US2921172A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Open coil electric heater
Assignee: TUTTLE ELECTRIC PRODUCTS Inc
•
Filing: 1957-03-26
•
Granted: 1960-01-12
•
Expires: 1977-03-26
Abstract
No abstract record available.
Inventors
- 👤 Amos W Hackman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 11:45
CPC Classifications
H; H05; H05B; H05B3/00; H05B3/20; H05B3/22; H05B3/32
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2732475A
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US1102393A
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US1234670A
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US1687357A
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US1827508A
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US1844678A
Cited
US1957227A
Cited
US2557832A
Cited
US2752476A
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US2730603A
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US2682599A
Cited
US2799761A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1963-01-11 | 1963-07-13 | 1964-01-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-01-11 | 1967-07-13 | 1968-01-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-01-11 | 1971-07-13 | 1972-01-12 | $7700.00 | Window Closed / Lapsed |