US2263164A - Anode - Google Patents

Description

Nov. 18, 1941. H, J 'DNLEY 2,263,164

ANODE Filed Feb. 25, 1941 46 Z/ECO/V/U INVENTOB A. a. 0/9/45) AT ORNEY Patented Nov. 18, 1941 ANODE Hampton J. Dailey, Bloomfield, N. J., assignor to Westinghouse Electric & Manufacturing Company, East Pittsburgh, Pa., a corporation of Pennsylvania Application February 25, 1941, Serial No. 380,417

7 Claims.

My invention relates to discharge devices, and especially to the anode structure therein.

An object of the invention is to provide an anodewith good gas-absorbing qualities.

A still further object of the invention is to a provide a gas-absorbing anode that is easi y fabricated to close dimensions and inexpensive.

Other objects and advantages of the invention will be apparent from the following description and drawing in which:

Fig. 1 is an elevational view of a typical dis-' charge device embodying my invention.

Fig. 2 is a cross-sectional view through the anode of Fig. 1 illustrating a preferred embodiment of my invention.

F18. 3 is an enlarged cross-sectional view of a small portion of the electrode base and coating.

One or the problems in industrial tubes has.

- been the liberation-of gases during operation which change the operating characteristics of the tube. Heretofore tantalum has been utilized in view of its gas-absorbing qualities. Tantalum, however, a very expensive.

. It is an object of my invention to utilize zir-- conium because of its good gas-absorbing qualities. The zirconium, however, as heretofore used,

ported in turn by certain cross insulators I1, I81

and i9. One of these cross insulatoiis [8 provides means for resiliently supporting the cathode it with a spring 28 resiliently supporting a hook 2|. for the upper part of the filament. A cross bar 22 in the lower part of the tube supports the grid structure on the lower reentrant press, and from this cross bar 22 is a connection 23 passing through press I l as a grid lead.

The anode of my invention surrounds the cathode and grid structure. This anode 25 is preferably of the oval cross section disclosed in Fig. 2 and extends axially of the tube the distance of the effective electron-emitting portion of the rather elongated in view of the shape of the I cathode.

As disclosed in Fig. 2, the inner sides and 3| provide an extensive electron-receiving surface.-

In order to support the anode I preferably locate, eight projecting bosses on the upper and lower portions of both sides of the anode. Two of these bosses 32 and 33 are on the upper portion of the anode inFig. 1 and symmetrically spaced on each side of the longitudinal axis of the tube. The lower portion of the anode has two similar bosses 34 and 35 aligned with the top bosses. The rear side of the anode has two similar bosses 36- and 31 on the upper portion and two similar bosses, not shown, on the lower portion. These bosses have aligned openings 38 therethi'ough. Standards 40 are threaded through the aligned openings in each upper and lower pair of bosses and standards 40 are secured in the bottom insulator scales of! easily and has proven unsatisfactory.

I9 as disclosed in Fig. 1. The upper ends ll of these standards are bent over to the reentrant press 42 at the upper end of the tube and secured thereto.. A connection 43 extends through 'the press to the anode exterior connection It at the upper end of the tube. The exterior connections for the cathode and grid preferably extend through the lower base 45 of the tube.

In forming the anode I select amorous roughsurfaced material as a base and fabricate itto the desired shape, such as disclosed in Figs. 1 and 2. The material which I have found especially desirable is carbon in the form of graphite.

I then mix the zirconium powder with a binder or carrier and preferably utilize a nitrocellulose binder because the volatile constituents are easily baked out and the residue from the binder is essentiaily'carbon. The zirconium powder is preferably of about 325 mesh fineness, and after being mixed with ,the binder, can be sprayed or painted on the outer surface 46 and inner surface 41 of the carbon base 48 of the anode.

melts on the electrode. The anode is then assembled in the tube.

I have found that no other baking was necescathode It. The anode has its main oval axis 5 sary than that used in exhausting the tube. One

, the zirconium layer.

minute at ,1200" C. induction treatment was usually suificient to eliminate visible ionization in the tube. The binder was baked out and. a firmly bonded zirconium'layer remained on the carbon anode. The carbon with its'suriace pores well-filled with thezirconium film, provides a layer which does not easily flake ofi during operation. The firm bond between: the two is illustrated in the enlarged view in Fig. 3.

. If a metal base is desired, I roughen the surface, preferably by sand or carborundumblast ing, and then fill the artificially made pores with The grid 85 may be coated with zirconium to reduce secondary emission.

My invention is also adapted for tubes utilizing mercury vapor as the zirconium absorbs the undesired gases;

My invention has accordingly produceda cheap zirconium on said porous carbon base with the" portion of said coating contiguous to the base embedded in the pores thereof.

3. The method of treating an electrode to have I gasrabsorbing properties which. comprises selecting a base having large surface pores and filling ,said pores with zirconium.

4. The method of treating an electrode to have gas-absorbing propertieswhich comprises select,- ing a base having large surface'pores, filling said pores withzirconium powder and a binder and evaporating the binder. I I

to the porous material by portions of the coating.

' entering pores contiguous to said coating.

and easily fabricated anode with good gas-absorbing qualities.

Although I have shown and described a specific embodiment of my invention, 1 do not desire to be limited thereto asva'rious other modifications of the same may be made without departing from the spirit and scope of the appended claims.

i claim:

3.. An electrode for a discharge device comprising porous base and a coating of zirconium on saidporous'base with theportion of said coating contiguous to the base embedded in the pores thereof.

2. An electrode. for a discharge device comprising a porous carbon base and a coating of "ening the exposedsuriface of ,ametal base for 6. The method of treating an electrode to have gas-absorbing properties which comprises selecting a base havingthe inherent characteristic of porous rough-surfaced material, and smoothing I the exposed surface by both filling the outer pores thereof and coating the surface with zirconium.

7. The method of treating an electrode to have gas-absorbing propertieswhich comprises roughproducing artificial pores, and'smoothing the roughened surface by both filling the said artificial pores and coatingthe surface with airconium.

HAMPTON J. DAILEY.

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