Patent US2540280A successfully refreshed from Google Patents.
US2540280A
Expired / Lapsed
US
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Gas-fired forced air heater
Assignee: NORMAN PRODUCTS Co
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Filing: 1948-09-01
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Granted: 1951-02-06
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Expires: 1968-09-01
Abstract
No abstract record available.
Inventors
- 👤 Jr Edward A Norman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 20:30
CPC Classifications
F; F24; F24H; F24H3/00; F24H3/02; F24H3/06; F24H3/065
Claims Analysis
Total Claims: 0
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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) | 1954-02-05 | 1954-08-07 | 1955-02-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-02-05 | 1958-08-07 | 1959-02-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-02-05 | 1962-08-07 | 1963-02-06 | $7700.00 | Window Closed / Lapsed |