US2457138A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rectifier
Assignee: STC PLC
•
Filing: 1947-07-22
•
Granted: 1948-12-28
•
Expires: 1967-07-22
Abstract
No abstract record available.
Inventors
- 👤 Charles A Escoffery
- 👤 Walter H Hawk
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 23:42
CPC Classifications
H; H10; H10W; H10W72/00; H10D; H10D99/00
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) | 1951-12-28 | 1952-06-28 | 1952-12-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1955-12-28 | 1956-06-28 | 1956-12-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1959-12-28 | 1960-06-28 | 1960-12-28 | $7700.00 | Window Closed / Lapsed |