Patent EP0050495A2 successfully refreshed from Google Patents.
EP0050495A2
Expired / Lapsed
EP
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Manufacture of a flexible stranded body
Assignee: Balfour Beatty PLC
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Filing: 1981-10-16
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Granted: —
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Expires: 2001-10-16
Abstract
Abstract An overhead electric conductor with optical fibres 3 loosely housed in the bore of a central core 1, which bore also contains a greasy water-impermeable medium 4, is manufactured by causing a preformed elongate metal member 2 of U-shaped transverse cross-section and the optical fibres to advance in the direction of their lengths, the rate of advance of the fibres being restrained. As the U-shaped elongate member 2 is transversely folded around the optical fibres 3, greasy water-impermeable medium 4 is injected into the bore of the elongate metal member 2 under a controlled pressure. The consistency of the greasy water-impermeable medium 4, the pressure and rate at which it is injected into the bore and the degree of restraint imparted to the optical fibres 3 is such that, in a predetermined length of the conductor, the length of the optical fibres exceeds the length of the bore by a controlled extent, preferably 1 to 3%.
Inventors
- 👤 Philip Dey
- 👤 Bernard Gaylard
- 👤 David Alexander Taylor
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 16:49
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/04; G02B6/06; H; H01; H01B; H01B5/00; H01B5/08; H01B5/10; H01B5/108; D; D07; D07B; D07B1/00; D07B1/14; D07B1/147; G02B6/44; G02B6/4401; G02B6/4429; G02B6/44384; G02B6/4479; G02B6/4483; G02B6/4484; G02B6/4486; G02B6/4488; G02B6/449; H01B13/00; H01B13/06
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
245 words
A method of manufacturing a flexible stranded body of the kind described, which method comprises causing a preformed elongate member of metal or metal alloy of approximately U-shaped transverse cross-section to travel in the direction of its length, feeding into the space bounded by the U-shaped elongate member at least one optical fibre, transversely folding or otherwise shaping the advancing U-shaped elongate member in such a way as to form a substantially circumferentially rigid central core having a closed elongate compartment within and extending throughout the length of the core in which the or each advancing optical fibre is loosely housed, and applying around the central core so formed at least one layer of helically wound bare elongate elements of metal or metal alloy, characterised in that the rate of advance of the or each optical fibre is restrained and in that water-impermeable medium of a grease-like nature is injected into the elongate compartment under a controlled pressure, the consistency of the greasy water-impermeable medium, the pressure and rate at which it is injected into the compartment and the degree of restraint imparted to the or each advancing optical fibre being such that, in a predetermined length of the stranded body, the length of the or each optical fibre exceeds the length of the elongate compartment by a controlled extent and the space within the elongate compartment not occupied by the or each optical fibre is substantially filled with water-impermeable medium in a greasy state.
Claim 2
Independent Claim
245 words
A method of manufacturing a flexible stranded body of the kind described, which method comprises causing a preformed elongate member of metal or metal alloy of approximately U-shaped transverse cross-section to travel in the direction of its length, feeding into the space bounded by the U-shaped elongate member at least one optical fibre, transversely folding or otherwise shaping the advancing U-shaped elongate member in such a way as to form a substantially circumferentially rigid central core having a closed elongate compartment within and extending throughout the length of the core in which the or each advancing optical fibre is loosely housed, and applying around the central core so formed at least one layer of helically wound bare elongate elements of metal or metal alloy, characterised in that the rate of advance of the or each optical fibre is restrained and in that water-impermeable medium of a grease-like nature is injected into the elongate compartment under a controlled pressure, the consistency of the greasy water-impermeable medium, the pressure and rate at which it is injected into the compartment and the degree of restraint imparted to the or each advancing optical fibre being such that, in a predetermined length of the stranded body, the length of the or each optical fibre exceeds the length of the elongate compartment by a controlled extent and the space within the elongate compartment not occupied by the or each optical fibre is substantially filled with water-impermeable medium in a greasy state.
Claim 3
Dependent Claim
80 words
A method as claimed in Claim 1, characterised in that the consistency of the greasy water-impermeable medium, the pressure and rate at which it is injected into the elongate compartment and the degree of restraint imparted to the or each advancing optical fibre are such that, in a predetermined length of the stranded body, the length of the or each optical fibre exceeds the length of the elongate compartment by a controlled amount lying in the range 1 to 3%.
Claim 4
Dependent Claim
129 words
A method as claimed in Claim 1 or 2, characterised in that at least one substantially rigid tube having an external diameter which is less than the internal diameter of the elongate compartment is positioned in the space bounded by the U-shaped elongate member and extends beyond the means by which the U-shaped elongate member is transversely folded or otherwise shaped to form the central core, the or each advancing optical fibre is fed into the upstream end of the rigid tube and greasy water-impermeable medium is injected through a port in the wall of the tube, excess water-impermeable medium flowing out of the downstream end of the tube and in an upstream direction between the U-shaped elongate member and the rigid tube and out of the U-shaped member.
Claim 5
Dependent Claim
56 words
A method as claimed in Claim 3, wherein the pressure and rate at which greasy water-impermeable medium is injected into the rigid tube are such that water-impermeable medium, flowing towards the downstream end of the tube, draws the or each optical fibre along the tube and into the elongate compartment of the advancing U-shaped elongate member.
Claim 6
Dependent Claim
52 words
A method as claimed in Claim 3 or 4, wherein the rigid tube has in its bore guide means for positioning a single optical fibre within the elongate compartment or two or more circumferentially spaced guide means for positioning two or more optical fibres in circumferentially spaced positions within the elongate compartment.
Claim 7
Dependent Claim
34 words
A method as claimed in Claim 5, wherein the rigid tube is caused to rotate about its longitudinal axis so that the or each"bptical fibre fed into the elongate compartment follows a helical path.
Claim 8
Dependent Claim
51 words
A method as claimed in Claim 5, wherein the rigid tube is caused to oscillate about its longitudinal axis so that the or each optical fibre being fed into the elongate compartment follows a helical path whose direction of lay reverses at spaced positions along the length of the stranded body.
Claim 9
Independent Claim
33 words
A method as claimed in any one of the preceding Claims, wherein restraint is imparted to the or each advancing optical fibre by causing it to travel between a pair of pinch rollers.
Claim 10
Dependent Claim
157 words
Apparatus for use in the manufacture of a flexible stranded body of the kind described by the method claimed in Claim 1, which apparatus comprises means for causing a preformed elongate member of metal or metal alloy of approximately U-shaped transverse cross-section to travel in the direction of its length, means for feeding into the space bounded by the U-shaped elongate member at least one optical fibre, and means for transversely folding or otherwise shaping the advancing U-shaped elongate member in such a way as to form a substantially circumferentially rigid central core having a closed elongate compartment within and extending throughout the length of the core in which the or each advancing optical fibre is loosely housed, characterised in that the apparatus also includes means for injecting a water-impermeable medium of a grease-like nature into the elongate compartment under a controlled rate and pressure, and means for imparting restraint to the or each advancing optical fibre.
Claim 11
Dependent Claim
80 words
Apparatus as claimed in Claim 9, characterised in that the apparatus also includes at least one substantially rigid tube which has an external diameter less than the internal diameter of the elongate compartment and which is positioned in the space bounded by the U-shaped elongate member and extends beyond the means for transversely folding or otherwise shaping the U-shaped elongate member to form the central core, the rigid tube having at least one port for injection of greasy water-impermeable medium.
References Cited (Backward Citations)
No citation records indexed.
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