Patent US2976797A successfully refreshed from Google Patents.
US2976797A
Expired / Lapsed
US
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Chimney construction
Assignee: Individual
•
Filing: 1958-09-22
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Granted: 1961-03-28
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Expires: 1978-09-22
Abstract
No abstract record available.
Inventors
- 👤 William S Newbill
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 12:19
CPC Classifications
F; F23; F23J; F23J11/00; F23J13/00; F23J13/02; F23J13/025
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US98800A
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US2372707A
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US2437771A
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US2634720A
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US2713301A
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US2856837A
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US2841071A
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US2800850A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-03-27 | 1964-09-26 | 1965-03-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-03-27 | 1968-09-26 | 1969-03-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-03-27 | 1972-09-26 | 1973-03-28 | $7700.00 | Window Closed / Lapsed |