US2570187A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Subscriber signaling system
Assignee: Zenith Electronics LLC
•
Filing: 1948-07-21
•
Granted: 1951-10-09
•
Expires: 1968-07-21
Abstract
No abstract record available.
Inventors
- 👤 Nathan W Aram
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 05:34
CPC Classifications
H; H04; H04N; H04N7/00; H04N7/16; H04N7/167
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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US2472774A
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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) | 1954-10-08 | 1955-04-09 | 1955-10-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-10-08 | 1959-04-09 | 1959-10-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-10-08 | 1963-04-09 | 1963-10-09 | $7700.00 | Window Closed / Lapsed |