US4793685A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical cable with nonmetallic reinforcing elements
Assignee: Balfour Beatty PLC
•
Filing: 1987-01-02
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Granted: 1988-12-27
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Expires: 2007-01-02
Abstract
Abstract An elongate flexible core 1 especially suitable for use in an optical cable to be employed as an aerial cable has in its outer circumferential surface circumferentially spaced, longitudinally extending grooves 3 in which optical fibres 34 will be loosely housed and comprises extruded plastics material and a multiplicity of longitudinally stressed elongate flexible non-metallic reinforcing element each substantially encapsulated in the extruded plastics material, the multiplicity of non-metallic reinforcing elements being substantially evenly distributed throughout the cross-sectional area of the core. The non-metallic reinforcing elements preferably extend helically around the axis of the core a long length of lay and preferably constitute 60 to 70% by volume of the extruded plastics material. The non-metallic reinforcing elements are preferably made of an aromatic polyamide and the plastics material may be a thermoplastics material, a thermosetting material or a thermotropic liquid crystalline polymer. The core 1 may be a single elongate flexible body or it may comprise a plurality of elongate flexible bodies extending helically around the axis of the core.
Inventors
- 👤 John E. Taylor
- 👤 Christopher J. White
- 👤 Jonathan E. Nevett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 19:37
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/44; G02B6/4401; G02B6/4429; G02B6/4434; G02B6/4407
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
70 words
An elongate flexible core for use in an optical cable, which core has in its outer circumferential surface a plurality of circumferentially spaced, longitudinally extending separate grooves, wherein the core comprises extruded plastics material and a multiplicity of longitudinally stressed elongate flexible non-metallic reinforcing elements each substantially encapsulated in said extruded plastics material, the multiplicity of non-metallic reinforcing elements being substantially evenly distributed throughout the cross-sectional area of the core.
Claim 2
Dependent Claim
70 words
An elongate flexible core for use in an optical cable, which core has in its outer circumferential surface a plurality of circumferentially spaced, longitudinally extending separate grooves, wherein the core comprises extruded plastics material and a multiplicity of longitudinally stressed elongate flexible non-metallic reinforcing elements each substantially encapsulated in said extruded plastics material, the multiplicity of non-metallic reinforcing elements being substantially evenly distributed throughout the cross-sectional area of the core.
Claim 3
Dependent Claim
89 words
An elongate flexible core for use in an optical cable, which core has in its outer circumferential surface a plurality of circumferentially spaced, longitudinally extending separate grooves, wherein the core comprises a plurality of elongate flexible bodies extending helically around the axis of the core, each of which bodies comprises extruded plastics material and a multiplicity of longitudinally stressed elongate flexible non-metallic reinforcing elements each substantially encapsulated in said extruded plastics material, the multiplicity of non-metallic reinforcing elements being substantially evenly distributed throughout the cross-sectional area of the body.
Claim 4
Dependent Claim
89 words
An elongate flexible core for use in an optical cable, which core has in its outer circumferential surface a plurality of circumferentially spaced, longitudinally extending separate grooves, wherein the core comprises a plurality of elongate flexible bodies extending helically around the axis of the core, each of which bodies comprises extruded plastics material and a multiplicity of longitudinally stressed elongate flexible non-metallic reinforcing elements each substantially encapsulated in said extruded plastics material, the multiplicity of non-metallic reinforcing elements being substantially evenly distributed throughout the cross-sectional area of the body.
Claim 5
Dependent Claim
38 words
An elongate flexible core as claimed in claim 2, whereineach elongate body has a cross-section approximating to a sector of a circle and each elongate body has in its outer arcuate surface at least on longitudinally extending groove.
Claim 6
Dependent Claim
135 words
An elongate flexible core for use in an optical cable, which core has in its outer circumferential surface a plurality of circumferentially spaced, longitudinally extending separate grooves, wherein the core comprises a central stranded member comprising a plurality of elongate flexible bodies which extend helically around the axis of the core and, extending helically around the central stranded member, a plurality of elongate flexible bodies, each of which flexible bodies has a cross-section approximating to a sector of an annulus in the outer arcuate surface of which is at least one longitudinally extending groove and comprises extruded plastics material and a multiplicity of longitudinally stressed elongate flexible non-metallic reinforcing elements each substantially encapsulated in said extruded plastics material, the multiplicity of non-metallic reinforcing elements being substantially evenly distributed throughout the cross-sectional area of the body.
Claim 7
Dependent Claim
135 words
An elongate flexible core for use in an optical cable, which core has in its outer circumferential surface a plurality of circumferentially spaced, longitudinally extending separate grooves, wherein the core comprises a central stranded member comprising a plurality of elongate flexible bodies which extend helically around the axis of the core and, extending helically around the central stranded member, a plurality of elongate flexible bodies, each of which flexible bodies has a cross-section approximating to a sector of an annulus in the outer arcuate surface of which is at least one longitudinally extending groove and comprises extruded plastics material and a multiplicity of longitudinally stressed elongate flexible non-metallic reinforcing elements each substantially encapsulated in said extruded plastics material, the multiplicity of non-metallic reinforcing elements being substantially evenly distributed throughout the cross-sectional area of the body.
Claim 8
Dependent Claim
39 words
An elongate flexible core as claimed in claim 4, wherein the elongate flexible bodies of the central stranded member are so deformed and compacted together that any tendency for the flexible bodies to spring transversely apart is substantially eliminated.
Claim 9
Dependent Claim
41 words
An elongate flexible core as claimed in claim 1, wherein at any position along the length of the elongate flexible core the proportion of non-metallic reinforcing elements in the extruded plastics material lies in the range 60 to 70% by volume.
Claim 10
Dependent Claim
27 words
An elongate flexible core as claimed in claim 1, wherein the non-metallic reinforcing elements extend helically within the extruded plastics body with a long length of lay.
Claim 11
Dependent Claim
54 words
An elongate flexible core as claimed in claim 1, wherein the core has an overall diameter lying in the range 4 to 15 mm and the multiplicity of longitudinally stressed elongate flexible non-metallic reinforcing elements extend helically within the extruded plastics body with a lay length lying in the range 50 to 300 mm.
Claim 12
Dependent Claim
27 words
An elongate flexible core as claimed in claim 1, wherein the longitudinally stressed, elongate flexible non-metallic reinforcing elements of said composition are made of an aromatic polyamide.
Claim 13
Dependent Claim
17 words
An elongate flexible core as claimed in claim 1, wherein the plastics material is a thermoplastics material.
Claim 14
Dependent Claim
18 words
An elongate flexible core as claimed in claim 1, wherein the plastics material is a thermosetting plastics material.
Claim 15
Dependent Claim
18 words
An elongate flexible core as claimed in claim 1, wherein the plastics material is thermotropic liquid crystalline polymer.
Claim 16
Dependent Claim
43 words
An optical cable comprising an elongate flexible core as claimed in claim 1, at least one optical fibre loosely housed in at least one of the circumferentially spaced, longitudinally extending separate grooves of the core and, surrounding the core, an outer protective sheath.
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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) | 1991-12-27 | 1992-06-27 | 1992-12-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-12-27 | 1996-06-27 | 1996-12-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-12-27 | 2000-06-27 | 2000-12-27 | $7700.00 | Window Closed / Lapsed |