Patent US2381978A successfully refreshed from Google Patents.
US2381978A
Expired / Lapsed
US
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Impulse transmitter
Assignee: AT&T Inc
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Filing: 1943-08-05
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Granted: 1945-08-14
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Expires: 1963-08-05
Abstract
No abstract record available.
Inventors
- 👤 Robert C Mathes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:51
CPC Classifications
H; H04; H04M; H04M1/00; H04M1/26; H04M1/27; H04M1/272
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) | 1948-08-13 | 1949-02-12 | 1949-08-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1952-08-13 | 1953-02-12 | 1953-08-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1956-08-13 | 1957-02-12 | 1957-08-14 | $7700.00 | Window Closed / Lapsed |