US2770670A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Carrier telegraph switchboard supervisory system
Assignee: AT&T Inc
•
Filing: 1952-05-09
•
Granted: 1956-11-13
•
Expires: 1972-05-09
Abstract
No abstract record available.
Inventors
- 👤 Leland A Gardner
- 👤 John L Hysko
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 06:26
CPC Classifications
H; H04; H04L; H04L12/00; H04L12/02; H04L12/04
Claims Analysis
Total Claims: 0
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1959-11-13 | 1960-05-14 | 1960-11-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1963-11-13 | 1964-05-14 | 1964-11-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1967-11-13 | 1968-05-14 | 1968-11-13 | $7700.00 | Window Closed / Lapsed |