US1444961A

US1444961A - Arc-lamp electrode

Info

Publication number: US1444961A
Application number: US303301A
Authority: US
Inventors: Howard B Eynon
Original assignee: Nat Carbon Co Inc
Current assignee: National Carbon Co Inc
Priority date: 1919-06-11
Filing date: 1919-06-11
Publication date: 1923-02-13
Anticipated expiration: 1940-02-13

Description

Feb. 13. 1923. 1,444,961.

\ 'H. B. EYNON.

ARC LAMPELECTRODE.

nu-:0 JUNE 11, 1919.

I'LB. EYNUN ATTORNEY Patented Feb. 13, 1923. I

at it. la. 9

HOWARD B. EYNON, OF LAKEWOOD, OHIO, A SSIGNOR TO NATIONAL CARBON COMPANY, INC., A CORPORATION OF NEW YORK.

ARC-LAMP ELECTRODE.

' Application filed June '11,

T all whom it may concern:

Be it known that I,HO\VARD B. EYNON, a citizen of the United States, residing at Lakewood, in the county of Cuyahoga and State of Ohio, have invented a certain new and useful Improvement in Arc-Lamp Elec trodes, of which the following is a full, clear,

and exact description.

This invention relates to an improvement I negative electrodes especially adapted for use in projection apparatus.

One of the most important requirements which must be fulfilled for this type of service is are steadiness and my. invention relates to,'and especially discusses an electrode structure which satisfies this particular requirement.

I have found that the arc has a very strong tendency to spring from the hottest part of a negative electrode and to remain there. I have found this to be especially true in the case of pure .carbon electrodes or with electrodes in which no flaming ingredient is present in close proximity to the portion .of.

the electrode from which the are springs. Although the same is true of electrodes containing small amounts of flaming material to a limited extent, the presence of flaming material is undesirable because it reduces the temperature of the 'arc stream and the intrinsic brilliancy. i 1 A preferred embodiment of the invention is illustrated in the accompanying drawing, which shows a vertical section through the improved electrode. a Referring to they drawing, reference character 1 designates an. outer shell preferably of pure carbon. The shell'after baking is tively. porous carbon. I v trodcis used in combination with a suitable in arc lamp electrodes, and particularly tov 1919. Serial No. 303,301.

provided with a core 2 consisting of carbon 40 flour. mixed with a carbonaceous binder, such 5 as a mixture oftar and benzol. After coring the article is dried or baked to set'the binder. This results in a practically pure carbon article having a shell of dense ca'rbon and a central core of less dense and rela- When such an elecpositive,-the arc will tend to spring from the-central core during burning" because when the are springs therefrom the core does not conduct heat to the shell readily. The spot from which the arc springs therefore tends to have a highertemperature for the reason given. On account of its central location there is also a greater tendency for the arcyto spring from the core'than from the surrounding shell. a

Although I have set forth what, I be- :lieve is a reasonable explanation of the steadinessof the electrodes, it must be understood that my invention is not necessarily limitedtheretop 'Having described -my invention, what I" claim is:.-. -A negative. electrode havinga body portion consisting entirely of carbon, said body portion comprising a relatively dense and substantially pure carbon shell, and a core for said shell consisting of. a-relatively less densefiller of carbonaceousmaterial having a carbonaceous binder incorporated therewith, such filler being a good electrical conductor and a poor conductor'of heat.

In testimony whereof, I hereunto affix my signature.

HowA-Ri B. EYNON.