US1818053A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Duplex automatic air vent valve
Assignee: Individual
•
Filing: 1928-11-05
•
Granted: 1931-08-11
•
Expires: 1948-11-05
Abstract
No abstract record available.
Inventors
- 👤 Elger Joseph
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 14:02
CPC Classifications
F; F24; F24D; F24D19/00; F24D19/08; F24D19/082; F24D19/083; F24D19/085; F24D19/087; Y; Y10; Y10T; Y10T137/00; Y10T137/2931; Y10T137/3003; Y10T137/3084; Y10T137/309; Y10T137/3099; Y10T137/7287; Y10T137/7358; Y10T137/7439; Y10T137/7455
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) | 1934-08-10 | 1935-02-09 | 1935-08-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1938-08-10 | 1939-02-09 | 1939-08-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1942-08-10 | 1943-02-09 | 1943-08-11 | $7700.00 | Window Closed / Lapsed |