US2897279A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automatic telephone exchange systems
Assignee: Siemens Edison Swan Ltd
•
Filing: 1956-11-21
•
Granted: 1959-07-28
•
Expires: 1976-11-21
Abstract
No abstract record available.
Inventors
- 👤 Flood John Edward
- 👤 Ronald S Hopkins
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 18:04
CPC Classifications
H; H04; H04Q; H04Q3/00; H04Q3/42
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2764634A
Cited
US2738382A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1962-07-27 | 1963-01-26 | 1963-07-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-07-27 | 1967-01-26 | 1967-07-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-07-27 | 1971-01-26 | 1971-07-28 | $7700.00 | Window Closed / Lapsed |