US2581316A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High rating fire-tube boiler and method of boiler operation
Assignee: Individual
•
Filing: 1945-10-01
•
Granted: 1952-01-01
•
Expires: 1965-10-01
Abstract
No abstract record available.
Inventors
- 👤 John J Wolfersperger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 22:12
CPC Classifications
F; F22; F22B; F22B9/00
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2097255A
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US974166A
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US1097698A
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US1948537A
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US1948538A
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US1986561A
Cited
US2173115A
Cited
US2321109A
Cited
US2404335A
Cited
US2264226A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1954-12-31 | 1955-07-02 | 1956-01-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-12-31 | 1959-07-02 | 1960-01-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-12-31 | 1963-07-02 | 1964-01-01 | $7700.00 | Window Closed / Lapsed |