Patent US2021647A successfully refreshed from Google Patents.
US2021647A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Control mechanism for burners
Assignee: Individual
•
Filing: 1931-06-25
•
Granted: 1935-11-19
•
Expires: 1951-06-25
Abstract
No abstract record available.
Inventors
- 👤 Lancey Ralph W De
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 23:31
CPC Classifications
F; F23; F23N; F23N5/00; F23N5/20
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
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) | 1938-11-18 | 1939-05-20 | 1939-11-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1942-11-18 | 1943-05-20 | 1943-11-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1946-11-18 | 1947-05-20 | 1947-11-19 | $7700.00 | Window Closed / Lapsed |