US2858403A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Silicon carbide immersion heating device
Assignee: Unifrax I LLC
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Filing: 1956-04-23
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Granted: 1958-10-28
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Expires: 1976-04-23
Abstract
No abstract record available.
Inventors
- 👤 Jr Gurdon M Butler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 15:43
CPC Classifications
H; H05; H05B; H05B3/00; H05B3/10; H05B3/12; H05B3/14; H05B3/148
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
82 words
A RESISTANCE TYPE IMMERSION HEATING DEVICE COMPRISING AN ELONGATED NON-METALLIC, INORGANIC RESISTANCE HEATING ELEMENT, A CLOSED END CARBON SHEATHE SURROUNDING SAND HEATING ELEMENT AND SPACED THERRFROM OVER MOST OF ITS LENGTH, ONE END OF SAID HEATING ELEMENT BEING IN ELECTRICALLY CONDUCTIVE CONTACT WITH THE CLOSED END OF SAID CARBON SHEATH, THE OPPOSITE END OF SAID HEATING ELEMENT HAVING A TERMINAL MEMBER OF LOWER ELECTRICAL RESISTANCE EXTENDING FROM SAID SHEATH, THE PROTRUDING END OF SAID HEATING ELEMENT BEING ELECTRICALLY INSULATED FROM SAID SHEATH.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-10-27 | 1962-04-28 | 1962-10-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-10-27 | 1966-04-28 | 1966-10-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-10-27 | 1970-04-28 | 1970-10-28 | $7700.00 | Window Closed / Lapsed |