Patent EP0286349A2 successfully refreshed from Google Patents.
EP0286349A2
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Optical fiber cable
Assignee: AT&T Inc
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Filing: 1988-04-05
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Granted: —
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Expires: 2008-04-05
Abstract
Abstract An optical fiber cable (20) includes a core (21) comprising at least one optical fiber (24) which is enclosed in a tubular member (34) and which includes a sheath system (40). The sheath system includes two strength members 42-42 which extend linearly longitudinally along the cable parallel to a longitudinal axis (29) of the cable. The strength members are enclosed in a plastic jacket (46). The strength members have predetermined relative tensile and compressive stiffnesses. The stiffnesses are such that the strength members are capable of withstanding expected compressive as well as tensile loading and are coupled sufficiently to the jacket to provide a composite arrangement which is effective to inhibit contraction and which controls the position of the neutral axis during bending while providing suitable flexibility. The strength members in a preferred embodiment are made of a metallic material such as steel and have tensile and compressive stiffness which are substantially equal to cause the plane of bending to extend through the strength members. In other embodiments, the core is filled with a waterblocking material, the tubular member is enclosed by a water absorbent tape and/or a metallic shield and metallic conductors may extend colinearly with the strength members.
Inventors
- 👤 Michael Douglas Kinard
- 👤 Andrew John Panuska
- 👤 Mickey Ray Reynolds
- 👤 Manuel Roberto Santana
- 👤 George Harry Webster
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-10 01:50
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/44; G02B6/4401; G02B6/4415; G02B6/4416; G02B6/4422; G02B6/4426; G02B6/4429; G02B6/443; G02B6/4432; G02B6/4433; G02B6/4434; G02B6/44384; H; H01; H01B; H01B7/00; H01B7/17; H01B7/28; H01B7/282; H01B7/285
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
127 words
An optical fiber cable, which comprises a core comprising at least one optical fiber, a tubular member which encloses said core, and a jacket which is made of a plastic material and which encloses said tubular member, characterized in that a strength member system is disposed adjacent to said tubular member and comprises two diametrically opposed linear members extending parallel to a longitudinal axis of the cable and being coupled to said jacket, the strength members having predetermined relative tensile and compressive stiffnesses to control the location of the neutral axis of the cable in bending, with the compressive stiffness of the strength members and the coupling thereof to the jacket being sufficient to provide a composite which is effective to inhibit substantially contraction of said cable.
Claim 2
Dependent Claim
127 words
An optical fiber cable, which comprises a core comprising at least one optical fiber, a tubular member which encloses said core, and a jacket which is made of a plastic material and which encloses said tubular member, characterized in that a strength member system is disposed adjacent to said tubular member and comprises two diametrically opposed linear members extending parallel to a longitudinal axis of the cable and being coupled to said jacket, the strength members having predetermined relative tensile and compressive stiffnesses to control the location of the neutral axis of the cable in bending, with the compressive stiffness of the strength members and the coupling thereof to the jacket being sufficient to provide a composite which is effective to inhibit substantially contraction of said cable.
Claim 3
Dependent Claim
34 words
The optical fiber cable of claim 1, characterised in that the tensile and compressive stiffnesses are such that the neutral axis of the cable in bending is caused to extend through said strength members.
Claim 4
Dependent Claim
22 words
The optical fiber cable of claim 1, characterised in that said tensile and compressive stiffnesses of said strength members are substantially equal.
Claim 5
Dependent Claim
44 words
The optical fiber cable of claim 1, characterised in that each of the optical fibers is provided with a coating and wherein the ratio of the plurality of coated optical fibers to the cross-sectional area within the tubular member does not exceed about 0.5.
Claim 6
Dependent Claim
30 words
The optical fiber cable of claim 1, characterised in that each of said strength members has a tensile modulus and a compressive modulus each being about 206 x 10⁶ KPa.
Claim 7
Dependent Claim
41 words
The optical fiber cable of claim 1, characterised by a tape which is made of a water absorbent material and which is interposed between said tubular member and said jacket, and wherein said strength members are in engagement with said tape.
Claim 8
Dependent Claim
36 words
The optical fiber cable of claim 1, characterised by a corrugated metallic shield which is disposed about said core, and wherein each of said strength members is in engagement with an outer surface of said shield.
Claim 9
Dependent Claim
47 words
The optical fiber cable of claim 1, CHARACTERISED IN THAT said core is provided with a waterblocking material, and wherein the waterblocking material has a critical yield stress which is not greater than about 70Pa at 20°C and a shear modulus less than about 13kPa at 20°C.
Claim 10
Dependent Claim
191 words
The cable of claim 1, CHARACTERISED IN THAT said waterblocking material is a composition of matter which comprises a) about 77 to 95% by weight of an oil selected from the group consisting of: i. paraffinic oil having a minimum specific gravity of about 0.86 and a pour point of less than -4°C and being of ASTM type 103, 104A or 104B; ii. naphthenic oil having a minimum specific gravity of about 0.86 and a pour point less than -4°C and being of ASTM type 103, 104A or 104B; iii. polybutene oil having a minimum specific gravity of about 0.83 and a pour point of less than 18°C; iv. triglyceride-based vegetable oil; v. polypropylene oil; vi. chlorinated paraffin oil having a chlorine content between about 30 and 75% by weight and a viscosity at 25°C of between 100 and 10,000 cps; vii. polymerized esters, and viii. any mixture thereof; and b) about 2 to 15% weight colloidal particles selected from the group consisting of hydrophobic fumed silica, hydrophilic fumed silica, precipitated silica, and clay, the colloidal particles having a BET surface area in the range from about 50 to about 400m²/g.
Claim 11
Dependent Claim
31 words
The optical fiber cable of claim 1, CHARACTERISED IN THAT at least one insulated metallic conductor is associated with each of said strength members and extends adjacent thereto and colinearly therewith.
Claim 12
Dependent Claim
35 words
The optical fiber cable of claim 1, characterised in that said jacket has a generally oval cross section with each strength member being disposed in one of the portions having a minor radius of curvature.
References Cited (Backward Citations)
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