US2897126A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Vitreous silica and its manufacture
Assignee: Saint Gobain Quartz SAS
•
Filing: 1955-12-02
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Granted: 1959-07-28
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Expires: 1975-12-02
Abstract
No abstract record available.
Inventors
- 👤 George Henri
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 18:21
CPC Classifications
C; C03; C03C; C03C23/00; Y; Y10; Y10S; Y10S65/00; Y10S65/04; Y10T; Y10T29/00; Y10T29/42
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
92 words
THE METHOD OF REMOVING ABSORPTION BANDS AT ABOUT 2-3 MICRONS OR AT ABOUT 2450 ANGSTROMS FROM SUBSTANTIALLY PURE VITREOUS SILICA THAT HAS BEEN MOLDED FROM QUARTZ CRYSTALS HAVING NO INCLUDED OH IONS AND WHICH HAVE BEEN GROUND TO BETWEEN 200 AND 300 MESH AND FUSED WITHOUT A FLAME SLOWLY UNDER VACUUM; COMPRISING HEATING THE VITREOUS SILICA TO BETWEEN 850* C. AND 1300* C. AND SUBJECTING THE HEATED SILICA TO A D.C. POTENTIAL OF FROM 500 V./CM. TO 1000 V./CM. UNTIL A VEIL FORMS IN THE SILICA AND TRAVELS TO ONE SURFACE THEREOF.
References Cited (Backward Citations)
GB255118A
Cited
US1832607A
Cited
US1997263A
Cited
US1969379A
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US1969658A
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US1955451A
Cited
US2270718A
Cited
US2268823A
Cited
US2504368A
Cited
US2561818A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1962-07-27 | 1963-01-26 | 1963-07-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-07-27 | 1967-01-26 | 1967-07-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-07-27 | 1971-01-26 | 1971-07-28 | $7700.00 | Window Closed / Lapsed |