Patent US3432815A successfully refreshed from Google Patents.
US3227431A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Crucible externally lined with filamentary carbon
Assignee: National Research Corp
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Filing: 1961-11-22
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Granted: 1966-01-04
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Expires: 1981-11-22
Abstract
No abstract record available.
Inventors
- 👤 Robert W Steeves
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 21:58
CPC Classifications
F; F27; F27D; F27D1/00; F27D1/0003; F27D1/0006; C; C23; C23C; C23C14/00; C23C14/22; C23C14/24; C23C14/243; F27B; F27B14/00; F27B14/08; F27B14/10
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
65 words
A CARBON CRUCIBLE CAPABLE OF BEING HEATED BY A 9600 C.P.S. INDUCTION COIL TO A TEMPERATURE ABOVE 1400* C. IN A VACUUM SYSTEM, A LAYER OF FINE FLEXIBLE CARBON FIBERS SURROUNDING SAID CRUCIBLE, SAID INDIVIDUAL FIBERS HAVING A THICKNESS LESS THAN 10 MILS AND BEING NONCONDUCTING TO A 9600 C.P.S. INDUCTION FIELD, AND A LAYER OF INSULATION MATERIAL SURROUNDING SAID LAYER OF FINE CARBON FIBERS.
Claim 2
Dependent Claim
65 words
A CARBON CRUCIBLE CAPABLE OF BEING HEATED BY A 9600 C.P.S. INDUCTION COIL TO A TEMPERATURE ABOVE 1400* C. IN A VACUUM SYSTEM, A LAYER OF FINE FLEXIBLE CARBON FIBERS SURROUNDING SAID CRUCIBLE, SAID INDIVIDUAL FIBERS HAVING A THICKNESS LESS THAN 10 MILS AND BEING NONCONDUCTING TO A 9600 C.P.S. INDUCTION FIELD, AND A LAYER OF INSULATION MATERIAL SURROUNDING SAID LAYER OF FINE CARBON FIBERS.
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) | 1969-01-03 | 1969-07-05 | 1970-01-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-01-03 | 1973-07-05 | 1974-01-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-01-03 | 1977-07-05 | 1978-01-04 | $7700.00 | Window Closed / Lapsed |