Patent US722161A successfully refreshed from Google Patents.
Patent EP0157610A2 successfully refreshed from Google Patents.
EP0157610A2
Expired / Lapsed
EP
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Sheated optical fibres
Assignee: British Telecommunications PLC
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Filing: 1985-03-29
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Granted: —
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Expires: 2005-03-29
Abstract
Abstract A sheath for optical fibres comprises a compound sheath having an inner sheath (41) of high modulus and density, and an outer sheath layer (42) of low density material. The outer sheath layer may be of foamed polyethylene and the inner sheath of polypropylene, both conveniently formed by extrusion.
Inventors
- 👤 Stephen Anthony Cassidy
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 17:37
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/44; G02B6/4401; G02B6/4429; G02B6/443; G02B6/4407; G02B6/4438
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
63 words
An optical fibre member including a sheath comprising an inner sheath containing one or more optical fibres, and an outer sheath containing the inner sheath, wherein the inner sheath comprises material of a first elasticity modulus, wherein the outer sheath comprises material having a second elasticity modulus and low density, and wherein the first modulus is high as compared to the second modulus.
Claim 2
Dependent Claim
63 words
An optical fibre member including a sheath comprising an inner sheath containing one or more optical fibres, and an outer sheath containing the inner sheath, wherein the inner sheath comprises material of a first elasticity modulus, wherein the outer sheath comprises material having a second elasticity modulus and low density, and wherein the first modulus is high as compared to the second modulus.
Claim 3
Dependent Claim
20 words
An optical fibre member as claimed in claim 1, wherein the outer sheath is directly adhered to the inner sheath.
Claim 4
Dependent Claim
31 words
An optical fibre member as claimed in claim I or claim 2, wherein the inner sheath is in the form of a matrix of sheathing material surrounding the fibre or fibres.
Claim 5
Dependent Claim
24 words
An optical fibre member as claimed in claim 1 or claim 2, wherein the inner sheath comprises a sleeve surrounding the fibre or fibres.
Claim 6
Dependent Claim
24 words
An optical fibre member as claimed in any one of the preceding claims , wherein the inner sheath loosely surrounds the fibre or fibres.
Claim 7
Dependent Claim
28 words
An optical fibre member as claimed in any one of claims 1 to 4, wherein the inner sheath forms a tightly fitting envelope to the fibre or fibres.
Claim 8
Dependent Claim
23 words
An optical fibre member as claimed in claim 3, wherein the inner sheath comprises a coating applied to the optical fibre or fibres.
Claim 9
Dependent Claim
27 words
An optical fibre member as claimed in any one of claims 1 to 6, wherein the inner sheath is formed by extrusion about the fibre or fibres.
Claim 10
Dependent Claim
25 words
An optical fibre member as claimed in any one of the preceding claims, wherein the outer sheath is formed by extrusion about the inner sheath.
Claim 11
Dependent Claim
23 words
An optical fibre member as claimed in any one of the preceding claims, wherein the outer sheath comprises cellular material of low density.
Claim 12
Dependent Claim
28 words
An optical fibre member as claimed in any one of the preceding claims, wherein the outer sheath is of a substantially greater cross-sectional area than the inner sheath.
Claim 13
Dependent Claim
34 words
An optical fibre member as claimed in any one of the preceding claims, wherein the material of the outer sheath has an elasticity modulus of between 10 7 and 1 0 8 Nm -2.
Claim 14
Dependent Claim
25 words
A sheath as claimed in claim 12 wherein said modulus is a of the order of 5 x 1 0 7 Nm - 2 .
Claim 15
Dependent Claim
16 words
A sheath as claimed in any preceding claim, wherein the outer sheath layer comprises foamed polyethylene.
Claim 16
Dependent Claim
21 words
A sheath as claimed in any preceding claim wherein the inner sheath has a modulus of the order of 10 Nm.
Claim 17
Dependent Claim
16 words
A sheath as claimed in claim 15 in which the inner sheath is formed of polypropylene.
Claim 18
Dependent Claim
44 words
An optical fibre member including a sheath, wherein the sheath comprises an inner sheath in the form of a thin annular sleeve of relatively high density polymer, and an annular outer sheath enclosing the inner sheath and formed of relatively low density foamed polymer.
Claim 19
Dependent Claim
44 words
An optical fibre member including a sheath, wherein the sheath comprises an inner sheath in the form of a thin annular sleeve of relatively high density polymer, and an annular outer sheath enclosing the inner sheath and formed of relatively low density foamed polymer.
Claim 20
Dependent Claim
35 words
An optical fibre member as claimed in claim 17, wherein the sleeve contains a plurality of optical fibres and the sleeve fits sufficiently tightly for the enclosed optical fibres to be placed under radial compression
References Cited (Backward Citations)
No citation records indexed.
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