US923783A - Automatic furnace-regulator. - Google Patents

Description

M. J. & H. B. FARQUHAR. AUTOMATIC FURNACE REGULATOR.

APPLICATION rum) JAN. 30,1905.

3 7 3 V Patented June 1,1909.

I Specification otLetteraPatent.

STATES 1?ATEN T OFFICE. MILTON J. FAR I-JH-ar. AND; HENRY B. FARQUHAR, or WILMINGTON,

DIRECT 'AND MIESNE ASSIGNMENTS, TO nun .MINGTQN, 01110,; ooRPoaAmo in10.

' 1 j awom'mc runnacnmnem'ron.

FARQUHQIFL FURNACECOMPANY, OF WIL- Patented June 1, 1909.

OHIO, ASSIGNORS, BY

Oflxinal implication flledilarelr i b, 1902,8erla1 No; 98 ,:445. D1v1ded and thls appltcaflon flied {mumv.80, 1905.

v v s m aagaasa,

To all whm'tmiytmm:

residing at .Wilcounty of of Ohio, have inventedcertain new and useful Improvements in Automatic Furnace- I applied to a furnace aforesaid application Re ulators' foll heat regulatin ciples' explained, or

and we do hereby declare the owing to be, a full, clear, and exact descript-ion of the invention, such as will enable others skilled in the art to which it appertains to make and use the same. v This invention (for which the resent-application is filed as a division 0 our pendmg application Serial No 98445, filed March Hot air furnace relates to furnaces, in

'clusive also of stoves or similar heating a paratus,

and more particularly to automatic mechanism for rendering the furnace or re-box self-regulating.

The invention embraces a novel reliable heat-governor operated by the expansion and contraction of the fire-box; the object of which is to effectively control automatically the temperature of the fire-box and regulate the combustion of fuel to best advantage.

7 In the accompanying drawings, which form a part of this specification, we have represented the automatic heat-regulating mechanism embodying our present invention such as shown in our Serial 'No. 98445,

wherein the general arrangement of the fire-v fines etc., is horizontal, the products of combustion passing out through an indirect draft flue. -While certain claims are made herein to the general combination of suchafujrnace and automatic governing mechanism .operating on the prin performing substantially the same functions, it will'be understood nevertheless that the present invention box, airand smoke is not essentially limited to the construction and embodiment shown, and that the heatregulator or mechanism 4 constituting the Clinton and State ings, and then more mechanism tothe 15, 1902, for an invention entitled- Ii 3 principal: feature of this case is susceptible Be, it known that we, M1L'roN- 'J.;Fm5 QUHAR and HENRY B. Fanqunamboth citi zens'of the United States, mington, in the of other applications and wide utility, while are also susceptible to modifications. With these remarks in View, the invention will be its 'detai-lsof construction and arrangement fully described with reference to the draw? articularly pointed out anddefincd in the c aims at the end of the description.

Fi gitu inal. vertical section of. the furnace. Fig. 2 is a fragmentary side elevation showing the relation of draft and check-doors. Fig. 3 is a perspective View, showing a portion of the air-box broken away and disclosing the interior fire-box. Fig. 4 is a detail view of the adjuster for. the regulating mechanism. Y

Inasmuch as no specific claim is made herein to the improved construction of the fire-box per 86 (since the same isfully described and claimed in our aforesaid application Serial No. 98445), a brief explanation of its construction, and operation will be sufficient.

The numeral 1 denotes the outer casing of the air-box; and 2 is the fire-box,3 its backplate and 4 its front plate. The fire-box'is inclosed within the air-box, except its front plate 4, which is outside the front wall-of the air-box and has dampers, of which 12 is the fire-door, 13 the ash-door, and 14 the check-door or valve of the smoke-box 10, which is shown located at the base of the furnace front. The fire-box is shown of horizontal tubular form, so that the direction of its expansion tion is longitudinal of the furnace.

the automatic regulating all the necessary doors or.

and contrac-' me 1 of the drawings is a central 1011-.

" Within the fire-box, 6 denotes the fire-pit or i fuel,-space;15 the ash-pan below the ate; 7 aflue or passage behind the rear. bri ge-wall 9, or between it and the back-plate 3 of the furnace; and 8 aflue or passage in the bottom of the fire-box formed-along under the ash-pan to the smokefrom said passage 7 The heat-governor or re box 10. The products of combustion pass over the rear bridge-wall down the passage 7 and forward through the flue or passage 8 to the front smoke-box, which has an outlet opening to the chimney or smoke-pipe 11.

Air is of course supplied to the fuel from the ash-door, passing up through the grate; and in this our improved type of furnace, preferably an air-blast is also admitted. from the rear of the ash-pan up through a passage in the bridge-wall 9 to the fire-space above the fuel, where it meets the gases at a heat sufficint to ignite the mixture.

lating mechanism operates upon the ashoor 13- to control the air admitted to the fuel, and upon the check-door 14 in the smoke-flue or smokebox 10*to check the draft when necessary. It utilizes a weight, as 15, to open the ash-door, and the force of expansion of the fire-box when heated against an inclosing framework not heated to close the ash-door and open the check-door. Said frame-work, as shown, consists of a rear cross-piece 16, having pins or projections 26 that bear against the rear wall 3 of the fire-box to receive the thrust therefrom when the fire-box expands with heat; and a front cross-piece '17 and opposite connecting rods 21 and 22; the

rod 21 connecting one end of the rear crosspiece 16 with an adjusting lever 20 attached to the front cross-piece 17, which has a graduated arc 18 and a locking rack 19 for holding said adjusting-lever in place; and the other rod 22 connecting. the opposite end of the rear cross-piece 16 with a pendent lever 23 shown fulprumed at on the front-crosspiece 17 so as to draw said lever, inward when the expansion of the fire-box acts against the inclosing frame- work 16, 17, 21, 22, etc., with sufficient force to overcome the I Weight 15, which tends to hold said lever 23 outward. The lever 23 is rocked on the edge or fulcrum 2% formed on the bar or front cross-piece 17. Pivotally suspended as at 25 from its lower end is a bent lever 28', the elbow 27 of whifli is a sliding fulcrum. From the lower part 31 of this lever extends a for ward arm 32 carrying the aforesaid weight 15. When the furnace is at low temperature, the weight 15-holds the upper part 30 of bent lever 28 outward, and thereby holds outward the lever 23 also. In this position, a lug 33 on the upper part 30 is out of contact with the lug 29 on the ash-door. Now, when the rising temperature and consequent expansion of the fire-box pulls the connecting-rod 22 rearward, it pulls the lever 23 inward, likewise moving the upper part 30 of the bent lever 28 toward the stove, allowing its fulcrum 27 to slide downward. Said upper part 30 now carries with it the ash-door 13, by virtue of the engagement between the parts 33 and 29. The same movement, if continned after reaching the position for holding the ash-door closed, changes the fulcrum of the lever 28 to 29, and raises the lower arm 32 and with it the check-door 14, a la 34 from which overhangs the said arm. T ese movements tend to close the ash-door and open the check-draft door.- The purpose in opening the latter is to supply the necessary draft to the chimney from the outside, instead of from the fire-box; thus relieving draft from the fuel. This mechanism will automatically maintain just the necessary opening of the ash-door to providethe requisite draft for kee ing a practically constant temperature. ture will be compensated for by restriction of the ash-door opening, and any sudden or,v

great increase by openin of the check-door. Any decrease from the desired temperature will be compensated for by the outward movement of the lever 23, which draws upward the lever 28, whose lower inclined part 31 engages the lug 29 and opens the ash-door. The inclosing frame- work 16, 17, 21, 22, etc., can-be extended or shortened by the adjusting lever 20, so as to cause the expansion of the fire-box to act on the frame at different temperatures; so that the furnace may be arranged to maintain the desired tempera ture. The said frame-work may surround the fire-box as herein-described, or may occupy one side only, being suitably connected with the front and rear plates of the fire-box.

The broad principle of the heat-regulator is the transmission of motion due to expan sion of the fire-box through a non-expanding member to a suitable lever-mechanism for controlling the position of the draft or check; doors. To secure sufiicient action, it is important that the non-expanding member be kept as cool as possible; and it is therefore protected by a shield, being in the present instance placed outside the casing of the airbox where it is shielded from the rays of heat front the fire-box and where it is kept cool by exposure to the surrounding air.

o claim as our invention and desire to secure by Letters Patent of the United States:

1. In a furnace, the combination with an expansible fire box and surrounding air-box or casing for the medium to be heated, of a four sided frame-work not affected by heat inclosing the air-box and arranged to re ceive the thrust from expansion of the firebox, and regulating mechanism for the draft opening or openings operated by said framework when moved by expansion of the furnace.

2. In a furnace, the combination with a heater having a draft-door, of a thermostatic governing mechanism comprising a pendent lever, asecond intermediately-fuL crumed lever pendent from said first mentending to hold the same position to maintain said door 0 en, and heat-governed. means connected wit said first mentioned lever for moving the same under rise of temperature in a direction which moves the second lever in a manner to close said door.

3. In a furnace, the combination with an expansible fire-box provided with a draftdoor and check-door, of a vertically-dis posed lever (28) intermediately fulcrumed and connected with said draft-door and provided with a' weight for holding said lever in a position to'maintain said draft- -door open, and mechanism connected withsaid fire-box and actuated by expansion thereof and connected with said lever for moving the same in a direction to close said door,'and means .whereby said check-door is controlled by said lever.

The combination of a horizontallydisposed expansible fire -box, and a surrounding casing for medium .to be heated, of a non-expanding frame-work surrounding said casing and com rising front and rear cross-pieces at the front and rear of the furnace respectively, a tie-rod connecting-said cross-pieces at one 'sideofthe furnace, a damperscontrolling lever fulcrumed on one of said cross-pieces, and a tie-rod connecting the opposite cross-piece and said lever and arranged at the other side of'the furi iace, and means extending from one end ing said rame-work receives aainst one of said cross-pieces, whereby the thrust of ex pansion of the fire-box.

The combination with the expansible lire-box, of the non-expanding frame-work comprising front and. rear cross-pieces, a damper operating lever fulcrumed on one cross-piece, a rod connecting saidlever with the opposite cross-piece, an adjustin lever connected to one cross-piece and 'aving means for locking; it in place, and another rod connecting said lever and the other cross-piece. v 6. The combination with the ash-door and check-door, of a endent lever, a bent lever pivotally-suspen ed therefrom whose elbow constitutes a slidin fulcrum, and having a lower arm underlying a In on the check door, temperature control ed means for moving said pendent lever inward and out-- ward, inward movement thereof causing inward movement ofthe upper part of said bent. lever, and means whereby on such inward movement of said upper part it en gages and "moves inward the ash-door, while the continued movement after the door is closed causes the said lower arm to lift the check-door.

7. A furnace having, n combmation, a

of the fire-box through said casing and bearsite cross-piece at one side of the horizontallydisposed tubular fire-box rovided with a front fire door and ash oor thereunder, said firebox having an internal grate and ash pan so arranged as to provide in the rear and bottom of the fire-box an indirect draft and smoke passa c, said passage having its finaloutlet at te base of the front of said fire-box, a smoke-pipe or chimney in c'oimnunicataon with said final out-let, a check-door under the ash-door for controlling admission of air into said smoke-pipe, and mechanism mounted on the furnace operated by expansion and contraction of. thefire box and including a front pendent lever connected withthe ashdoor and check-door for automatically controlling the same.

8. In a furnace, the combination with an expansible, fire-box and surrounding air-box or casing for the medium to be heated, of a frame-work not affected by heat inclosing the casing, means for impartin the thrust of expansion of the fire-box to sai frame-work, 'a draft damper, and a lever operated .by said frame-work'for controlling said damper.

9. In a furnace, the combination with a horizontally expansible fire-box and surrounding air-box or casing 'for the medium to be heated, of a non-expanding frame-work surrounding the casing, thrust pins interposed between the rear cross-piece thereof and theback of the fire-box, and adamperiz mtrolling mechanism actuated by said ame.

fire-box, of' the non-expanding frame-work surrounding the furnace and comprising 'ating lever fulcrumed on. one cross-piece, atie-rod connecting said lever and the oppo furnace, and an adjustable tie-rod connecting said cross-pieces at the opposite side of' the furnace, the said frame-work being ada ted to {)eceive the thrust-of expansion of t e fire- 11. In a furnace, the combination with the hinged ash-door'having a lug thereon, of a pendent bent lever whose elbow constitutes a sliding fulcrum, the upper part of said lever having a lug overlying the lug on the ash-door, heat controlled means connected with said lever for drawing its upper art inward as the temperature rises, an a lever.

hinged ash-door having a lug'thereon, ofa pendent bent lever whose elbow constitutes a sliding fulcrum, the upper part of said lever having a lugoverlying the lug on the ash door, heat-controlled means connected with said lever for drawing its upper part inward as the temperature rises, a h nged check-door 10. The combination with the expansible front and rear cross-pieces, a damper-'operweight acting upon the lower part of said 12. In a furnace, the combination with the having a lug overlying the lower part of heater to rock both of said levers and close said lever, and a weight acting upon the said door when the heater expands.

lower part of said lever. In testimony whereof we aflix our signa- 13. The combination with a'longitudinally tures, in presence of two witnesses.

-5 expansible heater, provided with a draft MILTON J FARQUHAR door of a pendent level" asecond lever, provided with a weighted end, pendent there- HENRY FARQUHAR' from and adapted to engage said draft-door Witnesses: and normally hold it open, and means con- C. W. SWAINE,

- 10 meeting said first mentioned lever and said E. R. K. HAYES.

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