US2171238A - Discharge device and electrode - Google Patents

Description

Aug. 29, 1939. D. s. GUSTIN I DISCHARGE DEVICE AND ELECTRODE Filed Sept. 2, 1937 l NVENTOR 2.5. @VJf/AA ATTORNEY Patented Aug. 29, 1939 PATENT OFFICE DISCHARGE DEVICE AND ELECTRODE Daniel s. Gustin, Bloomfield, N. J., assignor to Westinghouse Electric & Manufacturing Company, 'East Pittsburgh, Pa., a corporation of Pennsylvania Application September 2, 1937, Serial No. 162,087

3 Claims. (01. 176-126) This invention-relates to discharge devices,

I and more particularly, to electrodes therefor which will not disintegrate under the extreme conditions to which they may be subjected in service.

The principal object of my invention, generally considered, is the provision of an improved form' of electrode for discharge devices, which has a relatively large surface area, which retains the electron emission material, and which occupies a relatively small space.

Another object of my invention is the provision of an electrode for discharge devices formed of fine tungsten Wire braided into a sleeve or ribbon, thereby making the surface area large while maintaining the volume small, so as to facilitate heating to the proper emission temperature, and at the same time providing the desired area for the emission.

A further object of my invention is the formation of a discharge device having electrodes, each consisting of braided tungsten wire formed into a sleeve .or hollow cylinder, open or closed at both ends, and impregnated with or containing a quantity of electron emission material, each cylinder being supported from a lead wire and disposed with its axis transverse to that of the envelope.

Other objects and advantages of the invention relating to theparticular arrangement and construction of the'various parts will become apparent as the description proceeds.

Referring to the drawing illustrating my invention:

Fig. 1 is a longitudinalsectional view of one end portion of a discharge device having elec trodes embodying my invention, one electrode being'shown inside elevation with parts broken elevation.

Fig. 3 is a greatly enlarged elevational view of .a portion of the sleeve or ribbon, formed by braiding fine wire of tungsten or other suitable metal, which serves for the construction of the electrode embodying my invention.

Fig. 4 is an edge view of the portion of the sleeve or ribbon shown in Fig. 3. v Fig. 5 is a view corresponding to Fig. 1, but showing a modified form of electrode and lead wire removed from the enclosing envelope.

Fig. 6 is a view similar to Fig.5, but-showing still another form of my electrode.

Referring to the drawing in detail, and first considering the embodiment of my invention illustrated in Figs. 1 to 4 inclusive, there is shown one end portion of a discharge device or I I into each end of which extends a leading-in conductor I2 carrying an electrode I3, only one of which is illustrated, as by means of a U- shaped piece of wire I4, the central portion of the wire I4 being welded or otherwise secured to the inner end of the ,leading in, conductor I2, as indicated at I 5 and the arms welded or other-'- wise secured to the electrode I3 adjacent its ends, as indicated at I6 and I1.

In the present embodiment, the electrode I3 is constructed from a ribbon I8 formed by braiding fine wires I9, desirably made of tungsten, but which may, if desired, be made, for use under certain circumstances, of other suitable metals such as platinum, molybdenum, or nickel, as indicated in Figs. 3 and 4. series of fine wires I9 may be Woven or braided together, diagonally or otherwise, to form a sort of metallic cloth or ribbon I8, which is then bent to hollow cylindrical form, as indicated in Figs.

1 and 2, the meeting edges of the ribbon being secured together by welding or in any other desired manner, as indicated at 20, and the end portions of said joined, edges being united to the leading-in conductor I2 in any convenient or desired manner, as indicated by the intermediate conductor I4. If desired, a seamless sleeve may be Woven from the wires I9 and directly united to the conductor I2 or intermediate Wire I4.

The electrode I3, on account of its manner of formation, providesa relatively large effective area to which may adhere electron emission material, such as a mixture of the alkaline earths, say, barium oxide and strontium oxide. These oxides may be applied to'the braided electrode I3rby dipping the same in, or spraying In other words, a.

.tube I0 comprising a glass or vitreous envelope with, a solution of compounds of alkaline earth.

metals and igniting to leave the oxides thereon. For example, asolution of the nitrates of barium and strontium may be applied to the braided electrode I3, after which the same is ignited to leave the oxides thereon. Or a suspension of the carbonates or other compounds of said alkaline earth metals may be applied to the electrode I and subsequently decomposed either by direct ignition, or by forming a discharge between the electrodes I3 in the envelope II.

-A further way of applying the electromemission material to the hollow cylindrical electrodes I3, is by filling said hollow electrodes with the material and closing the ends to prevent loss. On account of the weaving of the wires l9 to form the electrodes l3, there is plenty of space th'erebetween for allowing any electron-emission material enclosed in the hollow cylinder I; to operate 1' the generation and release of electrons.

Turnin now to Fig. 5, we find an electrode l3 supporte from -a leading-in conductor I! by means of a U-shaped wire II. The electrode I3 is constructed exactly like the electrode l3 of the previous embodiment, except that flange 20 formed by the union of the edge portions of the ribbon or metallic cloth I8, is slightly cut away at the ends, and caps 2| and 22 are applied over the hollow cylindrical cathode [3 to prevent loss of electron emission material 23 housed therein. .Although caps have been shown, it will be understood that plugs may be employed in st'ead for closing the ends of the cylindrical electrode.

Referring nowv to the embodiment of my invention illustrated in- Fig. 6, there is shown an electrode l3 supported from the leading-in conductor l2 by means of a U-shaped wire ll. The electrode I3 of the present embodiment is identical with the electrode I3 of the first embodiment except that the flange portion 20'', formed at the joint between the meeting edges of the wire ribbon or cloth l8 forming the hollow cylindrical electrode, is cut away and the end portions of said electrode closed about electron v emission material I! contained therein by pinching or crimping the ends of said cylindrical portion as indicated at 2| and 22 Instead or in addition to having the hollow cylindrical electrodes l3, l3, and l3 filled with electron emission material, it will be understood that such material may be applied to the outer surface or the mesh of the electrodes impregnated with said material, as described in connection with the embodiment of Flgs.1 to 4 inclusive.

From the foregoing disclosure, it will be seen .that I have devised an improved form of discharge device having electrodes adapted to function as electron emitting devices. These electrodes have large surface areas for retaining the emission material and occupy relatively small spaces, being desirably woven trom. the fine tungsten wire into a foraminous sleeve, or

. into a ribbon and subsequently formed into such vention have been disclosed, it will be understood that modifications may be made within the spirit and scope of the appended claims.

I claim: e 1. An electric discharge device comprising a sealed envelope, a leading-in conductor extending into each end of said envelope, an electrode secured to the inner end of each conductor, each electrode being formed of braided wire bent to cyli cal form with free edge portions overlap ed and connected to form an outstanding flange portion and carrying electron-emission material, and connecting means between each electrode and. its conductor comprising a U- shapedwire the arms of which are secured to the electrode flange and the intermediate portion of which is attached to the conductor.

2. An electric discharge device comprising a sealed envelope, a leading-in conductor extend- I ing into each end of said envelope, and an electrode secured to the inner end of each conductor by means of a U-shaped wire, the ends of which are secured to the said electrode and an inter- 1 mediate portion of which is secured to said con- DANIEL S. GUS'I'IN.

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