US1023371A - Electric furnace. - Google Patents

Description

Patented Apr. 16, 1912.

C. T. FULLER.,

ELECTRIC FUBNAGE.

APPLIUATION FILED Dnc. ao. 190s.

Inventor* Carl TFhller, b

Y u muy Witnesses v y WM' @fw 1i/z W7 fie' UNITED STATES Y OFFICE.

CARL T. FULLER, OIF-EAST ORANGE. NEW' JERSEY, .ASSIGNOR TO GENERAL ELTCTR-IC COMPANY, A CORPORATION OF NEW YORK.

ELECTRIC FURNACE.

Specification of Letters Patent.

Patented Apr. 16, 1912.

Divided and this application tiled December lie it known that i, CARL T. FULLER, a eitizen ot the United States, residing at Cast ()range,eom1t v ot' Essex. State ot; New Jersey7 have invented eertain new and uur t'ul v[mprovementa in lileetrie lturnaeest ot' whieh the t'ollowing is a Speeitieation.

M v present invention eompriees an apparat'un lsuitable for use in the produetion ol 'retraetmwf' eleetrieal emuluetors. Aaut-li as ineandeseent lamp lilaments, turnaee li aterst and the like.

Mit* improved apparatus comprises4 a tubular heater throng-h whieh hydrogen or other redueing gas ma}7 he passed and in whieh tilameut' eontaining boats may be ].\laeed. these boats being ot sueh nature and so constructed that the hydrogen is tree y'to aet on the tlanientxs without danger that the latter will beeome contaminated b v carbon or other material vaporized in the iiurnaee.

lln the aeeompanying drawing` ltigure l is a eeetional elevation ot a t'urnaee, partly diagrammatic. and Fig. Q is a perspeetive vien ot the shuttle or boat in which the filaments or threadI arer inelosed during treatment'.

The 'turnaee illustrated in ltig. 'l eom prises. a graphite heater tube 1 supplied with enrrent through Suitable terminals 2 and and i'neloaed in a proteetive eoating l ol5 eote or other refractory material. .W'ithin th s tube. a seeond tube 5 ma)7 be inserted and withdrawn. 'lhiseet-.ond tube is con tinuously supplied with h vdrogen through a rubber tube and Serves as a reeeptaele lor the boats or shuttlesftcontaining the nnit'erial to be treated. prefer that tuta` 5 shouldhave a Small bore at the end eonneet' ing with the ruhber'tube t3 and should have an enlargement at. the. end containing the. boat T.

The retraetory boat eonsista ot' a troughshaped member having Side wallal 8 and a eentral web tt and having a lining olii-extraetor)Y material l() consisting ot rutile or otl other materials hereinafter mentioned. A' post. 1l oll rutile is mounted atV one end ot the boat. to serve as au anehoring deviee lor the tlaments under tnreatnnfnt.`

My invention may be used and applied for mauxY purposes. ln latent. #929.578

granted to me July 27. 1905i on applieation tiled August 24, 190i', Ser. No. 390.048, tot

` dnetors.

whieh applic-ation this appueation ia a ruvision) l have t'leseribed in' detail its use as applied to the produetion ot' tungaten conln this. mode of emplovmenta. the tube 5' ia witlulrawn from the iinrnaee, the tilamentarv bodies or threads to be treated inthe t'urnae ari arranged in bundles on arutile paeking l ot boat the boats are introdneed into the tube 5. and the tube is returned to its position "within vthe heater tube l, a Stream ot' hydrogenthrough tube being n'laintained during this time; The lamenta ry bodies in the boats are converted into pure tungsteii threadbI or wires in a eonunirativel)Y Short time, and are Iturther tired at Snell a high temperature and tor such a length ottime as will eonuriletelwiY sinter and .shrink the tungsten threads or vireS and render them Suitabletor mount'- ing in lamps withoutfurther treatment. 'lheee baking and tiring operations require not more than about'v eight"y minutes at a temperature otl about 1-1-75 to i550 degrees eentigrade.

The unfavorable intluenee of earbon from .the heating members ot the turnaee during the tiring or high heat treatment can be guarded against by the. use. of proper material -t'or the boat or shuttle illustrated in Fig. 2 ot the d airing. In generaLI prefer that the boat' `shall consist. of or eompriae a material haringl a high atlinity for carbon., or at leaat. having as great'a tendency to absorb carbon as doithe filaments under treatment. Sueh a bod)v :iets as an absorbing shield to taire up any carbdn 'Vapor given ott by the turnaee tu e.

Ot the various materials used by me in constructing the boats, I have obtained best. results with a carbon boat having a pat-lting ot rutile Ti()2 the materials being arranged as shown in ltig. 2 of the drawing. t have also Sueeesst'nlly used carbon boats lined with powdered tungsten. Either rutile. lor powdered tungsten serves, by virtue ot its high atlinitzy tor earbon, to prot'eet the filaments trom whatever earbon vapor may be eirenlating through the tube. '.lhese. materials algo ponaeas the very important requisite ot notv stieking to the filaments or combining therewith. in this respeet being similar to powdered siliea Whieh l have aueeesatnlly used. and being. in my opinion41 `tar superior to oxide of the earth metal@7 go complete shrinkage.

suoli as thorium, magnesium, cerium, etc. By the' use of materials which do not become j sticky', the filaments are free to move longitudinally in the boats and are free to under- \Vhen treated as above described, they do undergo this shrinkage, and they attain an electrical resistance Which remains 'substantially' constant l throughout their normal life as filaments in l 1 0/lamps, `This resistance is directly comparaing has great commercial advantage in that it permits simultaneoustreatinent of dozens 'oreven hundreds of filaments, and furthermore yields conductors, which, forany furnace run, 'are sure to be uniform in size, composition, and electrical properties,- and ,therefore adapted for use in series Without previous sorting and Weighing or other calibiation.

Although I have in my patent above re- '25 -ferred to described my improved apparatus in connection vgith a process for the production of tungsten conductors by reducing an Oxid with hydrogen andthen effecting comn' plete shrinkage and sintering of the refrac- -0 "tory re'sidue,.it should be understood that my invention is applicable to the production of conductors of various other refractory Confesof this patent may be obtainedfor in said tube in the metalsand materials, such for instance as molybdenum, boron, zirconium, tant-alum, titanium, graphite, or compounds or alloys of any of these or `of other materials of the sanle general refractory nature.

lVhat I claim as new and desii'e to secure by Letters Patent of the United States, is:

' l. The combination of a carbonaceous resistance tube, means for supplying electrical energy thereto to heat the same, means for supplying hydrogen to said tube, and a charge protecting boat heated by said tube, said boat consisting in'part of rutile.

Q. The combination with a carbon tube resistance heater, of means for continuously supplying yhydrogen thereto, and a charge protecting boat of carbon lined with rutile inclosed and heated by said-tube and also protected by said hydrogen.

3. In an electricfuinace, the combination of a carbonaoeous tube, means for heating said tube, means for supplying hydrogen to one end o'f said tube, and a refractory boat, having marked affinity for carbon, mounted pat-h of said hydrogen, said boat being open. l

Inwitness whereof, I have hereunto set my hand this 28th day of December, 1908.

C. T. FULLER. Vitnesses:

J. H.,E`Liiii s, S. W. WmTEHEAD.

ve cents each, by addressing the "Commissioner of Patenti Washington, D. C.

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