US2558491A - Method of manufacturing electric discharge tubes - Google Patents
Method of manufacturing electric discharge tubes Download PDFInfo
- Publication number
- US2558491A US2558491A US41362A US4136248A US2558491A US 2558491 A US2558491 A US 2558491A US 41362 A US41362 A US 41362A US 4136248 A US4136248 A US 4136248A US 2558491 A US2558491 A US 2558491A
- Authority
- US
- United States
- Prior art keywords
- cathode
- tube
- pressure
- substances
- emissive
- 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 - Lifetime
Links
- 238000004519 manufacturing process Methods 0.000 title description 16
- 239000000126 substance Substances 0.000 description 42
- 239000007789 gas Substances 0.000 description 38
- 208000028659 discharge Diseases 0.000 description 27
- 150000001875 compounds Chemical class 0.000 description 23
- 238000000034 method Methods 0.000 description 23
- 238000010438 heat treatment Methods 0.000 description 21
- 238000000354 decomposition reaction Methods 0.000 description 13
- 230000003993 interaction Effects 0.000 description 8
- 230000000694 effects Effects 0.000 description 6
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 4
- 230000003213 activating effect Effects 0.000 description 4
- 230000007423 decrease Effects 0.000 description 4
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 3
- 229910002651 NO3 Inorganic materials 0.000 description 3
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 description 3
- 239000013543 active substance Substances 0.000 description 3
- 238000010304 firing Methods 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 150000002739 metals Chemical class 0.000 description 3
- 238000005086 pumping Methods 0.000 description 3
- 229910052786 argon Inorganic materials 0.000 description 2
- 241000183024 Populus tremula Species 0.000 description 1
- 229910000287 alkaline earth metal oxide Inorganic materials 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000009931 harmful effect Effects 0.000 description 1
- 238000007654 immersion Methods 0.000 description 1
- 238000003780 insertion Methods 0.000 description 1
- 230000037431 insertion Effects 0.000 description 1
- QSHDDOUJBYECFT-UHFFFAOYSA-N mercury Chemical compound [Hg] QSHDDOUJBYECFT-UHFFFAOYSA-N 0.000 description 1
- 229910052753 mercury Inorganic materials 0.000 description 1
- 150000002823 nitrates Chemical class 0.000 description 1
- 230000000737 periodic effect Effects 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
- 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
Definitions
- the invention relates to a method of manufacturing electric discharge tubes, according to which method the cathode has applied to it compounds which are adapted to be dissociated by heat and thus to produce readily emitting substances,
- the invention relates in addition to electric discharge tubes manufactured by such a method and to an apparatus for carrying out such a method.
- the invention is based on recognition of the fact that during the forming operation the atmosphere in the discharge tube must fulfill particular requirements.
- This gaseous atmosphere is formed by gases emanating from various sources. Firstly there is the gas which is normally contained in the tube, generally therefore air. Secondly, as a result of heating the tube, gas is evolved from all the components thereof, for example the wall and the electrodes. Thirdly, gas is evolved by decomposition of the compounds on the cathode.
- decomposition takes place at such an instant of the cycle of manufacturing the discharge tube that the gases evolved upon decomposition have disappeared from the tube, at least in part, be-
- decomposition will be started preferably early in the cycle so that at the instant at which heating is started, the forming pressure again prevails in the tube, the probability of production of non-emissive compounds being thus slightest.
- the cathode may be heated. for example, practically immediately at the start of the exhaustion, since at this instant the decrease in pressure per unit time is considerable and it has been found that the gases evolved from the other components of the discharge tube, for example water vapour, practically do not affect the com-' pounds thus formed on the cathode.
- the discharge tube is treated in the usual manner in the method according to the invention.
- Figure 1 shows a graph of the pumping time for tube evacuation plotted against the pressure in the tube
- Fig. 2 illustrates the sequence of operations of the apparatus used in the method of invention.
- the pumping time T is plotted on the horizontal axis, the pressure P on the vertical axis.
- the exhaustion curve which would occur if the cathode were not heated is designated by the curve a.
- This curve has a substantially exponential variation but for two kinking points.
- the kinking point A is due to the heating and de-gassing operations to which the tube and its components are subjected being started; the kinking points on the curve L-l are produced upon exit of the tube from the heating zone (furnace).
- the dotted line parallel to the horizontal axis designates the forming pressure. Curve a intersects this dotted line at point Q and according to the methods hitherto adopted, heating of the cathode has invariably been started at this point. Owing to this heating a quantity of gas is evolved, so that the pressure evolved is substantially equal.
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Manufacture Of Electron Tubes, Discharge Lamp Vessels, Lead-In Wires, And The Like (AREA)
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| NL2558491X | 1947-08-19 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US2558491A true US2558491A (en) | 1951-06-26 |
Family
ID=19874737
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US41362A Expired - Lifetime US2558491A (en) | 1947-08-19 | 1948-07-29 | Method of manufacturing electric discharge tubes |
Country Status (2)
| Country | Link |
|---|---|
| US (1) | US2558491A (fr) |
| FR (1) | FR970402A (fr) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1894948A (en) * | 1929-10-29 | 1933-01-24 | Siemens Ag | Manufacture of electron discharge devices |
| US1909916A (en) * | 1931-05-11 | 1933-05-16 | Ora S Duffendack | Electron emitter and method of making same |
| US2041802A (en) * | 1933-06-30 | 1936-05-26 | Bell Telephone Labor Inc | Electron emitter |
| US2184323A (en) * | 1933-06-23 | 1939-12-26 | Hans J Spanner | Cathode activation and degassing |
-
1948
- 1948-07-29 US US41362A patent/US2558491A/en not_active Expired - Lifetime
- 1948-08-17 FR FR970402D patent/FR970402A/fr not_active Expired
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1894948A (en) * | 1929-10-29 | 1933-01-24 | Siemens Ag | Manufacture of electron discharge devices |
| US1909916A (en) * | 1931-05-11 | 1933-05-16 | Ora S Duffendack | Electron emitter and method of making same |
| US2184323A (en) * | 1933-06-23 | 1939-12-26 | Hans J Spanner | Cathode activation and degassing |
| US2041802A (en) * | 1933-06-30 | 1936-05-26 | Bell Telephone Labor Inc | Electron emitter |
Also Published As
| Publication number | Publication date |
|---|---|
| FR970402A (fr) | 1951-01-04 |
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