US1203635A - Support for metallic glow-filaments. - Google Patents

Description

- candescent ANTON LEDERER,

OF ATZGEBSDOBF, NEAR VIENNA, AUSTRIA-HUNGARY. I

SUPPORT FOR METALLIC GLOW-FILAMENTS.

No Drawing.

, To all whom it may concern:

Be it known that I, ANTON LEDERER, a subject of the Empire of Austria-Hungary, residing at No. 83, Atzgersdorf, near Vienna, in the Province of Lower Austria, Austria- Hungary, have invented certain new and useful Improvements in Supports for Metallic Glow-Filaments, of which the following is a specification.

My invention relates to im rovements in metallic supports for metal ic glow filaments for electric incandescent lamps, and it has for its object to provide metallic supports of such a construction and composition that they will prevent bulging of the filament when the latter expands in consequence of its being heated by the electric current.

The necessity of supporting metallic glow filaments in electric incandescent lamps has been proved long since. Metallic filaments, however, do not allow the use of metallic supports, asis customary with electric inlamps having carbon filaments. When supports of platinum or other bare (non-oxidized) metals are used, it has been observed that the filaments may become fritted to the support. This fact is of no disturbing influence with lamps that are continuously in use, that is to say, that are not frequently cut out of circuit. However, if a lamp is repeatedly and often cut in and'out of circuit, as is usually the case, it is observed that the filament surrounded and held by the support visibly bulges in the part of its length adjacent contact with the support. This bulging may cause short circuiting and other disagreeable disturbances. This phenomenon may be explained as follows: When the filament becomes fritted to the support and then strongly contracts after having been cut out of circuit, there is formed at the place of 'fritting a kind of angle or knot which prevents the free and unhindered expansion of the filament. With the successive operations of the lamp, new enlargements or knots are liable to be formed at other points along the length of filament so that the filament cannot readily slide through the support and it is thus caused to bulge outward.

This present invention has for its ob1ect Specification of Letters Patent.

to the point ofto prevent deformations of the glow filament such as those above described, and still to allow the use of metallic supports, by coating the supports with an extremely thin layer of a compound of the metal used Eatented Nov. '7, 19.16; Application filed September 18,1806. Serial No. 335,152. 1

for the support, preferably with an oxid of such metal. The layer of oxid being extremely thin, the support formed according to the present invention retains its power of conducting heat, so that, on the one hand, no reduction of the oxid can take place and, on the other hand, the glow filament is prevented from fritting to the metallic support by the protecting coating of oxid.

The supportingwire may be easily and conveniently provided with a coating of 02nd by passing it through an oxidizing flame. Nickel is an excellent metal for use as the oxidized filament support, but I do not wish to be restricted to the use of nickel, since any metal which is sufficiently refractory and which can be covered with a protective coating of one of its compounds is suitable for my use. I am aware that filamer t supports havev heretofore been made having filament-supporting loops or rings of refractory oxids attached to their ends. My filament supports are distinguished from these by the fact that my protective coatings are composed of compounds of the supporting metals themselves, and by the fact that the coatings do not extend beyond the ends of the supports, and are thus interposed between the filaments and the supporting wire. Since the filaments are separated from the metal wire only by the thin coating, from the filament, and harmful localization of heat is thereby avoided.

What I claim as my invention and desire to secure by Letters Patent is:

heat is quickly conducted away 1. In a metal filament incandescent lamp, 1

v ment' and the mckel wire.

wire of highrefractability consisting of a, 5 nickel wire coated with "an oxid of nickel.

c 4.; A shield for the'support ofan incandescent metal bod consisting of a coating of en oxid of the metal out of which said being this interposed. between the said fila- 3. As a support for incandescent metal, a,

support is made, the said coating being thus interposed between the incandescent metal MD body and the metal of the support.

In witness whereof I haig e hereunto set my hand in presence of two witnesses.

ANTON nnnnnnn Witnesses: JoHANN Lnson ALvnsTo S. Hoe'on.