US1018500A - Forming device for metallic filaments. - Google Patents

Description

H. w. JACKSON. FORMING DEVICE FOR-METALLIC FILAMENTS.

n APPLICATION FILED JALLQ, 1908.-

Patennea F'eb.27 1912.

UNITED STAWENT OFFICE.

nmmr w. 'Jn'oxson, or East omnonnnw JEBSEY, nssien'on TO WESTINGHOUSE LAMP comrnmr, n oonronn'rron or NEW YORK.

FORMING DEVICE FOR METALLIC FILAMENTS.

Specification of Letters Patent. Patented Feb. 27,, 1912,

Application filed January 9, 1908. Serial No. 410,042.

To all whom it may concern Be it knownthat LllunnY-XV, JAcnsoN, a citizen of the United States, and resident of East Orange, county of Essex, State of New J ersey,-have invented certain new and useful Improvements in Formingllevices for Metallic Filaments, of which the followin is a specification.

y invention relates to the manufacture of metallic filaments for incandescentlamps, such, for example, as filaments of-tungsten or molybdenum. The handling of such filamerits in the preliminary stages of the manu- .facture is'a matter requiring delicate treat ment owing to the fragile nature of the filaments, particularly in their pasty or unre- .duced condition. For example, a tungsten filament, when first squirted, consists of me t-allic tungsten, tungsten oxide, and a carbonaceous binder. The reduction of this heterogeneous pasty strip to metallic tungsten consists broadly in introducing the same into a reducing atmosphere, say .of hydroen and nitrogen in equal parts, and passmg a current of electricity through the strip .while held within thereducmg atmosphere,

whereupon the oxygen of the oxids and the carbon of the binder combine to form carbbnic oxid or carbon .dioxid which, being the untreated filaments in clamps and sus-- pend them within a metallic air-tight receiver, the said receiver being connected with suitable devices whereby it can be exhausted.

The remainder of the operation has heretofore consisted in exhausting the air from the metallic receiver, admitting the reducing atmosphere in suflicient quantity, and then applying the electric current to produce the heating and metallization of the filaments.

Owing to the fact that air' currents or gaseous currents are liable to ,beset up within the receiver in the process of exhausting the receiver and admitting? the redueigigi gases, and to the further fact; that it is d cult to get'at' the filaments in the box or receiver in such a way as to'give them care-- ful handling, there has been. fun undue amount of breakage of the filaments in their delicate state beforetreatment. By the pres-- .ent invention I obviatethe greater part-oat this breakage by providing a preliminary treatment in which the untreated filaments are handled individually and are always in a position where they can be readily seenand carefully manipulated. When this preliminary treatment is concluded, and a complete or partial metallization of.the filaments has taken place, they are placed ingroups in the receiver already mentioned and are given the treatment above described. But, since the elements of each filament have been sintered together and compacted by the preliminary treatment, the filaments in the receiver are in much better condition for undergoing the final treatment by which complete metallization is insured.

I prefer to utilize the present invention as a preparation -for the .final treatment, although it should be understood that it is possibleto complete the reduction of the-filaments to pure metal by the process which I have here called a preliminary process.-

- My invention will be understood by reference to the accompanying drawing in which Figure 1 is an elevation-0f an apparatus adapted to the carrying out of my invention;

Figs. 2 and 3 are detail views of the clamps in which the untreated filaments are hung or supported; and F igs. 4 and 5 are details of the slide rodsfI use in carrying out my invention.

In vthe drawing 1 is a base, support, or table of wood or other suitable material, and 2 is 'a frame, preferably of metal, secured to the said base. Below the base I show a bracket, 3,-in which a large pulley, 4, and small pulleys or rollers 5 and 6 are suitably journaled. The pulley, 4', is capable ofbeing operated in reverse directions by means of treadles, 7 and 8, anda belt or cord, 9. In being so 0 erated the pulley serves through the me ium of a cord, 10, to move alternately ,upward tw'o hollow slitt'ed slide rods, 11 and 12. These slide rods are guided in their upward movement by.screws,'l3-and 14, entering slits, 15 and 16, in the respective rods and b the heads, 17 and 18, on the frame 2. he slide rods may be returned to their lowermost ositions by hand or any suitable means, or t ey may be so weighted.

as to drop down of themselves when released from suspension the pulley 4'.

pair of clamps, 19 and 20, the details of which are shown in Figs. 2 and 3. Referring to Fig. 3, it will be seen that each clamp consists of a movable portion (say 20) pivoted at 21' and pressed by a spring 22 so as to bring its lower end into contact with a stationary metallic. part, 23, attached to an insulating back or plate, 24. The parts 20 and 23 are cut away slightly near their lower ends so as to-leave a narrow opening, 25, the sides of which press upon the ends of the untreated filaments which are supported by the clamps. Through the interior of the hollow slide rods, 11 and 12, pass circuit wires, 26 and 27, which are connected at the top of each slide rod with contact springs, 43 and 44, re spectively, the same being mounted on an insulating block 45 secured to the top of the slide rod. Corresponding to the contact springs. 43 and 44, there are secured to the plate, 24, on each clamp two contact pieces, 46 and 47, which. can readily be set in under drogen and nitrogen in equal part.

trical connection with the clamps 19 and 20. The clamps can thus be readily inserted and removed. When the clamps are inserted with the filament in place, and current is turned on through the wires 26 and 27 from a suitable source, this current will pass through the filaments and do its work of assisting in the reduction thereof. The slide rods, 11 and 12, may be conveniently constructed of brass or other suitable metal, but each rod is insulated from the clamps by means of. the insulating back or plate,.24, and the back or head, 45.

The untreated filaments are inserted in the clamps not yet mounted, .which clamps are afterward. placed on the top of the slide rod, as described. Referring to. Fig. 1, a filament, 28. may be assumed to have just been inserted in the clamps and to be ready for the preliminary treatment. Now by operating the treadle. 8. the slide rod, 11, will be lifted and the filament carried up into the interior of a receiver. 29, preferably of glass or other transparent material. this receiver being open at the bottom and allowing the filament to pass freely inside. The'top ofthis receiver is connected by a rubber tube 30, with a tube, 31, passing through a suitable stopper, 32, into a vessel, 33, the mouth of which is closed by the said stopper. Another tube, 34, passing through the said stopper enters a liquid 35, inside the vessel, and is' connected at its outer end by a rubber tube, 36, with any suitable reservoir adapted to supply under pressure a proper mixture of some reducing gas, such as e function of theliquid, 35 is that of washing and purifying the gas before it'passes into the top of the receiver, 29, where, being lighter than air the reducing gaseous mix ture remains in the top of the receiver when the pressures are properly adjusted. A suitable liquid for the purpose may be composed of a solution of paragallic acld andcaustic potash. The same connection exists from the corresponding receiver, 37, to the vessel,

} 38, and. the connections generally are so en-. tirely similar that it is not thought necessary untreated state upon the clamps, 19 and 20,

as already described, the operator may now press upon the treadle' 8 so as to lift the .slide rod, 11, with the clamps and the filament, up into the receiver, 29, carrying it far enough so that the filament will hang within the reducing atmosphere near the top of the receiver. Then by means of any suitable switch (not shown) the appropriate current may be turned on and a reduction of the filament, either partial or complete may take place within the receiver. At all times, the filament is under the observation of the operator and inasmuch as each filament is handled and treated separately and I filament has undergone sufiicie'nt treatment to change it partially or completely into pure metal. The removed filament, if only partially treated, may then be subjected to the treatment now commonly employed, that is to say, it may be mounted with others within a metallic receiver and treated as described in the early part of this specification. A new'clamp with a fresh filament can then be applied to the top of the rod 12, and the movement of the pulley, 4, being reversed by operating the treadle, 7, a similar course of procedure may go on with the filament 28, and so on.

I claim as my invention 1'. -,[mapparatus of the character described, the combination with receivers open at the bottom and connected with means for sup plying gas thereto, of reciprocable supportsmovable into and out of said receivers and having terminal devices, means for effecting simultaneous movement of said supports in opposite directions, and mechanically connected insulated filament clamps detachably cngaging the said terminal devices.

the combination with receivers, of reciprocaopposite directions, of filament clamps deble supports movable into and out of said tachably' carried by the said supports and receivers, means for efiecting simultaneous engaging the terminal devices.

movement of said supports in opposite di- Signed at New York, in thecount y of New 5 rections, and filament clamps detachably York, and State of New York, this 4th day 15 carried by the said su ports. v of J anuary A. D. 1908. 3. In apparatus of the character described, HENRY W. JACKSON. the combination with reciprocable supports Witnesses: having terminal devices, and means for 7M. H. CAPEL, 1o effecting simultaneous movement thereof in GEORGE H. STQGKBRIDGE.

Copies of this patent may he obtained for five cents each, byeddressing the Commissioner of Patents,

' Washington, D. G.

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