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US2499288A
Expired / Lapsed
US
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Vacuum analyzer
Assignee: Individual
•
Filing: 1947-07-02
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Granted: 1950-02-28
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Expires: 1967-07-02
Abstract
No abstract record available.
Inventors
- 👤 John G Backus
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 20:21
CPC Classifications
H; H01; H01J; H01J49/00; H01J49/26; H01J49/28; H01J49/30
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) | 1953-02-27 | 1953-08-29 | 1954-02-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-02-27 | 1957-08-29 | 1958-02-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-02-27 | 1961-08-29 | 1962-02-28 | $7700.00 | Window Closed / Lapsed |