US2539623A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Communication system
Assignee: AT&T Inc
•
Filing: 1947-02-12
•
Granted: 1951-01-30
•
Expires: 1967-02-12
Abstract
No abstract record available.
Inventors
- 👤 Raymond A Heising
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 01:24
CPC Classifications
H; H03; H03M; H03M1/00; H03M1/12; H03M1/22
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2272070A
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US2406019A
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US2307868A
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US2381928A
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US2426454A
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US2373134A
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US2417831A
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US2418521A
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US2402432A
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US2451044A
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US2437707A
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US2453461A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1954-01-29 | 1954-07-31 | 1955-01-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-01-29 | 1958-07-31 | 1959-01-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-01-29 | 1962-07-31 | 1963-01-30 | $7700.00 | Window Closed / Lapsed |