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US2812686A
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US
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Smoke photometer
Assignee: Johns Manville Corp
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Filing: 1953-12-22
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Granted: 1957-11-12
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Expires: 1973-12-22
Abstract
No abstract record available.
Inventors
- 👤 Sinclair David
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 18:59
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/17; G01N21/47; G01N21/49; G01N21/53
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1960-11-11 | 1961-05-13 | 1961-11-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-11-11 | 1965-05-13 | 1965-11-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-11-11 | 1969-05-13 | 1969-11-12 | $7700.00 | Window Closed / Lapsed |