Patent US2680677A successfully refreshed from Google Patents.
US2680677A
Expired / Lapsed
US
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Process for growing quartz crystals
Assignee: EIDP Inc
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Filing: 1951-02-28
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Granted: 1954-06-08
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Expires: 1971-02-28
Abstract
No abstract record available.
Inventors
- 👤 Edward C Broge
- 👤 Ralph K Iler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 17:14
CPC Classifications
C; C30; C30B; C30B7/00; C30B29/00; C30B29/10; C30B29/16; C30B29/18
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
58 words
A PROCESS FOR THE PRODUCTION OF CRYSTALLINE SILICA AT BELOW PH 13 COMPRISING HEATING TO A TEMPERATURE OF ABOUT 300* TO 550* C. AT A SUPERATMOSPHERIC PRESSURE ABOVE ABOUT 1200 P. S. I. G. A SOL OF DENSE, AMORPHOUS SILICA PARTICLES FROM 10 TO 150 MILLIMICRONS IN DIAMETER IN THE PRESENCE OF A NUCLEUS OF CRYSTALLINE ALPHA QUARTZ.
References Cited (Backward Citations)
US1506118A
Cited
US2467341A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1957-06-07 | 1957-12-07 | 1958-06-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1961-06-07 | 1961-12-07 | 1962-06-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1965-06-07 | 1965-12-07 | 1966-06-08 | $7700.00 | Window Closed / Lapsed |