US2827519A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Subscriber line ringing in an electronic telephone system
Assignee: General Dynamics Corp
•
Filing: 1955-05-16
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Granted: 1958-03-18
•
Expires: 1975-05-16
Abstract
No abstract record available.
Inventors
- 👤 Frank A Morris
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 22:23
CPC Classifications
H; H04; H04Q; H04Q11/00; H04Q11/04
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1023482A
Cited
US2069915A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-03-17 | 1961-09-16 | 1962-03-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-03-17 | 1965-09-16 | 1966-03-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-03-17 | 1969-09-16 | 1970-03-18 | $7700.00 | Window Closed / Lapsed |