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Patent US3490420A successfully refreshed from Google Patents.
US3490420A
Expired / Lapsed
US
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Induced draft oil-fired water heater
Assignee: Gulf Research and Development Co
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Filing: 1967-12-13
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Granted: 1970-01-20
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Expires: 1987-12-13
Abstract
No abstract record available.
Inventors
- 👤 William Edward Kramer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 07:55
CPC Classifications
F; F24; F24H; F24H1/00; F24H1/18; F24H1/20; F24H1/205
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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US2684054A
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US2987061A
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US2974650A
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US2998764A
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US3082758A
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US3120225A
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US3180322A
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US3394693A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-01-19 | 1973-07-21 | 1974-01-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-01-19 | 1977-07-21 | 1978-01-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-01-19 | 1981-07-21 | 1982-01-20 | $7700.00 | Window Closed / Lapsed |