Patent US2414440A successfully refreshed from Google Patents.
US2414440A
Expired / Lapsed
US
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Voice frequency ringer
Assignee: STC PLC
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Filing: 1945-02-21
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Granted: 1947-01-21
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Expires: 1965-02-21
Abstract
No abstract record available.
Inventors
- 👤 Brandt Walter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 22:52
CPC Classifications
H; H04; H04J; H04J1/00; H04J1/02; H04J1/14; H04Q; H04Q1/00; H04Q1/18; H04Q1/30; H04Q1/44; H04Q1/444; H04Q1/446; H04Q1/4465
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) | 1950-01-20 | 1950-07-22 | 1951-01-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1954-01-20 | 1954-07-22 | 1955-01-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1958-01-20 | 1958-07-22 | 1959-01-21 | $7700.00 | Window Closed / Lapsed |