US1469158A - Draft regulator - Google Patents

Description

5 M 9 A, E E N E E K L w Sept. 25,, 1923.

DRAFT REGULATOR 3 Sheets-Sheet 1 Filed Feb. 5, 1921 Qfioma-foz William L'Keene Sept v.25, i923.

DRAFT REGULATOR Filed Feb. 5, 1921 w. L. KEENE 3 Sheets-Shet 2 William LKeene 5 Sheets-Sheet 5 Filed Feb. 5, 1921 swam V600 WiHiaYriL-Keene.

Patented Sept. 25, 1923. Y r V UNETED STATEE @E itFlfiE,

WILLIAM L. KEENE, F WATERVILLE, MAINE;

RAFT 7 REGULATOR.

Application filed Febr'uary 3, 1921. Serial no. 442,178.;

To all whom it may concern: similar reference characters indicate similar 7 50 Be it known that 1,.WILLIAM L. Knenn, parts, 7 a citlzen of the United States, residing at Flgure 1 15 an elevation ofmy device,

Waterville, in the county of Kennebeo and showing the parts in onepof their operative State of Maine, have invented certain new posltions, the relative position thereof in a" and useful limprovementsv in Draft Reguheatingsystem being shown in Figure 6,

lator's, of which the following is a specifi- Figure 2, a'plan of the same, certain porcation. tions being omitted, I My said invention relates to a draftregu- Figure 3, a detail of acircuit breaker and lator for controlling the fire used in operatstop,

ing steam generators, thus determining the Figures 4 and 5 are details of parts shown 60 steam pressure in such generators and reguin Figures 1 and 2, and I g lating the heat given off by them in opera- Figure'6, an elevationshowing the devicetion. Such draft regulators are peculiarly in its relation to a furnace.

adapted for use in connectionwith steam or in the drawings reference character .10

hot water heating systems for dwellings, but indicates a furnaceof a steam or hot water 65 their utility is not limited thereto. heating system, which is connected to a It is an object of my invention to provide pressure operated device 11, here shown as a draft regulator which may be controlled of the diaphragm type to be operated by by the pressure of the steam but which is steam. In use any device which will produce 7 A' further object of my invention is "to 'perature;

operated by means preferably mechanical satisfactory 'results may be substituted 7 entirely independentof the steam pressure, "therefor. such for. instance that in which whereby a very small variation of pressure water actson a thermostatic tube to vary may operate to open or close the damper. the lengthof the same according to the temprovide a thermostat which may be con- 'A lever 12*is attached to the pressure dotrolled by the temperature of the air in a vice 11 in the usual way and this lever has room to be heated and which forms an auxilconnected thereto a rod 18- carrying, a series iary controlling means in'addition to the of collars 1e, 15 and 16. lhe rod is guided 30 pressure control heretofore mentioned. by an opening in the support A. and a 1 Another object of my invention is to probracket 17 projecting from'the" main frame vide means whereby the damper may be p I a closed when the steam. reaches the desired The operating mechanism for the damper pressure regardless of the temperature of 18 comprises a rock arm 19 mov ed in one the atmospherein rooms to be heated. In direction by alweight. 2Q, and in the other this way overheating of dwellings is preby a chain 21 connected to a crank 22 having vented. aplurality of openingsitherein" for adjust- Another object is to: provide a device of ment of the'chaini lhe crank 22 is mounted the character described in which the 0011- on a shaft 24 carrying at. its opposite end trolling mechanisms may beset so as to be-a crank 23 connected bya-chain 21 to theinoperative and when they are so set the'furnacedoor 23' and thisshafthas fixed v draft will be cut off. I 1 thereon a pinion 25 meshing with agear 26 A further object of my invention is to on ashaft 27; The shaft 27-has a sprocket] provide a device of this kind which can be gear 28 overwhichpa sses a sprocketv chain 45 operated either by the steam pressure alone 29 having'at oneend-a weight 30 'andjhaving I or by steam pressure and roomheat-coinnear the other end an adjustable stop '31 bined. i V which fmay take the form offa bolt passing Referring to the accompanying drawings through a link of the 'chain 29 and havingl which are made a part hereof whi h a nut threa edion one thereof. ,The

sprocket is'connected to the gear 26 by apawl 82 engaging" a ratchet 33 and intended to permit the sprocket to rotate freely in one direction. In this manner the sprocket is adapted to be driven in'one direction by the Weight 80- until its. limit of IIIOYlfIYl-Ei'lt 7 reached and the same may readily be re-set carries at its end a pin l lcomprising end portion or apiece about the shaft. 7

Adjacent the pin 44 is a pivoted armature in add lion rod 47 under pressure ofiits p iew 5:2 is

by a pull on the opposite end or" the chain. Adjacent the pinion a gear 8- is fixed to shait Q L-and this engages a pini on a shaft 36 which also carries a gear 37 engaging a pinion 38 on a shaft 39v Sha -ft 39 has a gear 40 meshing with a pinion 41 on a shaft 42, thelatter carrying a tan brake 43 of the usual type. All these shafts are ournaled in the frame workB and the shaft 4-2 projects through the frame work and the of SPIlIlg'WlIe weuno.

having a projecting portion forming a stop by means of which the armature acts as a detent to engage the pin to prevent re- A pair of electro tation of theshatt e2.

the armature in one direction and a red at pivoted at one end to the armatureis im pelled' in a direction to Withdraw the armature from the electro-magnets by a light spring located in cash :7 48. .The shaft 2% to ture out 0:? cngagementwith pin and'has a-not/ h adapts-ti to be en" I; to stop rotation. i the bu the weight'motor by engagement with the upper lever hav-ing a hook to enxhe-pin' and the lower lever caving an ed end portion-Rvhich the pin may e [The levers ailapi edito be held l'iGfiCli position where-"they may engage pin i:t'when the pro ection or riser on either lever. dropsv into ti'ielnetch' '51. on disk 51.

. at. to e titted outot 1-5 :projectlng tron'i the coliar tion by a p t al.

wardl y from.collarfil l into engagement wit lever-:53 .tolift the same' ifvhen vthe notches otdiskblarie properly POSl'DlOIlGQl 7 noperative position by the disk 51 but spring pres'sed pin i l extends un Lever 53 carries a spring which constitutes one member of a circuit closer, the other mei'nbcr being an adjustable bin 55 mounted in a bracket 56 on support- A. A second circuit breaker is located at one end of the frame and comprises a member 57 pivoted at 57 and contacting'with the head oi pin 58 said member having a handle 80. A slidable member 59 pivoted to the movable element 57 has at its turther end an en larged head with an upwardly extending portion 60 adapted to engage the lowerend ot' the armature and draw the detent d7 away from disk 49. I

At any convenient place, as onthe wall of a rooui to be heated is placed a thermostat comprising a base 61 carrying a thermostatic u'ieinber 62hai'ing a bent portion extending,

from its point of attachment to the base and terminatingin astraight portion. Near the end of the straight portion is a contact member having a head 64in alinement'with its pivot or varying its posit on, andcarrying a :-i(i]i]&li'i1'i screw (53- ior determining; the

limit to which the room temperature may fall. The member 62 is somade as to con tract when the tempo 'ature "tails Wherebyit may n she contact, with the adjusting screw 33. When this-thermostat is not/to be used k the circuit and retract the'armature. thcr circuit breaker is provided in juxtaposition to thesprocket chain and'com prises a lever 65 pivoted on an insulatedbolt 6 oi :onducting' material. and adapted .to

contact with another insulated bolt 67 "of Sili'illtll material on the frame. The lever 65 carries a pin 71 extending beneath a "pawl 72 also pivoted on screw 66. The rodG8eX- the circuit breaker at 57 may be operated to I tends ddwnward from lever 65 and carries at 1' Illa I movement of pin 71 j lowers the pawl 72 ,whi h. upon engagement with the notch in I disk 'Zdon shaft 24, stops the rotation of the various shafts of the device. This prevents overtravel of the chain whereby it might run the s n-ticket. and the interrupt on ot the circuit prerents waste ofCurrent. A wire 7 2 connects the screw 67 to one terminal of the room thermostat. A second wire 7 5 extends from screw 6': to Le screw 76v on the main me which supports at its otherendthe e r .This casin j is electricallyronneetcd codisk' l i) by-a-leat' spring 77. r

. ltdesired. I may provide. a latchQatTZ,

and the room thermostat 61 is shown in the V drawings andparticularly in Figure 1. In

this figure the current may pass from the batteryto the-roomv thermostat, thence by wire 74-,screw 67', pivoted "arm65, screwfio', wire 75, screw 76, casing 48, spring 77, and

disk-49 to shaft 24; and'from, this shaft, through disk 51 detent 53, spring 54, pin 55' and bracket '56 to WHQ'IS. From wire 78 current passes to electro-magnets- 46 thence to pin 58 and circuit closer 5t and back to the battery by wire 79. W 1th the parts in the position shown the damper-is closed and the furnace door which moves as the damper is also closed and the device is subject'to variations in room temperature and also to the action of pressure device 11- in the following manner; when the thermostat 11 draws the rod 13 down sufficiently-to close the circuit at 54 55 and with draw detent from notch 51, the shaft 24 becomes subject only to the electrical mechanism controlled by the room temperatureyii e., it is held from rotationby the detent on armature 45. Thedamper cannot be opened until the room temperature has fallen sufiiciently to close the circuit at'63 when the electromagnetwill be energized and will retract armature 45 and its detent, thus permitting the weight 30 to act as a motor to operate the shaft 42 through the train of gearing-untilnotch 51' comes in position for engagement by the riser on-detent 52,' i. e. until the shaft:24 has made a half reyolution and. the damper til the thermostatll raises the rod 13: i.

until thie temperature of the hot water heating system, or the temperature and pressure of the. steam'heating; system. or'likc coiitrolling feature has risen sufliciently'to actuate the thermostat as indicated; whereupon detent 52'is raised by pin 15 and the weight 'motor comes into action again to rotate the shaft 24 and close the damper, the 'disk 51 now holding the armature away 'lro m pin '44 by means of-r'od 47 and the circuit bein broken at 5.0. Rotation ceaseswhen-notch '51 comes: over the stop-lug ciifldetent 'w,

' detentis which is forced upward by'springpressed pin 14' and the end ofthedetent-now en-H gagesipin 44 ,to halt the-action of the weight 1 7 -motor..

VVhen detent 53 engages 44' disk 49 has revolved sotar that rod 47 is onthe verge of dropping into; the notch on the disk. VVhen' now the rod 13gfalls. due to decreasing steam pressure or the-like,J-sotaras to fremove-detent 53, it sin'iultaneously-permits 1 :shatt24 to-rotate until rod 47 falls-into its notch, orawingr armature 45 ll1tSO-POSltlOT] to engage, pin- 44aiid stop such rotation, and also closes the c rcuit of the statat 54, 55. This completes the cycle.

Assuming that the device to be oporiiti' by steam pressure alone the circuitinay be broken by actuation ofthe circuit-closer 57.

Thereupon, the dam-per being in its;close.-:i position, :as

.sho'wninFigur-e 1, will remain I so until the action-0i the pressure device 11 lowers the rod 13 due. to the lowered tenr room .tlierino- 'perature of tllQWELiIBl (or other-controlling condition) to such a degree. that the lever 53 falls so far as to'relea se the pin 44 troi'n disk 51 has rotated so far that the: leverr52 is permitted to fall bv' engagement of its lu f with notch '51 whereupon the pin 44- is;

caught by thehook on detent 52 and held I against rotation, the arm 22pointine down ward from sha t 24 and the damper 18 being in open position. The parts will'now stav in this relation while the fire builds up andthe steam pressure increases until the pin .15

lifts .detent 52 to, releasepin 44{w '-enth e weight 30' resume-s its operation and 'HTUS arm 22 to the position shown in" Figure 1.

lever being: actuated by the spring'pressed ;,7iii 14. to enter its lug ainthe'notch of disk 51'whereby'its outer end is po'sitionedto engage .the pin 44 and hold it until the pre sure device 11 again lowers-the rod 13. ":Tbe .lug of the detent which is out oi": acti on rides on the periphery of the disk 51 whereby-tho pin 44.w r i The-purpose ofthe spring pre sed pin14 isto providelost motion connection bet'\veen vice may be mentioned the fact that is not dependentonthe. steam pressure torfactuadctent with the movement oitv restrained from engaging the tion of thedampcrtthe weight motor being arranged to actuate the same positively and the steam pressure serving merelyto actuate iYlQ'Q'Q-I lllZG device which controls thenction of-the weightin otor; that since-it does not depend on steam pressure or water'heat' I or'the in temperature; that due to its construction.

"the damper will be closed when the device is put out of operation as an entirety, and

heat is sufficient whether the room tempera ture has by that time risen to the desired heightor not. 7 w V Various modifications of my device or of parts thereof will occur to those ski ledin the art, and I do not limit myself to the" precise form shown in the drawings, nor-to the particular use described, the scope of the invention being defined in the ,appended claims} 3 i As an exainple of such n'iodifications the thermostatic element inay consist of a rod "or tube projecting into the furnace itself or into the'fluid heated by the furnace, whether same be water or air. The thermostatic controllingineans may operate on a damper Wltl'lln the'smolre pipe or a check draft damper or it may operate on a valve controlling ingress of heated air, or steam or any device equivalent to any of the above meansf Various other motors; e.;g.,spring motors, maybe substituted for the weight motor shown. a

Having thus fully described my said invention what I ela-i'mas new and desire to secure by Letters Patent,'is:

1. In combination, a pressure controlled device, a rod extending upwardly therefrom,

a damper, arotary shaft tomove the damper,

a motor for rotating: the shaft, means. for

locking the shaft to hold the damper open [or closed comprising a pair of-detents and means on said upwardly extending rodfor moving said detents, substantially .as set forth.

2. In combination, a shaft, means tending torotate'thesame in one direction, a temper attire-controlling device connected to the shaft and adapted to be operated by rotation of the: shaft, means to lock the device and its.

driving means in a predetermined position, a disk on said shaft to hold saidjlocking means inoperative and a pressure controlled means co-operating with the disk'to control the locking means, substantially set forth.

In combination, a shaft, means tending to rotate the same in one direction, a temperature-controlled" device connected] to the shaft, means to lock theshaft in predeter- 'mined positions comprising a second shaft geared to the first, and having a finger extending therefrom ,':a pair of Jdetents adapted to engage the finger alternately, and meansto control the detentsincluding means a ttheaboil'er, substantially asjset' i with thedisli to control} the locking tached jfO forth. 7

' a, lnscombination, a shaft, means tending to rotate} the same n one'd1rect1'on; a'tem-- perature -controlling device connected to the shaft, means to lock the shaft in predetermined positions comprising. a second shaft geared to the first, and having a finger extending therefrom, a pluralityfof detents adapted to engage the finger alternately, and means on the first'shaft for holding the'detents out of engagementat predetermined times, substantially as set forth;

I 5. In combinat on, ashaft,meanstending to rotate the same, in one directiomt-a temiperaturerontrolling'device connected to the shaft, means to lock the shaft in predetermined. positions comprising a-second' shaft gearedto the first,rand having a finger extending therefrom, a plurality of "detent-s 'adaptedto engage the finger alternately,

means onthe first shaft for holding some of the dctents out of'engagement at predetermined times, and an 'electro-ma gnet,adapted y .85

to move one of the detents out ofengageinent'with the finger at another time, substantially 'as set forth. 5 1

6. In combination, a shaft, means tending to rotate thesame,zin one direction, atempei'ature-controlling device" connected to the shaft, means to lock the-shaftin predeteri'iiiiiedpositioiis coinprisng a second shaft geared to the first, and having a finger extending therefrom, a plurality of detents adapted to engage the finger alternately, an elect ic-magnet for disengaging one of Sitld detents from the finger, ,a thermostat for con.-

trollin its action and means connected to V the boiler whereby the remaining detents' may be released, substantially as set forth.

1n confibinat on, a shaft, meanstendiug to rotate the same in one direction, a'temperatnre-controlling device connected to the shaft, means tolock the shaft in predetermined positions comprising a; second shaft geared to the first, and having a finger e tending therefrom, a pair of deten s adapted to engage the finger alternately,means to control the detents including" a pressure operated device, a rod attached thereto and havingiaqfixed abutmei'it and a-yieldable abutment for engagement with the respective detents, and anotched disk on the first shaft adapted to co-act with said rod to control said detents, substantially as set forth. S. In combination, a shaft, means tending to rotate the same in'one direction, attemperatui;'e-controlling device connected to the shaft and adapted to be operated by rotation of'itlie shaft, a second shaft gearedto the first" and having a projecting pin, de-

tents to'en'gage said pin alternately to pie 7 vent'rotation of the shaft, a' disk onthe first shaft having a notch for alternately engaging projections on the respective detents, and apressure controlled device .co-o'peratmeans, siflbstatially as set'forth; V i V V 9 i o t n, sha trm ans; tendin to rotatethesame in onedire'ction, a tempen detents attire-controlling device connected to the shaft and adapted to be operated by rotation of'the sh: first medium co-operating with the disk to control the loclnng means;substantially as set forth. 7

10. in a heating system, a shaft, means tending to rotate the same in one direction, a temperatu-recontrolling device connected to the shaft and adapted to be operated by rotation of the shaft, a second-shaft geared "to the first, a plurality of locking means whereby said second shaft and its connected mechanism may be locked in predeterminedposit-ions, meanscontro'lled. from a source of heat for releasing the one of said locking means, and means controlled by the temperature of "a room for releasing another locking means, substantially as set forth.

'11.Incombination, a shaftfmeans tending to rotate the same in one direction, a temperature-controlling device connected to the shaft and adapted to be operated by rotation of'the shaft,'a second shaft geared to the first, means whereby said second shaft and its connected mechanism may be locked in predetermined positions, auxiliary looking means acting on said second shaft in "another POSllZlOIl and -temperature-controlledV means for releasing both sets of locking means, substantially as setforth.

12. 111 a. heating system, a snaft means tending to rotate the same in one direction,

a temperature-controlling device connected to the shaft and adapted to be opened fa'nd;

closedv by rotationof the shaft, a second shaft'geared to the first, a plurality of look ing means whereby sa d second shaft and 1ts connected mechanism 'may be locked in prodetermined positions, means controlled from a source of heat forreleasmg theone of locking means, an armature connected to the second locking means, and a thermostat electrically connected to. operate-said armature, substantially as set forth.

18. In combination a temperature controlling device and means to operate the same comprising a shaft, a finger thereon, a plurality of holding devices forthe finger. means to retract one of the holding devices comprising an electro-magne't, a thermostat in-circuit therewith, and means to move another holding means toward the finger and thereby, break said circuit, substantially as set forth.

14. In combination a temperature-controlling" device and means to operate the a second shaft geared to the same comprising a shaft, afinger themes,"

a detent to engage the finger, an electromagnet toret-ract the detent, a sprocket gear connected to'drive said shaft, a chain onthe sprocket, anweight on the chain, yieldable means to limit the movement of the chain by the weight,and a circuit breaker adapted to'be operated by said yieldable means to break the circuit of said electro-magnet, sub-" stantiallyas set forth.

' 15.111 combination, a temperature-controlling device, and means. to operate the same comprising a'weight motor, and a train of gear ng, means'for engaging a'shaft of said-gearing to stop the movement thereof,

means'to engage another shaft to lock the motor against rotat1on,'sa1d means, being,

normally held out ofopera'tive position and being restored toaction by said motor near, the limlt of its trave1, substant1ally as set forth.

16. A heating system comprising a tem-" aerature-controllin '"device 'a furnace and b 7 a I means for operating said devicecomprisin'g a thermostat adapted tobe placed in a room to be heated, and; a 'second thermostat c onnected to the furnace and adapted to operate the temperature controlling "device inde" pendently of the first thermostat, and means whereby the first thermostat be rendered inoperative, substantially as set forth.

'17. A heating system comprising a tem perature-controllingfdevice, a furnace, andf meansfor operating salddevice" comprismg a thermostat adapted {to be placed in a room to be heated, and a second thermostat connected-to the furnace and adapted to control said device in conjunctionwith' the first or independently thereof, substantially" asset forth. 1

18.111 a heating system, a furnace, a:-

damper, means for actuating the damper, meansto lock the damper in open or closed" position, a pressure device connected to the{' furnace, v mechanical. means connected to the pressure device for controlling the locking means, and means whereby the .pressuredevice may be'putoutof action, substantially asiset forthi" y '19. In a heating system, a furnace,'a

.damoer' means foract-uatincr the dam er. .L 7 b 1 means to lock' the damper in open or closed position, a pressure device, a vertically mov able rod connected to the pressure device for: controllingthe locking' means, arollar. on." the rod and means to hold the rod inclevatedposition whereby th'e'damper controlqling mechanism is rendered inoperative, sub stantially' as set forth.

2 0. In: a heating system, a furnace, a damper, means for actuating the damper comprising rotating shaft, a pair of 'de tents adapted to engage the shaft in alteration to lockthe damper in open or closed position, a pressure controlling devlce connected to the furnace, a rod on the pressuredevice adapted to release the detents from saidshaft and means 'Whereby the rod may be held in inoperative position, such means permitting the damper actuating mechanism to close the damper, substantially "as set forth. 7 i

21 In a heating system, 7 a furnace, damper, means for actuating the damper, a plurality of detents to lock the damper 1n predetermined positions, a room thermostat,

an electro-magnet controlled thereby for re leasing one of said detents, a furnace pressure device, a rod actuated bythe pressure device for controllingthe remaining detents, means for locking sald rod 1n inoperative positioniwhereby said rod also breaks the circuit of-said electro-magnet and permits the damper actuating means to' close the damper, substantially as set forth.

. 22. In combination, a temperature con: j trolling device and means to'operate the same. comprising a shaft,a finger thereon,

means for holding the finger against rota- ,tion, an electro-magnet for retracting said holding means and a circuit closer adapted to deenergize said electromagnet and simultaneously Withdraw. the holding means, substantially as set'forth. V p 7 p 28. in a heating system, a furnace, .a damper, means for actuating the damper andvthe furnace door, means to lock the damper and thefurnace door in open or closedip osition, pressure controlled device connected to the furnace, means connected to,

J the pressure device for controlling the lock-' ing means, and meanswvhereby thethermostat may, be ,put out of action substantially as set forth.

24:. ln'a'heating system, a furnace, a damper, means for actuating the; damper V and. the furnace" door, means to lock the damper and the. furnace door in open or closed/position, a thermostat, a vertically movable rod connected to the thermostat for controlling the lock ng means, a collar on the :rodand means to hold the rod in elevated QQSlUOIl av-hereby. the controlling means for the damperand the furnace door is rendered inoperat ve.

. 25 111221, heating system, a draft regulating device, mechanical means "for opening and'closing said device, connected to the furnace for normally controlling said mechanical means, a room thermostat supplementing the action oft-he second said means to prevent openingof the draft until the room temperature falls to a predetermined extent, an electric circuit for the room thermostat, and meansactuated by the firstnamed thermostat for making and breaking saidcircuit, substantially as set forth. v

26. In a heating system, a furnace, a draft regulating'device thereon, and means gov= erning said devicecomprising a rotary shaft memes connected to; the draft controlling device, a eight motor for rotating the shaft, temperature-controlled means to put the motor into and out of action, andmeans to engage the shaft to stop the operation of the controlling devices with the draft off as the Weight motor approaches its limit of action, substantially as set forth. h '27. A heating system comprising a furnace, draft regulating 'means' therefor, a

its. 'n otor for operating said draft regulating moans, means controlled by the heating medrum to govern themotor, temperature con trolled means adapted to look the motor 'Whereby the motor cannot operate to increase the draft until; acted upon by the,

temperature controlled means, substantially as set forth. 5

28.1 1 heating system comprising a fur 'nace, a damper, a motor for opening an d closing the damper and the furnace door, means connectedto the furnace to mechanically operate to cause the motor to close the damper, 7 temperature controlled means adapted to lock the motor; in such position whereby the'motor cannot;operatetoopen the damper until acted upon by the tem- 1 perature controlled means,substantially as nace a damper a motor for openin and.v

7 .L n b closing't-he damper and the furnace door, temperature} controlling device, pressure controlled means connected mechan-ically to the furnace and the motor "whereby" upon :reaching a predetermined pressure the said pressurecontrolled means alsoopera-ting the motor-to place the motor entirely under-the. control of the temperature controlling device when, and only vvhen thepressurehas dropped to a predetermined point, said tern perature controlling] devicethen. "being adapted to operate the motor to openithe" furnace .door and ainper,substantially as 1 set forth. c

' 31. A heating system comprising.a rurnace, a damperya motor for opening and closing the damper and the furnace door, a temperature controlling device, pressurecontrolled means connected inechanioal'ly to the furnace and the motor whereby upon. reaching :a predetermined pressurethe said pressure controlled means also operating the motor to lace the motor entirely under the.

control'of the temperature controlling device When and only when the pressure has dropped to a predetermined point, said tem- In Witness whereof, I have hereunto set perature controlling device then being my hand and seal at vVaterville, Maine, this 10 adapted to operate the motorto open the twenty-fifth day of January, A. D.'ninefurnace door and damper, and means Whereteen hundred and twenty-one.

by the temperature controlling device may YVILLIAM L.-KEENE. [1,. s.]

be eliminated leaving the motor at all times Witnesses: under the control of the pressure control- ALLISONCHOATE NIoKERsoN,

ling means, substantially as set forth. WELLINGTON A. BLAIR.

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