Patent US2548831A successfully refreshed from Google Patents.
US2548831A
Expired / Lapsed
US
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Dictating machine
Assignee: Dictaphone Corp
•
Filing: 1945-03-28
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Granted: 1951-04-10
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Expires: 1965-03-28
Abstract
No abstract record available.
Inventors
- 👤 John H Trevitt
- 👤 John E Renholdt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 12:53
CPC Classifications
G; G11; G11B; G11B25/00; G11B25/06
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2030638A
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US2071972A
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US1939412A
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US2102366A
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US2152585A
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US2127593A
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US2070180A
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US2284836A
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US2223723A
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US2270832A
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US2212672A
Cited
US2380754A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1954-04-09 | 1954-10-09 | 1955-04-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-04-09 | 1958-10-09 | 1959-04-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-04-09 | 1962-10-09 | 1963-04-10 | $7700.00 | Window Closed / Lapsed |