Patent US2677728A successfully refreshed from Google Patents.
US2677728A
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US
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Process of and apparatus for developing visible sound records synchronized with invisible recordings on magnetic tapes
Assignee: BRITISH ACOUSTIC FILMS Ltd
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Filing: 1947-09-15
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Granted: 1954-05-04
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Expires: 1967-09-15
Abstract
No abstract record available.
Inventors
- 👤 Kolb Otto Kurt
- 👤 Petersen Axel Carl Georg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 23:49
CPC Classifications
G; G11; G11B; G11B5/00; G11B13/00; G11B13/04; Y; Y10; Y10S; Y10S101/00; Y10S101/37
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1213150A
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US1653467A
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US1808046A
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US1759581A
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US1949840A
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US2039742A
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CH177647A
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DE677613C
Cited
US2279018A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1957-05-03 | 1957-11-02 | 1958-05-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1961-05-03 | 1961-11-02 | 1962-05-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1965-05-03 | 1965-11-02 | 1966-05-04 | $7700.00 | Window Closed / Lapsed |