US2534846A
Expired / Lapsed
US
⏱️ 0.0 years remaining
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Assignee: EMI Ltd
•
Filing: 1947-09-08
•
Granted: 1950-12-19
•
Expires: 1967-09-08
Abstract
No abstract record available.
Inventors
- 👤 Ambrose Edmund Jack
- 👤 Pacey Derek John
- 👤 Salmon Joseph Gerard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 17:20
CPC Classifications
G; G02; G02B; G02B5/00; G02B5/20; G02B5/28; G02B5/284; G02B26/00; G02B26/001; G02F; G02F1/00; G02F1/01; G02F1/21
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1044502A
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US2118160A
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US2010307A
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US2109540A
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US2185379A
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GB473061A
Cited
US2330172A
Cited
US2281280A
Cited
US2312888A
Cited
US2352777A
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US2392978A
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US2455763A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1953-12-18 | 1954-06-19 | 1954-12-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-12-18 | 1958-06-19 | 1958-12-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-12-18 | 1962-06-19 | 1962-12-19 | $7700.00 | Window Closed / Lapsed |