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Patent US2505728A successfully refreshed from Google Patents.
US2505728A
Expired / Lapsed
US
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Selective signaling system and apparatus
Assignee: AT&T Teletype Corp
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Filing: 1945-06-14
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Granted: 1950-04-25
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Expires: 1965-06-14
Abstract
No abstract record available.
Inventors
- 👤 Walter J Zenner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 22:53
CPC Classifications
H; H01; H01H; H01H67/00; H01H67/22; H01H67/26
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) | 1953-04-24 | 1953-10-24 | 1954-04-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-04-24 | 1957-10-24 | 1958-04-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-04-24 | 1961-10-24 | 1962-04-25 | $7700.00 | Window Closed / Lapsed |