US3549402A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Silicon nitride composition and articles thereof
Assignee: Unifrax I LLC
•
Filing: 1969-05-06
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Granted: 1970-12-22
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Expires: 1989-05-06
Abstract
No abstract record available.
Inventors
- 👤 Ellsworth D Whitney
- 👤 Philip H Crayton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 12:11
CPC Classifications
C; C01; C01B; C01B21/00; C01B21/06; C01B21/0602; C04; C04B; C04B35/00; C04B35/515; C04B35/58; C04B35/584; C04B35/593; C01P; C01P2002/00; C01P2002/70; C01P2002/72
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
GB245762A
Cited
US2866685A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-12-21 | 1974-06-22 | 1974-12-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-12-21 | 1978-06-22 | 1978-12-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-12-21 | 1982-06-22 | 1982-12-22 | $7700.00 | Window Closed / Lapsed |