US4533378A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Modified zirconia induction furnace
Assignee: Furukawa Electric North America Inc
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Filing: 1982-05-28
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Granted: 1985-08-06
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Expires: 2002-05-28
Abstract
Abstract A high temperature induction furnace (10) for drawing lightguide fiber (52) from a silica preform (44) has an axially located tubular zirconium dioxide susceptor (34) therein. Prior to use, at least a portion of the inside surface of the susceptor (34) is coated with a vapor deposited silica "soot" (54). The silica soot (54) is then consolidated at an elevated temperature. Surprisingly, such a technique substantially eliminates migration of zirconium dioxide particles from the susceptor (34) to the preform (44) and/or the fiber 52 without deleteriously affecting the susceptor (34) and/or the operation of the furnace (10).
Inventors
- 👤 Un C. Paek
- 👤 Charles M. Schroeder, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 06:23
CPC Classifications
C; C03; C03B; C03B37/00; C03B37/01; C03B37/02; C03B37/025; C03B37/029; C03B2205/00; C03B2205/60; C03B2205/62; C03B2205/63; C03B2205/64; C03B2205/70
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
91 words
A method of preventing particles from migrating from the surface of a tubular zirconium dioxide susceptor onto a lightguide fiber being drawn from a preform axially located within said susceptor, comprising the steps of: vapor depositing a thin porous layer of silica soot on the inside surface of the zirconium dioxide susceptor; and activating a high frequency induction coil, surrounding the susceptor, to heat said susceptor to consolidate the soot layer to form a thin fused silica layer on the inside surface of the susceptor to prevent particles from migrating therefrom.
Claim 2
Independent Claim
91 words
A method of preventing particles from migrating from the surface of a tubular zirconium dioxide susceptor onto a lightguide fiber being drawn from a preform axially located within said susceptor, comprising the steps of: vapor depositing a thin porous layer of silica soot on the inside surface of the zirconium dioxide susceptor; and activating a high frequency induction coil, surrounding the susceptor, to heat said susceptor to consolidate the soot layer to form a thin fused silica layer on the inside surface of the susceptor to prevent particles from migrating therefrom.
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) | 1988-08-05 | 1989-02-04 | 1989-08-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-08-05 | 1993-02-04 | 1993-08-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-08-05 | 1997-02-04 | 1997-08-06 | $7700.00 | Window Closed / Lapsed |