Electricity: conductors and insulators – With fluids or vacuum – Conduits – cables and conductors
Reexamination Certificate
1998-03-12
2001-08-28
Nguyen, Chau N. (Department: 2831)
Electricity: conductors and insulators
With fluids or vacuum
Conduits, cables and conductors
C174S08400S, C385S101000
Reexamination Certificate
active
06281431
ABSTRACT:
BACKGROUND OF THE INVENTION
The invention relates to a multi-core electric cable, which cable has an outer sheath which surrounds at least one electric pilot line and/or at least one optical fibre line and/or tube therefor in addition to the cores of the cable, and to a cable joint comprising an end portion of such a cable, each of the cores of the cable being electrically connected to respective cores of another electric cable or electric cables within a casing. Particularly, but not exclusively, the invention relates to high voltage oil filled power cables, eg 132 kV power cables, and such joints therefor.
High voltage, eg 132 kV, cable installations including oil filled cables often include low voltage pilot lines for powering switching alarms and oil pressure alarms, for example. Recent developments have resulted in the inclusion of optical fibre communications lines alongside power cables, for example in the same trench as the cables, and the inclusion of optical fibre temperature sensing lines providing a distributed temperature sensing capability for monitoring the temperature of an operating cable along its length, which sensing lines may be taped along or helically around the cable oversheath.
BRIEF SUMMARY OF THE INVENTION
According to an aspect of the present invention, there is provided a cable joint comprising an end portion of a multi-core electric cable which cable has an outer sheath which surrounds at least one electric pilot line and/or at least one optical fibre line and/or tube therefor in addition to the cores of said cable, each of the cores of the cable being electrically connected to respective cores of another electric cable or electric cables within a casing, the or each electric pilot line and/or the or each optical fibre line and/or tube therefor being connected to a like line or tube outside said casing.
The joint may be a straight-through joint interconnecting two multi-core cables.
The joint may be a transition joint and may comprise the end portion of one oil filled multi-core electric cable, the end portion of one non-oil-filled multi-core electric cable and barrier means, the casing containing oil only to the side of the barrier means closest to said oil filled cable.
According to another aspect of the present invention, there is provided a cable joint comprising an end portion of a multi-core oil filled electric cable which cable has an outer sheath which surrounds at least one electric pilot line and/or at least one optical fibre line and/or tube therefor in addition to the cores of said cable, each of the cores of the cable being electrically connected to respective cores of another electric cable or electric cables within an oil filled casing, the or each electric pilot line and/or the or each optical fibre line and/or tube therefor being connected to a like line or tube outside said casing.
Preferably, the casing comprises a first casing portion for encasing connections between said cores, a second, end casing portion for encasing the cores and the or each line of said electric cable, and a stepped portion interconnecting said first casing portion and said end casing portion, the or each electric pilot line and/or the or each optical fibre line and/or tube therefor extending through the stepped portion.
The stepped portion may be provided by a flange which extends laterally, relative to a longitudinal axis of the casing, between adjacent respective ends of said first casing portion and said end casing portion.
The end casing portion may have an inwardly facing surface which extends in the direction of a longitudinal axis of the casing, said inwardly facing surface having a substantially circular cross-section taken laterally of said longitudinal axis of the casing.
The first casing portion may have an outwardly facing surface which extends in the direction of a longitudinal axis of the casing, said outwardly facing surface having a cross-section, taken laterally of said longitudinal axis of the casing, in the form of a substantially equilateral three sided figure, each side of the figure having a substantially straight side-portion intermediate arcuate end side-portions.
Preferably, said first casing portion and said end casing portion are i) disposed such that the geometrical centres of their respective lateral cross sections are aligned in the direction of the longitudinal axis of the casing, and ii) dimensioned such that, if their respective lateral cross-sections are superimposed one upon the other, the substantially circular lateral cross-section of the end casing portion circumscribes the three sided figure formed by the first casing portion in lateral cross-section.
Preferably, the flange extends substantially perpendicularly to the longitudinal axis of the casing such that the stepped portion comprises three segment-shaped steps.
The first casing portion may be disposed intermediate two adjacent said end casing portions, and two respective said stepped portions may interconnect the first casing portion and respective ones of said end casing portions.
The joint may be a straight-through joint and comprise the end portions of two said multi-core oil filled electric cables, respective conductors of the cores of the respective cable end portions extending within the intermediate first casing portion, and the or each electric pilot line and/or the or each optical fibre line and/or tube therefor of each of the respective cable end portions extending through a respective one of said stepped portions.
The joint may be a branch joint and comprise the end portion of said multi-core oil filled electric cable and the end portions of a plurality of single core oil filled electric cables, respective conductors of the cores of the respective multi-core and single core cable end portions extending within the intermediate first casing portion, the or each electric pilot line and/or the or each optical fibre line and/or tube therefor of said multi-core cable extending through one of said stepped portions, and any said like line or tube associated with said single core cables extending through the other of said stepped portions.
The cores of one said multi-core electric cable may be connected to the respective cores of another electric cable or other electric cables by means of respective ferrules.
The joint may be a stop joint and comprise the end portions of two said multi-core oil filled electric cables, respective cores of the two cable end portions being connected to opposite ends of respective electrodes which extend within said first casing portion, the or each electric pilot line and/or the or each optical fibre line and/or tube therefor of each of the respective cable end portions extending through a respective one of said stepped portions.
The intermediate first casing portion may comprise two casing sections connected to opposite ends of barrier means, said electrodes extending through said barrier means within said first casing portion.
According to another aspect of the present invention, there is provided a multi-core oil filled cable having a outer sheath which surrounds at least one electric pilot line and/or at least one optical fibre line in a respective tube therefor in addition to the cores of said cable.
The or each optical fibre line may comprise at least one communications line and/or at least one temperature sensing line.
REFERENCES:
patent: 5418878 (1995-05-01), Sass et al.
patent: 5455881 (1995-10-01), Bosisio et al.
patent: 5467420 (1995-11-01), Rohrmann et al.
patent: 42 40 170 (1994-06-01), None
patent: 0 274 228 (1988-07-01), None
patent: 0 646 817 (1995-04-01), None
patent: 0933786 A (1999-08-01), None
patent: 448511 (1936-06-01), None
patent: 2 302 184 (1997-01-01), None
patent: 58-42010 (1983-03-01), None
patent: 8-223765 (1996-08-01), None
patent: WO 96/02081 (1995-07-01), None
Birelli General plc
Finnegan Henderson Farabow Garrett & Dunner L.L.P.
Nguyen Chau N.
LandOfFree
Multi-core cable and cable joint does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Multi-core cable and cable joint, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Multi-core cable and cable joint will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2541307