US4154592A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of drawing optical filaments
Assignee: Corning Glass Works
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Filing: 1978-02-21
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Granted: 1979-05-15
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Expires: 1998-02-21
Abstract
Abstract A method of forming an article such as an optical waveguide filament by disposing a draw blank in a cylindrical muffle. The muffle is heated to a temperature sufficient to cause a first end of the blank to reach the drawing temperature of the material thereof. A filament is drawn from the first end of the blank while a helium-containing gas flows through the muffle in such a direction that it is exhausted from that end of the muffle from which the filament is being drawn.
Inventors
- 👤 Alan C. Bailey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:54
CPC Classifications
C; C03; C03B; C03B37/00; C03B37/01; C03B37/02; C03B37/025; C03B37/027; C03B37/02736; C03B37/029; C03B2205/00; C03B2205/60; C03B2205/80
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
88 words
The method of drawing filaments of thermoplastic material from an elongated draw blank comprising the steps of: disposing said blank in a cylindrical muffle, heating said muffle to a temperature sufficient to cause a first end of said blank to reach the drawing temperature of the material thereof, drawing a filament from said first end of said blank, and flowing helium-containing gas through said muffle during at least a portion of said drawing step, said gas containing an amount of helium sufficient to reduce variations in filament diameter.
Claim 2
Independent Claim
88 words
The method of drawing filaments of thermoplastic material from an elongated draw blank comprising the steps of: disposing said blank in a cylindrical muffle, heating said muffle to a temperature sufficient to cause a first end of said blank to reach the drawing temperature of the material thereof, drawing a filament from said first end of said blank, and flowing helium-containing gas through said muffle during at least a portion of said drawing step, said gas containing an amount of helium sufficient to reduce variations in filament diameter.
Claim 3
Dependent Claim
43 words
A method in accordance with claim 1 wherein the step of flowing a helium-containing gas through said muffle comprises flowing a helium-free gas through said muffle until about 10 cm of said draw blank remains, and thereafter flowing helium-containing gas through said muffle.
Claim 4
Dependent Claim
17 words
A method in accordance with claim 2 wherein said helium-containing gas contains up to 84 percent helium.
Claim 5
Dependent Claim
19 words
A method in accordance with claim 3 wherein said helium-containing gas flows at a rate up to 15 CFH.
Claim 6
Dependent Claim
17 words
A method in accordance with claim 4 wherein said helium-containing gas consists of helium, oxygen and nitrogen.
Claim 7
Dependent Claim
17 words
A method in accordance with claim 1 wherein said helium-containing gas comprises up to 84 percent helium.
Claim 8
Dependent Claim
23 words
A method in accordance with claim 6 wherein said helium-containing gas flows through said muffle at a rate of up to 15 CFH.
Claim 9
Dependent Claim
17 words
A method in accordance with claim 7 wherein said helium-containing gas consists of helium, oxygen and nitrogen.
Claim 10
Dependent Claim
50 words
A method in accordance with claim 1 wherein the step of disposing comprises disposing a helium-containing blank in a cylindrical muffle and wherein the step of flowing comprises flowing a helium-free gas through said muffle until said blank is substantially helium-free and thereafter flowing a helium-containing gas through said muffle.
References Cited (Backward Citations)
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 |