US2852621A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Voice switching in telephone transmission systems
Assignee: Telephone Manufacturing Co Ltd
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Filing: 1952-11-18
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Granted: 1958-09-16
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Expires: 1972-11-18
Abstract
No abstract record available.
Inventors
- 👤 Ryall Leonard Ernest
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 08:37
CPC Classifications
H; H04; H04B; H04B3/00; H04B3/54; H04B1/00; H04B1/38; H04B1/40; H04B1/44; H04B1/46; H04M; H04M9/00; H04M9/001; H04M9/08; H04M9/10; H04B2203/00; H04B2203/54; H04B2203/5429; H04B2203/5437
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-09-15 | 1962-03-17 | 1962-09-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-09-15 | 1966-03-17 | 1966-09-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-09-15 | 1970-03-17 | 1970-09-16 | $7700.00 | Window Closed / Lapsed |