Patent US3749561A successfully refreshed from Google Patents.
US3749561A
Expired / Lapsed
US
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Method of producing crystalline glass containing portions having different crystallization extents
Assignee: Fujifilm Holdings Corp
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Filing: 1972-03-23
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Granted: 1973-07-31
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Expires: 1992-03-23
Abstract
Abstract A METHOD FOR PRODUCING A CRYSTALLINE GLASS ARTICLE OF THE LI2O-AL2O3-SIO2 SYSTEM HAVING GLASS PORTONS OF HORIZONTALLY DIFFERENT CRYSTALLINE EXTENTS WHICH COMPRISES SUBJECTING A TRANSPARENT CRYSTALLINE GLASS TO A FURTHER CRYSTALLIZING TREATMENT IN THE PRODUCTION OF A CRYSTALLINE GLASS, FORCIBLY COOLING A PORTION OF SAID TRANSPARENT CRYSTALLINE GLASS DURING THE HEAT TREATMENT, THE OTHER PORTION OF THE TRANSPARENT CRYSTALLINE GLASS REMAINING UNCOOLED WHEREBY THE PORTION REMAINING UNCOOLED IS WITH THE DIFFERENCE BETWEEN THE SPECIFIC GRAVITY OF THE TRANSPARENT CRYSTALLINE GLASS PORTION AND THE OPAQUE CRYSTALLINE GLASS PORTION BEING LESS THAN 1.2% IS DISCLOSED.
Inventors
- 👤 S Kuwayama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 19:44
CPC Classifications
C; C03; C03C; C03C10/00; C03B; C03B32/00; C03B32/02
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) | 1976-07-30 | 1977-01-29 | 1977-07-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-30 | 1981-01-29 | 1981-07-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-30 | 1985-01-29 | 1985-07-31 | $7700.00 | Window Closed / Lapsed |