US2309770A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Constant level device
Assignee: Individual
•
Filing: 1940-02-03
•
Granted: 1943-02-02
•
Expires: 1960-02-03
Abstract
No abstract record available.
Inventors
- 👤 Roy W Johnson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 06:20
CPC Classifications
F; F23; F23D; F23D5/00; F23D5/12; F23D5/14; Y; Y10; Y10T; Y10T137/00; Y10T137/7287; Y10T137/7329; Y10T137/7358; Y10T137/7381; Y10T137/7394; Y10T137/7397; Y10T137/794; Y10T137/8085
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) | 1946-02-01 | 1946-08-03 | 1947-02-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1950-02-01 | 1950-08-03 | 1951-02-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1954-02-01 | 1954-08-03 | 1955-02-02 | $7700.00 | Window Closed / Lapsed |