US2153728A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ultra high frequency signaling
Assignee: AT&T Inc
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Filing: 1936-10-07
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Granted: 1939-04-11
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Expires: 1956-10-07
Abstract
No abstract record available.
Inventors
- 👤 Southworth George Clark
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 22:04
CPC Classifications
H; H03; H03D; H03D9/00; H03D9/06; H03D9/065; H01; H01J; H01J19/00; H01J19/78; H01J19/80; H01J21/00; H01J21/36; H03B; H03B5/00; H03B5/18; H03B5/1817; H03B5/1835; H03F; H03F3/00; H03F3/54
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) | 1942-04-10 | 1942-10-10 | 1943-04-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1946-04-10 | 1946-10-10 | 1947-04-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1950-04-10 | 1950-10-10 | 1951-04-11 | $7700.00 | Window Closed / Lapsed |