US4276072A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical fiber fabrication
Assignee: ITT Inc
•
Filing: 1977-06-07
•
Granted: 1981-06-30
•
Expires: 1997-06-07
Abstract
Abstract High purity glass preforms for optical fiber manufacture are provided by depositing, using chemical vapor deposition techniques, high purity materials upon a removable hollow tubular deposition substrate of a radio frequency energy susceptible material. The substrate is subjected to radio frequency energy for the purposes of heating the substrate and the high purity glass-forming materials in vapor form are passed through the hollow substrate so that the heated substrate causes a reaction resulting in the deposition of the high purity materials on the inner surface of the substrate. The hollow tubular substrate is subsequently removed from the high purity glass materials to provide a cylinder of high purity glass. During the processing, the hollow substrate functions as a substrate, radio frequency energy susceptor and reaction enclosure. One embodiment of the invention contemplates that the substrate and the high purity glass materials will have different coefficients of thermal expansion so that after deposition of the glass-forming materials, the materials and the substrate may be simultaneously cooled by an amount sufficient to cause the substrate to break and fall away from the deposited glass-forming materials, leaving a cylinder of high purity material.
Inventors
- 👤 Brian O'Brien, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 13:38
CPC Classifications
C; C03; C03B; C03B37/00; C03B37/01; C03B37/012; C03B37/014; C03B37/018; C03B37/01861
Claims Analysis
Total Claims: 37
Claim 1
Independent Claim
135 words
A method for forming a high purity glass preform, comprising the steps of: providing a removable hollow tubular deposition substrate of a radio frequency energy susceptible material; enclosing said substrate as a susceptor inside a primary high-frequency induction coil having a plurality of turns; varying the distance between said plurality of turns; subjecting the substrate to radio frequency energy to heat said substrate; passing high purity glass-forming materials in vapor form through the hollow substrate wherein the heat from the substrate causes a reaction resulting in the depositing of the high purity materials on the inner surface of the substrate; and subsequently removing the hollow tubular substrate from the high purity material to provide a cylinder of high purity material, whereby the hollow substrate functions as a substrate, radio frequency energy susceptor and reaction enclosure.
Claim 2
Independent Claim
135 words
A method for forming a high purity glass preform, comprising the steps of: providing a removable hollow tubular deposition substrate of a radio frequency energy susceptible material; enclosing said substrate as a susceptor inside a primary high-frequency induction coil having a plurality of turns; varying the distance between said plurality of turns; subjecting the substrate to radio frequency energy to heat said substrate; passing high purity glass-forming materials in vapor form through the hollow substrate wherein the heat from the substrate causes a reaction resulting in the depositing of the high purity materials on the inner surface of the substrate; and subsequently removing the hollow tubular substrate from the high purity material to provide a cylinder of high purity material, whereby the hollow substrate functions as a substrate, radio frequency energy susceptor and reaction enclosure.
Claim 3
Dependent Claim
25 words
The method of claim 1 wherein the depositing of high purity material is performed substantially simultaneously along all parts of the length of the substrate.
Claim 4
Dependent Claim
15 words
The method of claim 1 wherein the high purity material deposits as a fused glass.
Claim 5
Dependent Claim
30 words
The method of claim 1 wherein the high purity material deposits as a soot and additionally comprising the step of fusing the soot by raising the temperature of the substrate.
Claim 6
Dependent Claim
23 words
The method of claim 1 additionally comprising the step of controlling the deposition rate at different points along the length of the substrate.
Claim 7
Dependent Claim
24 words
The method of claim 5 wherein the step of controlling the deposition rate comprises the step of controlling the temperature at the different points.
Claim 8
Dependent Claim
32 words
The method of claim 5 wherein the step of controlling the deposition rate comprises the step of controlling the flow rate and concentration of the vapor containing the high purity glass materials.
Claim 9
Dependent Claim
19 words
The method of claim 1 wherein the first step includes selecting a substrate that comprises a graphitic carbon cylinder.
Claim 10
Dependent Claim
19 words
The method of claim 1 wherein the first step includes selecting a substrate that comprises a high temperature ceramic.
Claim 11
Dependent Claim
25 words
The method of claim 1 wherein the first step includes selecting a substrate that comprises a refractory material which becomes electrically conducting at elevated temperatures.
Claim 12
Dependent Claim
32 words
The method of claim 1 additionally comprising the steps of repeating the aforementioned steps using different glass forming materials and a different size substrate to obtain another cylinder of high purity material.
Claim 13
Dependent Claim
21 words
The method of claim 11 wherein one cylinder comprises silicon oxide and the other cylinder comprises an index of refraction modifier.
Claim 14
Dependent Claim
29 words
The method of claim 11 including the steps of inserting one cylinder within the other cylinder and heating said cylinders to collapse them and form a fiber optic preform.
Claim 15
Dependent Claim
26 words
The method of claim 13 including the step of heating the fiber optic preform to its softening temperature and drawing the preform into an optical fiber.
Claim 16
Dependent Claim
32 words
The method of claim 1 wherein the step of removing the substrate comprises heating the deposition substrate to incandescence in the presence of oxygen-containing gas whereby the substrate is removed by oxidation.
Claim 17
Independent Claim
121 words
A method for forming a high purity glass preform, comprising the steps of: providing a disposable deposition substrate in the form of a hollow cylinder of a material having a first thermal expansion coefficient; depositing high purity glass forming materials on the inner surface of the substrate using chemical vapor deposition techniques, said materials having a second thermal expansion coefficient lower than the first expansion coefficient of the substrate material; simultaneously heating the disposable substrate and deposited glass forming materials during the depositing step; and subsequently cooling the deposited glass forming materials and substrate by an amount sufficient to cause the substrate to crack and fall away from the deposited glass forming material to provide a cylinder of high purity material.
Claim 18
Independent Claim
121 words
A method for forming a high purity glass preform, comprising the steps of: providing a disposable deposition substrate in the form of a hollow cylinder of a material having a first thermal expansion coefficient; depositing high purity glass forming materials on the inner surface of the substrate using chemical vapor deposition techniques, said materials having a second thermal expansion coefficient lower than the first expansion coefficient of the substrate material; simultaneously heating the disposable substrate and deposited glass forming materials during the depositing step; and subsequently cooling the deposited glass forming materials and substrate by an amount sufficient to cause the substrate to crack and fall away from the deposited glass forming material to provide a cylinder of high purity material.
Claim 19
Dependent Claim
25 words
The method of claim 16 wherein the depositing of high purity material is performed substantially simultaneously along all parts of the length of the substrate.
Claim 20
Dependent Claim
30 words
The method of claim 16 wherein the high purity material deposits as a soot and additionally comprising the step of fusing the soot by raising the temperature of the substrate.
Claim 21
Dependent Claim
26 words
The method of claim 16 wherein the step of heating comprises passing an electric current through the substrate to heat it by means of resistive heating.
Claim 22
Dependent Claim
20 words
The method of claim 16 wherein the step of heating the substrate comprises enclosing it in a high temperature furnace.
Claim 23
Dependent Claim
19 words
The method of claim 16 wherein the first step includes selecting a substrate that comprises a graphitic carbon cylinder.
Claim 24
Dependent Claim
31 words
The method of claim 21 wherein the step of heating the substrate comprises enclosing the substrate as a susceptor inside a primary high frequency induction coil having a plurality of turns.
Claim 25
Dependent Claim
19 words
The method of claim 16 wherein the first step includes selecting a substrate that comprises a high temperature ceramic.
Claim 26
Dependent Claim
25 words
The method of claim 16 wherein the first step includes selecting a substrate that comprises a refractory material which becomes electrically conducting at elevated temperatures.
Claim 27
Dependent Claim
27 words
The method of claim 16 wherein the step of cooling comprises the step of subjecting said substrate deposited glass forming materials to a cooled stream of gas.
Claim 28
Dependent Claim
19 words
The method of claim 25 wherein the cooling step includes selecting a cooling gas that is an inert gas.
Claim 29
Dependent Claim
32 words
The method of claim 16 additionally comprising the steps of repeating the aforementioned steps using different glass forming materials and a different size substrate to obtain another cylinder of high purity material.
Claim 30
Dependent Claim
29 words
The method of claim 26 including the steps of inserting one cylinder within the other cylinder and heating said cylinders to collapse them and form a fiber optic preform.
Claim 31
Dependent Claim
26 words
The method of claim 28 including the step of heating the fiber optic preform to its softening temperature and drawing the preform into an optical fiber.
Claim 32
Independent Claim
152 words
A method for forming a high purity glass preform, comprising the steps of: providing a removable hollow tubular deposition substrate of a radio frequency energy susceptible material; enclosing the substrate as a susceptor inside a primary high-frequency induction coil, having a plurality of turns; subjecting said substrate to radio frequency energy to heat said substrate; radiating heat back to the substrate by providing the induction coil with a surface which reflects a substantial amount of heat back to the heated substrate; passing high purity glass-forming materials in vapor form through the hollow substrate wherein the heat from the substrate causes a reaction resulting in the depositing of high purity materials on the inner surface of the substrate; and subsequently removing the hollow tubular substrate from the high purity material to provide a cylinder of high purity material, whereby the hollow substrate functions as a substrate, radio frequency energy susceptor and reaction enclosure.
Claim 33
Independent Claim
152 words
A method for forming a high purity glass preform, comprising the steps of: providing a removable hollow tubular deposition substrate of a radio frequency energy susceptible material; enclosing the substrate as a susceptor inside a primary high-frequency induction coil, having a plurality of turns; subjecting said substrate to radio frequency energy to heat said substrate; radiating heat back to the substrate by providing the induction coil with a surface which reflects a substantial amount of heat back to the heated substrate; passing high purity glass-forming materials in vapor form through the hollow substrate wherein the heat from the substrate causes a reaction resulting in the depositing of high purity materials on the inner surface of the substrate; and subsequently removing the hollow tubular substrate from the high purity material to provide a cylinder of high purity material, whereby the hollow substrate functions as a substrate, radio frequency energy susceptor and reaction enclosure.
Claim 34
Independent Claim
172 words
A method for forming a high purity glass preform, comprising the steps of: providing a disposable deposition substrate in the form of a hollow cylinder of a graphitic carbon having a first thermal expansion coefficient; depositing high purity glass-forming materials on the inner surface of the substrate using chemical vapor deposition techniques, said materials having a second thermal expansion coefficient lower than the first expansion coefficient of the substrate material; enclosing the substrate as a susceptor inside a primary high-frequency induction coil having a plurality of turns for simultaneously heating the disposable substrate and the deposited glass-forming materials during the depositing step by subjecting said substrate and deposited material to radio frequency energy; varying the spacing between the turns of the primary high-frequency induction coil in order to control the heating of the substrate along its length; and subsequently cooling the deposited glass-forming materials and substrate by an amount sufficient to cause the substrate to break and fall away from the deposited glass-forming material to provide a cylinder of high purity material.
Claim 35
Independent Claim
172 words
A method for forming a high purity glass preform, comprising the steps of: providing a disposable deposition substrate in the form of a hollow cylinder of a graphitic carbon having a first thermal expansion coefficient; depositing high purity glass-forming materials on the inner surface of the substrate using chemical vapor deposition techniques, said materials having a second thermal expansion coefficient lower than the first expansion coefficient of the substrate material; enclosing the substrate as a susceptor inside a primary high-frequency induction coil having a plurality of turns for simultaneously heating the disposable substrate and the deposited glass-forming materials during the depositing step by subjecting said substrate and deposited material to radio frequency energy; varying the spacing between the turns of the primary high-frequency induction coil in order to control the heating of the substrate along its length; and subsequently cooling the deposited glass-forming materials and substrate by an amount sufficient to cause the substrate to break and fall away from the deposited glass-forming material to provide a cylinder of high purity material.
Claim 36
Independent Claim
139 words
A method for forming a high purity glass preform, comprising the steps of: providing a disposable deposition substrate of an oxidizable material in the form of a hollow cylinder of a material having a first thermal expansion coefficient; depositing high purity glass-forming materials on the inner surface of the substrate, said materials having a second thermal expansion coefficient lower than the first expansion coefficient of the substrate material; simultaneously heating the disposable substrate and deposited glass-forming materials during the depositing step; heating the substrate, prior to cooling, to incandescence in the presence of oxygen to oxidize and remove a portion of the substrate; and subsequently cooling the deposited glass-forming materials and substrate by an amount sufficient to cause the remaining substrate to crack and fall away from the deposited glass-forming material to provide a cylinder of high purity material.
Claim 37
Independent Claim
139 words
A method for forming a high purity glass preform, comprising the steps of: providing a disposable deposition substrate of an oxidizable material in the form of a hollow cylinder of a material having a first thermal expansion coefficient; depositing high purity glass-forming materials on the inner surface of the substrate, said materials having a second thermal expansion coefficient lower than the first expansion coefficient of the substrate material; simultaneously heating the disposable substrate and deposited glass-forming materials during the depositing step; heating the substrate, prior to cooling, to incandescence in the presence of oxygen to oxidize and remove a portion of the substrate; and subsequently cooling the deposited glass-forming materials and substrate by an amount sufficient to cause the remaining substrate to crack and fall away from the deposited glass-forming material to provide a cylinder of high purity material.
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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) | 1984-06-29 | 1984-12-29 | 1985-06-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-06-29 | 1988-12-29 | 1989-06-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-06-29 | 1992-12-29 | 1993-06-30 | $7700.00 | Window Closed / Lapsed |