US3937625A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Radio frequency preparation of pure glass
Assignee: International Standard Electric Corp
•
Filing: 1974-08-02
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Granted: 1976-02-10
•
Expires: 1994-08-02
Abstract
Abstract Pure glass is prepared in a water-cooled radio frequency heated silica crucible. An encapsulated graphite susceptor is used to preheat the glass batch material to avoid contamination. The preheater is removed after the r.f. power becomes effective to couple into the melt. The cooling prevents the melt from wetting the crucible and eliminates a further source of contamination.
Inventors
- 👤 Clive Edward Ernest Stewart
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 04:58
CPC Classifications
C; C03; C03B; C03B5/00; C03B5/02; C03B5/025; C03B5/021; C03B5/16; C03B5/18; C03B5/183; C03B5/185; C03B5/225
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
76 words
A method of preparing glass including placing glass batch materials in a crucible, inserting an encapsulated contamination-free susceptor into the crucible, applying a radio frequency field to heat the susceptor to melt the glass, removing the susceptor and applying said radio frequency field to further heat the melt for fining and homogenizing the glass, and cooling the crucible with liquid to provide a lower temperature than the melt to prevent the melt from wetting the crucible.
Claim 2
Independent Claim
76 words
A method of preparing glass including placing glass batch materials in a crucible, inserting an encapsulated contamination-free susceptor into the crucible, applying a radio frequency field to heat the susceptor to melt the glass, removing the susceptor and applying said radio frequency field to further heat the melt for fining and homogenizing the glass, and cooling the crucible with liquid to provide a lower temperature than the melt to prevent the melt from wetting the crucible.
Claim 3
Dependent Claim
32 words
The method as claimed in claim 1 wherein the crucible is made of silica and includes a water jacket, cooling water being passed through the jacket over the base of the crucible.
Claim 4
Dependent Claim
21 words
The method as claimed in claim 1 wherein the susceptor is positioned in the batch material in the crucible during preheating.
Claim 5
Dependent Claim
15 words
The method as claimed in claim 1 wherein the susceptor is of silica encapsulated graphite.
References Cited (Backward Citations)
US1034824A
Cited
US1572873A
Cited
US2186718A
Cited
US2402582A
Cited
US2749379A
Cited
US2877280A
Cited
US2930098A
Cited
US3156549A
Cited
US3205292A
Cited
US3337675A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-02-09 | 1979-08-11 | 1980-02-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-02-09 | 1983-08-11 | 1984-02-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-02-09 | 1987-08-11 | 1988-02-10 | $7700.00 | Window Closed / Lapsed |