US1553618A - Electric furnace - Google Patents

Description

Sept. 15, 1925. 1,553,618

L. D. KAY

ELECTRIC FURNAC E Filed May 22, 1923 4 Sheets-Sheet 1 Sept. 15, 1925.

L. D. KAY

ELECTRI C FURNACE Filed May 22, 1923 4 Sheets-Sheet 2 Sept. 15, 1925. 1,553,618

- L. D. KAY

ELECTR I C FURNACE Filed May 22, 1923 4 Sheets-Sheet 3 Sept. 15, l 925.

L. D. KAY

ELECTRIC FURNACE Fild May 22,

1923 4 Sheets-Sheet 4 Patented Sept. 15, 1925.

UNITED STATES LLOYD D. KAY, OF LOS ANGELES, CALIFORNIA.

ELECTRIC FURNACE.

Application filed May 22, 1923. Serial No. 640,71-1.

To all "whom it may concern:

Be it known that I, LLOYD D. KAY, a citizen of the United States, residing at Los Angeles, county of Los Angeles, and State of California, have invented a new and useful Electric Furnace, of which the following is a specification.

This invention relates to furnaces, and, while many features of the invention may be utilized under other circumstances, the invention is expected to be especially useful as applied to an electric furnace. In a certain type of electric furnace, the body of the furnace is mounted on an axis so that it is capable of being tilted when the molten metal is being poured. In orderto tilt the furnace, gears have been employed, for example, a worm-wheel and worm, but where a worm-wheel or gear-wheel is employed there is always a slight'amount of back-lash present which will permit a slightlost motion in operating the device; The presence of this'lost motion is objectionable for many reasons, among which is the fact that'the' ticularly.illustrating the device for adjustmg the tiltof the furnace.

shifting of the molten bath from one side of the furnace to the other side may suddenly take up the back-lash and give the molten metal an impetus toward the low end of the furnace; this is dangerous.

furnace, it is desirable to have the metal run off ata level as far removed as possible.

' 'wtr'i'c cables'ito them from the slag.

Theg'eneral object of this invention is to provide a-furnace of simple construction having means for overcoming these difficulties and in which the metal in the furnace is counter-balanced: also to provide a 'construction which will enable the furnace to' be tilted without the exertion of great force; also to provide a furnace that is so constructed that the metal poured from it will be drawn off as far as possible from the floating slag.

v A further object is to provide simple means for supporting and adjusting the electrodes and to provide simple means for counterbalancing them and compensating in In'pouring the metal from such a tilting The invention consists in the novel parts and combination of parts to be described hereinafter, all of which contribute to produce an efficient electric furnace.

A preferred embodiment of the invention is described in the following specification, while the broad scope of the invention is pointed out in the appended claims.

. In the drawings:

Figure 1 is a front elevation of a furnace embodying my invention.

Figure 2 is a plan of the body of the furnace with the cover removed and showing other parts broken away. ..-Figure 3 is a cross-section through the furnace body taken on a line 33 of F igure 2.

1 Figure 4 is a side elevation particularly illustrating the counterweight mechanism.

.3 Figure 5 is a plan illustrating the details of the means. for,.adjusting.the electrodes and their counterweights. I

Figure 6 is a side elevation showing'a portion of 'theibodyof the furnace and par- Figure 7 isua seotiontakenabout on the .line77 of Figure 6 and,particularly illustrating the details of the adjustingv screw.=

Figure 8 is a 5 plan particularly illustrating .the details, of the electrode frames and" shQwingthe-means for connecting the elec- Figure'9 is a verticalsectionftaken about {on the line 99 of Figure jS illustrating the porting the'electrodes in the holders. I .Flgure' 10 is a vertical section taken about on the line 1010 of F ignre 8 u on an enlarged scale and further illustratlng details of the connection for theelectric cable's.

Figure 11 is a vertical section taken about on the line 1111 of; Figure'S and showing the connection for the fixed end of the cable. In practicing the invention, I provide a furnace body which is supported so as to rotate on a substantially horizontal axis. This body is provided with one ormorepouring spouts. I provide an adjustable means for positively holding this body against rotation on the axis in either direction. By the term positively holding I mean to say that the device I employ is constructed so it is devoid of back-lash, hence it is impossible for a slight-rockingamovement of the body to take place on its axis unless that movement is caused by the adjustment of the adjusting means. The body 1 may be formed of a 5 sheet metal shell with 'firebri'ck lining 2 and provided with a pouring spout 3 at each end. This body is preferably of slightly elongated form and supported to rock in its middle plane on a substantially horizontal axis near its center of gravity, for-which purpose the opposite sides of the shell are provided with trunn'ions 4. These trunnions may be supported in pedestal bearingsb which support the'body over an ash pit 6. The furnace may be'provide'd with a cover '7 of any suitable construction through which aplurality of electrodes '8 pass, each electrode being passed through an insulating sleeve 9 which supports it effectively uponthe cover.

I provide simple means for raising and lowerin the electrode and for counterbalanci'ng t em in such away that when the electrode becomes worn and is fed down- "g'wardly so thatits center of gravity approache s'theaxis of rotation of the furnace, then there is a corresponding movement of its 'cou'i'ite'rweight toward the axis ofrotation.' In 'tliis"way, "I-not'only counter-bal- "since each electrode," but-I compensate for the i'nward feeding I movement 'of the electrode, thereby preventing :the weighv-of the electrodes "frominterferingin-any way with the "tilting ofth'e furnace? Furthermore, I 'mi'nint these electrodes on a frame which is ways- This frame has aiimpw'ai'dextensmn 12about in line with the-'si'tte offthe wall bf Z the fiirriacejfanditalsolhasja downward ex-'- tension "13 'vvhilr' 'is' located Qnfthe outer side I er dnaadjacait pefl'estal' beai-ing The extehsi'ori' 12 operates as a "guide for the electrodes for which --purpose "it is preferably I con'sfr'u cted bf "a plurality "of I -beams or trod'e"fran'ic 15 (see Figs-*1 and 8): These -"clec'trddframes maybe formed with an 'upper arm 16 andiai lower-arm 17,ea0h arm being" provided: with a yoke 1 8 (see-Fig. '8)

at' its'"innerendbarryingrollers 19 which "engage 'infthe channels on opposite sides of the I-beam 'At thempperfend of each I-beam guide sheaves o'r pulleys *20 are provided over which a cord- 21 passes'which is attached at 22 to itscorresponding electrode frame. I i The lower end-*of this cord 21 is attached toa device of special construction which may be operated at will to lower the electrode, and this operation of lowering the rigid with the body of' the -flirnace and,

corresponding counter-weight 23. In orderto adapt these counter-weights to use with electrodes of difi'erent weights, each counterweight consists of an open receptacle (see Fig. 4) the interior of which may. be filled with scrap-iron 28 or similar material,-

The cords 21 and 27 wrap about thedru m in opposite directions so that when the upper cord 21 is payed out to permit theelectrode 8 to descend, then'the corresponding counterweight will be'slightly raised in its guideway. Any suitable means may be provided for operating the drums '26. In 5 .I. illustrate a simple worm wheel 29 rigid with the: drum and actuated by a worm 3Q iwith an operating 'wheel 31 (see {Fig In order ftO- provide a considerable, depth of-metal alt-the pouring spout, I prefer to construct the ends of the'bas1ii 32 in the firebrick liningso that the channel (through whi'chthe metal flows invgoing to the spout -fl ends of thebasin;withi convergmgisides or side-walls 33. In -this -way, ;as. theu metal flows outqinto-the end of the .iof-"the an'etal increasesand, hence the rnetal fwhich flows out of thespout; wilL betaken from a considerable depth belowQtdre k s lag floating on "the; surfacei of the I molten rmass.

1 is very much contracted-in widthfa n d 7700 is mpl he is p ypaaprgridh eih The bottom (if the furnacehas upwardlyjn 1 clined end walls indicated by the dotted lines- 34 in- Fig. 4. The slagis held' by, a gate 3; i a;

By reason o'f-the constant raisingand lowering of theelectrodesyany ;ca.ble connection is subjected to-slight movement. Ipro "vide a. connection of; simple construction which-"can be readily made and which msures an ample area of contact at the connection as well as insuring a secure connec-;;

tion. In order to accomplish this,, I ,provide an electrode holder 35 forieach elec trode with atapered socket :36 which is in metallic connection t he hglderi For convenience, this, tapered socket {may be;

formed in a-small bracket 37 bo lte dion the side of the electrode holder. The bracket 37 is preferably constructed of copper or brass and the tapered s0cket36 isisi'm'ply a tapered bore. This bore receivesja "tapered,

plug 38 which has the same angle of taper as the socket, and this plug is secured to the end of the flexible cable 39 which carries thecurrent to or from the electrode. Plug 38 is simply in the form of a hollow cone with opening 40 at its large end. In securing the plug to the end of the cable, the end of the cable is bared'of insulation and the plug is held in a vertical position and filled with molten metal such as lead. The 0 bareend of the cable is then thrust through the opening 40 and jammed down to the bottom or small end of the plug. This will displace a considerable amount of lead, but leaves the inner chamber of the plug completely filled with lead, which operates as a good conductor connecting all sides of the end of the cable with the adjacent wall of the plug. The plug may be held in the socket by means of a threaded stem 11 at its small end which passes loosely through an opening 42 at the inner end of the socket and is secured in place bya nut 43. The fixed end of the cable 39 is preferably provided with a similar plugand socketconnection (see Fig. 11)" which the socket 4-1 is constructed as part of a fixed bracket45 which is mounted'on' an insulating support46. This socket receives a taperedplug 47 secured to the cable in the same way as described in con .nection with 'the plug 38'. In order to alm :A low for .the'tilting of the furnace and the j ra'ising orflowering"0f"the "electrodes the "cable 39p'referably is permittedto hang in loop; (see Fig. 1). .In order totilt the furn aceilatjavill,Ifprovide an adjusting der vic'e whi ch isl preferably .in the form 'of a 'crew d'evi'ce 48 "(see Fig. 6). This gialyfc actpd -wa the body of the fur- ":nace -Foi" this purpips'e, thejarm {19 may red 21 ectlyfto' the' outermost truncatedito'receive a l oose'pin 50"arid in this piii a feed-screw 51 'ha's'a swivel head 52.

The outer} end of the: adjusting screw 51 carries'a I' ut 5:3, .the sides o f'which are formed into pinsonpintles 54' which rock in the upper e'nd of the pedestal bracket 55. This nut 53 is'threaded"preferably with a square'thread tofit the square thread on the screw 51, and the endof the screw is pro vided with,a-liand wheel 56 for rotating it.

' 'lVi'th this organization of parts, it will be noted that the device 48 will hold the body 55 positively against a slight movement in either direction on its axis. At the same time, the hand-wheel 56 and the threads on the screw 51 give sufficientleverage to enable the molder to tilt the furnace at will.

In order to hold the electrodes 8 in position, each holder 35 is formed with a tapered bore 57, the large end of which is disposed upwardly (see Fig. 9), and in this bore I place a pair of tapered bushings 58 which have flanges at their upper ends, and are inend of this arm is bifurserted from above. These bushings are bored to the diameter ofthe electrode so that when they are pressed downwardly they act as wedges in the conical bore 57 and clamp the electrode in place. There is nothing connected to them; they are freely movable upwards with their path unobstructed so that they can be instantly dislodged by a blow under the flange.

Each electrode holder 35 is effectively insulated from the electrode frame which supports it by means of an insulating plate 59 to which the holder is securedby means of insulated bolts 0 (see Figs. 8 and 9).

The counterweights 23 are placed at such a level that when cooperating with the electrodes, the weights may project below the lower edge of the guide plate 24. \Vhen the furnace is to be tilted, the electrodes should be lowered, and the counterweights raised to any point desired to enable the weights to operate as an effective counterbalance for themetal as the furnace tilts. As the furnacetilts, of course the weights rest against the sides of the-frame bars, 25, and so they swing away from the vertical plane of the furnace. In this way their lever arm 'as a counterbalance increases, thefurther the furnace is tilted. i

' In order to guide the back-plate 24 as the furnace is tilted, I provide. two .rollers- 61, which are carried respectively in brackets 62. One of theserbracketsis attached to the pedestal 5 at one side and' the other'at the other side (see FigsL'l and=14)..-

It is understood that the embodiment of I the invention described. hereiniisz onl'y -one ociate dwith mn arm 49 which is of many embodiments this invention may take and'I do not wish to be limited inthe practice of my invention nor=in my-claims to the particular embodiment set forth. 13%;

What claim is: ,1 1. In an electric furnace, the combination of a body having a.'fire-brick lining,

trunnions supporting the body tocrotate on a substantially horizontal axis,- .a pouring spout carriedby' the body at fits end, a pin loosely mounted in the arm, an adjusting screw having a swivel connectionwith the pin, a nut mounted'to rock on a=.fix'd.axis,-

and having a thread connection with the screw, 'and a hand wheel attached directly to the screw for rotating the screw to rock the arm and tilt the furnace body on its axis.

2. In an electric furnace, the combination of a fire-brick lined body, means for supporting the same to rotate on a substantially horizontal axis, an electrode guiding frame carried by the body and extending upwardly above the same, an electrode guided on the guide frame and extending down into the furnace, a counterweight for the electrode supported so as to move about the said horizontal axis when the body is tilted, and carried below the said axis of &

rotation, means for raising and lowering the electrode, and means for tilting the body on .its axis of rotation.

3. In an electric furnace, the combination of a fire-brick lined body, means for supporting-the same to .rotate on a substantially horizontal axis, an electrode guiding frame carried :by the body and extending upwardly above then-same, an. electrodeguided on the guide frame-and extending down into the furnace, a counterweight for the electrode carried-in the guiding frame below the said axis of rotation, means connected with the electrode and the counterweight operating :to lower the electrode and raise the counter --weight, and means for tilting the body on its axzis of rotation.

4. :In-an electric furnace, the combination of=a dire-brick lined body, means for supporting the same to rotate on a substanatiaillyrhorizontal axis, a guide frame carried "by the body and having an upward extensionafor-guiding an electrode and a downfwardaextension for guidinga counterweight, an electrode frame guided on the guidefn'ame and having means for holding an electrode, a counterweight guided in the :lower portion of the guide frame below the axis of rotation of the body, means for raising :and lowering the electrode frame and thecou'nterweight, and means for tilting the body on its axis of rotation.

5. 'In an electric furnace, the combination of "a fire-brick lined body, means for supporting'thesame to rotate on a substantiallv horizontal axis, a :guide-frame carried by "the body and having an upward extension for guiding-an electrode and a downward extension for guiding .a counterweight, an electrode frame guided on the guide-frame and having means for holding an electrode, a counterweight guided'in the-lower portion o'f the guide-frame below the axis of rotal tlOlbOf the body, means for raising and lowering the electrode frame and the counterweight, means for tilting the body on its :axis of'rotation, and a flexible electric cable heldifixed :at-one end and connected at its .=other end :with the electrode.

6. Inaan electric furnace, the combination of a ifire-br'ick lined body, means for supporting the same=to rotate on a substantially horizontal axis, a guide-frame rigid with sion, means for raising and lowering each (electrode and its .conrespondmg counterweight, and means for tilting the body on its axis of rotation.

7. In an electric furnace, the combination of a body, means for supporting the same to V rotate on a substantially horizontal axis, and a .spout carried by :the body at its ends, a fire brick lining forming a-basin within the body and having sides converging toward the said spout, whereby when the furnace is tilted'the depth ,O-f metal .is increased in the vicinity of the pouring spout, thereby facilitating the ,pouring of the metal from a depth 'below the slag.

:8. In an electric furnace, the combination of an electrode holder having .a tapered socket metallically connected therewith an insulated cable,a tapered plug receiving the end of the said cable, a packing of conductive material surrounding the end of the cable within the ,plug, and providing metal between the side of the cable and the wall .of the plug, and means for securingthe plug in the tapered socket.

9. In an electric furnace, the combination of a body having a fire-brick '-lining,,means for supporting .etheobody .to rock on a fixed substantially horizontal axis passing trans versely through .the body, a pouring spout carried by the body at its end, an arm rigid,

with the body, a .nut-and-screw device associated with the arm for swinging the arm in either direction to tilt the furnace body on its axis and having a swivel support for the screw at the arm and another swivel support for the'screw ata fixed point, and

a hand wheel connected directly to the nutand-screw device for rotating the screw in unison with the hand wheel.

Si ned at Los Angeles, California, this 8th day of May, 1923.

LLOYD D. KAY.

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