US2471832A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Internal-combustion heater with knipp's singing tubes
Assignee: Stewart Warner Corp
•
Filing: 1945-03-23
•
Granted: 1949-05-31
•
Expires: 1965-03-23
Abstract
No abstract record available.
Inventors
- 👤 Mccollum Thelma
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 22:19
CPC Classifications
B; B64; B64D; B64D13/00; B64D13/06; B64D13/08
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1952-05-30 | 1952-11-29 | 1953-05-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1956-05-30 | 1956-11-29 | 1957-05-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1960-05-30 | 1960-11-29 | 1961-05-31 | $7700.00 | Window Closed / Lapsed |