US2558021A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermionic vacuum tube and circuit
Assignee: Leland Stanford Junior University
•
Filing: 1942-03-24
•
Granted: 1951-06-26
•
Expires: 1962-03-24
Abstract
No abstract record available.
Inventors
- 👤 Russell H Varian
- 👤 Packard David
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 14:14
CPC Classifications
H; H01; H01J; H01J19/00; H01J19/78; H01J19/80; H03; H03F; H03F1/00; H03F1/08
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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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) | 1954-06-25 | 1954-12-25 | 1955-06-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-06-25 | 1958-12-25 | 1959-06-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-06-25 | 1962-12-25 | 1963-06-26 | $7700.00 | Window Closed / Lapsed |