US2424571A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Telegraph alarm system
Assignee: AT&T Inc
•
Filing: 1943-09-01
•
Granted: 1947-07-29
•
Expires: 1963-09-01
Abstract
No abstract record available.
Inventors
- 👤 Wilmarth Y Lang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 22:46
CPC Classifications
H; H02; H02J; H02J13/00
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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US1877635A
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US1895718A
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US2164324A
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US1910867A
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US1971686A
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US2003047A
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US2207744A
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US2135295A
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US2190540A
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US2273383A
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US2266826A
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US2271305A
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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) | 1950-07-28 | 1951-01-27 | 1951-07-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1954-07-28 | 1955-01-27 | 1955-07-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1958-07-28 | 1959-01-27 | 1959-07-29 | $7700.00 | Window Closed / Lapsed |