Patent US1877540A successfully refreshed from Google Patents.
Patent US2311238A successfully refreshed from Google Patents.
US2311238A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Air-flow indicator
Assignee: Individual
•
Filing: 1941-08-29
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Granted: 1943-02-16
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Expires: 1961-08-29
Abstract
No abstract record available.
Inventors
- 👤 Donald J Mackinnon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:12
CPC Classifications
G; G01; G01P; G01P5/00; G01P5/02; G01P5/04; G01F; G01F1/00; G01F1/05; G01F1/20; G01F1/22; G01F1/26; G01L; G01L7/00
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1946-02-15 | 1946-08-17 | 1947-02-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1950-02-15 | 1950-08-17 | 1951-02-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1954-02-15 | 1954-08-17 | 1955-02-16 | $7700.00 | Window Closed / Lapsed |