US4607017A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Silicon nitride based cutting tool
Assignee: Osram Sylvania Inc
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Filing: 1985-06-20
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Granted: 1986-08-19
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Expires: 2005-06-20
Abstract
Abstract A silicon nitride based cutting tool is disclosed consisting essentially of in percent by weight about 5% aluminum oxide, about 6% yttrium oxide, from about 1.5% to about 5.5% silicon dioxide, and the balance silicon nitride, and having a density of at least about 99% of the theoretical density.
Inventors
- 👤 Robert W. Wolfe
- 👤 Dale E. Wittmer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 12:32
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/515; C04B35/58; C04B35/584; C04B35/593; Y; Y10; Y10T; Y10T82/00; Y10T82/29
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
49 words
A silicon nitride based cutting tool consisting essentially of in percent by weight about 5% aluminum oxide, about 6% yttrium oxide, from about 1.5% to about 5.5% silicon dioxide, and the balance silicon nitride, said cutting tool having a density of at least about 99% of the theoretical density.
Claim 2
Dependent Claim
49 words
A silicon nitride based cutting tool consisting essentially of in percent by weight about 5% aluminum oxide, about 6% yttrium oxide, from about 1.5% to about 5.5% silicon dioxide, and the balance silicon nitride, said cutting tool having a density of at least about 99% of the theoretical density.
References Cited (Backward Citations)
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US4280973A
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US4323325A
Cited
JPS5888175A
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JPS5921580A
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US4462817A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-08-18 | 1990-02-17 | 1990-08-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-08-18 | 1994-02-17 | 1994-08-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-08-18 | 1998-02-17 | 1998-08-19 | $7700.00 | Window Closed / Lapsed |