Patent US2181484A successfully refreshed from Google Patents.
US2181484A
Expired / Lapsed
US
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Electric heating element
Assignee: REFINOIL Manufacturing CORP
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Filing: 1937-01-12
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Granted: 1939-11-28
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Expires: 1957-01-12
Abstract
No abstract record available.
Inventors
- 👤 William D Harris
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 19:19
CPC Classifications
H; H05; H05B; H05B3/00; H05B3/78; H05B3/82
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1942-11-27 | 1943-05-29 | 1943-11-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1946-11-27 | 1947-05-29 | 1947-11-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1950-11-27 | 1951-05-29 | 1951-11-28 | $7700.00 | Window Closed / Lapsed |