US1059366A - Process of preparing filaments for incandescent lamps. - Google Patents

Description

Patented Apr. 22, 1913.

. gt} INVENTOR AT'TORNEY W. G. HOUSKEEPER.

PROCESS OF PREPARING FILAMENTS FOR INGANDESGENT LAMPS.

APPLICATION FILED AUG. 6, 1910. RENEWED SEPT. 13, 1912.

WITNESSES:

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UNITED STATES PATENT OFFICE. wIL IIAH-G, H OUSKI EPEB, OI PHILADELPE IAQPENNSYLVANIA, ASSIGNOR T0 WEST- INGI H OUSE LAIP COMPANY, A CORPORATION OF PENNSYLVANTI A.

PROCESS OF PREPARING FILAMENTS FOR INCA NDESCENT LAM-PS.

ama... of mm; rum.

Patented Apr. 22, 1913.

Application fled August 8, 1910, Sci-1:180. 575,987. lenewed September 18, 1912. Serial No. 720,278.

ment in Processes of Preparing Filaments for Incandescent Lamps, of which the following is a specification. Y

My invention. relates to processes of treating filamentary material for the purpose of rendering the same suitable for filaments of electric incandescent lamps, and it has for its object to provide a process whereby alternating current may be employed instead of direct current for the purpose of heating the filaments and sintering its particles together.

In an application, Serial No. 486,925, filed March 31, 1909, by Harry D. Madden and myself, and assigned to the Westinghouse Lam Company, is set forth a process of treating filamentary material'which consists in applying different amounts of electric current to different portions thereof, the object of such treatment being to gradually heat the filament in order to carbonize the binder for the main ingredients of the filamentary material, and to thereafter sinter together the particles of said ingredients.

It has been found that, if single-phase alternating current is applied to the fila-- mentary material, in practising this process, the filament is alternately heated and cooled,

and, consequently, it alternately expands and contracts, with the result that it is frequently broken during treatment. According to the present invention, I propose to so apply polvphase currents to the different sections of the filament that the total length of the portion of the, filament under treatment will remain substantially uniform, in order that there may be substantially no greater strain upon the filament than when direct current is employed in practising the process.

The single figure of the accompanying drawing illustrates, diagrammatically, suitable apparatus for practising my invention.

As set forth in the'above-mentioned application, the untreated filamentary material 1, after leaving the press2, passes through a series of terminal devices, 3, 4, 5, 6, 7, 8

and 9, that preferably consist of apertured lates or members, the portions of which adacent to the apertures therein are amalgamated, and across the apertures in which extend bodies of mercury '10, that are maintamed in the apertures by capillar and surface. tension, and the sur aces of which are preferably of-concave form. The terminal devices 3, 4 and 5 are connected, in series with lamps 11, 12 and 13, respectively, or with other suitable current-regulating devices, to one terminal of a two-phase source 14, the other terminal of the same phase of which is connected to the terminal device 6, an auto-transformer 15, or other suitable current regulating device, being rovided for adjusting the total amount 0 current supplied to the filament through the termicurrent supplied to the filament through the terminal devices 6 to 9, inclusive. While certain kinds of filaments may be treated in air, as shown, others are preferably treated in a non-oxidizing atmosphere, the process being otherwise the same.

As the currents traversing the portions of action' the filamentary material above and below the terminal device 6 are different. in phase, the one portion will behottest when the other is coolest. The result is that when the upper portion is contracting, the lower portion is expanding, and vice versa, and the total length ofvthe portion of the filament under treatment remains substantially uniform. There is, consequently, little or no strain upon the filament resulting from its expansion and contraction, and but little liability of its breakage.

Of course, the invention is not limited to the use of two-phase currents, but the circuits may obviously 'be arranged so that three or any other suitable number of phases or current may be applied to the filament.

I claim as my invention:

1. The method of treating filamentary material which consists in simultaneously passing differently phased electric currents through diflerent portions thereof.

material which consists in simultaneously passing. different amounts of electric current througi different portions thereof, the currenttraversing certain portions of the filamentary material being-of a different phase from that traversing other portions thereof.

. 3. Apparatus of the character described,

, comprising a-fplurality of alined terminal members, a source of polyphase alternating currents and connections between the said source and the said terminal members whereby a conductor engaging the said terminal members have diflerently phased currents applied to different portions thereof.

4. Apparatus of the character described, comprising a plurality of alined terminal members, a source of polyphase alternating members will have vcurrents and connections between the said source and thesaid terminal members whereby a conductor engaging the said terminal 'iflerently phased cur.-

rents applied to different portions thereof,

and means includedin said connections whereby different amounts of current are .WILLIAM G. HOUSKEEPER.

Witnesses CHARLES KELLY, C. W. YOUNGHOLM.

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