US2332944A - Electrode holder - Google Patents

Description

Oct .19 w. R. STEWART 2,332,944

ELECTRODE HOLDER I. Filed May 7, 1942 I s Sheets-Sheet 1 1/ E YER 7% ZZ /WTSZz rZi Oct. 26, 1943. w. R. STEWART ELECTRODE HOLDER Filed May 7, 1942 3 Sheets-Sheet 2 Oct..26, 1943. w. R. STEWART 2,332,944

ELECTRODE HOLDER Filed May 7, 1942 s Sheet-Sheet 5 Patented Oct. 26, 1943 ELEQTRODE HOLDER William R. Stewart, Sterling, 111., assignor to Northwestern Steel and Wire Company, Sterling, 111., a corporation of Illinois Application May 7, 1942, Serial No. 442,014

8 Claims.

This invention .relates to a holder or clamp especially adapted to support a member while placing the member in good electrical contact therewith.

Specifically the invention relates to electrode holders useful on electric melting furnaces.

"While the invention will hereinafter be specifically described in connection with an electric furnace for the melting and refining of steel it should be understood that the holders of this invention are adapted'for general'usage and that the invention includes within its scope all uses of the holders.

In electric metal melting furnaces electrodes such as carbon rods depend from supports into the body or hearth of the furnace. These electrodes must, from time to time, be adjusted relative to their supports in order that progressive feeding of the electrodes into the hearth por tion of the furnace can continue as the electrodes are used up. It is quite customary to" add elec-- trode lengths to the tops of partially used elec: trodes so that the feeding of the'electrodes'into the hearth as the same burn up may continue without wastage of electrode'material;

Since the electrodes" must receive electrical current it is highly desirable that the supporting members or holders for the electrodes have good electrical contact therewith. This electrical contact should not be rendered inefficient by heating of the holders such'as'n'ormally occurs during operation of an electric furnace.

The present invention now provides electrode holders which can receive electric current therethrough for energizing the electrodes gripped thereby. The holders of this invention have appreciable area contact with the electrodes" so as to establish excellent electricalflconductivity between the electrodes'and holders? I The holders of this invention canbe quickly clamped around electrodes or loosened'froi'n electrodes as desired. As a result of this feature the electrodes can'readily be adjusted relative to the holders.

A special feature of this invention includes the provision of coolant pasasgeways in the hold- I ers so that cooling material may be, circulated.

therethrough to prevent excessive heating of the rent without danger of establishing short circuits. g

Another feature of this invention resides in the utilization of hollow tubes to'con'duct coolant and electrical current to the holders. The coolant will pass through the tubes while the electrical current will be conducted by-the tubes.

It is, then; an-object of the invention to provide a holder or-clamp capable of being quickly adjusted for gripping a member and for loosening the gripped member.

A still further object "of the invention is to provide a, holder capable of establishing good electrical contact with a held member over an appreciable area of 'the inemberfl A still further object of the invention is to provide an electrode-holder especially adapted for use on electric melting furnaces which is not rendered inefficient by heat.

- A still further and specific object of this in vention isto provide an electrode holder for electric furnaces which is: capable of supporting an electrode in goodyelectricalicontact therewith and which isadaptedto' be cooled during use by flow of a coolant therethrough.

Another specific object or the. invention is to provide an electrode holder for electric melting furnaces which will not warp during use and which can be" readily loosened from an electrode held thereby. 1

Other and further objects of the invention will be apparent to those skilled in the art from the following detailed description of the annexed sheets of drawings which, by way of preferred example, illustrate one embodiment of the invention.

Onthe drawings:

Figure 1 is a top plan'view'of an electric melting furnace equipped with electrode holders according to this invention.

Figure 2 is a side elevational-viewof the melting furnace and electrode holders illustrated in Figure 1 and alsoshowing the manner in which the electrode holders can be raised or lowered relative to the body portion of thefurnace.

Figure 3 is an enlarged fragmentary plan view of one of the electrode holders with parts cut away and shown in horizontal cross section.

Figure 4 is a fragmentary side elevational view of the electrode holder illustrating the same in gripping relation to an electrode.

Figure 5 is a front end elevational view along the line V-V of Figure 4. Y

Figure 6 is a vertical cross-sectional view hearth for the materials to be charged therein. A horizontally swingable cover I2 is provided for the body H and this cover may have an extension 12a for supporting three vertical columnsdii. A carriage i4 is movably mounted on each 091* umn I3 so that it can be raised and lowered relative to the cover of the furnace. on the carriage M can, for example, roll on opposite rounded end walls of the column. The carriage structure and the manner of supporting the same relative to the furnace can of course be modified widely and it is merely intended to show a movable type of mounting for better illustrating the electrode holder of this invention.

As shown in Figure 2, the tops of the columns l3 can have supports such as thereon carrying pulleys I6 over which a cable or other lifting device I? can be passed. The cable fl is also-directed around a pulley i8 carried by the carriage structure l4. One end of the cable can be anchored to the support ll as at Ila for example. Actuation of a cable will thereby raise and; lower a carriage (4 on its supporting column l3.

Each carriage M has a laterally projecting tubular mounting part or clamping sleeve 19. As; best shown in Figure 7, each tubular. mounting part I9 is composed of semi-cylindrical mating sections Ha, Ha having ou'tturned flangesJQb,

I92) for receiving bolts therethrough to-draw, the half-sections together inclamping relation.

around an inserted member.

A rigid metal tube 2! is inserted in each memher If) and is surrounded by a sleeve 22.0f mica or other electrical insulation sothat the tube. 2| will be in insulated relation to itsmOuntingsup port 53. clamped tightly around the 'mica sleeve v22 ;so that the tube 2! will be fixedly mounting member l9.

Each tube 2! projects longitudinally beyond the end of its mounting member l9 and, has its projecting free end vertically slotted as at 2 l a and 2th to receive metal plates 23. in Figure '7, the slots 2la are in vertical align-. ment on one side of the tube 2! while the slotsZlb are in vertical alignment on the other sideoi the tube 24 so that the plates 23 wi 1l be mounted in should be understood, of course, that any other,

spaced vertical relation from each other. [The suitable manner of securing the plates to the tube can be used. The slots project inwardlyfrom the free end of the tube 2| for an appr ciable distance as shown in.Figures 3 and 4 50 that an appreciable length of each plate'23. can be disposed in a slot.

The plates 23 project beyondtheiree end. of the tube 2| and receive therebetween the shank 25a of the electrode h0lderg5. Conductor plates 26 are disposed between each plate 23 and th e shank 25a. Bolts 21 extendthrough the plates-23, the conductor plates 25, and the shank 25a lan d have heads 21a on one ofthe, ends thereof-and rs; 14a.

The mounting support l9 can hecarried by the A hown nected power lines 32. to the tubes 28.

rearwardly in spaced relation above the tube 2| and the mounting sleeve I9. The tubes are then bower l outwardly to clear the sides of the carriage l4 and are affixed to the carriage M by means ot brackets 25 lined with a sleeve of mica or other insulatingmatfirialiiill so that the tubes will be in insulated relation to the carriage assembly and .wjlthave ggod-electrical contact with the electrode 25 through the conductor plates 23. The mica sleeve 22 of the assembly will prevent flow -e t curren o th carria erroin the plates zs ndtubeszl. r

Th rear. ends of. the tubes :23. :haye; current conducting clamps 3i thereon to whichar mem Curre s thus-supplied Co la t con uits 3 z a e cou le to th :rear ends of. the tubes.28.,for flow Dim-, cooling-fluid.- thr u h t tubes. 'I hesecone uitsfflccan :be. mad of i ulat on m te ial or can-be connected in insulated ;relation with the. tubes 38; "I:he inner endslof the tubes mare closedzasby means of caps 2 8a or other closure meanagEigdn The electrode holders;25.-are.,thus in fully insulated relation to the SQQPOrting structulTe and receive current fromthapowerlines 32 through; the tubes 28. The ael t ode holdersflieaeh clamp an electrodehtwhichextehd throu h the:

cover '12, of the furnace into the-body portion; M i

. 0f th u nace. .I'hre e ectrodes. an l thre zelecsi trad hold r 25 ate. .-n-. ur s. e ndfi.

Since,th electrod s-hare used ndurinabhe melt ie operat on, ts s necessary toyradually eed. tneelectrodes'into thaboey-l uto'f' theI r-I.

new. d iorrthi air a e-the carriages M- ean;

lower d as desir -ct wheathaele tr de ho1d ers ,Z5, however, .apppeaoh. the -cover i 2; of the furnace, it. is, necessary tbsadd le stas-tosuie- Qfi dfiEr d, i0 lliS purpose, additional eleeq trode mat ialis' i st nedto theuppe endsofi th partially used ele tmdesanttheel ct o e:hol

ers mustb loosenedpso that thaa deqzie gt s;

of e ectrode. material can el ntothefurnaoe.

It has, heretoforeloeen-oaitea problem to loosenthe elect ode. mag ir mthe eripaed el trodes i e the samelwould become used .-to the holdera n h defec .in previously "known .electrode olders resides th t= that. thetsam will become warped "(1 18, 0-. heat Irom and .will expand so,as,to. be out-,of,goodelectrical th u nace.

ontact with. the electrodes :W ll a permittin h el ct ode t slip. Frqquentlylithe electrode.

unfit for use.

In accordance with this invention the Iel'ectrode holders can'be: maintained in a cool condition eventhough theyare 'subjected-to intenseheat from the: furnace. Alsoiii-accordance with "this therewith.

The electrode holder; 25, laslshown-in zfiiiguresn 3 and hasthe sbankmort qn 2.5.aabetweemthe.

v o ductor-plates 2 1 clampinaiaws) 2512.

extend from the shank portion 25a around the electrode While these clamping jaws25b are shown as each having a-semi-cylindrical contour it should be understood that they can have any desired shape depending upon the shape of the member to be gripped thereby.

The shank portion 25a is preferably hollowed out as at 250 at the transition point between the shank and clamping jaws so as to facilitate springing the jaws toward and away from each thfl Each jaw 25b preferably has extended top and bottomsections 25d to increase the area contact between the electrode E and the clamping jaws. These sections or extensions, of course, can be eliminated-if desired.

As best shown in Figures 3, 4 and 5, the clamping jaws 25b terminate in spaced opposed ears orlugs 25e extending outwardly from the free ends of the jaws. The lugs 25e have recesses 25) extending inwardly from the free ends thereof. These recessesof the respective lugs are in alignment with each other and receive square or rectangularinternally threaded bushings 35 in non-, rotatable relation therein. Each bushing 35 has flanges 35a on opposite ends thereof for retaining the bushings against endwise movement in the recesses. These flanges. engage the inner and outer walls of the lugs respectively.

"The flanges engaging the outer ,walls of the lugs may be heavier than the. flanges engaging the inner walls since they are intended to carry appreciable loads when the jaws are tightly clamped around the electrode. The inner flanges 35a',can be of lighter construction since they are prir'n'ar'ily expanding means for loosening the clamping jaws from a clamped electrode.

' The alignedsets of bushings 35 in the recesses are adapted to receive the oppositely threaded ends of double shanked bolts 36. The bolts 36 have turning heads or knobs 36a disposed between the lugs e for engagement with a wrench tt rotate the bolts for expansion and contrac tion'fof. the clamping jaws 25b.

In order to protect the bolts, one of the clamp ing lugsj 25e can have a lipped' portion or flange; 2'5 g'vextending from the upper end thereof over the space between the lugs while a similar lip or, flange can be formed on the lower end of the other lug to extend across this space. The bolts arethusjextended through a chamber defined by thfe'lugs 25e'1and the top and bottom lips 25g.

Rotation of the bolts in one direction will move the bushings away from each other thereby causing the inner flanges 35a on these bushings to spread the lugs apart and thereby spread theclamping jaws. Reverse rotation of the bolts willfdraw the-bushings 35 toward each other and; cause the outer flangeson these bushings to draw the lugs 25etoward each other. This, of course, will draw the clamping jaws together for gripping the electrodes.

The clamping jaws will flex mostly at the transition area adjacent the shank 25a since the hollow portion or cut-out portion 250 renders the assembly somewhat flexible at this area. The jaws, however, will be contracted uniformly around the electrodes so as to exert uniform gripping pressure thereagainst over an appreciable area thereof.

The electrode holder 25 is preferably formed of cast metal having good electrical conducting capacity coupled with heat resistivity. A suitable metal for this purpose is Mallory Metal No. 333 sold by T. R. Mallory 8: Co. Inc. This is a tungsten alloy having;e specially good electrical conductivity coupled 'with heat resistivity. This metal is cast aroundtubes or pipes 40 which are bent aserpentine path extending through theshank area, the clamping jaw area and into the lug areas of the electrodes. Thepipe 40 can be coiled, for example, to enter the top wall of the electrode at the rear end of the and extend forwardly through the and one of theclamping jaws to the lug of this clamping jaw. The pipe can then be reversed on itself to pass. back through the same clamping jaw to the rear end of the shank. Sev-, eral such reverse bends of the pipe can be made to provide a serpentine passageway along one side. oflthe electrode. As shown in Figure 6, the pipe can then extend to the other side of the shank at the rear bottom end thereof and be coiled. in a similar finanner to pass through the opposite clamping jaw andlug The end of the pipe 'willithen emerge out of the top-wall of .the shank'adjacent the incoming end of the pipe. I'heends of the. pipe. Micah then be connected to tubes 4| and 42.1 re spectively. The tube extends into one of theconducto'r tubes 28 while the tube 42 extefi'ds'iritoth other conductort'ube 28.-Q The tubes 4 l and 42 can be brazed or welded or otherwise coupled to the tubes 28. Coolant material can be introduced into the rear end of'one tube 28 of each pair for flowing through the;electrodejcontained coiled tube' or pipe 40'. The other'tube. 28 of each pair can receive the' coolant. frorn theelectrode holder to discharge the same. j. Y. Obviously; of course, the electrode holder could be internally, cored to'p'rovide' a hollow passageway for flowof coolanf'therethrough. The cast: ingof. the electrode holder metal around a coiled pjjs. a 'convenient method of forming. the as sagewayf" Q l Any s uitable typeof coolantic'an' be used, such as water; for example. Since the coolant. will flow'in good heatfxfchang'e relatidnlwith all areas' of the electrod holderjno, portion of the holder willbeconre' over eated.,

'Fromf'the'jabovefldescriptions it will be un; derstood that thisiinvention now provides an im-. provedholderlb'r 'clamp especially, useful for clamping electrodes in electric melting "furnace constructions. Theholders of'this invention are duickly'clamped around a member to be held thereby and are quickly loosened from .such a held member; The holders are mounted in a manner such that they have good electrical con: tact over. extende'dareas with a source of elec trical current as well as with the member gripped thereby. 'Iheholders, can be internally passaged for receiving cooling Quid andare arranged so asto be readily mounted'in insulated relation with a supportinglstru cturesuch as an electric furnace carriage mounting.

The electrical current can be fed to the holders of this invention by means of hollow tubes which also convey coolant to and from the holders.

It will, of course, be understood that various details of the invention may be varied through a wide range without departing from the principles of this invention and it is, therefore, not the purpose to limit the patent granted hereon otherwise than necessitated by the scope of the appended claims.

I claim as my invention:

1. An electrode holder adapted for electric melting furnaces and the like having a carriage supporting column and a carriage ridable on said column-which -comp'rise'sa -clamping sleeve projecting from saidcarriagem tube-clamped in said sleeve in insulated relation therewith, saidtube havinga free endwith inwardly projecting slots, spaced opposed plates secured int-he Slotsof'said tube, an electrode holdenhaving a shank -portion disposed between --said plates, "conductor platesinterposed-between said shank portion-and saidplates, means clampingsaid-shank'portion and said conductor plates-between-said plates, said electrode holder havingcoolant circulating passageways thereinyametal tube securd-toea'ch conductor plate for circulating currentthrough said plate'and electrode li'olderf-means connecting the interior of each tube with the-passages in said electrode" holder, means"mounting said tubes on-said carriagein insulated relationtherefrom; andmeans for connecting oneof said'tubes witha-source of coolant-'forcirculation through the said tube and-throughtheelectrodefiholder into the other tube'for' dischargetheren'om.

- '2. An' electrode mounting assembly for meltingfurnaces and the like comprising-aparriage adapted to be 'mounted-fon vertical movement relative to a furnace,'a-rigid ttibe carried by said carriage in insulated relation therefrom, a pair of spaced opp-osed'rigid plates. alflixed to said tube, an electrode hold-er' having ashank portion dis-' posed between said; plates; conductor plates inter-posed between said platesandc opposite sides of said shank portion; means'clamping said conductor-plates fand shankpo'rtion between said plates, a pair of hollow metal'tubes extending from saidcarriage to said conductor plates, insu-' lation means maintaining said' 't ubes in'n1sulated relation to said carriage, means joining each tube with a conductor plate in vgood. electrical contact therewith, said 'electrode'holder having a coolant circulating passage 'ther'ethrough, a conduit connecting one end of said passage withv one (it said tubes, a second conduit. connecting the other end of said passage with jthej'other 'oifsaid tubes, means" connecting said tubes' with j a. source 2 of electrical current; means connecting one ofsfaidi tubes witha cooling medium; and mearisiconriedting' the other of said tubes witli'fajdrain whereby said tubes will convey electrical currentflan'd coolant through said electrode holder in insiil 'ated;

relation Withsaid carriage.

3.. Electrode mounting. means fore electriejfurnaces and the like whichfcompris'esia vertically movable carriage, a metal tubeexteridingifrom' said carriage in insulated relation-therefrom, a pair of plates projecting in spaced Opposed relation from said tube,.an'd an electrode holder h'av'- ing a shank portion clamped betweensaidlblatfesj 4.1m an electrode holder 'a ss'embly mounting members including plate-li e mounting means, a plate-like current conductor,.meanslforsupplying current to said conductor,.lanleleetrode.

aesaeer holder havinga shank andelectrode clamping jaws-associated therewith; sald= shank being disposed in surfaceengagementwitlr said conductor, means for secur-ing said' mounting means, said shank; and said conductor tightly insurface-cngagement to afford a-mountingarm for said-jaws, and means for supporting-said arm on A a furnace or-ti eiike. j

5. 1m electrode holder comprising-a holder having a shank portion-and opposed clamping jaw portions integral with said shank portion; eachjaw'portionhaving a plurality of superimposed" passageways i therein extending into the shank portion and defining separate serpentine circulating paths througheach jaw-andea'chslde of the shank portion beginning'and temiinatlng in the shank portion; said shank portion "having a passageway joining the beginning-or onepath with the terminal-end -ofthe-ctherpath,- a draintube communicating with the terminal end-"of saidone path, and akioolant feed tube communi-' eating with the beginning of said'otherpath whereby coolant will first be circulated through one clamping j aw and one side' of the shank-portion and thence" through the other-Side or the shank-portion-and-other clamping-jaw.

6. -Electrode mounting-'-means"-for electric iur-' naces and thelike which-comprises a supportya' metal tube extending from saidfsupport'iwinsw' latedrela-tion therefrom; a, pain of spaced" opposed metal plates "projecting from" said tube, and "'an electrode-holder having ashank portion-clamped between said plates.

'7. Electrode mounting means. foneiectric tun-Q naces andthe'; likawhicli' comprises a metal tube" having spac'ed parallel slotse gtending inwardly? from one emithel eoi a'rpetal plate 'sepm'edin" e'ach'slot and 'tproje'cting'frorn saidtubein spaced,

opposed relation,-.and. an' el ectrode holder having a' shank portion" clamped between said metal P es. c; L 1 lv i 8. An efeetiodefhjold r' asseinbly comprising at pair of spaced opposeqpiates anelectrode holder having a shankexteiidin'gjoetween' saidfplates plate conductors j between said? shank, and? said.

plates; means securingsaid shank, plate conduc-i tors"and opposedjp latesitogfiheii to form a lani'i nated block; a; passaged conductor secured .to each plate conductozjisaid eleotrode holder hav ing fluid circulating passages therein' tubes, conne'ctingthe electrode holder; pas'sa' es...w ithi the conductor passages means for. electrically ener gizing jboth passaged' conductors to flow current through tl e condu ctionplates'to the holder, means ductor into the holder, .and meansj'for; draining fi 'idfrom theothei'passaged onductor to main- 7

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