US2704571A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Safety control circuit for forced draft
Assignee: —
•
Filing: —
•
Granted: 1955-03-22
•
Expires: 1972-03-22
Abstract
No abstract record available.
Inventors
No inventors recorded.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 22:45
CPC Classifications
F; F24; F24H; F24H9/00; F24H9/20; F24H9/2064; F24H9/2085; F24H15/00; F24H15/10; F24H15/128; F24H15/30; F24H15/305
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1732174A
Cited
US2168859A
Cited
US2137581A
Cited
US2259299A
Cited
US2188565A
Cited
US2251055A
Cited
US2432314A
Cited
US2412990A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1958-03-21 | 1958-09-20 | 1959-03-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1962-03-21 | 1962-09-20 | 1963-03-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1966-03-21 | 1966-09-20 | 1967-03-22 | $7700.00 | Window Closed / Lapsed |