Patent US4523938A successfully refreshed from Google Patents.
US4523938A
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US
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Method of and apparatus for continuously monitoring diameter variations of an optical fiber being drawn
Assignee: Telecom Italia SpA
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Filing: 1982-07-02
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Granted: 1985-06-18
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Expires: 2002-07-02
Abstract
Abstract An optical fiber, being drawn from a preform and wound upon a reel, passes between parallel plates of a capacitor connected in a measuring circuit which, from the capacitance variations due to changes in fiber diameter, controls a reel-driving motor to minimize these variations. The capacitor may have a constant charge, as by having one of its plates made of an electret, in which case the capacitance variations are determined from voltage changes. A calculator connected to the measuring circuit translates these variations into numerical values representing the fiber diameter which can be visually displayed.
Inventors
- 👤 Giorgio Grego
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 03:10
CPC Classifications
G; G01; G01B; G01B7/00; G01B7/12; G01B7/125; C; C03; C03B; C03B37/00; C03B37/01; C03B37/02; C03B37/025; C03B37/0253
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
80 words
A method of minimizing variations in the diameter of an optical fiber being drawn from a preform, comprising the steps of: (a) passing said fiber between two parallel plates of a constant-charge capacitor, one of said plates being an electret; (b) continuously comparing the potential of the other of said plates with a reference voltage; and (c) modifying the fiber-drawing speed in response to differences between said potential and said reference voltage in a sense tending to reduce said differences.
Claim 2
Independent Claim
80 words
A method of minimizing variations in the diameter of an optical fiber being drawn from a preform, comprising the steps of: (a) passing said fiber between two parallel plates of a constant-charge capacitor, one of said plates being an electret; (b) continuously comparing the potential of the other of said plates with a reference voltage; and (c) modifying the fiber-drawing speed in response to differences between said potential and said reference voltage in a sense tending to reduce said differences.
Claim 3
Dependent Claim
146 words
In an apparatus for drawing an optical fiber from a preform, including heating means for fusing a preform to be converted into an optical fiber, winding means downstream of said heating means for continuously drawing said fiber from said preform, and variable-speed drive means coupled with said winding means, the combination therewith of: a constant-charge capacitor with a pair of parallel plates spacedly flanking said fiber between said heating means and said winding means, one of said plates being an electret; a source of reference voltage; and comparison means with inputs respectively connected to the other of said plates and said source for detecting differences between said reference voltage and the potential of said other of said plates, said comparison means having an output circuit connected to said drive means for modifying the speed of said winding means in a sense tending to reduce said differences.
Claim 4
Dependent Claim
146 words
In an apparatus for drawing an optical fiber from a preform, including heating means for fusing a preform to be converted into an optical fiber, winding means downstream of said heating means for continuously drawing said fiber from said preform, and variable-speed drive means coupled with said winding means, the combination therewith of: a constant-charge capacitor with a pair of parallel plates spacedly flanking said fiber between said heating means and said winding means, one of said plates being an electret; a source of reference voltage; and comparison means with inputs respectively connected to the other of said plates and said source for detecting differences between said reference voltage and the potential of said other of said plates, said comparison means having an output circuit connected to said drive means for modifying the speed of said winding means in a sense tending to reduce said differences.
Claim 5
Dependent Claim
46 words
An apparatus as defined in claim 2, further comprising calculating means connected to said comparison means for converting said differences into numerical values representing deviations of the fiber diameter from a predetermined magnitude, and display means connected to said calculating means for visualizing said numerical values.
Claim 6
Dependent Claim
35 words
An apparatus as defined in claim 2 or 3 wherein said capacitor is provided with dielectric spacing means keeping said plates separated from each other and from the vicinity of the path of said fiber.
References Cited (Backward Citations)
GB680695A
Cited
GB855595A
Cited
US3088297A
Cited
US3221171A
Cited
US3865564A
Cited
US4060965A
Cited
US4123242A
Cited
GB2020816A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-06-17 | 1988-12-17 | 1989-06-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-06-17 | 1992-12-17 | 1993-06-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-06-17 | 1996-12-17 | 1997-06-18 | $7700.00 | Window Closed / Lapsed |