Patent US3705789A successfully refreshed from Google Patents.
US3705789A
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Method for floating zone melting
Assignee: Siemens AG
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Filing: 1967-04-13
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Granted: 1972-12-12
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Expires: 1987-04-13
Abstract
Abstract FLOATING ZONE MELTING OF A VERTICALLY MOUNTED ROD IS PERFORMED WHILE ENERGIZING A LEVITATING FIELD WINDING BY ALTERNATING CURRENT OF MEDIUM FREQUENCY (500 HZ.-500 KHZ.) AND MAINTAINING THE LOW-FREQUENCY (BELOW 300 HZ.) AMPLITUDE FLUCTUATIONS OF THE ENERGIZING CURRENT BELOW 5%, PREFERABLY BELOW 1%. USED AS CURRENT SOURCE IS AN ALTERNATING-CURRET GENERATOR WHOSE EXCITATION OR FEEDER DIRECT CURRENT IS SMOOTHED BY ELECTRONIC FILTERING.
Inventors
- 👤 Wolfgang Keller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 14:27
CPC Classifications
C; C30; C30B; C30B13/00; C30B13/16; C30B13/20; Y; Y10; Y10S; Y10S117/00; Y10S117/901; Y10S117/917
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) | 1975-12-12 | 1976-06-12 | 1976-12-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-12-12 | 1980-06-12 | 1980-12-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-12-12 | 1984-06-12 | 1984-12-12 | $7700.00 | Window Closed / Lapsed |