Patent US2415412A successfully refreshed from Google Patents.
US2415412A
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Method of forming vacuum tubes
Assignee: AT&T Inc
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Filing: 1943-07-31
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Granted: 1947-02-11
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Expires: 1963-07-31
Abstract
No abstract record available.
Inventors
- 👤 Charles E Buchwald
- 👤 Sherman K Shull
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 20:17
CPC Classifications
H; H01; H01J; H01J5/00; H01J5/20; H01J5/22; H01J5/26; H01J19/00; H01J19/42; H01J19/46; H01J2893/00; H01J2893/0001; H01J2893/0002; H01J2893/0005; H01J2893/0006; H01J2893/0033; H01J2893/0037; H01J2893/0041; H01J2893/0043; Y; Y10; Y10S; Y10S425/00; Y10S425/012; Y10T; Y10T29/00; Y10T29/49; Y10T29/4981
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1950-02-10 | 1950-08-12 | 1951-02-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1954-02-10 | 1954-08-12 | 1955-02-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1958-02-10 | 1958-08-12 | 1959-02-11 | $7700.00 | Window Closed / Lapsed |