Patent US4034031A successfully refreshed from Google Patents.
US4034031A
Expired / Lapsed
US
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Method of manufacturing grid electrodes for electron tubes
Assignee: US Philips Corp
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Filing: 1975-10-16
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Granted: 1977-07-05
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Expires: 1995-10-16
Abstract
Abstract Method of manufacturing grid electrodes wherein a grid sleeve is produced by depositing pyrolytic graphite on a polished mandril of glassy carbon and provided with apertures by means of the laser beam, then the finished grid is provided, by means of hot gas pyrolysis, with a second layer of highly oriented pyrolytic graphite, and thermally and/or mechanically after-treated at 3000° to 3800° K and 10-500 bar.
Inventors
- 👤 Bernhard Lersmacher
- 👤 Horst Seifert
- 👤 Johannes Wilhelmus Antonius Krol
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 20:14
CPC Classifications
C; C23; C23C; C23C16/00; C23C16/22; C23C16/26; H; H01; H01J; H01J19/00; H01J2893/00; H01J2893/0001; H01J2893/0012; H01J2893/0019; H01J2893/0022
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
110 words
A method of manufacturing grid electrodes for electron tubes, in which pyrolytic graphite is deposited by thermal decomposition of carbon-containing gases on a mandril having a smooth surface and the resulting molded body is separated from the mandril and provided with grid-like apertures, characterized in that the molded body after the formation of the grid is covered again with a thin layer of pyrolytic graphite and that the steps of deposition on the mandril and the covering again of the molded body having grid-like apertures are carried out at a temperature of the carbon-containing gas that is higher than the temperature of the mandril and of the molded body, respectively.
Claim 2
Independent Claim
110 words
A method of manufacturing grid electrodes for electron tubes, in which pyrolytic graphite is deposited by thermal decomposition of carbon-containing gases on a mandril having a smooth surface and the resulting molded body is separated from the mandril and provided with grid-like apertures, characterized in that the molded body after the formation of the grid is covered again with a thin layer of pyrolytic graphite and that the steps of deposition on the mandril and the covering again of the molded body having grid-like apertures are carried out at a temperature of the carbon-containing gas that is higher than the temperature of the mandril and of the molded body, respectively.
Claim 3
Dependent Claim
34 words
A method as claimed in claim 1, characterized in that the temperature of the carbon-containing gas is at least 100° K. higher than the temperature of the mandril and of the molded body, respectively.
Claim 4
Dependent Claim
19 words
A method as claimed in claim 2, characterized in that before depositing the pyrolytic graphite the mandril is polished.
Claim 5
Dependent Claim
17 words
A method as claimed in claim 3, characterized in that a mandril of glassy carbon is used.
Claim 6
Dependent Claim
35 words
A method as claimed in claim 4, characterized in that the molded body after the formation of the grid is covered with a layer of pyrolytic graphite which is from 1 to 100 μm thick.
Claim 7
Dependent Claim
24 words
A method as claimed in claim 5, characterized in that the grid electrodes are subjected to a thermal after-treatment at 3000° to 3800° K.
Claim 8
Dependent Claim
28 words
A method as claimed in claim 6, characterized in that the thermal after-treatment is carried out under an inert gas at a pressure of 10 to 500 bar.
Claim 9
Dependent Claim
23 words
A method as claimed in claim 7, characterized in that the molded body is provided with grid-like apertures by means of laser beams.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-07-04 | 1981-01-03 | 1981-07-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-07-04 | 1985-01-03 | 1985-07-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-07-04 | 1989-01-03 | 1989-07-05 | $7700.00 | Window Closed / Lapsed |