Patent US4261936A successfully refreshed from Google Patents.
US4261936A
Expired / Lapsed
US
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Jacketed optical filamentary material with thermoplastic core
Assignee: Mitsubishi Chemical Corp
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Filing: 1978-12-15
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Granted: 1981-04-14
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Expires: 1998-12-15
Abstract
Abstract An optical filamentary material with a thermoplastic optically transparent core and a lower index of refraction sheath is spaced from a protective jacket by a heat shield which thermally protects the optical filamentary material during extrusion and application of a jacketing polymer.
Inventors
- 👤 Martval J. Hartig
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 22:30
CPC Classifications
B; B29; B29D; B29D11/00; B29C; B29C48/00; B29C48/15; D; D01; D01D; D01D11/00; D01D11/06; G; G02; G02B; G02B6/00; G02B6/02; G02B6/02033; B29C48/03; B29C48/05
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
129 words
Method for reducing the detrimental effect on the ability to transmit light of polymeric optical filamentary material during manufacture of a cable for transmission of light from said optical filamentary material, said material comprising (a) a cylindrical core of a substantially amorphous optically transparent thermoplastic polymeric material having a second order transition temperature from 80° C. to 140° C.; and (b) a substantially amorphous transparent polymeric sheath for (a) having an index of refraction at least 0.1% lower than that of (a), wherein a polymer jacket which is exterior to (a) and (b) is extruded at a temperature at least equal to the second order transition temperature of (a), said method comprising placing a heat shield over said optical filamentary material before said jacket is extruded over said material.
Claim 2
Dependent Claim
129 words
Method for reducing the detrimental effect on the ability to transmit light of polymeric optical filamentary material during manufacture of a cable for transmission of light from said optical filamentary material, said material comprising (a) a cylindrical core of a substantially amorphous optically transparent thermoplastic polymeric material having a second order transition temperature from 80° C. to 140° C.; and (b) a substantially amorphous transparent polymeric sheath for (a) having an index of refraction at least 0.1% lower than that of (a), wherein a polymer jacket which is exterior to (a) and (b) is extruded at a temperature at least equal to the second order transition temperature of (a), said method comprising placing a heat shield over said optical filamentary material before said jacket is extruded over said material.
Claim 3
Dependent Claim
23 words
The method of claim 1 wherein said heat shield is a solid prior to, during, and after its application to (a) and (b).
Claim 4
Dependent Claim
16 words
The method of claim 2 wherein said heat shield comprises yarns of fibers of poly(p-phenylene terephthalamide).
Claim 5
Dependent Claim
40 words
The method of claim 1 wherein said polymer jacket is of a second jacketing polymer which is extruded at a relatively higher extrusion temperature over said heat shield which comprises a first jacketing polymer having a relatively lower extrusion temperature.
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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) | 1984-04-13 | 1984-10-13 | 1985-04-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-04-13 | 1988-10-13 | 1989-04-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-04-13 | 1992-10-13 | 1993-04-14 | $7700.00 | Window Closed / Lapsed |