US2874223A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Mixed-ringing party-line telephone system
Assignee: TDK Micronas GmbH
•
Filing: 1953-08-27
•
Granted: 1959-02-17
•
Expires: 1973-08-27
Abstract
No abstract record available.
Inventors
- 👤 Robert W Hutton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 17:30
CPC Classifications
H; H04; H04Q; H04Q3/00; H04Q3/42
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1487996A
Cited
US1727133A
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US2340555A
Cited
US2497782A
Cited
US2542272A
Cited
US2765368A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1962-02-16 | 1962-08-18 | 1963-02-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-02-16 | 1966-08-18 | 1967-02-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-02-16 | 1970-08-18 | 1971-02-17 | $7700.00 | Window Closed / Lapsed |