Patent US2554835A successfully refreshed from Google Patents.
US2554835A
Expired / Lapsed
US
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Recording system
Assignee: AT&T Inc
•
Filing: 1947-06-25
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Granted: 1951-05-29
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Expires: 1967-06-25
Abstract
No abstract record available.
Inventors
- 👤 Rudolph F Mallina
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 09:23
CPC Classifications
H; H04; H04L; H04L25/00; H04L25/38; H04L25/40; H04L25/42
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1813908A
Cited
US2023446A
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US2000764A
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US2131322A
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US2302081A
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US2398755A
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US2382251A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1954-05-28 | 1954-11-27 | 1955-05-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-05-28 | 1958-11-27 | 1959-05-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-05-28 | 1962-11-27 | 1963-05-29 | $7700.00 | Window Closed / Lapsed |