GB339451A - Improvements in or relating to electron emitting cathodes for electric discharge devices - Google Patents
Improvements in or relating to electron emitting cathodes for electric discharge devicesInfo
- Publication number
- GB339451A GB339451A GB3487529A GB3487529A GB339451A GB 339451 A GB339451 A GB 339451A GB 3487529 A GB3487529 A GB 3487529A GB 3487529 A GB3487529 A GB 3487529A GB 339451 A GB339451 A GB 339451A
- Authority
- GB
- United Kingdom
- Prior art keywords
- barium
- oxide
- filament
- coating
- tartrate
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J9/00—Apparatus or processes specially adapted for the manufacture, installation, removal, maintenance of electric discharge tubes, discharge lamps, or parts thereof; Recovery of material from discharge tubes or lamps
- H01J9/02—Manufacture of electrodes or electrode systems
- H01J9/04—Manufacture of electrodes or electrode systems of thermionic cathodes
- H01J9/042—Manufacture, activation of the emissive part
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Solid Thermionic Cathode (AREA)
Abstract
339,451. Gramophone Co., Ltd., and Baker, G. B. Nov. 14, 1929. Vacuum tubes.-Electron emitting cathodes for electric discharge devices are prepared by coating a refractory core or an oxide-coated filament with a substance which, on heating in the absence of appreciable oxygen, leaves a residue containing the oxide of an electron-emitting metal and free carbon. The tartrates of the alkali or alkaline earth metals, for example caesiuum tartrate or barium tartrate, may be used as coating-substances which are applied either to a refractory core such as tungsten, platinum, or nickel or its alloys, or to an oxide coated filament comprising a refractory core coated with barium oxide which may contain free barium. The oxide coated filament or a filament of refractory material may be dipped into or drawn through a paste containing barium tartrate, barium carbonate preferably being added to the paste when the refractory filament is used. After coating, the filament is heated to a temperature between 800‹-1000‹ C. in an atmosphere of carbon dioxide, the coating of barium tartrate thus being converted into barium, oxide and free carbon. The barium oxide combines with the carbon dioxide present to form barium carbonate, and a filament having a coating of barium carbonate and free carbon is obtained.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB3487529A GB339451A (en) | 1929-11-14 | 1929-11-14 | Improvements in or relating to electron emitting cathodes for electric discharge devices |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB3487529A GB339451A (en) | 1929-11-14 | 1929-11-14 | Improvements in or relating to electron emitting cathodes for electric discharge devices |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB339451A true GB339451A (en) | 1930-12-11 |
Family
ID=10370999
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB3487529A Expired GB339451A (en) | 1929-11-14 | 1929-11-14 | Improvements in or relating to electron emitting cathodes for electric discharge devices |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB339451A (en) |
-
1929
- 1929-11-14 GB GB3487529A patent/GB339451A/en not_active Expired
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