US4032313A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for producing optical fibers by using crucibles
Assignee: Canon Inc
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Filing: 1976-07-15
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Granted: 1977-06-28
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Expires: 1996-07-15
Abstract
Abstract An apparatus for producing an optical fiber has a plurality of crucibles piled-up one upon another, each of which has a spinnerette positioned at a bottom portion to permit the molten glass to outflow therethrough and an overflow passage positioned at a side wall. With the apparatus of the construction described which is being heated as a whole, an optical fiber is spun from the spinnerettes while the crucibles are charged with their respective molten glasses in predetermined time intervals in such rates that when the molten glasses in the crucibles exceeds predetermined levels, the excess portion of the molten glasses are permitted to overflow through the overflow passages to associated receptacles, thereby the levels of the molten glasses in the crucibles are maintained constant during the entire spinning operation and the bubbles formed in the molten glasses are caused to outflown with the excess portions to enable an optical fiber of improved quality to be spun.
Inventors
- 👤 Mituhiro Tokuhara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 08:17
CPC Classifications
C; C03; C03B; C03B37/00; C03B37/01; C03B37/02; C03B37/022; C03B37/023; C03B5/00; C03B5/16; C03B5/26; C03B5/262
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
277 words
An apparatus for producing an optical fiber using crucibles which comprises: heating means for heating materials to be melted for forming the optical fiber, a melting unit arranged to be heated by said heating means, said melting unit comprising at least two nested crucibles including an upper crucible and a lower crucible with said upper crucible positioned within said lower crucible, each said crucible comprising a bottom wall and side walls extending upwardly from said bottom wall, said bottom wall of said upper crucible spaced upwardly from said bottom wall of said lower crucible, each of said upper and lower crucibles having an upper end with an opening therein, each of said crucibles being provided with a one-hole spinnerette positioned in said bottom wall thereof, and the spinnerette holes of the crucibles being in vertically spaced alignment, overflow passage means provided in said side walls of at least one of said crucibles below the upper ends thereof and arranged so that when the molten material contained therein exceeds a predetermined level, the excess portion of the molten material is permitted to overflow therethrough, material supply means for supplying the optical fiber materials into the opening of said crucibles in amounts such that excess portions of the molten materials located above the level of said overflow passage means overflow from said overflow passage means during the entire spinning operation, wall means located exteriorly of said crucibles for receiving the overflow of molten materials from said overflow passage means, and fiber drawing means located below said spinnerette holes and arranged to spin the optical fiber while drawing those portions of the molten materials which outflow through said spinnerette holes.
Claim 2
Independent Claim
277 words
An apparatus for producing an optical fiber using crucibles which comprises: heating means for heating materials to be melted for forming the optical fiber, a melting unit arranged to be heated by said heating means, said melting unit comprising at least two nested crucibles including an upper crucible and a lower crucible with said upper crucible positioned within said lower crucible, each said crucible comprising a bottom wall and side walls extending upwardly from said bottom wall, said bottom wall of said upper crucible spaced upwardly from said bottom wall of said lower crucible, each of said upper and lower crucibles having an upper end with an opening therein, each of said crucibles being provided with a one-hole spinnerette positioned in said bottom wall thereof, and the spinnerette holes of the crucibles being in vertically spaced alignment, overflow passage means provided in said side walls of at least one of said crucibles below the upper ends thereof and arranged so that when the molten material contained therein exceeds a predetermined level, the excess portion of the molten material is permitted to overflow therethrough, material supply means for supplying the optical fiber materials into the opening of said crucibles in amounts such that excess portions of the molten materials located above the level of said overflow passage means overflow from said overflow passage means during the entire spinning operation, wall means located exteriorly of said crucibles for receiving the overflow of molten materials from said overflow passage means, and fiber drawing means located below said spinnerette holes and arranged to spin the optical fiber while drawing those portions of the molten materials which outflow through said spinnerette holes.
Claim 3
Dependent Claim
69 words
An apparatus for producing an optical fiber using crucibles according to claim 1, wherein said overflow passage means in said side walls of said crucibles arranged in nested relation to each other include at least one said crucible with a plurality of overflow passages positioned at different heights above said respective bottom wall thereof, and plugs for said overflow passages for closing said overflow passages when not in use.
References Cited (Backward Citations)
US1538229A
Cited
US2493260A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-06-27 | 1980-12-27 | 1981-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-06-27 | 1984-12-27 | 1985-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-06-27 | 1988-12-27 | 1989-06-28 | $7700.00 | Window Closed / Lapsed |