US2282097A - Nonemitting electrode structure - Google Patents
Nonemitting electrode structure Download PDFInfo
- Publication number
- US2282097A US2282097A US326584A US32658440A US2282097A US 2282097 A US2282097 A US 2282097A US 326584 A US326584 A US 326584A US 32658440 A US32658440 A US 32658440A US 2282097 A US2282097 A US 2282097A
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- United States
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- electrode
- grid
- thorium
- tungsten
- molybdenum
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- Expired - Lifetime
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- 229910052751 metal Inorganic materials 0.000 description 13
- 239000002184 metal Substances 0.000 description 13
- ZSLUVFAKFWKJRC-IGMARMGPSA-N 232Th Chemical compound [232Th] ZSLUVFAKFWKJRC-IGMARMGPSA-N 0.000 description 12
- 229910052776 Thorium Inorganic materials 0.000 description 12
- 239000000463 material Substances 0.000 description 12
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 12
- 229910052721 tungsten Inorganic materials 0.000 description 12
- 239000010937 tungsten Substances 0.000 description 12
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 11
- 150000002739 metals Chemical class 0.000 description 10
- 229910052750 molybdenum Inorganic materials 0.000 description 10
- 239000011733 molybdenum Substances 0.000 description 10
- 229910052715 tantalum Inorganic materials 0.000 description 10
- GUVRBAGPIYLISA-UHFFFAOYSA-N tantalum atom Chemical compound [Ta] GUVRBAGPIYLISA-UHFFFAOYSA-N 0.000 description 10
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 8
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 6
- 239000007789 gas Substances 0.000 description 5
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 4
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 4
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 4
- 239000011248 coating agent Substances 0.000 description 4
- 238000000576 coating method Methods 0.000 description 4
- 229910052739 hydrogen Inorganic materials 0.000 description 4
- 239000001257 hydrogen Substances 0.000 description 4
- 229910052697 platinum Inorganic materials 0.000 description 4
- 229910052799 carbon Inorganic materials 0.000 description 3
- 238000010438 heat treatment Methods 0.000 description 3
- 238000002844 melting Methods 0.000 description 3
- 230000008018 melting Effects 0.000 description 3
- 230000000737 periodic effect Effects 0.000 description 3
- 239000002344 surface layer Substances 0.000 description 3
- 229910002804 graphite Inorganic materials 0.000 description 2
- 239000010439 graphite Substances 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- 239000010410 layer Substances 0.000 description 2
- 229910052759 nickel Inorganic materials 0.000 description 2
- 238000007747 plating Methods 0.000 description 2
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000010405 anode material Substances 0.000 description 1
- 239000010406 cathode material Substances 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 239000004615 ingredient Substances 0.000 description 1
- 229910052741 iridium Inorganic materials 0.000 description 1
- GKOZUEZYRPOHIO-UHFFFAOYSA-N iridium atom Chemical compound [Ir] GKOZUEZYRPOHIO-UHFFFAOYSA-N 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 229910052762 osmium Inorganic materials 0.000 description 1
- SYQBFIAQOQZEGI-UHFFFAOYSA-N osmium atom Chemical compound [Os] SYQBFIAQOQZEGI-UHFFFAOYSA-N 0.000 description 1
- 238000013021 overheating Methods 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- ZCUFMDLYAMJYST-UHFFFAOYSA-N thorium dioxide Chemical compound O=[Th]=O ZCUFMDLYAMJYST-UHFFFAOYSA-N 0.000 description 1
- 229910003452 thorium oxide Inorganic materials 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J19/00—Details of vacuum tubes of the types covered by group H01J21/00
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J19/00—Details of vacuum tubes of the types covered by group H01J21/00
- H01J19/28—Non-electron-emitting electrodes; Screens
- H01J19/30—Non-electron-emitting electrodes; Screens characterised by the material
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J2893/00—Discharge tubes and lamps
- H01J2893/0001—Electrodes and electrode systems suitable for discharge tubes or lamps
- H01J2893/0012—Constructional arrangements
- H01J2893/0019—Chemical composition and manufacture
- H01J2893/002—Chemical composition and manufacture chemical
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J2893/00—Discharge tubes and lamps
- H01J2893/0001—Electrodes and electrode systems suitable for discharge tubes or lamps
- H01J2893/0012—Constructional arrangements
- H01J2893/0019—Chemical composition and manufacture
- H01J2893/0022—Manufacture
- H01J2893/0023—Manufacture carbonising and other surface treatments
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S428/00—Stock material or miscellaneous articles
- Y10S428/922—Static electricity metal bleed-off metallic stock
- Y10S428/9265—Special properties
- Y10S428/929—Electrical contact feature
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/12—All metal or with adjacent metals
- Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
- Y10T428/12535—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.] with additional, spatially distinct nonmetal component
Definitions
- This invention relates to a non-emitting electrode structure for space discharge devices and more particularly for use in connection with thoriated types of hot cathodes.
- any cathode material that is, thorium or thorium oxide is evaporated or sputtered from the cathode, some may deposit on one or more of the other hot electrodes which should be normally non-emitting. If the material out of which the hot electrode is made is a suitable base for the thorium, then it is obvious that the deposited thorium will result in emission from what should normally be a non-emitting electrode.
- a substance should have a high melting point
- Tungsten as a material for grids is difficult to handle since it is tough and springy. Furthermore, any thorium falling on tungsten will result in emission if the tungsten is hot since tungsten is an excellent base.
- Tantalum is ordinarily suitable for grid and anode electrodes. It has one serious drawback however in that its gas absorption characteristics under high temperatures are not always suitable to working conditions.
- tantalum On an extreme overload some absorbed gases may be released with disastrous results to the tubes. If the tantalum is thoroughly cleaned and free of all gas, it provides a rather excellent base in the event that any thorium falls on it.
- Molybdenum is not as easily handled as tantalum and does not absorb gases as readily as tantalum. However, when thorium falls on it, molybdenum is even a better base material than tantalum so that any electrode operating at an elevated temperature will tend to emit.
- any one of the above three metals without regard to their characteristics of being a satisfactory base material for thorium.
- Any one of the metals, that is tungsten, tantalum or molybdenum, when treated as described herein retains its normal properties as previously pointed out, when used as a grid or anode with the exception that substantially all tendency for emission of electrons due to thorium falling thereon is suppressed and eliminated so completely that this is no longer a factor in the choice of metal.
- this invention contemplates the use of tungsten, tantalum or molybdenum as a material for grids and anodes and subjected to the following treatment.
- a quantity of any one or more of the metals of group 8 'of the periodic table of elements is applied to any one of the three base materials that is tungsten, tantalum or molybdenum.
- the application may either be in the form of a plated coating or may be melted into the material to form an alloy.
- the quantity of such additional metal or metals of group 8 may be very small and in practice the added ingredient is generally driven out by heat to the surface of the base material to form a coating.
- a base wire of tantalum, tungsten or molybdenum may be plated with platinum, the coating being extremely minute for the sake of cheapness rather than anything else.
- platinum iridium or osmium may be used. Any one of the three latter elements is particularly desirable for the reason that the melting points are high and vapor pressures are low.
- This tendency to non-emission may be due to the fact that the thorium does not remain on the material but is driven off. However, irrespective of how this occurs, I have found that this 2 tendency toward non-emission may be enhanced to an even greater degree by the application of carbon to the treated electrode.
- a molybdenum wire which has been suitably cleaned by heating in 2 a hydrogen atmosphere may have a thin plating of latinum thereon.
- the hydrogen cleaning of the wire may occur after plating if desired.
- this wire may be washed in hot water.
- the wire may then be made up into the 30 form of a grid or other electrode and then sprayed with a mixture of alcohol and aquadag. Thereafter this electrode may be heated in a hydrogen atmosphere until the surface is shiny and clean. This heating may be done during the 35 final evacuation and Kettering steps.
- the hydrogen atmosphere is not a necessity since the customary evacuation conditions may create a reducing atmosphere around the wire.
- a grid or anode electrode treated in this manner will have 40 posing one of the normally non-emitting electrodes.
- a space discharge device may have an envelope l0 or glass or any other suitable material the interior of which is suitably evacuated.
- a stem H Supported within envelope N as by means of a stem H are a plurality of electrodes consisting of a cathode l2 of the thoriated type adapted to emit when heated.
- a control grid l3 Surrounding cathode l2 is a control grid l3 and beyond the grid is an anode I4.
- Anode I may be of metal and if desired and as far as this invention is concerned may be handled in the same way as grid IS.
- the anode may also consist of graphite.
- grid l3 as an example of a normally non-emitting electrode which under operating conditions may be hot and upon which thorium may be deposited from cathode I2, is constructed of any one of the metals tantalum, tungsten or molybdenum treated as previously described.
- a space discharge device having a thoriated incandescible cathode and a non-emitting electrode having a core of the group tungsten and molybdenum, said core having as a cover over its entire surface an intimately bound thin surface layer oi. one or more metals or group eight of the periodic table with the outer surface of.
- a space discharge device having a thoriated incandescible cathode and a non-emitting electrode having a core of the group tungsten and molybdenum, said core having as a cover over its entire surface an intimately bound thin surface layer of one or more metals of group eight of the periodic table having a melting point of the order of platinum and having the outer surface of said layer carbonized.
- a space discharge device having a thoriated incandescible cathode and a non-emitting electrode having a core of the group tungsten and molybdenum, said core having as a cover over its entire surface an intimately bound thin surface layer of platinum with the outer surface carbonized.
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- Solid Thermionic Cathode (AREA)
- Discharge Lamp (AREA)
Description
y 1942. w. G. TAYLOR 2,282,097
NON-EMITTING ELECTRODE STRUCTURE Filed March 29, 1940 Coating of mefa/ of group 8 Carbon/zed l surface (2/7192? Zf/Of Patented May 5, 1942 UNITED STATES PATENT OFFICE NONEMITTING ELECTRODE STRUCTURE Warren G. Taylor, Chicago, Ill.
Application March 29, 1940, Serial No. 326,584
3 Claims.
This invention relates to a non-emitting electrode structure for space discharge devices and more particularly for use in connection with thoriated types of hot cathodes.
In order to obtain certain characteristics in a space discharge device it is frequently necessary to dispose grids and even anodes quite close to cathodes. Since the thoriated type of cathode operates at a high temperature, it is evident that the physical proximity to the cathode of normally non-emitting electrodes will result in heating of these latter electrodes. This is particularly true of grid electrodes.
In addition thereto, electron bombardment will elevate the electrode temperature. Reflection and radiation from an anode or solid plate will also tend to heat grids. The net result is that a so-called cold electrode is in reality an electrode which is normally operating at an elevated temperature.
In the event that any cathode material, that is, thorium or thorium oxide is evaporated or sputtered from the cathode, some may deposit on one or more of the other hot electrodes which should be normally non-emitting. If the material out of which the hot electrode is made is a suitable base for the thorium, then it is obvious that the deposited thorium will result in emission from what should normally be a non-emitting electrode.
The closer a grid electrode is to the cathode, the hotter it is likely to be, the more likely it is to have thorium deposited on it, and the greater the efiect of the emission, since a grid in this position exercises an extremely delicate control.
In order to be satisfactory as a'grid material, a substance should have a high melting point,
low vapor pressure, should surrender substantially all absorbed gases when hot during the evacuation process, should not itself sensibly emit electrons under all operating conditions, and in addition have the usual normal commercial requirements of cheapness and workability. f the metals generally available, iron and nickel would be satisfactory except that they melt and vaporize too easily. Thus, in tubes having carbon or graphite anodes it is necessary to heat the electrode to extremely high temperatures for relatively long times during processing and this usually results in an overheating of the metallic electrodes. Furthermore, during operation many tubes are subjected to extreme overloads where the grid and anode electrodes are operated at a temperature corresponding to red heat or higher.
Under such conditions, iron or nickel would not stand up.
Tungsten as a material for grids is difficult to handle since it is tough and springy. Furthermore, any thorium falling on tungsten will result in emission if the tungsten is hot since tungsten is an excellent base.
Tantalum is ordinarily suitable for grid and anode electrodes. It has one serious drawback however in that its gas absorption characteristics under high temperatures are not always suitable to working conditions.
On an extreme overload some absorbed gases may be released with disastrous results to the tubes. If the tantalum is thoroughly cleaned and free of all gas, it provides a rather excellent base in the event that any thorium falls on it.
Molybdenum is not as easily handled as tantalum and does not absorb gases as readily as tantalum. However, when thorium falls on it, molybdenum is even a better base material than tantalum so that any electrode operating at an elevated temperature will tend to emit.
By the invention herein disclosed it is possible to utilize as a grid or anode material any one of the above three metals without regard to their characteristics of being a satisfactory base material for thorium. Any one of the metals, that is tungsten, tantalum or molybdenum, when treated as described herein retains its normal properties as previously pointed out, when used as a grid or anode with the exception that substantially all tendency for emission of electrons due to thorium falling thereon is suppressed and eliminated so completely that this is no longer a factor in the choice of metal.
In general this invention contemplates the use of tungsten, tantalum or molybdenum as a material for grids and anodes and subjected to the following treatment. A quantity of any one or more of the metals of group 8 'of the periodic table of elements is applied to any one of the three base materials that is tungsten, tantalum or molybdenum. The application may either be in the form of a plated coating or may be melted into the material to form an alloy. The quantity of such additional metal or metals of group 8 may be very small and in practice the added ingredient is generally driven out by heat to the surface of the base material to form a coating.
Thus, for example, a base wire of tantalum, tungsten or molybdenum may be plated with platinum, the coating being extremely minute for the sake of cheapness rather than anything else. Instead of platinum, iridium or osmium may be used. Any one of the three latter elements is particularly desirable for the reason that the melting points are high and vapor pressures are low.
Thus, if a grid must withstand a high tem- 5 metals will withstand extremely high temperal0 tures and will be easily driven oif. However, as long as any one of these metals remains on the surface of the base material, there will be practically no tendency for emission to occur even at an elevated temperature in case any thorium 1o settles on the electrode.
This tendency to non-emission may be due to the fact that the thorium does not remain on the material but is driven off. However, irrespective of how this occurs, I have found that this 2 tendency toward non-emission may be enhanced to an even greater degree by the application of carbon to the treated electrode.
' Thus, as an example, a molybdenum wire which has been suitably cleaned by heating in 2 a hydrogen atmosphere may have a thin plating of latinum thereon. The hydrogen cleaning of the wire may occur after plating if desired. Thereafter this wire may be washed in hot water. The wire may then be made up into the 30 form of a grid or other electrode and then sprayed with a mixture of alcohol and aquadag. Thereafter this electrode may be heated in a hydrogen atmosphere until the surface is shiny and clean. This heating may be done during the 35 final evacuation and Kettering steps. The hydrogen atmosphere is not a necessity since the customary evacuation conditions may create a reducing atmosphere around the wire. A grid or anode electrode treated in this manner will have 40 posing one of the normally non-emitting electrodes.
Referring to the drawing a space discharge device may have an envelope l0 or glass or any other suitable material the interior of which is suitably evacuated. Supported within envelope N as by means of a stem H are a plurality of electrodes consisting of a cathode l2 of the thoriated type adapted to emit when heated. Surrounding cathode l2 is a control grid l3 and beyond the grid is an anode I4. Anode I may be of metal and if desired and as far as this invention is concerned may be handled in the same way as grid IS. The anode may also consist of graphite. In any event, grid l3, as an example of a normally non-emitting electrode which under operating conditions may be hot and upon which thorium may be deposited from cathode I2, is constructed of any one of the metals tantalum, tungsten or molybdenum treated as previously described.
What is claimed is:
l. A space discharge device having a thoriated incandescible cathode and a non-emitting electrode having a core of the group tungsten and molybdenum, said core having as a cover over its entire surface an intimately bound thin surface layer oi. one or more metals or group eight of the periodic table with the outer surface of.
said layer carbonized.
2. A space discharge device having a thoriated incandescible cathode and a non-emitting electrode having a core of the group tungsten and molybdenum, said core having as a cover over its entire surface an intimately bound thin surface layer of one or more metals of group eight of the periodic table having a melting point of the order of platinum and having the outer surface of said layer carbonized.
3. A space discharge device having a thoriated incandescible cathode and a non-emitting electrode having a core of the group tungsten and molybdenum, said core having as a cover over its entire surface an intimately bound thin surface layer of platinum with the outer surface carbonized.
WARREN. G. TAYLOR.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US326584A US2282097A (en) | 1940-03-29 | 1940-03-29 | Nonemitting electrode structure |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
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US326584A US2282097A (en) | 1940-03-29 | 1940-03-29 | Nonemitting electrode structure |
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US2282097A true US2282097A (en) | 1942-05-05 |
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US326584A Expired - Lifetime US2282097A (en) | 1940-03-29 | 1940-03-29 | Nonemitting electrode structure |
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Cited By (26)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2417459A (en) * | 1945-05-21 | 1947-03-18 | Eitel Mccullough Inc | Electron tube and electrode for the same |
US2425090A (en) * | 1942-08-24 | 1947-08-05 | Eitel Mccullough Inc | Method of making cathodes |
US2450007A (en) * | 1942-11-23 | 1948-09-28 | Standard Telephones Cables Ltd | Carburized filament and method for treating the same |
US2497090A (en) * | 1947-12-13 | 1950-02-14 | Eitel Mccullough Inc | Electrode and method of making the same |
US2497111A (en) * | 1947-07-25 | 1950-02-14 | Eitel Mccullough Inc | Electron tube having carburized thoriated cathode |
US2497109A (en) * | 1946-02-04 | 1950-02-14 | Eitel Mccullough Inc | Electrode for electron tubes |
US2497110A (en) * | 1946-02-04 | 1950-02-14 | Eitel Mccullough Inc | Method of making electrodes |
US2682101A (en) * | 1946-06-01 | 1954-06-29 | Whitfield & Sheshunoff Inc | Oxidation protected tungsten and molybdenum bodies and method of producing same |
US2719797A (en) * | 1950-05-23 | 1955-10-04 | Baker & Co Inc | Platinizing tantalum |
US2720494A (en) * | 1950-01-09 | 1955-10-11 | Harold R Suter | Process of preparing catalytic elements |
US2771666A (en) * | 1950-03-18 | 1956-11-27 | Fansteel Metallurgical Corp | Refractory bodies |
US2788460A (en) * | 1951-05-23 | 1957-04-09 | Itt | Electrodes for electron discharge devices and methods of making same |
US2788289A (en) * | 1951-06-29 | 1957-04-09 | Climax Molybdenum Co | Method of forming protective coatings for molybdenum and molybdenum-base alloys |
US2844868A (en) * | 1954-06-01 | 1958-07-29 | Sylvania Electric Prod | Method of joining refractory metals |
US2864026A (en) * | 1953-03-20 | 1958-12-09 | Philips Corp | Electric discharge tube |
US2876400A (en) * | 1953-02-27 | 1959-03-03 | Siemens Ag | Composite electrodes for directional crystal devices |
US3024522A (en) * | 1959-07-24 | 1962-03-13 | Gen Electric | Rhenium bonded composite material and method |
US3045333A (en) * | 1951-10-18 | 1962-07-24 | Rem Cru Titanium Inc | Titanium coated article |
US3092749A (en) * | 1960-04-15 | 1963-06-04 | Gen Electric | Electron discharge device |
US3096421A (en) * | 1958-04-16 | 1963-07-02 | Walter G Finch | Superconducting contact devices |
US3188720A (en) * | 1965-06-15 | Method of sealing and joining and articles made thereby | ||
US3259782A (en) * | 1961-11-08 | 1966-07-05 | Csf | Electron-emissive structure |
US3458408A (en) * | 1962-11-16 | 1969-07-29 | Monsanto Co | Method for making an inductive heating element for zone refining apparatus |
US3489602A (en) * | 1965-05-25 | 1970-01-13 | Hughes Aircraft Co | Method of impregnating porous tungsten and resulting article |
US3544285A (en) * | 1966-11-16 | 1970-12-01 | Imp Metal Ind Kynoch Ltd | Oxidation-resistant coatings |
US5343126A (en) * | 1992-10-26 | 1994-08-30 | General Electric Company | Excitation coil for an electrodeless fluorescent lamp |
-
1940
- 1940-03-29 US US326584A patent/US2282097A/en not_active Expired - Lifetime
Cited By (26)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3188720A (en) * | 1965-06-15 | Method of sealing and joining and articles made thereby | ||
US2425090A (en) * | 1942-08-24 | 1947-08-05 | Eitel Mccullough Inc | Method of making cathodes |
US2450007A (en) * | 1942-11-23 | 1948-09-28 | Standard Telephones Cables Ltd | Carburized filament and method for treating the same |
US2417459A (en) * | 1945-05-21 | 1947-03-18 | Eitel Mccullough Inc | Electron tube and electrode for the same |
US2497109A (en) * | 1946-02-04 | 1950-02-14 | Eitel Mccullough Inc | Electrode for electron tubes |
US2497110A (en) * | 1946-02-04 | 1950-02-14 | Eitel Mccullough Inc | Method of making electrodes |
US2682101A (en) * | 1946-06-01 | 1954-06-29 | Whitfield & Sheshunoff Inc | Oxidation protected tungsten and molybdenum bodies and method of producing same |
US2497111A (en) * | 1947-07-25 | 1950-02-14 | Eitel Mccullough Inc | Electron tube having carburized thoriated cathode |
US2497090A (en) * | 1947-12-13 | 1950-02-14 | Eitel Mccullough Inc | Electrode and method of making the same |
US2720494A (en) * | 1950-01-09 | 1955-10-11 | Harold R Suter | Process of preparing catalytic elements |
US2771666A (en) * | 1950-03-18 | 1956-11-27 | Fansteel Metallurgical Corp | Refractory bodies |
US2719797A (en) * | 1950-05-23 | 1955-10-04 | Baker & Co Inc | Platinizing tantalum |
US2788460A (en) * | 1951-05-23 | 1957-04-09 | Itt | Electrodes for electron discharge devices and methods of making same |
US2788289A (en) * | 1951-06-29 | 1957-04-09 | Climax Molybdenum Co | Method of forming protective coatings for molybdenum and molybdenum-base alloys |
US3045333A (en) * | 1951-10-18 | 1962-07-24 | Rem Cru Titanium Inc | Titanium coated article |
US2876400A (en) * | 1953-02-27 | 1959-03-03 | Siemens Ag | Composite electrodes for directional crystal devices |
US2864026A (en) * | 1953-03-20 | 1958-12-09 | Philips Corp | Electric discharge tube |
US2844868A (en) * | 1954-06-01 | 1958-07-29 | Sylvania Electric Prod | Method of joining refractory metals |
US3096421A (en) * | 1958-04-16 | 1963-07-02 | Walter G Finch | Superconducting contact devices |
US3024522A (en) * | 1959-07-24 | 1962-03-13 | Gen Electric | Rhenium bonded composite material and method |
US3092749A (en) * | 1960-04-15 | 1963-06-04 | Gen Electric | Electron discharge device |
US3259782A (en) * | 1961-11-08 | 1966-07-05 | Csf | Electron-emissive structure |
US3458408A (en) * | 1962-11-16 | 1969-07-29 | Monsanto Co | Method for making an inductive heating element for zone refining apparatus |
US3489602A (en) * | 1965-05-25 | 1970-01-13 | Hughes Aircraft Co | Method of impregnating porous tungsten and resulting article |
US3544285A (en) * | 1966-11-16 | 1970-12-01 | Imp Metal Ind Kynoch Ltd | Oxidation-resistant coatings |
US5343126A (en) * | 1992-10-26 | 1994-08-30 | General Electric Company | Excitation coil for an electrodeless fluorescent lamp |
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