US429776A - Furnace for heating metals - Google Patents

Description

4 Sheets-Sheet 1.

(No Model.)

W. SELLERS. FURNAGE PoR HEATING METALS.

No. 429,776. Patented June 10, 1890.

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4 sham-sheet 2.

Patented June 10, 1890.

W. SELLERS.

\ FURNAGE EUR HEATING- METALS.

Secwn n1/Ef (No Model.)

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4-Sheets-Sheet 3.

(No Model.)

W. SELLERS. PURNAGE POR HEATING METALS.

Patented June l0, 1890.

lfwerdan (No Model.) 4 sheets-sheet 4. W. SELLERS. PURNAUE POR HEATING METALS.

No. 429,776. Patented June 10, 1890.

Inv/emr:

4UNITED STATES PATENT OFFICE.

lVILLIAM SELLERS, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO THE EDGE MOOR IRON COMPANY, OF DELAIVARE.

FURNACE FOR HEATING METALS.

SPECIFICATION forming part of Letters Patent No. 429,776, dated J' une 10, 1890.

Original application led March 1'1, 1887, Serial No. 230,558. Divided and this application file-d May 16, 1888. Serial No. 274,072. (No model.)

To all whom t may concern; ing and closing the annealing-chamber; and 5o Be it known that I, VILLIAM SELLERS, of Fig. Il is a partial elevation on the line V W the city and county of Philadelphia, iii the of Fig. G,showing the details of apparatus for State of Pennsylvania, have invented certain raising and lowering the charge and the po- 5 new and useful Improvements in Furnaces for sitioii of the prime mover vertically. Fig. l2,

Heating Metal and in the Appliances for Sheet his an elevation of one end of the fur- 55 Charging and Discharging the Same, of which nace, showing in section one of the four hytlie following is a specification. draulic cylinders and pistons which raise and As these improvements were first designed lower the cover and its connection therewith. 1o for use in connection with annealiiig-cham- It is well known that in the manufacture bers, I have represented in the drawings and of steel castings, particularly in those of conoo described in the .specifications such furnaces siderable weight, that au important molecuaiid aiinealing-chanibers with their charging lar change is effected by subjecting such castaiid discharging apparatus, the improvement ings to an equable heating ata bright-red i 5 -in the art of aunealing'effected thereby formtemperature and to a uniform cooling, and

ing the subject-matter of another application that this change results in important addi- 65 now on file in the United States Patent Office; tions to the ultimate strength and ductility and I do hereby declare the following to be of the metal while imparting to it greater unia full and exact description of said furnaces, forinity in these particulars throughout the zo annealing-chambers, and charging and dismass. It is also well known that all forgings charging apparatus,-reference being had to of steel in which the whole mass is not fin- 7o the accompanying drawings, forming part of ished at a uniform heat will be subject to this specification, in whichinternal strains, which are liable to result iu Figure l, Sheet l,is a plan with one-half in fracture from trivial shocks, and as it is diffi- 2 5 section on the line L M. Fig. 2, Sheet 1, is a cult in most cases and impossible in many to side elevation with one-lialf in section on the finish such forgings at a uniform heat it is 7 5 line I K. Fig. 3, Sheet 2, is an end view in the recognizedruie to subject all to an annealsection on the line A B. Fig. et, Sheet 2, is ing operation-that is, to heat them evenly in an end view of the furnace-chamber in secan open fire to ared heat and then embed them 3o tion on the line O D. Fig. 5, Sheet 2, is an in hot ashes or other non-conductingmaterial end elevation of one-lialf of the complete furwhich will exclude the air or prevent its circu- 8o nace, showing a section of the cooling area on lation, or to heat them in a furnace and allow the line G Il and a section of the dowiitake them to cool off slowly with the furnace in and chimney-flue on the line E F. Fig. 6, which they were heated. The former is ob- 3 5 Sheet 3, is a sectional plan showing the relaj ectionable by reason of the difficult-y in protive position of the several devices for opencuring-a uniform heat, which is only possible 85 ing and closing the lieating-clianiber and the with small objects, and theuuiformity of the annealing-chamber aud charging and discoolingisuncertain,wliile thelatter, although charging both chambers. Fig. 7, Sheet 4, is it effects great uniformity in cooling, involves 4o a partial elevation on the lines N O of Fig. 6; a great loss of heat, because both metal and Fig. 8, Sheet- 4, is a section on the lines P Q furnace must cool off together, and the heat 9o of Fig. 9, showing the detail of apparatus for' of the furnace must be restored with the next raising and lowering the charge preparatory` charge. It involves a great loss of time, beto and subsequent to its transmission and the cause the furnace cannot be used for heating 45 apparatus of transmission. Fig. 9, Sheet 4, a second charge until the first has beencooled is a section on the line R S of Fig. G,showing off and withdrawn. It involves additional 95 detailsof the apparatus of transmission. Fig. plant, because additional furnaces are re- 10, Sheet 4, is a section on the lineT Uof Fig. quired to compensate for suoli intermittent 6, showing the detail of apparatus for openheating, and these require larger space to contain them. It must be observed that there is a radical difference between the cooling operations in these two systems. In the first the air is excluded or its circulation is impeded as far as possible. In the second the uniformity of temperature is maintained throughout the closed heating-chamber by a free circulation of the heated gases within this chamber after the furnace is closed to the external air, while the reduction of temperature is effected by conduction to the external air through the outer wall of the heatin g-chamber and by radiation from the outer surface of these walls.

In the practice of the art of annealing steel castings and steel forgings, in which latter I include all wrought-steel, I have discovered that it is not always necessary, and oftentimes not useful, to prolong the cooling, as in the case where the furnace and its contents are cooled off together. For wroughtsteel what is generally required is uniform cooling, and it is only requisite to prolong the cooling to effect its uniformity, and when the metal has a nearly uniform cross-section the coolingmay be accelerated with improvement to the quality of the metal. This points to a separation of the heating and cooling chambers for annealing purposes, and my invention comprehends such a separation and also improvements in both heating and cooling chambers and the mode of charging and discharging the same. The advantages of the improved cooling-chamber cannot be availed of except in conjunction with a heatingchamber; but my improved heating-chamber and the devices for charging and discharging the same may be used, and I contemplate using them for heating purposes alone without any connection with an annealing-chamber.

It is one object of my present invention to provide a heating-chamber which can be charged and discharged without the use of doors; and it is a further object to provide a means for opening` and closing the heatingchamber which shall be simple in construction and easy to operate.

It is a further object to open and close the heating-chamber, so that this chamber may be charged and discharged from either side at will.

It is a further objectto provide a means for opening and closing the heating-chamber which shall effect the necessary movement without damage to this chamber, and it is a further object to provide a means for charging the heating-chamber with long bars or plates and discharging the same without dragging them over the hearth of this chamber; and to these ends my invention consists in a heating-furnace provided with a heatingchamber without openings to the surrounding air above the hearth or the supports which sustain t-he material to be heated, on which hearth the material is heated by the circulation of products of combustion within and throughout the heating-chamber; and it further consists in a heating-furnace provided with a heating-chamber and a set or series of hinged supports near the plane of the hearth of the heating-chamber, upon which supports the cover, which forms the sides and top of the heating-chamber rocks to open and close the heating-chamber; and it further consists in a heating-furnace provided with a heatingchamber and a set or series of hinged supports upon each side of the furnace and near the plane of the hearth of the heating-chamber, upon either of which supports the cover, which forms the sides and top of the heatingchamber, may rock to open and close the heating-chamber upon either side at will; and it further consists in a heating-furnace pr0 vided with a heating-chamber and a set or series of hinged supports near the plane of the hearth of the heating-chamber, upon which supports the cover, which forms the sides and top of the heating-chamber, is rocked by hydraulic cylinders, which have a common supply of pressure-water; and it further consists in a heating-furnace provided with a heatingchamber and a set or series of transferringracks with means for moving these racks both horizontally and vertically when loaded with the material to be charged to or discharged from the heating-chamber.

In order that my invention may be clearly set forth, I will now describe a furnace embodying my invention, which I have constructed and used in the manufacture of steel eye-bars for bridges and other structures. For thc purpose named the furnace must be very long, and it is therefore fired from both ends to obtain a more uniform distribution of the heat, (see Fig. 2, Sheet 1,) in which the grate-bars VY are shown clearly in full lines at one end, and the outline of a similar firing-chamber is shown in dotted lines at the other end. The downtake N is placed midway between the two firing-chambers and connects with the flue leading to the chimney shown by dotted lines passing under the lastmentioned tiring-chamber. In order more effectually to obtain a uniform distribution of the heat, each firing-chamber discharges a very small proportion of its gaseous products of combustion into the heating-chamber A above it. The larger portion of these heated gases enter the flucs between the firing-chambers and the downtake N', and they pass out of these lines through the openings a a a a in the top of the fire-brick covering of these tiucs and firing-chambers, (see Figs. l and 2,) which covering forms the bottom O of the heating-chamber. As thus arranged, thc passage of the heated gases in to the heating-chamber may be controlled at will by placing .tire-bricks partially or en`" tirely over such of the openings a a a a in which it may be desired to retard or to cxclude the delivery of the heated gases; and, lastly, to further facilitate the equal distribution of the heat,l provide the firing-cham- IOC Abe avoided.

bers with fan-blast or other forced blast, so that the heating-chamber may be worked under a pressure above that of the atmosphere, whereby the heated gases may be forced to any part of the heating-chamber and the oxi dizing currents due to a minus pressure may To sustain the bars which are to be annealed, I provide rectangular cast-i ron hollow supports b l) t) b, the sides of which are perforated with circular openings, (see Figs. I, 2, and 3,) which supportsrest upon the bed or hearth of the heating-chamber O; and to vopen and close this chamber for the purpose of charging and discharging the material to be annealed, I divide it upon a horizontal plane below the top of the supports h h h h and near the plane of the bed or hearth, so that the cover P P which forms the sides and top of this chamber, might be removed as a whole at that horizontal plane. This cover is supported in an iron frame-work which can rock or tilt vupon the pins c c, Fig. 3, and such pins are provided at each of the vertical posts c c c c', on the sides of the furnace. (See Fig. l.) The corresponding vertical supports for the cover P P are provided at their lower ends with semi-cylindrical sockets which it over the pins c c, forming, with the sockets, open hinges, upon which the cover may be rocked or tilted in such manner` as to open the heating-chamber upon one side or the other at will. This cover is shown by dotted lines in Fig. 3 as tilted to the position for charging the chamber. As thus arranged, the cover of the heating-chamber can be raised by a force but little in excess of half the weight of the cover, and the chamber can be charged and discharged from either side in the plane of its bed. WVhen the chamber is to be charged and discharged from one side only, the cover may be counterbalanced, so as to still further reduce the force required to raise it. I have availed myself of the iron framing which is required to support the cover when tilted, as shown, to support the corrugated iron roof which protects the furnace and its machinery from the weather.

To tilt the A cover P P', I provide two hydraulic cylinders Q Q at each end of the' furnace. (See Figs. 1, 5, 6, and 7.) The axes of these cylinders are inclined,and their pis-` tons and piston-rods are connected to the ends of the beams R R by the pins fr, Fig. 5, and are arranged to vibrate in the cylinders, to accommodate themselves to the curve in which the ends of the beams R R will move as they' rod, sliding freely through the cover, causes it to move back and forth across the cylinder with the vibration of the piston-rod. The piston itself is not` cylindrical, but rather a section of a sphere provided with the usual` hydraulic packing. The Vibration of the piston is so slight that the packing is sufficient to accommodate it.

High-pressure water from an accumulator or other supply is admitted by a valve to the two cylinders on the side it is desired to raise or open. The weight of the cover is sufficient Eto close it when the exhaust-valve is opened and the water is permitted to escape from the cylinders. In raising and lowering this cover upon either set of hinges it isimportant that the under side of the cover on its open side should be maintained parallel to the bottom of the heatingchamber, as otherwise it would be twisted and its brick work would fall to pieces. If mechanical force was employed for this purpose, some devices for maintaining the cover in position when raised, as also some squaring devices to maintain its parallelism while raising, would be required; but by the use of the two hydraulic cylinders operated from the same source of supply and through one valve further devices than the hinged supports for maintaining the cover in position when raised or its parallelism while raising are not required.

To charge and discharge the materials to be annealed, Iprovide on each side of the furnace a series of wrought-iron frames d d d d, the top of each one of which is composed of a pair of rectangular bars riveted together upon interposed thimbles to receive and to support the material as it comes to the furnaceand as it is discharged therefrom. The thimbles between these top bars are about one and one-half inches in length and six inches apart to afford convenient fulcra for the hand-levers which move the material to its proper position. On the discharging side the top rail is divided into two, for a purpose hereinafter described. (See Figs. 1, 2, 3, and 5.) Between these wrought-iron frames I provide on each side of the furnace pairs of cast-iron boxes s s s s, each one of the pair set opposite to the other, so as to work together, as hereinafter described, and these boxes are provided at each end with a verti cally-sliding frame or box e e c c, which carries a roll upon its upper end, having its axis parallel to the side of the furnace, and a roller at its lower end, having its axis at right angles to the side of the furnace. These lower rollers rest upon inclined planes c' c' c' t', Figs. 2, 3, 5, S, and 9, which are secured to and are carried upon the channel-bars m m m m, which bars extend the whole length of the furnace, and are supported upon rollers having their axes fixed in the boxes s s s s at right angles to the furnace. The two channel-bars on one side of the furnace are united together by the cross-bracing T and T", Fig. 6, and are attachedo the pistonrod of the-hydraulic cylinder Z, Fig. 6, by the cross-bracing T', and a similar crossbracing connects the two other bars. These two sets of channels are connected together by the lever U, which vibrates about thepin n in the end of the iron framing of the furnace, .(see Fig. 1,) so that the two sets of channel-barson the opposite sides of the furnace IOO IIO

when moved must move in opposite directions. The inclined planes fz 't z' fz' are secured to these channel-bars, so that when moving in opposite directions they will raise or lower the boxes e e e e on both sides of the furnace simultaneously by means of the rollers inthe lower ends of these boxes resting upon thcinelined planes. (See Fig. S.)

The inclined planes t' fi t' L' are provided with horizontal surfaces at their larger ends, so that when the rollers on the bottom of the boxes e e e c are raised or lowered by the iuclined surfaces they will rest upon these fiat surfaces or upon the channel-bars, for which purpose the channel-bars m m m m have a greater movement than the length of the inclines y1l L' 1T t'. A

I have shown and described the raising device as a series of inclined planes, these being the simplest in form and perhaps the least liable to get out of order; but other wellknown mechanicaldevices-such as screws or toggle-joints-may be substituted, or the lifting may be done with hydraulic jacks under each of the vertically-sliding frames orboxes e e e c, all of the hydraulic jacks being connected to one supply-pipe and to one discharge-pipe, so as to be operated by one valve. The upper rollers in the boxes@ e c e next the furnace on each side are supported and turned by the shafts lV "W, resting in bearings upon the tops of the boxes e e c c, which, for the purpose of being turned with facility, are provided with the hand-wheels p p p p, Figs. l, 2, and 5. The rollers on these shafts are gearpinions shrouded, the shrouding being wide enough to support the weight, while the gearpinions impel it, as hereinafter described. (See Figs. 8 and 9.)

For the purpose of supporting and moving the materials into and out of the heatingchamber, I provide a series of transferringracks t tf t, Figs. S and 9, having a length at least sufficient to cover three rollers-that is to say, to cover two rollers on one side of the furnace and to extend across and through the lower edge of the cover of the heatingchamber far enough to rest upon the roller on the opposite side of this chamber, for which purpose openings r o r r are provided in the sides of the heating-chamber. These racks are composed of two rectangular bars of iron having a cast-iron rack suitable for meshing with the pinions on the shafts IV IV', riveted between them.v The openings 0 fr r /r are provided with vertically-sliding covers, which can be readily raised to admit the racks.

The annealing-chamber B has about the same capacity as the heating-chamber. The cover X is composed of plate-iron riveted together and stayed with angle-irons to give it sufficient stability to be hoisted and lowered, and when the chamber is being charged and discharged and when lowered to place is supported in a channel-groove extending all around the base and filled with sand. The bottom is composed of plate-iron, riveted to the channel-groove and supported from the wrought-iron frames (l CZ l (l. Openings through this bottom are provided to admit the outer row of boxes e c e e; but as these openings are the only ones into this chamber no circulation of air can occur through them, and, moreover, they are provided with closefitting covers to protect the rollers in the top of the boxes e e e e, when lowered to place, from the heat of the cooling mass in the annealing-chamber, The cover X when raised is suspended at two points by chains passing over the pulleys Y Y and the top of the heating-chamber down to and under other similar pulleys y y on the sides of the boxes s s, (see Fig. 7,) from whence they go around similar pulleys y2 y2, carried by the cross-bracing T T', and from thence to the sides of the boxes s s, where they are attached. The movement of the channel-bars, carrying with them the lower pulleys, will move the cover double the distance traversed by the channel-bars, and when raised the cover may be maintained in this position by passing keys through the chain-links below the pulleys on the sides of the boxes s s, and the channel-bars may be operated thereafter to perform any of their other functions.

I have described the cover B as of plateiron, but it may be made of fire-brick as well, and I contemplate making it so whenever it is requisite to prolong the cooling beyond ,what can be readily accomplished in the plateiron structure. rlhe time of cooling in the plate-iron structure, however, may be greatly modified by varying the thickness of the metal, or the plates may be double, with an air-space between them, and the width of this air-space may be less or more, or the plates may be covered with asbestus or other refractory felting, any one of which modifications will affect the rapidity with which the heat of the air within the chamber can be transmitted to that exterior to it without affecting the uniformity of its transmission, and such modifications will consequently affect the rapidity of the circulation of the air within the chamber and its cooling effect.

It is possible that with very great irregularities of section in the lnetal to be annealed it may be desired to accelerate or to retard the cooling of certain sections of the annealing-chamber, which can be effected by modifying the structure of any part of this chamber, as above indicated. I prefer, therefore, to use the plate-iron annealing-chamber, not only because its cooling properties can be readily modified,but because it is lighter and can be more easily transported than a firebrick chamber.

In practicing the art of annealing I have discovered that at least for certain classes of work it takes much longer to cool the metal to be annealed than it does to heat it, and under such circumstances I provide two or more annealing chambers mounted upon wheels or otherwise arranged, so that each IOO IIO

chamber can be in turn brought up to the heating chamber to be charged and then transported to some other locality to cool and to be discharged.

The furnace shown and described having `been built for annealing eye-bars, and such a bar being shown supported in position in the heating-chamber, (see Fig. 2,) I will now describe the operation of charging and discharging such bars, which are first assembled on the charging side and arranged edgewise that is, with their flat sides vertical. Distance-pieces are placed between to permit a free circulation of hot gases around each bar. They are bolted together through the holes in the eye to maintain this position and rest on the wrought-iron frames CZ d d d, so that the center of gravity of the mass of bars will fall just inside the outer set of rollers--that is, between these rollers 4and the annealingchamber. The boxes e c e e are now in their lowest position, and the racks are passed under the mass of bars and over the rollers, and so that the end of the racks will mesh'with the pinions on the shaft lV. The rollers are now raised by admitting the high-pressure water to the cylinder Z, which actuates the channel-bars m m m m, by which operation the load will be transferred from the wroughtiron frames d d d CZ to the racks t t t t. The cover P' P of the heating-chamber is.now raised to the position shown by dotted lines in Fig. 3, and then, by turning the handwheels p p p p, the mass of bars will be'carried into the heating-chamber over the castiron hollow supports l) b l) l). When in this position, a rectangular bar of iron u, that will pass freely between the wrought-iron supports d CZ cl d, is now laid on top of each cast iron hollow support b b l) b. The channelbars m m 'm m are then moved in the oppo-4 site direction, which will lower the mass of bars upon the rectangular bars resting upon the top of the cast-iron supports. The racks may then be withdrawn and the cover lowered to the position shown by the full lines in Fig. 3. As soon as the mass of bars has acquired the proper heat the cover should be tilted in the opposite direction, the racks inserted as before, but from the opposite side, then raised upon the rollers, so as to transfer the load upon the cast-iron supports to the racks. The rectangular bars upon the top of the cast-iron supports Z) b Z9 b should then be transferred to the wrought-iron supports d d d d in the annealing-chamber and placed between the two bars, of which each of these supports is composed, so as to rest upon the thimbles. ont over the wrought-iron frames on the discharging side and lowered upon the red-hot rectangular bars just transferred from the heating-chamber to these frames, and the racks can then be withdrawn. The cover P P of the heating-chamber is now lowered into place. The covers on the bottom of the annealing-chamber are then placed over the The heated mass may then be runouter row of boXes e ce e, andthe cover X of the annealing-chamber is lowered to its position in the channel-grooves, the sand in which makes it air-tight, and in this position it nemains until the bars are sufficiently cooled to be removed. In the meantime an other charge of bars may be placed in the heating chamber. The rectangular bars which are placed upon the top of the castiron supportsin the heating-chamber serve a twofold purpose. The space which they occupy upon the top of the support-s affords ample clearance for the mass of material which is being transferred to the heating-chamber and avoids the necessity, which otherwise would exist, of lowering this material to the level from which it started; but their main obj ect is to provide a support to this material in the annealing-chamber having a temperature equal to that of the metal which is to be annealed, so as thereby to avoid a local cooling, which would frustrate the object for which the annealing is resorted to. The bars may be removed from the annealing-chamber with safety before they are cool enough to handle, and to facilitate this operation the wrought-iron frames (l d d d are extended beyond the annealing-chamber, and when the cover X of this chamber is raised a bridge is thrown across the opening between the two top rails of the frames d d d d, the bars are disconnected, and they are slid'one by one onto the outer end of the wrought-iron frames, from which they may be removed at any time.

Then articles of smaller dimensions are to be annealed, they may be placed in cast-iron boxes provided with openings for the circulation of air or on grates which may be charged into the heating-chamber or discharged from the heating-chamber to the annealing-chamber, as above described.

By the arrangement of heating-chambers hereinbefore described certain advantages are secured in the maintenance of this chamber which at first sight are not apparent-- thus, access to the interior is conveniently obtained without the use of doors, which necessarily afford space through which dame and heated gases will escape. The loss of heat is not by any means the most serious loss, for at such points the doors and the adjoining parts of the furnace become overheated, so that it is impossible to maintain them in proper condition without resorting to water circulation, as. is well understood. This is not only expensive in first cost, but also in maintenance, and it absorbs a large amount of heat which -otherwise would be available for the charge. The line of opening to my heating-chamber being upon-the plane of the bed and horizontal, there is little tendency for flame or heated gases to escape at the joint, and the cost of maintenance is thereby largelyV reduced, while the economy of heating is promoted. When the chamber is charged and discharged from one side only, the transferring-racks may be used as canti- IOO levers, and but one shaft with its pinions to gear into the transt'eiring-racks will be required 'tor charging an d discharging the heating-chamber only, and it the vertical movement of this shaft is suflicient the charge may be transferred to the anhealing-chamber with this one shaft; but when the charge must be transferred to the annealing-chamber it will generally be more convenient to use two shafts with piuions gearing into the transferringracks, and they should be arranged so that both shafts can be raised and lowered simultaneously or alternately to suit the character of the work required of them, all of which will be'readily understood by any skilled meehanic.

I have filed two applications, of which this is a division of one, for processes in the art ot annealing steel castings and steel forgings, said application being serially numbered 230,558 and 284,001, filed March ll, 1887, and September 8, 1888, respectively.

I do not intend to claim in this application the improvement in the art of annealing steel castings or forgings which consists in first heating such casting or forging in a suitable furnace to an equable and proper temperature throughout the mass; then transferring such heated metal into an annealing-chamber, from which the surrounding air and the heated gases of the heating-furnace are excluded when this chamber is closed; then closing this chamber; then recharging the heating-furnace with other metal to be heated and annealed; then replacing the charged anhealing-chamber with another similar one not charged, the number of; annealing-chambers being so proportioned to the heating-capacity of the heating-furnace that the heating-chamber may receive heat, and discharge the metal tobeannealedconsecutivelyandcontinuously. Nor do I intend to claim in this application the improvementin the art of annealing steel castings and steel forgings which consists in first heating castings or forgings in a suitable furnace to an equable and proper temperature throughout the mass; then transferring such heated metal into an aunealing-chamber, from which the surrounding air and the heated gases of: the heating-furnace are excluded when this chamber is closed, and then closing this chamber so that the heated metal within it shall be cooled by the circulation of the air within this chamber. No1-dol intend to claim in this application the improvement in the art ot' annealing steel castings and forgings which consists in supporting the cast ings or fox-gings to be annealed upon heated su p ports with in the annealin g-chamber, which chamber is cooler than said heated supports. Nor do I intend to claim in this application the improvement in the art of annealing steel castings and steel forgings which consists in heating the articles to be annealed in an annealing-chamber and regulating the heatcon ducting capacity of the walls of said chamber, so that all parts of said casting or forging shall be uniformly and properly cooled, as all of the above form subject-matter of the two applications specifically mentioned above.

lVhat I claim as new, and desire to secure by Letters Patent, is-

l. In a heating-furnace, the combination, with a hearth provided with a flue connected to the chimney, of a cover forming the sides and roof of the heatingchamber, provided with feed-openings below the sides of such cover for the admission and discharge ot' the materials to be heated, substantially as de scribed.

2. ,In a heatingfurnace, the combination, with a hearth provided with a flue connected to the chimney, of a cover forming the sides and roof of the heating-chamber, provided with feed-openings below the sides of such cover and bearings near the level of the hearth, on which said cover can be rocked, with means for tilting the same.

3. In a heating-furnace, the combination, with a hearth provided with a flue connected to the chimney, of a cover forming the sides and roof of the heating-chamber, provided with feed-openings below the sides ol` such cover and bearings near the level of the hearth, on which said cover can be rocked with hydraulic cylinders that have a common supply of pressure-water operating through one valve for tilting the cover, substantially as described.

WM. SELLERS. Titnessesz JOHN L. PHILLIPS, EDw, R. HARPER.

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