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Patent US2979413A successfully refreshed from Google Patents.
US2979413A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of growing corundum crystals
Assignee: AT&T Inc
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Filing: 1957-06-14
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Granted: 1961-04-11
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Expires: 1977-06-14
Abstract
No abstract record available.
Inventors
- 👤 Albert A Ballman
- 👤 Anthony J Caporaso
- 👤 Robert A Laudise
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 20:58
CPC Classifications
C; C30; C30B; C30B29/00
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
134 words
THE METHOD OF GROWING CRYSTALS OF SYNTHETIC RUBY IN A CLOSED SYSTEM WHICH COMPRISES DEPOSITING CORUNDUM CONTAINING CHROMIUM ION IMPURITIES ON A SEED CRYSTAL OF CORUNDUM FROM AN AQUEOUS MEDIUM CONTAINING CORUNDUM AND A SOLUBLE CHROMIUM COMPOUND DISSOLVED THEREIN, SAID AQUEOUS MEDIUM BEING PRESENT IN AN AMOUNT SUFFICIENT TO OCCUPY AT LEAST 65 PERCENT OF THE FREE SPACE WITHIN SAID CLOSED SYSTEM AT ROOM TEMPERATURE AND BEING IN CONTACT WITH A MASS OF SOLID CORUNDUM, SAID MASS OF SOLID CORUNDUM BEING AT A TEMPERATURE HIGHER THAN THAT OF SAID SEED CRYSTAL, THE TEMPERATURE DIFFERENTIAL BETWEEN SAID MASS OF SOLID CORUNDUM AND SAID SEED CRYSTAL BEING NOT GREATER THAN ABOUT 20*C., THE TEMPERATURE OF SAID SEED CRYSTAL BEING AT LEAST 395*C., AND THE TEMPERATURE OF SAID MASS OF SOLID CORUNDUM BEING NOT MORE THAN 520*C.
Claim 2
Independent Claim
134 words
THE METHOD OF GROWING CRYSTALS OF SYNTHETIC RUBY IN A CLOSED SYSTEM WHICH COMPRISES DEPOSITING CORUNDUM CONTAINING CHROMIUM ION IMPURITIES ON A SEED CRYSTAL OF CORUNDUM FROM AN AQUEOUS MEDIUM CONTAINING CORUNDUM AND A SOLUBLE CHROMIUM COMPOUND DISSOLVED THEREIN, SAID AQUEOUS MEDIUM BEING PRESENT IN AN AMOUNT SUFFICIENT TO OCCUPY AT LEAST 65 PERCENT OF THE FREE SPACE WITHIN SAID CLOSED SYSTEM AT ROOM TEMPERATURE AND BEING IN CONTACT WITH A MASS OF SOLID CORUNDUM, SAID MASS OF SOLID CORUNDUM BEING AT A TEMPERATURE HIGHER THAN THAT OF SAID SEED CRYSTAL, THE TEMPERATURE DIFFERENTIAL BETWEEN SAID MASS OF SOLID CORUNDUM AND SAID SEED CRYSTAL BEING NOT GREATER THAN ABOUT 20*C., THE TEMPERATURE OF SAID SEED CRYSTAL BEING AT LEAST 395*C., AND THE TEMPERATURE OF SAID MASS OF SOLID CORUNDUM BEING NOT MORE THAN 520*C.
References Cited (Backward Citations)
US2642337A
Cited
US2785058A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-04-10 | 1964-10-10 | 1965-04-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-04-10 | 1968-10-10 | 1969-04-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-04-10 | 1972-10-10 | 1973-04-11 | $7700.00 | Window Closed / Lapsed |