Patent US3447790A successfully refreshed from Google Patents.
US3447790A
Expired / Lapsed
US
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Aluminum annealing furnace
Assignee: Sunbeam Equipment Corp
•
Filing: 1966-11-14
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Granted: 1969-06-03
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Expires: 1986-11-14
Abstract
No abstract record available.
Inventors
- 👤 Robert H Ross
- 👤 Robert Larko
- 👤 Walter Swartzfager
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 20:00
CPC Classifications
F; F27; F27D; F27D11/00; F27D11/02; C; C21; C21D; C21D11/00
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1923145A
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US2283007A
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GB559605A
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US2494135A
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US2680189A
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US2843036A
Cited
US2917299A
Cited
US2875997A
Cited
US3129933A
Cited
US3074644A
Cited
US3266725A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1972-06-02 | 1972-12-02 | 1973-06-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-06-02 | 1976-12-02 | 1977-06-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-06-02 | 1980-12-02 | 1981-06-03 | $7700.00 | Window Closed / Lapsed |