Patent US3822121A successfully refreshed from Google Patents.
US3822121A
Expired / Lapsed
US
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Production of light-conducting glass fibers by molten bath heating
Assignee: Nippon Selfoc Co Ltd
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Filing: 1970-12-24
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Granted: 1974-07-02
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Expires: 1990-12-24
Abstract
Abstract A GLASS FIBER COMPRISING A CORE AND A COATING LAYER RESPECTIVELY CONTAINING IONS OF HIGH AND LOW DEGREES OF CONTRIBUTION TO REFRACTIVE INDEX IS CONTINUOUSLY SPUN AND PASSED THROUGH A MOLTEN MEDIUM AT A HIGH TEMPERATURE OF A SPECIFIC GRAVITY SUBSTANTIALLY EQUAL TO THAT OF THE GLASS FIBER THEREBY TO CAUSE MUTUAL THERMAL DIFFUSION OF THE TWO KINDS OF IONS TO ESTABLISH A DESIRED REFRACTIVE INDEX DISTRIBUTION AS DEFORMATION, WHICH WOULD OTHERWISE BE CAUSED BY THE SOFTENING OF THE GLASS FIBER DUE TO THE HIGHTEMPERATURE TREATMENT, IS PREVENTED.
Inventors
- 👤 K Koizumi
- 👤 M Yoshida
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 20:11
CPC Classifications
C; C03; C03B; C03B37/00; C03B37/01; C03B37/02; C03B37/025; C03B37/027; C03C; C03C13/00; C03C13/04; C03C13/045; C03C13/046; C03C25/00; C03C25/10; C03C25/104; C03C25/106; C03C25/1061; C03C25/60; C03C25/601; G; G02; G02B; G02B6/00; G02B6/02
Claims Analysis
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References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-07-01 | 1977-12-31 | 1978-07-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-07-01 | 1981-12-31 | 1982-07-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-07-01 | 1985-12-31 | 1986-07-02 | $7700.00 | Window Closed / Lapsed |