US759318A

US759318A - Hot-air furnace.

Info

Publication number: US759318A
Application number: US16093203A
Authority: US
Inventors: Reuben H Sayre
Original assignee: GEORGE W KOTZEBUE
Current assignee: GEORGE W KOTZEBUE
Priority date: 1903-06-10
Filing date: 1903-06-10
Publication date: 1904-05-10
Anticipated expiration: 1921-05-10

Description

PATENTBD MAY 10, 1904.

R. H. SAYRE.

HOT AIR PURNACE. PPLIATION FILBD JUNE 10,1903.

4 SHEETS-SHEET 1.

N0 MODEL( l o 2 y.

PATENTED MAY l0, 1904.

R. H. SAYRE. HOT AIR PURNAGE.

APPLICATION FILED JUNE 10.1903.

4 SHEETS-SHEET 2.

N0 MODEL.

HOT AIR FURNACE.

APPLIOATION FILED JUNE 10,1903.

41519. 759,318. PATENTED MAY 10, 1904.

R. H. SAYRE.

HOT A1B FURNAGB.

APPLICATION FILED JUNE 10.1903.

4 SHEETS-SHEET L N0 MODEL.

Patented May 10, 1904.

PATENT OEEicE.

REUBEN Irl. SAYRE, OF NEW MARTINSVILLE, WEST VIRGINIA, ASSIG-NOR OF ONE-HALF TO GEORGE W. W EST VIRGINIA.

KOTZEBUE, OF NEW MARIINSVILLE,

HOT-Am FURNACE.

SPECIFICATION forming part of Letters Patent No. 759,318, dated May 10, 1904..

l Application filed .Tune l0, 1903. Serial No. 160,932. (No model.)

, Be it known that I, REUEEN H. SAYRE, a citizen of the United States, residing at New Martinsville, in the county of AWetzel and State of I/Vest Virginia, have invented a new and useful Hot-AirFurnace, of which the following is a specification.

This invention relates to liet-air furnaces such as ai'e used for heating buildings by means of air heated ina space .surrounding the furnace-casing proper and conducted from thence to the apai'tments to be heated.

My invention has for its object to provide a device of this class which shall possess superioi' advantages in pointof simplicity, durability, and general efficiency; and with these ends in vicwthe invention consists in the improved construction, arrangement, and combination of parts, which will be hereinafter full y described, and particularly pointed out in the claims.

` In the accompanyingdrawings, Figure 'l is a front elevation of a furnace constructed in accordance with the principles of my invention, parts of the same having been broken away for the purpose of illustrating the intei'ioi' construction. Fig. 2 is a longitudinal vertical sectional view. Fig. 3 is a horizontal sectional view taken on the line?. BinFig. 2. Fig. i isa perspective detail view illustrating the method of joining the furnacecasing, the intermediate casing, and the eXterior jacket at one of the front cornei's. Fig. 5 is adetail sectional view taken through a part of the furnace-casing and showing in plan the cap-pieces of the lire-lining. Fig. 6 is a perspective detail view showing the connection between one of the grate-bars and the rocker-bar. i

Corresponding parts in the several figures are indicated by similar numerals of reference.

In the constructionof my improved hot-air furnace three casi ngs are employed-namely, the inner casing I, which is the furnace-casing proper, the outer casing or jacket 2., and an intermediate casing 3, which is disposed between and spaced from the casing 1 and the," lracket 2. The several casings may be con-fy structed of any suitable appropriate material,

my preference being' in favor of sheet metal of suitable thickness, the inner or furnace casing being preferably of heavier' material to form a central longitudinally-folded i'ib 7,

the sides or flanges of said ridge-cap being connected with the arch member 5 by means vof rivets or other suitable connecting means, `thus forming in a simple, durable, and inexlpensive manner a comparatively rigid struci ture, which, as stated, constitutes the body of the furnace-casing and which by reason of the folded rib 7 is capable of expansion and contraction without straining bolts, rivets, ,and other connecting means.

8 designates the front of the furnace-casing,

-which consists of a plate adapted to fit between 4the front ends of the sides of the arch menibers of the casing, said plate heilig provided with flanges 9 to receive bolts or rivets i0, .whereby it is connected securely with the body of the easing. Suitably bolted upon or otherwise connected with the front side ofthe plate r8 is the furnace-front 1l, which preferably a

casting having flanges

12 and 13 at the sides Vand top thereof. This casting is provided with an opening for the feed-door 14, which is hingedly connected therewith and which is provided with a draft-slide l5 and which has an interior perforated lining IG, said parts being held together by means of bolts I7. Below the feed-doei' and a short distance above 'the grate is an opening' I8, covered by a door 19, through `which access may be had to the lire without necessity for opening' the fuel-doei'. The front frame oi' casting is furthermore provided near its lowei" end with a forwardlyextending ledge 2D and inclined flanges Q1, adjacent to an opening' 22, which communicates with the ash-pit. Suitably hinged to thc outer edge of the ledge 20 and adapted to normally IOO rest upon the ianges 21 is a door 23, having a draft-opening 24, which is normally closed by a door 25, which is hinged above the opening 24. rJhe latter may be uncovered by raising the draft-door 25. At times, however, when it is desired to have access to the ash-pit 26 and to the ash-pan 27, located therein, the door 23 may be thrown open, as indicated by dotted lines in Fig. 2 of the drawings. WV hen the door 23 is thus thrown open, the draftdoor will likewise swing open and will then form a supporting means by means of which the door 23 is maintained in an open position, enabling the ash-pan to be slid or moved outwardly upon the same preparatory to the removal thereof.

lnteriorly upon the sides 4 of the furnacecasing are bolted the grate-supports 28, which consist of cast-iron plates provided at their lower and upper edges with outwardly-extending ribs or

lianges

29 and 30, the former of which abut upon the bottom 31 of the furnace-casing, which consists of a sheet-metal plate having downturned flanges 32, connected by means of bolts or rivets, as 33, with the sides of said casing. The plates 28 of the grate-supports are extended somewhatabove the Lipper ribs 30, and they are connected with thel sides of the furnace-casing by means of bolts 34, which pass through said upwardlyextended portions of the plates and also through the latter intermediate of the

ribs

29 and 30. These braces or grate-supports in addition to supporting the grate, as will be presently described, also perform an important function in stiffening the side walls of the furnace-casing.

The grate of my improved furnace is composed of a frame 35, rectangular in shape and of such size and general conformation as to fit neatly between the slides of the furnace-casing. This frameis provided on its under side with longitudinal ribs 36, formed upon the sides of said frame, said ribs being provided at their ends with shoulders 37, adapted to rest upon the ribs 30 of the supporting-braces. rlhe upper sides of the side pieces of the frame are each provided with a plurality of sockets 38, in which are disposed the rocking gratebars 39, each of which is provided at its ends with trunnions 40, engaging the sockets 38, in which the said grate-bars 39 thus have a rocking or oscillatory motion. The individual grate-bars may be of any preferred construction; but they are preferably provided with teeth 4l at the front and rear edges thereof, whereby when the grate bars are rocked by means to be presently described the superimposed fuel shall be shaken and agitated to cause the ashes to escape between the gratebars into the ash-pit, while the coaction of said teeth will also serve to break up cinders and clinkers that may have formed in the fire-box.

Each of the grate-bars is provided at one end thereof with a downwardly extending arm 42, said arms being connected,by means of transverse pivots 43, with a pair of connectingbars 44, one on each side. The pivotal pins 43 are provided with heads 45 and with perforations 46, through which are inserted Cotterpins 47 to prevent the accidental displacement thereof. By .this construction the grate-bars will be normally connected, while at the same time any one of the grate-bars that may become burned out or otherwise injured may be readily removed and a new one substituted without necessity of disturbing the remaining bars of the grate. The connecting-bars 44 are spaced at their front and rear ends by means of interposed sleeves or thimbles 48, thus avoiding undue friction between said connectingbars and the arms of the grate-bars to be operated thereby. rlhe front ends of the said connecting-bars are connected, by means of a 8 5 link 49 extending through an opening 50 in the front of the furnace-casing, with the lower end of the lever 51, which is fulcrumed to a bracket 52 upon the front end of said casing a short distance above the opening 50. The connecting-pins 53, which pivotally connect the operating-lever 51 with the bracket 52 and with the link 49, are provided with Cotter-pins 54 to enable the parts to be conveniently disconnected for repairing purposes whenever this shall be found necessary.

1t is obvious that the opening 50 extends not only through the casting 1l, but also through the front plate of the furnace-casing; likewise that the latter is provided with openings to coincide with the openings in the said castingswhere the latter is provided with doors, &c. Such structural features as these are of course necessary and obvious to those skilled in the art to which my invention appertains.

It will be seen that by the means described the grate of the furnace may be conveniently shaken at any time by means of the lever 5l, thus causing the ashes and clinkers to pass into the ash-pit below the grate and into the ashpan 27, which, as described, is supported upon the botom 3l of the furnace-casing.

The front cross-bar 55 of the grate-frame 35 is provided with a plurality of openings 56 for the upward passage of draft. The air permitted to pass upward through these openings will commingle with the gases of combustion, thereby insuring a more perfect combustion and a more intense heat. This construction also serves to some extent to cool the front bar of the grate and to prevent the same from warping.

.The integral end pieces and the side pieces, which combine to form the grate-frame 35, are beveled to support the lining of the furnace, which is constructed of ordinary fire-brick. The front wall 57 of said lining is built up in such a manner as to surround the opening 18, which is in alinement with the top of the grate, and also around the opening of the feed-door,

IOO

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an arch 57u being formed in alinement with the casing-strip 57", which separates the said door-openings. The side linings 59 are built up of bricks, of which two tiers have been shown in the drawings. It may here be noted that the side walls of the furnace, as well as the back wall, which is to be hereinafter more fully described, are slightly tilted in an upward and outward direction, thus causing the lining-bricks to be supported in such a manner that collapsing of the lining is rendered absolutely impossible.

The back lining 62 is built up, as shown in Fig. 2, in contact with the rear ends of the side linings, which are thereby braced and supported against collapsing'. To furthermore bind the lining in its proper position and to materially strengthen and increase the life of the lining' of the furnacel provide cap-pieces, which may be made of east-iron and which are provided at their outer edges with iianges 64:, depending or overhanging the upper inner edges of the bricks constituting the lining upon the upper edge of which the said cap-pieces are supported. Said cap-pieces are provided with downward-extending lugs 65, which rest upon the upper edges of the upper bricks of the lining, thereby supporting thc said caps in an inclined position,as shown,and also forming an air-space 66 between the lining and the cap-pieces. The latter, which are shown in top plan in Fig. 5 of the drawings, are composed of the sides 67, the front piece 68, and the rear piece 69. The side pieces 67 are extended to the front of the furnace-wall, and the front piece 68 has square ends, which abut upon the said side pieces. Said front piece or cap 68 is also provided with a lug 70, which is perforated for the passagcof a bolt 71, which extends through the front wall of the furnacecasing, thus forming a very firm and solid connection between the parts. The rear ends of the side caps 67 and the ends of the rear cap 69 are mitered together, as shown. In this mannerI provide a lining which while simple in construction is extremely durable and of such a nature that the parts constituting said lining' may be easily taken apart and again assembled when necessary :for the purpose of repairs.

The back wall of the furnace consists of a plate 7 2, provided at its edges with flanges 7 3, which are connected with the adjacent side wallsof the furnace-casing by means of bolts or rivets 7 4, bolts being preferred in order to enable the parts to be disassembled when desired. This back wall abuts upon the rear lining' of the furnace and contributes to the retention of said lining in its proper position. Said back wall is provided near its lower end and in alinement with the rear end of the ashpit with an opening' 76, normally closed by means of a damper 77, which is hinged at the upper edge of said opening' and the lower edge of which is capable of opening' in a forward direction. AIt will be observed that when the ash-pan 27 is in position, as shown in Fig. 2 of the drawings, the movement of the damper 77 is quite limited, while when the ash-pan is removed this damper, which is provided with an operating-rod 78, may be thrown wide open. The purpose of this arrangement will be hereinafter more fully described.

79 designates the back wall of the furnacecasing, which consists of a plate havinglianges 80 fittingl between the side walls and the arched portion of the furnace-casing', said plate abutting also upon the rear flange of the bottom plate 31. This back wall is secured in position by means of fastening means 8l, extending through the fianges 80 and the adjacent parts of the furnace-casing. This back wall, in connection with the side walls, the front wall, the top arch, and the betteln, constitutes what may be designated the furnace-casing proper.

82 designates what I term a radiator-casing, which consists of a rectangular box or casing suitably constructed of sheet-metal plates, said casing being connected, as will be presently described, with the interior of the furnace-casing and with the smoke-exit, thus constituting a passage for the products of combustion. lower end with a rectangular opening 83, connected by a flanged collar 84 with a similar opening 85 in the lower part of the back wall of the furnace. Near its upper end the front side of the easing 82 is provided with a circular opening 86, which is in alinement with a similar opening' 87 in the furnace-wall 79. The

openings

86 and 87 are connected by means of a sleeve 88, the ends of which are turned down to form shoulders 89 and reduced ends 90. lln assembling' these parts thereduced ends 90 are extended through the

openings

86 and 87 and are clenched or bent upon the front wall of the casing 82 and upon the rear furnace-wall 79, thus fitting' the parts very tightly together without the use of rivets or other fastening means. Upon the front side of the rear furnace-wall 79 are mounted brackets 90, affording bearings for a shaft 92, carrying a damper 93, said shaft being' provided with a crank 94:, which is pivotall y connected with an operating-rod 95, extending' through the front furnace-wall and provided. with a knob or handle 96, by means of which it may be conveniently manipulated to operate the damper.

97 designates a plurality of angle-bars T- shaped in cross-section, which are riveted at intervals upon the inclined sides of the arch 5, which constitutes the top of the furnace-casing', said ribs or angle-bars cooperating with the longitudinal ridg'e-cap 6 to prevent warping' of the top of the furnace-casing.

The ang'es '12 of the casting' which constitutes a part of the front wall of the furnace are provided at their outer edges with ribs 98,

This casing 82 is provided at its TOO IIO

forming abutments against which are placed angular plates 99, the front edges of which, abutting upon the ribs 98, are bent to form U-shaped flanges 100, similar flanges 101 being formed at the outer edges of said angleplates. Additional plates 102 are provided, which are bent to form flanges 103, engaging the U-shaped flanges 100, where they are secured by means of bolts 104, extending through said flanges 100 103 and through the side flanges 12 of the casting 11, with which the

plates

99 and 102 are thus connected. U- shaped flanges 105, similar to the

flanges

101 and 100, are formed at the outer edges of the plates 102. It will be observed that the angular portions of the plates 99 rest against the front ends of the side walls of -the furnacecasing, being thus braced and retained securely in position. The plates 99 102 constitute the front ends of the

casings

3 and 2, to which reference has hereinbefore been made. Each of these casings is composed, essentially, of side plates and rear end plates, those of the outer casing or jacket 2 being designated, respectively` 106, 106, and 107, while the side walls of the intermediate casing 3 are designated 108 and its rear end wall 109. These several plates are provided at their adjacent edges with interlocking flanges 110, the flanges at the front ends of the plates 106 and 108 being interlocked, respectively, with the

flanges

105 and 101, as will be clearly seen in Figs. 3 and 4 of the drawings. The side plates of the outer casing are provided with braces 111, which serve to space them suitably from the walls of the intermediate casing 3.

1t will be understood that in assembling the parts the plates constituting the side walls and end walls of the casings may be simply slid together endwise, the lock-joints serving not only to connect, but also to space the side walls apart. The front ends of the side walls are similarly connected with the

plates

99 and 102, as will be readily-understood.

The plates 102 are provided at their upper ends with angular flanges 112, which normally occupy the position shown in Fig. 4 of the drawings, but which when the side walls 106 of the outer jacket are placed in position must be bent to the position shown in dotted lines in said Fig. 4, where they will not interfere with the placing in position of said side walls. These angular flanges are an important feature of the construction of the device, inasmuch as when in normal position they will form a lock which prevents the upward displacement of the side walls 106. An additional use of the said angular flanges still remains to be described.

Suitably supported upon the upper edges of the side and rear walls 108 and 109 of the intermediate casing 3 are strips 113, sigmoidal in cross-section, and these strips serve to sup-` port the lower edges of the cap 114 of the in? terinediate casing 3, which said cap is composed of front and rear end pieces 115 and of inclined side 'pieces 116, the lower edges of said side pieces and rear end pieces being supported in the grooves of the sigmoidal strips 113, while the lower edge of the front end piece is supported upon the top flange 13 of the front casting 11. The top of this cap is open, as will be clearly seen in Fig. 1 of the drawings.

The dome or cap of the outer casing or jacket 3 is designated 117, said dome or cap being constructed of inclined side pieces 118, connecting the front and rear end pieces 119 and 120. This cap or dome is also provided with a top piece 121, .which is in the form of a tray, the sides and ends of which are provided with flanges 122, interlocking with the upper edges of the sides and ends of-the cap. The latter is provided at its lower edges with flanges 123, supported upon flanges 124 of the sides and rear wall of the outer casing 3, said flanges 124 being bent or beaded upon the flanges 123, and thus firmly connected therewith. At the front end of the casing the outer parts 125 of the flanges 112, formed upon the plates 102, are bent or beaded upon the flange 123 of the cap, a portion of which is also supported upon the upper side of thc flange 13 of the front casting 11. 1n this manner a very simple, durable, and effective construction is secured.

Upon the under side of the top 121 of the cap or dome 117 is secured a V-shaped deflector 126, which serves to deflect the hot air contained in the space between the casing 3 and the furnace-casing in the direction of the exit-tubes 127, with a plurality of which the cap or dome 117 is provided. The tray 121, which constitutes the top, is to be filled with sand or similar suitable non-heat-conducting material for the purpose of preventing upward radiation, said non-conducting material being indicated in Fig. 1 at 128. r1`he exittubes 127 have flange connection with the sides of the cap or dome, as indicated at 129. It

is from these tubes that the hot air is piped to the apartments that are to be heated.

130 designates a smoke 'exit or thimble which has flanged connection with the rear side ofthe radiating-casing 86, whence it eX- tcnds through the rear walls of the domes or caps 114 and 117. Suitably connected with the protruding end of this thimble is a short pipe-section 131, equipped with a damper 132, which constitutes a check-draft. The end of the pipe-section that abuts upon the rear wall of the cap 117 is flanged, as shown at 133, in order to form a tight joint, whereby the escape of smoke at this point shall be positively prevented.

In order to supply the hot air generated by my device with the necessary moisture, I provide the side walls of the

casings

2 and 3 with

alining openings

134 and 135, through which.

water-tanks 136 are partly extended, said IOO IOS

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IIS

water-tanks being provided at their edges and sides with iianges 137 and at their lower edges with grooved flanges 138, adapted to engage the lower edges of the openings 134, upon which the said water-tanks are thus supported, only a few bolts being required to retain said water-tanks securely in position. It is clearly shown in Figs. 1' and 3 of the drawings how said watertanks extend through the side walls of both

casings

2 and 3 and into the hot-air space 139, which is the space between the intcrmediate casing 3 and the furnace-casing proper. The projecting' portions of said watertanks are covered by means of pivoted lids 140, permitting the contents of said tanks to be conveniently replenished.

The operation of my invention may be generally described as follows: Fuel of any suitable kind is supplied through the feeddoor and ignited, the necessary draft being primarily supplied by opening the draft-door 25, from whence the air ascends through the grate, the products of combustion finding an exit through the sleeve 88, connecting the

openings

86 and 87 in the radiator-casing 82 and the back plate 79 of the furnace-casing, the smoke passing from the casing 82 unobstructed through the sleeve 130 and to the final exit. At this time thc damper 77, which is operable by means of a crank 141 upon the shaft 78, which extends through the adjacent side walls of the

casings

3 and 2, is preferably closed. After the lire becomes brisk the damper 93 may be partially or entirely closed, when the products of combustion will be compelled to follow the course (indicated by arrows) between the back wall and the rear plate of the furnace-casing, through the sleeve or collar 34, upwardly through the radiator-casing, and outthrongh the sleeve 130 to the final point of exit. lThis, it will be seen, is a non-direct draft whereby the intensity of the lire is capable of being' thoroughly regulated. The damper 77 also serves as a check-draft, by opening' which a portion of the air entering through the draft-door 35 Amay be permitted to pass through the sleeve 34 and up and ont through the radiator-casing. It will be observed, however, that when the ash-pan is in position,4 thus limiting the extent of the opening of the damper 77, only a limited portion of the air entering through the draft-door may be thus disposed of. This is an important feature of my invention, inasmuch as if the damper 77 were at all times capable of being freely opened a surplus of the air needed to support combustion might be permitted to escape, thus endangering the life of the lire. The casing 82 serves to assist the furnace-casing proper in heating by radiation the air contained in the hot-air Vspace between the casings 1 and 2, to which space air may be admitted in any suitable, well-known, and convenient manner. It will be observed from the nature of the construction of the device` that the space 142, between the casing-

s

2 and 3, forms an absolutely dead-air space from which although said space opens at its upper end into the hot-air space proper the air will not rise and escape through the exit-tubes owing to the higher temperature of the air contained in the hot-air space proper 139, which owing to its higher temperature will rise, escape through the pipes 127, and at the same time obstruct the passage in an upward direction of the air contained in the dead-air space 142.

When it shall be desired to clean out the ash-pit the door 23 is swung open tothe position shown in Fig. 2, in which position itis supported by means of the draft-door 25. When the door 23 is in this position, the ash-V pan may be slid out and emptied, and while this operation is going on the check-draft or damper 77 is thrown open to its fullest extent, thus causing the air entering at the front to pass under the grate and out, partly through the sleeve 84 and casing 82 and partly between the furnace back wall and the back plate and through the damper opening in the latter, the damper 93 being meanwhile thrown open. Thus while the ash-pan is removed the soot and ashes accumulated in the lower end of the casing 32 may also be raked out and at the same time a sufficiency of air fo maintain combustion will ascend between the grate-bars, the products' of combustion escap-v ing through the damper-opening in the sleeve 88, thereby preventing smoke while the ashpit is being cleaned out.

From the foregoing it will be'seen that the draft of my improved furnace may be thoroughly regulated and that consequently the` heat developed by the furnace may be gaged. rlhe general construction of the furnace is simple and inexpensive and of such 'a nature that the component parts of the same maybe readily separated or assembled as occasion may require. Special provisions have also been made, as herein described, to prevent warping of those parts of the casings vwhich are exposed to excessive heat. rlhe furnace-v casing, as well as the intermediate casing and the outside jacket, is practically air-tight, and passage of smoke into the hot-air chamber or into the room where the furnace is located, as well as the passage of hot-air from the hot-air space, except through the ducts 127 provided for this purpose, is practically im` possible.

I have in the foregoing described la simple* and preferred construction of my invention; but I desire it to be understood that 1 do not hereby limit myself to the structural details -herein described, but reserve to myself the right to any changes, alterations, and modifi cations which may be resorted to within the scope of my invention and without departing from the spirit or sacrificing the utility of the same. l, also desire to state that my improved IOO IOS

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furnace may be supported upon a foundation constructed of cement, brick, or of any other suitable material adapted to the purpose.

Having thus described my invention. I claim- 1. In a hot-air furnace, a furnace-easing having side walls bent to form angular arch-sections abutting against each other and a ridgecap having a longitudinally-folded rib, said ridge-cap being secured to the angular arched sections which are thereby connected.

2. Afurnace-casing composed of side plates bent to form an angular arch or dome, in com bination with a superimposed ridge-cap having a longitudinally-folded strengthening-rib.

3. In a device of the class described, a furnace-casing composed of side plates bent to form an angular dome or arch, means including a ridge-plate having a longitudinally-folded rib for connecting' the meeting edges of the sides, and front and rear end plates having flanges engagingthe side members of the casing interiorly and connected therewith.

4. In a hot-air furnace, a sheet-metal furnace-casing in combination with stiifeningplates secured interiorly upon said easing, said lstiffening plates being provided with inwardly-extending ribs forming grate-supports.

5. In a hot-air furnace, a sheet-metal furnace-casing having a anged bottom raised above the lower edges of the side and end walls of such casing, in combination with plates secured vertically to the inner sides of the side walls and supported upon the bottom of the casing, ribs extending laterally from said plates, and a grate-frame supported upon said ribs.

` 6. In ahot-air furnace, the combination with a sheet-iron furnace-casing of plates secured vertically to the inner sides of the side walls, ribs or iins extending laterally from said plate at the lower ends of the same and resting upon the bottom of the furnace-casing, ribs or fins near the upper ends of said plates' extending laterally and supporting the grate-frame and securingbolts extending through 'the side walls of the furnace above the upper ribs or fins and between the upper and lower ribs or tins.

7 In ahot-air furnace, the combination with a sheet-metal furnace-casing, of stiffeningplates secured vertically to the side walls thereof and having laterally-extending supporting means, and a grate-frame, the sides of which are provided on their under sides with longitudinal ribs shouldered at their front and rear ends and engaging the said supporting means.

8. In ahot-air furnace, the combination of a furnace casing having interiorly disposed supporting means secured to the side walls and resting upon the bottom of the casing, a grate frame resting upon said supporting means and provided at its front end with a plurality of openings for the upward passage of air, and a suitable front lining supported upon the front end of the grate and having an arch or opening above said perforations.

9. In a hot-air furnace,the combination with the furnace-casing, of a casting bolted to the front wall of the same, said casting and front wall having suitable alining openings therein, one of said openings being disposed i'n alinement with the ash-pit of the furnace-casing and said casting being provided with flanges adjacent to the sides and to the lower edge of said opening, in combination with a door hinged to said lower-edge flange and normally supported upon the side flanges, and a draft-door hingedly connected at its upper edge with said ash-pit door, and forming a support for said door when the latter is open. 10. In a hot-air furnace, a furnace-casing, supporting means upon the side walls thereof, a grate-frame resting upon said supporting means and having a front piece provided with vertical perforations, doors in the front walls of the casing for the supply of fuel and to afford access to the ash-pit, an intermediate door in alinement with the top of the grate, a brick lining supported upon the grate-frame, the rear and side members of which are inclined to slightly tilt the side and rear linings, the front wall of said lining' having openings in alinement with the feed-door and with the door in alinement with the upper side of the grate, a cap piece mounted upon said front wall and spanning the sides thereof, said cap-piece being provided with a depending flange engaging the inner side of the Wall and with a perforated lug, and means for fasteningthe latter securely to the furnace-casing. 11. In a hot-air furnace, a furnace-casing, a fire-chamber andan ash-pit within said casing, a back wall abutting upon the rear lining-wall, an ash-pan normally located in the ash-pit, and a damper disposed adjacent to an opening near the lower end of the back wall and means for operating said damper to an extent limited by the presence of the ash-pan in the ash-pit.

12. In a hot-air furnace, a furnace-casing, a fire-chamber and an ash-pit within the same, a back wall having a damper near its lower end, a back plate constituting the rear of the furnace-casing and connnected tightly with the sides, top and bottom of the latter and a radiator-casing having connection with said back wall by means of 'sleeves near the upper and lower ends of said back plate, said upper sleeve being provided with a damper. 13. In a hot-air furnace, a casing, a firechamber and ash-pit Within said casing, a back wall having an opening near its lower end in alinement with theash-pit, a damper controlling said opening, a back plate forming the rear of the furnace-casing, a radiator-casing connected with said back plate by means of sleeves or collars, one of which is situated IOO IOS

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above the back Wall and the other in alinement with the ash-pitand with the damper in the lower end of the back wall, a damper controlling the opening through the sleeve above the back wall, and means for conveying products of combustion from the upper end of the radiator-easing to the final exit.

14. In a hot-air furnace, a furnace-easing having an angular dome, a ridge-cap disposed longitudinally upon said dome and having a long'itudinally-folded rib and T-ribs disposed exteriorly upon the sides of said dome.

15. In a hot-air furnace, a furnace-casing having' a front wall, a casting secured to said front wall and having openings alining with openings in the latter and closures for said openings, said casting being' provided with flanges at its sides and upper edge, plates having lock-iiauges secured to the sides of said casting, and casing-plates having' lockflanges engaging' those of the plates connected with the front casting.

16. In a hot-airfurnace, an intermediate casing having' rear and side walls, the latter eonnected slidingly by means of lock-joints with the edges of plates permanently connected with the furnace-easing proper, in combination with sig'moidal strips supported upon the upper edges of said side and rear walls, and a dome supported by said sigmoidal ribs, said dome being' open at the top thereof.

17. In a hot-air furnace, the combination of an interior furnace-easing, an intermediate ilurnaeeecasing, and an outer easing or jacket, the side walls of said intermediate casing and outer jacket being' connected with the central or inner casing through the medium of plates permanently connected with the latter, a dome supported upon the side and rear walls of the intermediate casing, said dome being open at the top thereof, and a donne supported upon the upper edges of the side and rear walls of the outer casing and constitutinga closure for the hotair chamber from which heated air may be conducted to the apartments to be heated.

18. In a hot-air furnace, an interior furnacecasing, a casting secured to the front wall of the same and having inclined ilanges In'ovided with ribs at their outer edges, angular plates connected with each other and with the inclined side iianges of the casting, the bodies of said angular plates being spaced apart and provided with lock flanges at their outer edges, angular flanges formed at the upper edges of the front or outer angular plates, casing-plates connected and interlocking with the respective angular plates, rear plates connecting' and spacing' the rear ends of said casing-plates, outWardly-extending flanges at the upper edges of the outer casing-plates, a dolne supported upon the inner easing-plate and also engaging the inclined iiange at the top of the casting upon the front side of the furnace, said dome being open at its upper end, an outer dome supported upon the iianges of the upper edge of the outer easing-plates and also engaging' the inclined flange of the front casting and the angular [langes at the upper edges of the angular connecting-plates, said dome being provided at its lower end with llanges overlapped and secured by the flanges at the upper edges of the outer easing-plates and at the upper edges of the angular connecting-plates.

19. In a hot-air furnace, an outer casing comprising side walls, an end wall connecting and spacing said side walls and connecting means between the front edges of the side walls and the furnace-casing proper, a dome for said outer casing or jacket supported upon and connected therewith, and a top for said dome comprising a V-shaped delieetor and a tray supported upon the upper edges of said V-shaped deiiector and adapted to receive a filling of non-heat-conducting material.

In testimony that l claim the foregoing as my own I have hereto al'lixed my signature in the presence of two witnesses.

REUB'EN H. SAYRE.

Witnesses:

H. J'ooHUM, Jr., J. Ross CoLHoUN.