US2551823A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heating system
Assignee: Individual
•
Filing: 1945-02-10
•
Granted: 1951-05-08
•
Expires: 1965-02-10
Abstract
No abstract record available.
Inventors
- 👤 William C Buttner
- 👤 Jerome R Bunce
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 22:18
CPC Classifications
B; B60; B60H; B60H1/00; B60H1/22; B60H1/2203; B60H1/2212; B60H2001/2268; B60H2001/2287
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1880178A
Cited
US1923614A
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US2165269A
Cited
GB469515A
Cited
US2188133A
Cited
US2308887A
Cited
US2332094A
Cited
US2321940A
Cited
US2379017A
Cited
US2391447A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1954-05-07 | 1954-11-06 | 1955-05-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-05-07 | 1958-11-06 | 1959-05-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-05-07 | 1962-11-06 | 1963-05-08 | $7700.00 | Window Closed / Lapsed |