Patent US2999972A successfully refreshed from Google Patents.
US2716232A
Expired / Lapsed
US
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Flux modulated ringer
Assignee: AT&T Inc
•
Filing: 1950-10-25
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Granted: 1955-08-23
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Expires: 1970-10-25
Abstract
No abstract record available.
Inventors
- 👤 James R Power
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 19:22
CPC Classifications
G; G10; G10K; G10K1/00; G10K1/06; G10K1/062
Claims Analysis
Total Claims: 0
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1958-08-22 | 1959-02-21 | 1959-08-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1962-08-22 | 1963-02-21 | 1963-08-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1966-08-22 | 1967-02-21 | 1967-08-23 | $7700.00 | Window Closed / Lapsed |