US2419557A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Branching circuits
Assignee: AT&T Inc
•
Filing: 1943-03-12
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Granted: 1947-04-29
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Expires: 1963-03-12
Abstract
No abstract record available.
Inventors
- 👤 Harald T Friis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 11:47
CPC Classifications
H; H01; H01P; H01P1/00; H01P1/20; H01P1/213; H01P1/2133
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1950-04-28 | 1950-10-28 | 1951-04-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1954-04-28 | 1954-10-28 | 1955-04-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1958-04-28 | 1958-10-28 | 1959-04-29 | $7700.00 | Window Closed / Lapsed |