Patent US2861131A successfully refreshed from Google Patents.
US2861131A
Expired / Lapsed
US
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Automatic telephone system
Assignee: Siemens and Halske AG
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Filing: 1954-05-11
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Granted: 1958-11-18
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Expires: 1974-05-11
Abstract
No abstract record available.
Inventors
- 👤 Villmann Walter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:55
CPC Classifications
H; H04; H04Q; H04Q3/00
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2277206A
Cited
US2502517A
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US2576189A
Cited
US2561298A
Cited
US2522119A
Cited
US2537188A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-11-17 | 1962-05-19 | 1962-11-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-11-17 | 1966-05-19 | 1966-11-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-11-17 | 1970-05-19 | 1970-11-18 | $7700.00 | Window Closed / Lapsed |