Patent US1844110A successfully refreshed from Google Patents.
US1844110A
Expired / Lapsed
US
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Determination of telephone quality
Assignee: AT&T Inc
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Filing: 1930-04-17
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Granted: 1932-02-09
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Expires: 1950-04-17
Abstract
No abstract record available.
Inventors
- 👤 John C Steinberg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:50
CPC Classifications
H; H04; H04B; H04B3/00; H04B3/02; H04B3/46
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) | 1935-02-08 | 1935-08-10 | 1936-02-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1939-02-08 | 1939-08-10 | 1940-02-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1943-02-08 | 1943-08-10 | 1944-02-09 | $7700.00 | Window Closed / Lapsed |