US3970768A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Grid electrodes
Assignee: Teledyne UK Ltd
•
Filing: 1975-07-30
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Granted: 1976-07-20
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Expires: 1995-07-30
Abstract
Abstract A method of making a pyrolytic graphite grid electrode for a high power transmitting tube includes the steps of holding a metallic grid electrode core between two copper blocks, heating the core to 1750°C by passing an electric current through it and passing a carbonaceous gas over the heated core so that graphite is deposited thereon. Because the graphite thickness is reduced towards the copper blocks supporting the core, where the grid is to be used in a high voltage tube annular shields are provided around the supported ends of the grid.
Inventors
- 👤 David Mark Wilcox
- 👤 William David Richard Rivers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 18:08
CPC Classifications
H; H01; H01J; H01J19/00; H01J2893/00; H01J2893/0001; H01J2893/0012; H01J2893/0019; H01J2893/0022
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
63 words
A method of making a pyrolytic graphite grid electrode comprising the steps of holding a metallic grid electrode core between relatively massive bodies which are of good thermal conductivity, passing a carbonaceous gas over said metallic grid electrode core whilst the grid electrode core is held at the temperature required for the deposition of pyrolytic graphite by passing an electric current through it.
Claim 2
Independent Claim
63 words
A method of making a pyrolytic graphite grid electrode comprising the steps of holding a metallic grid electrode core between relatively massive bodies which are of good thermal conductivity, passing a carbonaceous gas over said metallic grid electrode core whilst the grid electrode core is held at the temperature required for the deposition of pyrolytic graphite by passing an electric current through it.
Claim 3
Dependent Claim
21 words
A method as claimed in claim 1 in which the temperature is adjusted by controlling the amount of electric current passing.
Claim 4
Dependent Claim
41 words
A method as claimed in claim 1 wherein the metallic grid electrode core is an open wire mesh defining a hollow cylinder, at each end of which is present a relatively massive body whilst the metallic grid electrode core is heated.
Claim 5
Dependent Claim
24 words
A method as claimed in claim 3 wherein one of the relatively massive bodies is located on a support passing through the hollow cylinder.
Claim 6
Dependent Claim
13 words
A method as claimed in claim 4 wherein the support is water cooled.
Claim 7
Dependent Claim
40 words
A method as claimed in claim 1 in which these regions of the metallic grid electrode adjacent said relatively massive bodies are provided with electrically conductive shields to inhibit voltage breakdown at those regions in normal use of the electrode.
References Cited (Backward Citations)
US2764510A
Cited
US3187502A
Cited
US3107180A
Cited
US3138434A
Cited
US3379555A
Cited
US3399969A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-07-20 | 1980-01-19 | 1980-07-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-07-20 | 1984-01-19 | 1984-07-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-07-20 | 1988-01-19 | 1988-07-20 | $7700.00 | Window Closed / Lapsed |