Patent US4154591A successfully refreshed from Google Patents.
US4154591A
Expired / Lapsed
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Fabrication of optical fibers with improved cross sectional circularity
Assignee: AT&T Inc
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Filing: 1977-12-06
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Granted: 1979-05-15
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Expires: 1997-12-06
Abstract
Abstract Optical fibers are produced with improved cross sectional circularity. In the course of the fabrication process, the tubular preform from which the fibers are drawn, is collapsed under positive internal pressure. This removes most cross sectional noncircularities that may have developed during fabrication of the preform, and also ensures the collapse of the preform to a structure with circular cross section.
Inventors
- 👤 William G. French
- 👤 G. William Tasker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 03:59
CPC Classifications
C; C03; C03B; C03B37/00; C03B37/01; C03B37/012; C03B37/01205; C03B37/01225; C03B37/01248; C03B23/00; C03B23/04; C03B23/047; C03B23/053; C03B23/07; Y; Y02; Y02P; Y02P40/00; Y02P40/50; Y02P40/57
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
112 words
A method of fabricating an optical fiber comprising: rotating a tubular optical fiber preform about its cylindrical axis; heating a section of the rotating preform with a heat source; traversing relatively the rotating preform with the heat source; reducing the diameter of the preform to one of essentially circular cross section; and drawing the preform into a fiber; the invention characterized in that the diameter of the preform is reduced while maintaining the inner portion of the preform at a pressure greater than that of the ambient surroundings, and in that the length of the preform is substantially maintained while the diameter is reduced to yield a solid cylindrical optical fiber preform.
Claim 2
Independent Claim
112 words
A method of fabricating an optical fiber comprising: rotating a tubular optical fiber preform about its cylindrical axis; heating a section of the rotating preform with a heat source; traversing relatively the rotating preform with the heat source; reducing the diameter of the preform to one of essentially circular cross section; and drawing the preform into a fiber; the invention characterized in that the diameter of the preform is reduced while maintaining the inner portion of the preform at a pressure greater than that of the ambient surroundings, and in that the length of the preform is substantially maintained while the diameter is reduced to yield a solid cylindrical optical fiber preform.
Claim 3
Dependent Claim
14 words
The process of claim 1 wherein the preform is rotated about the cylindrical axis.
Claim 4
Dependent Claim
14 words
The process of claim 1 wherein the heat source traverses relatively the rotating cylinder.
Claim 5
Dependent Claim
26 words
The process of claim 3 wherein the heat source traverses the cylinder at least twice and the temperature of the cylinder is increased on each traversal.
Claim 6
Dependent Claim
27 words
The process of claim 3 wherein the heat source traverses the cylinder at least twice and the pressure internal to the cylinder is reduced on each traversal.
Claim 7
Dependent Claim
13 words
The process of claim 1 wherein the glass cylinder is a multilayered structure.
Claim 8
Dependent Claim
24 words
The process of claim 6 wherein the viscosity of an outer layer is greater than or equal to the viscosity of an inner layer.
Claim 9
Dependent Claim
14 words
The process of claim 1 wherein the preform is collapsed to a solid structure.
Claim 10
Dependent Claim
12 words
The process of claim 1 wherein the preform diameter is initially increased.
Claim 11
Dependent Claim
9 words
The product formed by the process of claim 1.
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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) | 1982-05-14 | 1982-11-13 | 1983-05-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-05-14 | 1986-11-13 | 1987-05-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-05-14 | 1990-11-13 | 1991-05-15 | $7700.00 | Window Closed / Lapsed |