Patent US1757729A successfully refreshed from Google Patents.
US1757729A
Expired / Lapsed
US
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Wave-transmission system
Assignee: AT&T Inc
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Filing: 1925-03-13
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Granted: 1930-05-06
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Expires: 1945-03-13
Abstract
No abstract record available.
Inventors
- 👤 Robert C Mathes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 09:46
CPC Classifications
H; H04; H04B; H04B1/00; H04B1/62; H04B1/64
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) | 1933-05-05 | 1933-11-04 | 1934-05-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1937-05-05 | 1937-11-04 | 1938-05-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1941-05-05 | 1941-11-04 | 1942-05-06 | $7700.00 | Window Closed / Lapsed |