US2405339A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Equipment for observing dial tone speed
Assignee: AT&T Inc
•
Filing: 1944-06-06
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Granted: 1946-08-06
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Expires: 1964-06-06
Abstract
No abstract record available.
Inventors
- 👤 Willis Milton Powell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 05:16
CPC Classifications
H; H04; H04M; H04M3/00; H04M3/22; H04M3/36
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) | 1949-08-05 | 1950-02-04 | 1950-08-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1953-08-05 | 1954-02-04 | 1954-08-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1957-08-05 | 1958-02-04 | 1958-08-06 | $7700.00 | Window Closed / Lapsed |