US2327727A - Baker's band oven - Google Patents

Description

Aug. 24, 1943. K. D. LOOSE ETIAL 2,327,727

BAKERS BAND OVEN l Filed July 1 9, 1940 s sheets-sheet 1 INVENTO ATTORNEY Aug. 24, 1943.

K. D.v LOOSE ET AL BAKERS BAND OVEN NN@ \w SN Filed July 19, 1940 8 Sh eets-Sheet 2 l# EMME; i i 4 1 I f N w WN im" Inl @Mmmm was k Aug. 24, 1943. K. D. LoosE ET AL BAKERS BAND OVEN Filed July 19, 1940 8 SheetS-Sheefl 3 INVENTo S -r )www4 M24-a, w ATTORNEY Aug. 24, 1943.

K. D. LoosE ET AL 2,327,727

BAKERS BAND OVEN Filed July 19, 1940 8 Sheets-Shet 4 l VENTO Aug. 2-4, 1943.

K. D. LOOSE-UAL BAKERS BAND OVEN 8 Sheets-Sheet 5 Filed July 19, 1949 K. D. LQOSE ET AL 2,327,727

BAKERAS B AND OVEN Filed July 19, 1940 8 Sheets-Sheet 6 im mw ATTOR Aug. 24, 1943.'

Filed July 19, 1940 8 sheets-sheetl 7 Wb E f E 1w .V m f hwk www@ P RMC? Q W E L u... S i 1 a K. D. LOOSE ETAL l BAKERS BAND OVEN Aug. 24, 1943. y

Aug. 24, 1943.

K. D. LoosE ET AL BAKERS BAND OVEN a lSmeets-sheet 8' Filed July 19, 1940 Fisio;

Patented Aug. 24, 1943 s ATENT OFFICE i BAKERs BAND' OVEN Kenneth D. Loose, Bronxville, N.`Y., and Charles W. Watkins, Dayton.v Ohio, assignors to Loose- Wiles Biscuit Company, a corporation of New York Application `lllly 19, 1940, Serial No. 346,304

'8 Claims.

The invention relates to band ovens for baking biscuits, cookies and the like, though without limitation to any particular 4baked product, its general objects being' to accomplish the baking process continuously,` efficiently and at a high..

production rate.

In the drawings:

Fig. 1 is an elevation, and Fig. 1a a plan, of the feed end of the new open;

Fig. 2, an elevation Vand Fig. 2a a plan, of a portion of the central part thereof ;V

Fig. 3, an elevation, and Fig. 3a a plan, of the delivery end;

Fig. 4, a" larger scale side elevation of the drive head;

struction; Y

Fig. '7 is a side elevation of the feed end; Fig. 8,- a plan thereof Fig'.` 9, a longitudinal vertical section of a porf tion of the tunnel jnear the feed end;

Fig. 10, a plan thereof;

Fig. 1l, a cross section" on line XI`XI of Fig.. 1;

Fig. 12, a cross section Fig. 1; y l

Fig. 13 is a cross section of aportion `of the tunnel wall illustrating itslaminated construction; l l

Fig. 14 is a crosssection on line XIV-XW of en? une' XII- Xn of Fig. V1.5 Fig. 14;

Vis a cross section online XV-XV of Fig. 17- is a cross section on `line XVII- XVII Fig. 18 is a longitudinalsection of the baking compartment section at the feed end of a band oven having 'a modified form of heat application; Fig. 19 is a topl plan view thereof, `partially broken out;V 1

Fig. 20 is across sectionV on line XX-XX of Fg.l9; Fig. 21 is a' section on line XXI--XXI ofFig. 19;and

Fig. 22 is a lcross section fon line XXII-XXII -of Fig. 19.

The oven proper consists of a baking chamber i inthe form of a tunnel `built of similar successive tunnel sections l supported in the upper parts of a series of upright external metal frames 2 rising from any suitable foundation' which however does not require to be a massive foundation as usual because the .weight per foot is well Figs. 5 and 6 are details of the burner con- Within ordinary factory floor load limits as later made apparent. These sections are. conveniently about 8 feet long, and inthe aggregate make a tunnel more than 100 and desirably about 500 feet long which is much longer than hitherto considered possible for band ovens. The ,space below the floor of the tunnel is closediin by a series vofpanels 3, of insulating material referred to below.

The Vendlessbaking band t is trained over a head or driving drum 5 at the delivery. end of I v the tunnel and a tail or take-up drum 6 .at the dough-receiving or feeding end. Its upper run Vpasses through the tunnel while its return run passes through the enclosed space under the tunnel, being suitably supported Ialong the length of both runsas later described. This band is shown as an imperforate endless steel sheet approxi mating 32" `in width and .048 in thickness in the present. case and is sufficiently exible to be practicable for use on drums of reasonably small diameter as indicated' but within the term band isincluded also woven-wire bands and any other conveyor suitable for supporting dough while baking. The direction of its travel is indicated by arrows.

The tail `drum 6 (Figs. 7 and 8) is a tension and take-up drum, being arranged'tokeep an appropriate and constant tension on the band at all times While also accommodating its very considerablechange of length due to temperature "change, a matter of `3 feet or more according to circumstances.` For this purpose, the drum is journalled in a wheeled truck 'l running onrails 8 secured to the tops of two main girders 9 which constitute part of the feed-end framework of the tunnel rigidly aligned with it. The truck is subject to the pull of a twin cable l0 supporting a suitable weightas the vmeans of applying the tension and the drum bearings ll on the truck arc adjustable by means of the set-bolts indicated `so that the angle of the drum axlecan be minutely changed as required to counteract any tendency for the band to work itself toward one side or other lof its proper course. This adjustment is made secure by givingthe truck a long wheel base on its rails and by using flanged Wheels l2 which fit the rails snugly thus to prohibit any lateral movement of the truck on the rails and insure that the closely adjusted angle given to thek drum will continue permanent as the length of the band changes under varyingtemperature.

The drum truck carries a clearer for the inner face of the band in the form of a plough I3 resiliently supported in` any suitable way, the

purpose of which is to clear the band of any foreign matter or object which might interfere with traction or injure the band if caught between it and the drum. The method of suspension comprises two spring-containing links I4 (Fig. 16) hung from the truck to carry the wide end of the ploughand Aa front link I5, also including a spring, to carryfthe apex of the plough. This link is hung from a cross yoke I6 supported in part by the links I II and by rollers II which run on the interior flanges of the side girders 9.

The tail drum B is also furnished with 1a do'c' 'tor knife I8 to keep it clean. This is carried on the xed arms I9 and provided with a trough 20 to catch the scrapings,

The working run of the band within theI oven tunnel rests on and is driven by the upper runs of a system of parallel endless steel cables or wire ropes 2| which carry the heavy vertical load and the driving tension. rIhese cables are trained 'over a set-offdrivefsheavesS22 at the 'de- 'liveryi'end and over fai/:corresponding set'of takeup :and itensioning :tail sheaves 23 yat the :feed

verdiA and v their 'return r'run's pass below the "tunfnel'whereithey are supported by a'number of intermediate sheaves lor Vcarriers zpresently revferred to. The Whole i system risflocated within `the ic'onnesfo'f the bandabetween 'its yuriner Yand lower runs, and the upper runs of thepables form.-falsupport for the :band which ispo-extensive with nearly its full length -an"d=on which the upperlbandrun rests withno otherthan 'frictional connection with it.

Yv-Theeable tail :sheaves Af2'3 arev--journalled-side byiside; 'but'ieach' independently of the others-in `a pair oifslipperblo'cks 24fwhich-areuconnned to slide in or 'between l:the Y; opposing channels ofl parallel I-.beams -125 (Fig. jl'lythe llatter being part'loftlie feed-'end frameworkgcarriedcn lthe sidefrgirderSFB; The two 'blocksforjeachrslieave "areeonnectedfbyfa yoke 26 to a 'weighted --ten- 'sion cable' 2'I 'which is `guided around-thef edges ofithe l lower"stretch of 'the bandg'byf appropriate f'cornerpulleys sothatthe Weights-.29v can-hang 1.below -Iandf at the -sid'e -ofwthe vfeed-end 'frarnework. i y

'The intermediate carrier `sheaves'faleove ire- `ierred toiare marked 30, andfoccur 'in setsfatappropriate intervals valong the tunnel,y preferably `one -set 'for eachlof-fthe (8- foot) sections. The sheaveseof' ea'ch setare kfast on -a-Xles 3| which extend-across ythe tunnel andthrough the thickness'of the tunnel `'walls to their bear-ings `v32 (-Fig..12)which 'arefplaced on the outsideof the wall.

'I'hefreturnmuns of thefc'ables lare vcarried'on -the tunnel '-'o'or 'but at'the same time fs'etizhigh enough ysofthat they are more pr less y'positively driven by the cables. Thus rdriven *t'hey 'are *'geiare'drby; sprocketl chains 35 to :drive kthercross shafts "36, .journalled :just below them, which llatter. areprovide'd with roll bosses A-r3I and support ,thereturnstretch :of the :band helping it mission 3I"from`-an electricm'otorfiiil fandy these foreroutofthe way orwhatever means may be V'employed for Y'removing the 4.baked goods.

" With the construction described, vall'the guidthe tunnel.

ance needed to keep the long, flexible and high speed band running true on the cable system can be accomplished by one, or at the most two, so-called automatic belt-a-ligners. These are well known devices indicated conventionally at 4I in Fig, 3. They can be placed outside of the oven and therefore belubricated and they work with minimum friction on the band.

The baking) heat is applied by acurrent of hot combustion gases owing longitudinally through In the case of the oven shown in Figs-1417, which is gas-fired, the current of hot gas lis derived from a series of gas burners 42 of aitype not heretofore used in band ovens. These burners' are supplied with fuel-gas and air, both under slight pressure, to form a mixture which burns from` the flaring nozzles 43 of which there By reason of the supply pressure, and principally by reason of the expansion in the nozzles, the names are pro- Ijected several' inhe'si'fromithel burner orifices', on :Which account thel'burnersv fareproperly termed v.blasttype They are arranged' 'crosswisef of :the itunneLwith @one four-:nozzle burner above the baridfarid onelve-nozzle burner belowthevband in each tunnel section, all proiiectingxtheir flames horizontally and in the saine direction, so that .in theaggregate they create, bythefefect of their own energyfa'iturbulent'fbaking,current of considerable :horizontal v4velocity, "counter to the direction' of ybairdtravel;

Fuel-gas and air'are supplied tothe'burne'rs 42 by a pipe system, designated generally bythefref- -erence Mpwhich takes 'itsfgas vand Yair fromithe manifolds 45 and 46 respectively mounted on--top `of thetunnel-andwillbe understood to have all the necessary and proper mixing andV regulatory adjuncts,'inc1uding thermostatical-ly governed valve mechanism 44a subjectzto control fby thermostatic bulb elements vrMtbrlocated inside "the tunnel (Fig. ll2) y, the;J purpose rbeing; to' maintain automatically constant,1preselected rates orheat transfer'to the goods. 1

The fuel system includes also system (see Fig. 6) represented -by themanifold tubes 41, one of which is common to all :of-the nozzles ofi, each burners and suppliedzwith a--spark ,plug-48-to ignite-afspecial-explosive fuel mixture supplied to it through a pipe line 49. The coursethrough the ,baking -tunneli-is'divided into a series of compartments each*l about 32 `reetY long,; or otherwise as desired, iand each of which can thus be separately controlled asto "temperature-according tothe requirements ofthe sort of goods to be baked, that is to; say, each, Ymay have'its -own thermostat (44h) controlling the temperature therein according to thedes'ired rpi'dgressof the bakirigaction. These compartments are des'ira'bly separated from eachother by interior baffles for" partitions'such as' indicated A'at F501 in Fig. `9. Theupper section Jof eachA partition includes a series of hinged a'ps '51 '('see 'Figfll whichhang toward the' top 'oftheband and at its sides, and these are so mountedthat they may all'be' rockedv to an? `opentposition when desired by turning the shaft 52 by means'oits exterior`crank 53 also shown inFig. 14, thereby enlarging the communication betweeiradjacent compartments. Y

"Each tunnel compartment .is provided with fan exhaust' Aoutlet 54fby which steamfzgases Ifrom of"a`fanz=56 (Fig. L2") "letsare located at ithe ifeed 'ends lf .thezcompa'rt- 'the goods drawnfto ran'dproducts of 'combustion are `withthe exhaust manifold' 55 'by the fsuc'tio'n "andi in eachf 'case "these .o'uta pilot ignition y Tasa/9,727 Y respective of the partitions 50, it `may ber'ioted that this distributionof the exhaustfoutletsnaturally divides the' tunnelinto baking compartments in which the baking conditions as .to heat `and moisture can be individually controlled.

As customary in band ovens the entrance and i eXitldoor-ways at lthe ends' of thev tunnel, are protected by exhaust hoods 58 and 59 connected to the ends of the exhaust manifold', so that combustion gases do not escape into the buildn The baking tunnel is constructed of floor panels resting on longitudinal sills secured tothe frame uprights 2, side-wall panels rising from the floor panels within the uprights, androof panels spanning the side walls. The nature of the material used to form these panels exercises .animportant inuence on' the operation of the oven as presently explained. Each panel is laminated of ilat slabs 6l), cast of wet cernentitious material which has been aeratedbefore'setting so that it sets as a porous, light and rigid'slab and has suilicient strength to serve as a structural building element. Specifically the preferred material is a gypsum plaster slab of which several types' are to be had, that known as'marinite being the one preferred.` A wall thickness of six one-inch slabs of this material` is used for the side walls and roof, and four suffice for the floor, the space below the tunnel being enclosed as before stated. Baking temperatures are in the order of 500`GO 1'". and theytemperature in the under-tunnel `space runs at about"350 F. A marinite slab 3 is desirably used as the floor of this space to insulate it from the building oor as shown in Fig. l2.`

The tunnel shown is internally lined, more particularlyas protection against possible mecharncalfinjury,` by thinner (1/2") slabs or sheets 5I of a generally similar cementitious but harder material, V*specifically a building wall element'v known as transite, which gives the tunnel'wall a smooth surface, light gray incolorj The `junctions between sheets are covered with battens and other bodies therein,` such heat as is received by the metal band passing by conduction through the latterto the dough. Heretofore radiant heat has been chiefiy relied on for the baking effect in nbandovens, the radiation being from the walls l and from numerous burners or other heating elev ments located'` along the length of the oven.

"The relative suppression of radiant transfer `affordsthe important advantage of a closer relation between'the rate of fuel supply and the thermo-chemical -change that constitutes baking. It permits a nicety of regulation ofthe baking process,` whether performed manually or automatically, that avoids a wastage of product that otherwise might be prohibitive in ovens -ofv such large capacity, and incidentally it makes' for better baking; also it quite effectually eliminates the tendency for the goods to over-bake along the margins of the band from the radiant side- Wall heat andltherefore it does away completely with the need for marginal shields or otherpro tectors for the goods such as have been heretofore resorted tolin the effort to secure an even bake across the band.

According to the thermal law, the rate of heat transfer from hot gases to other objects is pro-- portional to the relative velocity of the gas with respect `tosuch objects, and therefore in the present case the convection transfer ofr heat to the goods occurs at a high rate because the rela- .c tive velocity is high, being' the sum of the gas 52 of the same material and short corner braces 62a are used in the center of each section to hold the panels together.

It will be understood that the several panels are appropriately mounted in the framingwith thenecessary clearances to permit their thermal expansion harmlessly; v`also the individual `laminations of each panel arerheld together so that any differences in their individual expansions will not warp the panel. This is done by localizing the uniting bolts (not'shown) at the midportions of the panels, as will fbe Luide'rstood. Thus constructed, it is to be noted thatno metal is present in the tunnel walls except for the small corner brackets 62au and such bolts as unite the laminations. The opening in the l,roof

shown at b2b in Fig. 9 is an explosionvent nor` mally lightly closed. Inspection windows are also provided at appropriate intervals.

In such an oven as above described., heat transfer to the dough carried on the band occurs principally by convection and conduction, and to only l a minor degree by radiation; that is to say, most of the heat units required for baking arecarried to the dough directly by the stream` of hot gas Viiowing in the tunnel in contact withv it rather than by radiation from the walls of the tunnel velocity plus'that of `the band speed, the latter being in the order of feet or more per minute. An'optimum condition for convection transfer to the goods is thus established.

Since all bodies have the property of radiating heat :it is hotpossible' entirel'yto eliminate the radiant effect in band ovens. The oven walls and other parts,-pa rticularly metal parts in the tunnel, being also swept by the het gases, nece# sarily receive and accumulateheat some of which is radiated to the goods but,V in the present case,

thegvvallsfare" swept by a less relative velocity of gases than the band anddough (by the amount of f the band speed) andare therefore less favorably `disposed for taking up heat and vtherefore rela tivelyv lessactive as heat-delivering surfaces. By

taking advantage `of the lvelocity relation, we have found that the radiantubaking effect can be reduced to such extent, relatively to the amount of baking heat transferred by convection and band conduction, as to make itsinuence unobjection able from the point of view of baking control.

While this is `largely the effect of the high relative 'gas velocity, the character of the material of which the tunnel walls are composed is also of great importance. Besides having good insulating properties, in order to reduce heat wastage, the wall material should be of low Weight and density and have a low heat capacity because r`bodies of. j such properties have also low heatradiating eifect under band-oven conditions. i

The wallslabs of aerated plaster compound above referred to are selected on this basis since they are not only good insulators but are of low density and very low heat capacity being also Y very light. They Weigh in the order of less than 50 lbs. per cubic foot. This is much lighterthan fire-brick, building-brick, or even those flocculent orr granular ,insulating materials commonly used Yas )insulating filling between metal easement panels. vBesides which these, slabshave the ad vantage that their strength and rigidity, as already pointed out,`enable the tunnel walls,`in

` cluding the roof, to be built of them exclusively ipitoperty.

`with :the use ofilittle f. Orino metal, etherelby .zproducing asurronnding enclosure for the baking iband having .the .least .possible Eheat-ratdi'ating To l:the .sam-e "..end J of v:minimizing the rhea-t capacity .or radiant baking zeiiect, vall "those metal. parts insidethe tunnel @that are incidentto the vtransport ofthe goods through-itgas :Well as those parts which concern `the :distribution andilow of 'the `.combustion gasesfare :madeaslow in .total -mass .as consistent withftheir proper functioning.

iIn prior structures, when :adjustment :is made to reduce oventemperatureftherinterioremetal parts act assourcesof heat-.and .dela-y the change, and conversely, whenit is :sought to raise the oven temperature, they nabsorb 'heat :and delay the effect, thereby imposing Ka .time lag in temperature change which greatlyinterferes With the maintenance of constant temperature, and renders impractical theuse ofst'hermosta'ticregulators for that purpose. yIn the new oven, on the other hand, having practically fno linterior WallmetaL and in'which the dough issurrounded only by Walls of light Weight and loW density and heat capacityfthe time lag yis minimized yto 4a .degree that-is negligible and thermal regulation 'is thus '.m'ade Vso effective lthat .-thegprogress ofA thebaking L65 of afan-'65, d-rivenby a-motor-'l, whence .they

are discharged at a selected temperatureinto .a longitudinal -flue above the tunnel having branched flues-58 leading downzthe sides of the tunnel-with outlets into the tunnel respectively above and bel-ow the baking band .and on both sides. The upper flue loutlets 16-9 ,pass the hot gases, .under .appropriate damper regulation, as indicated, into an internal duct llllsuspended from vthe tunnel lroof Yand .extending not more than-about half the length .of the particularbaking compartment. This yduct can bemade of lightzsheet metal if desired in which case its Wall vthickness :Will be considerably thinner: than 'indicated in rthe drawings. In any case its heat capacity is low. `Its floor-.is provided with many holes -Tl (Fig. .119) and occasional deflectors "I2 slanted toward the holes.

The lower outlets '-13 (Fig. v20), from vthe 'branched vilues `t, pass lthe combustion gases,

lalso under appropriate damper control, into a similar lower internal duct lI4 mounted on the oor of the tunnel.

The upper andlower ducts, l0 and 114, are provided with damper-controlled outlets,'l5, attheir `far ends, adjustable from outside the tunnel, and it'will be recognized that the purpose of this construction is to admitthe gas-how, so that it will not have too violent impact on the goods at its ,point of entry or tend to concentrate its 'heating eiectatany ,particular locality while at the same time producing .the adequate longitudinal gas vvelocity Which,as before, is at a high rate yand preferably .counter to Ytheband travel. '.Byv means :of the'dampers15 theveloci-tyinthetwo cndsmf a compartmentgcan-be adjusted.

The .gases ,leavethe Icompartment yby :the Aouty .let 16 which is represented. in-the present case 'by-three laterally separatedhoods 1:5 let'into-the tunnelv roof v.and leading :through .a single return `Hue 17,on lthe ftunneltop ,back to the place of combustionv orburner- 63. Thereis .thus .a closed combustion ycircuit, 4including vthe tunnel compartment-and enough air ,as-may vbe required for ,combustion is.deliv.ered into this vcircuit 'bythe fan-64, while .a vconstant excess of tunnel gases,

steam, etc.,l is' being .evacuated'thrcugh `,the suc-` tion exhaust outlets 54 and manifold 55.

As in the internally-fired oven, the positions .en 4the tunnelv ofthe-several inlet and Iexhaust ducts divide itinto a series of baking compartments in which different baking vconditions can be maintained, yasrequired, and. automatically if desired by means =of thermostatic control fas -already -described, partitions (50) beingpresent as before. The vthermostat control is not indicated-in :these .gures 'but may-be the same vasali-'.eady.described and works withthe same quickness. of 'control of the heat input to the goods and for the same reason.

The Itunnel Walls .will rbe v.understood to'befof the same light weight and lowv heatcapacityas above described and -it maybe stated that the interior distributing ducts, lwhen mader of -metaL do no-tsadd appreCiabl-yvtothe ytotal m-assfof exposed metal per tunnel foot, sincejhey arefin substitution for the metal `buinerand pilot system used asrthe heat sourcein the-gas-red oven and not used in thisfform. The thermal characteristics are therefore -the same 4as in ,the gasred form andare such as to :insure that the baking occurs mainly by convection and'least by radiation and Vtherefore with the ,advantages above pointed out.

It will be understood that.immunthe.principlesv above explained, Yband ovens `can be constructed in many variant lforms .andoi' .any length re'- .quired and that.there.isno-intendedlimitation to' -either of the formsherein .used for exemplicagether in a suicient number of laminations tov form panels of requisite structural strength to .serve as horizontal wall sections yspanning the `opposingside walls and .as vertical side Wall sectionsrfor carrying theload of thehorizontal secn tions.

said tunnel .counter to the direction ,of `band travel.

3. A 'band oven divided into a series of successive compartments .each having a combustion system for circulating hot l.combustion ,products from an exterior source through any inlet at one end thereof and out of an outlet at the other end, the walls of such compartments being of material of low thermal capacity as compared to ordinary building brick or metal-lined Walls and the direction of ow of said products through said compartments being longitudinal thereof and at high velocity to cause the transfer of heat to the goods on the band to occur mainly by convection and least by radiation.

4. A band oven divided into a series of successive compartments each having a combustionsystem for circulating hot combustion products from an exterior source through an inlet at one end thereof and out of an outlet at therother end, the direction of flow of said products through all said compartments being the same and `counter to the direction of band travel.

5. A bakers band oven comprising, a baking tunnel formed of materials of relatively low thermal capacity, as compared with ordinarybuilding brick or metal lined walls, means for propelling gas at baking temperature through the length of said tunnel counter to the direction of travel of the working stretch of said band above, below and at the sides thereof, and in contact therewith, the velocity of the working stretch of the band being such as to cause heat transfer to the goods to occur mainly by convection and least by radiation.

6. In a band oven the improvement which consists n a combustion system comprising a series of blast-type burners set at intervals along the lengthof and within the baking tunnel above and below the baking band therein, projecting their flames horizontally and in the same direction.

'7.- In a band oven a baking tunnel having a series of exhaust outletslspaced along the length of the tunnel and a series of longitudinally spaced blast-type burners directed in the same direction within the tunnel and creating longitudinal gas flow through the spaces between the outlets.

8. In a band oven, the improvement which consists in a combustion system comprising a series of blast-type burners set at intervals along the length of and Within the baking tunnel above and below the baking band therein,` projecting their flames horizontally and in the same direction so as to form a longitudinal turbulent; gas flow, the tunnel Walls being composed of material of low thermal capacity as compared to ordinary -building brick or metal-lined Walls, Whereby the goods on the band receive heat predominantly by convection and least by'radiation.

KENNETH D. LOOSE.

CHARLES W. WATKINS.

CERTIFICATE oF CORRECTION.

Patent No. 2,527,727. August 2LT, 1915.

KENNETH D. LOOSE, ET AL.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page b, second column, line 68, claim 2, for "or less read --of 1ess; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 12th day of October, A. D. 1915 Henry Van Arsdale,

(Seal) Acting Commissioner of Patents

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