USRE7644E - Strohg - Google Patents

Description

J. 3. ARMSTRONG. I, FURNACES son HEATING STEEiI. INTE P RING. No 7,'644.

Reissued May 1 UNITED I To a l? whom iii may cmwcwa- Be ll) known that L Jeen BELMER Ame STRONG, cf the town cl Gr 1 mil, in the count of Wellington, in the Pronnce cl (.lntnrio, Genetic, carriage-spring manufacturer, have invented a new and useful Improvement in Furnaces for Heating Steel in Tempering; which imgircvenient is fully set forth in the to the accompanying drawings.

My invention relates to the heating of articles manci'actnmd from steel, or from steel and iron, in tempering. It consists of a close oven or retort, to which a pyrometer is zittaclied, heated from c blast-furnace pieced below the retort, er in any other convenient posi tion, the heat from the furnace being forced to circulate freely around the retort in lines which receive end discharge on alternate sides, the blast and discharge being regulated by pecnlicrly=constructed dampers, V

The object of my invention. is to uniformly raise-the temperature of the contents of the retort to any required degree of heat, and to hold the temperature stationery at such degree until the whole niece ciiziic contents has time cugiily end eniforuily acquired the desired cl cc cl'hcut.

y inreiitiec lies douliic ecilicc 'en in art lie 1 ring uniformly tc M eteted oiling in oil or any of the usual liquids; second, drawing or letting down the temper of steel, after hardening in usual vmy ta a; uniform degree.

In the accompanying drawings, Figure l is a longitudinal section, and Fig. 2 is a cross sccticrr, of e tempering-furnace constructed according to my invention. Fig. 3 is a detail of th'e damper used in regulating and distributing the heat. Fig. 41s a. detail of retort, showing fines, &c. Fig. 5 is a detail of cutoii dam'pcrs. Fig. 6 is a detail of furnace and retort doors. r

A is'a furnace, constructed, in the usual having an esh-pit/B, underneath. a are the usual grate-hers resting enlhe slce The retort forming the roof of the furnace.

Specification forming part ot' Letters Patent 1%. 170,438, datec wllcvemhor C Me 1, 18?? cpylicetion filed February 25 "following ececiiicetion, reference being bad way, of brick or other suitable materiel,'

walls 0. Immediately over the furnace tce. close retert D plain-iii, the bottom cf the JGHN B. ARMSTRQIIG, OF GUELPH,QNTARIO, GANADA.

i0, 187%; reissue No. 5162-452, carted walls, roof, and floor the retort e eonsiructcil ci'fire-clcy. firelnicir, orotiier sci tine material, when (lie retcrt is used fer lien-ting the steel to harden but when tile iurnzice is be used only for drawing the temper after hardening, oi cast or Wrought iron retort may be used, as it less degree of heat is requires? than in the former process. E are fines which take the Ii-nine, heated geses,&c., from the upper pert of the furnace, up cne side, over the top, and down the other side of the retcrt, the hunted gases, smoke, Ceca, escaping through suitable passages to n ccimncu vent. These tlucsli are narrow pzissz'iges, i'oriried along the whole length cf the retort, the intervening walls being tliin partitions, EQ'ci" iirecley or castiron. The flue-s are so arranged that they take the draft from; and deliver it at alter-mite sides or the 'urnece, tli us equalizing the (lie tribution of the heat over the whole surface of the retort. F is the blast-pipe placed beneath and extending under the whole length ot'tlie furnace. The'lilast-pipe I is cylindrical in shape, the upper surf-(tee being perforated with licles j; of any convenient diameter pieced at 2*.- regular distance apart tlirougli'cut the entire length under me i'nreece. Fitting within the enter pipe F is an inner revelving' tuce. or darn per, 1*, perlcrateil with liolecf ie crime rliciznice impart longitinlirnilly en e outer tube the only diil'erenec 'ceing tin tire liolesf ere elongated in EH31 verse illlfi'elli lfiil zinc are cut tc form :1 r ii en the tube The object in time cutting the iioles in tlie inner'tcbc or damper i is to able the operator to vary the position cf tire delivery of the blast, in order t c equalize the heat in the furnace and retort. Thus lie may give an equal distribution oftlie 'olest tlirengir out the entire length of the furnace, or nemaiy cut it 01%; partially orcutireiy, at one end, throwing the Whole blast into the other end, or vice verszi. G G are cutoff dampers, an ranged to close the exit ends of the liues E, regulating the discharge of the heated gcsee, 834)., from the furnace. H H are the doors, of the furnace and retort, hinged to and fitting on the frames ii, es slicwn. The frames H are bolted or fastened to the brick-work in cnyconvenient mtg, the opening' in. the from ti ec in it'or tlie riccrs being larger then the holes left frames.-

in the brick-work. [hus a rim of brick-Work appears aronnd'the entire inner edge of the The doors consist of'an open frame of iron, H, filled in with fire-bricks lathe bricks fitting, when the door is closed, within the opening left in the brick-work. Thus no portion of the iron door or frame is exposed to the action of the heat. As the fire-bricks are burned away they are pushed forward again and again --until consumed, when new bricks are inserted, as-before. I is a pyrometer of the usual construction, fitted to the top of the retort in such a way that the expand ing-bar extends-downward into the interiorof the retort Within an open guard-tube, i.

Having now described the parts of my in- Vention, I will proceed to describe its operation: For the purposes of example, We will suppose .that the retort is charged with single plateoast-steel carriage-springs. These springs are thick inthe center, tapering away to each end. The furnacenever cools during the night, the walls being constructed thick enough to retain the heat. The operator knows the degree of heat to which the steel requires to be raised in order to give it the desired temper. He watches the face ot'the pyrometer, and, by

manipulating the blast and blast-discharge,

he is enabled to bring the whole of the contents up. to, without exceeding, the proper degree of heat. Of course the thinner portion, of the plates reach that degree first; but they can-go no higher than the degree indicated on the pyrome'ter, waiting, as it were, until the thicker portion has been thoroughly permeated, and the whole mass is in one uniform heat, when the springs are taken out and dipped. r

In lowering or letting down the temper after hardening, the same operation is repeated, the operator knowing the particular degrees of heat which correspond to different tempers, and Working accordingly. In let ting down temper, the degree of heat is not required to be so high as in the former case, and the retort, if used specially for this purpose, may be constructed of cast-iron, Furnaces for tempering very long saws, 8m, may

be fitted with two pyrometers but in ordinary cases the heetrcan be perfectly regulated by V the spirally-allanged dampers with one.

The advantages gained by my invention are first,; that steel of regular vandirregular shapes and thicknesses can'be raised-tofwithout any portion being allowed to exceed,- a uniform degree of heat in tempering; second, that the blast to the furnace can be applied equally or unequally during its whole length, to suit circumstances; third, that by the application of the pyrometcr, the operator is enabledto' gage the heat in the retort, raisingior'loweringfthe temperature of the furnace accordingly, and, knowing the degrees of heat which give the steel certain tempers, he is-enabled tdt'urn out every charge to a known and exact temper.

I claim as my inveutiozr- 1. In a furnace for heating steel in tempering, the retort 1), formed, at intervals 1 around. its'entire length with partitions E1, to form narrow passages or flues E, said fiues being. arranged or opening alternately, first onone side and then on the other, so that they take the draft from and deliver it at alternate sides of the furnace, thus equaiizing the dis tribution of the-heat over the wholesurface of the retort, substantially as described, 7

2. The blast-pipe F, consisting of the inner pipe F, perforated with the spirally-arranged holes j in combination with the outer pipe F perforated with the holes f, arranged and operating substantially-as described, and for the purpose specified. I I

3. The doors H, consisting of the frames 11, constructed to leave a margin of brickwork between the inner edge of the furnace and retort openings, and the iron door 11 fitted in with fire-brick h, arranged and operating substantially as described, and for the purpose specified.

4. The combination and arrangement, in a furnace for heating steel in tempering, of furnate opening and discharging flues E E, blastpipe F F E, and doors H 151% H composed of 'iron and fire-brick, all constructed and adapted to operate substantially as and for the purposes described and shown.

. J. B. ARMSTRQNG. Witnesses:

T. H. SGARFF, WM. E. SLAK R.

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