Patent US2697428A successfully refreshed from Google Patents.
US2697428A
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US
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Forced-air, forced-draft unit heater
Assignee: NORMAN PRODUCTS Co
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Filing: 1951-01-03
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Granted: 1954-12-21
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Expires: 1971-01-03
Abstract
No abstract record available.
Inventors
- 👤 Jr Edward A Norman
- 👤 Charles A Reichelderfer
- 👤 Harold L Herzig
- 👤 Herman G Raymer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 11:16
CPC Classifications
F; F24; F24H; F24H3/00; F24H3/02; F24H3/06; F24H3/08; F24H3/087
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1421221A
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US1872785A
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US1903939A
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US2165269A
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US2346410A
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US2410547A
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US2492654A
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US2519496A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1957-12-20 | 1958-06-21 | 1958-12-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1961-12-20 | 1962-06-21 | 1962-12-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1965-12-20 | 1966-06-21 | 1966-12-21 | $7700.00 | Window Closed / Lapsed |