US1542385A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermionic cathode and method of making the same
Assignee: AT&T Inc
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Filing: 1920-10-12
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Granted: 1925-06-16
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Expires: 1940-10-12
Abstract
No abstract record available.
Inventors
- 👤 James E Harris
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:06
CPC Classifications
H; H01; H01J; H01J9/00; H01J9/02; H01J9/04; H01J9/042; H01J1/00; H01J1/02; H01J1/13; H01J1/14; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2913; Y10T428/2933; Y10T428/294
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) | 1928-06-15 | 1928-12-15 | 1929-06-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1932-06-15 | 1932-12-15 | 1933-06-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1936-06-15 | 1936-12-15 | 1937-06-16 | $7700.00 | Window Closed / Lapsed |