Patent US2477640A successfully refreshed from Google Patents.
US2477640A
Expired / Lapsed
US
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Sound recording method and apparatus
Assignee: Individual
•
Filing: 1944-06-27
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Granted: 1949-08-02
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Expires: 1964-06-27
Abstract
No abstract record available.
Inventors
- 👤 Homer R Montague
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:42
CPC Classifications
G; G11; G11B; G11B7/00
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2171150A
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US900706A
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US728867A
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US1326728A
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US1995253A
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US1967882A
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GB389101A
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GB406903A
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US2091826A
Cited
US2307237A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1952-08-01 | 1953-01-31 | 1953-08-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1956-08-01 | 1957-01-31 | 1957-08-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1960-08-01 | 1961-01-31 | 1961-08-02 | $7700.00 | Window Closed / Lapsed |