US2746249A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Spaced wall combustion apparatus
Assignee: Individual
•
Filing: 1936-09-14
•
Granted: 1956-05-22
•
Expires: 1956-09-14
Abstract
No abstract record available.
Inventors
- 👤 Francis R Bichowsky
- 👤 Robert H Canfield
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 22:50
CPC Classifications
F; F42; F42B; F42B19/00; F42B19/12; F42B19/22
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1108608A
Cited
US1154609A
Cited
FR492294A
Cited
US1459482A
Cited
US1506323A
Cited
US1531475A
Cited
US2168313A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1959-05-22 | 1959-11-21 | 1960-05-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1963-05-22 | 1963-11-21 | 1964-05-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1967-05-22 | 1967-11-21 | 1968-05-22 | $7700.00 | Window Closed / Lapsed |