein v'generally radial f relation within :saldi: cylinder ihead; and two ridges' on the vdoor of each.; offsaid chambers, said ridgesdiuerginginwardlyfand-each'ridge being in substantialr-alignment: with-.thef-juncture of adjacent passages.

13; In' an engine: headfon a multicylinder... internals-combustion engine,.fa plurality .of .intake portsandexhaust ports, a plurality'. of.. mixture distributing -..chambers..in .longitudinally spaced relation. on one.side.ofl.said engine head, each of said. distributingy chambers,y being disposed substantially..opposite.. thef.midpoi11t .of a group of intakeports,.intakepassages connecting each of said 'intake ports to its corresponding distributing chamber, exhaust passages leading from each of said exhaust ports to the opposite side of the engine head, said exhaust passages comprising a pluralitj7 of groups, each group extending in generally converging fashion from a group of adjacent exhaust ports, an exhaust chamber formed at the juncture of each of said groups of exhaust passages, said exhaust chambers being in spacedapart relation, and outlets on said exhaust chambers adapted to feed exhaust gases into a common header.

1li. In a cylinder head for a six-cylinder internal-combustion engine, six intake ports, a pair of mixture distributing chambers in spacedapart relation on one side of said head, each of said chambers being of inwardly flared shape and adjacent the midpoint of a group of three intake ports/three passages leading from each of said chambers to each of the intake ports in its corresponding group, said passages being of near- 10 ly equal length and extending in generally radial relation within said cylinder head, and tWo ridges on the floor of each of said chambers, said ridges dii/erging inwardly and each ridge being in substantial alignment with the juncture of adjacent passages, the cross-sectional area of each of said passages gradually decreasing and then increasing toward its corresponding intake port, Whereby said passages form venturis for the mixture ow.

ROBERT P. ERNEST.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,464,466 Church Aug. 7, 1923 1,656,051 Fekete Jan. 10, 1928 1,828,774 Godward Oct 27, 1931 1,842,771 Timian Jan. 26, 1932 2,085,818 Messinger July 6, 1937

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