Back to results
US 4,536,610 AGranted
Oil-filled, multi-core cable with at least one conductor differing from others
AssigneeSocieta' Cavi Pirelli S.p.A.
InventorAlberto Giussani
Life of this patent
Estimating the term…
Loading patent…
Loading patent…
AssigneeSocieta' Cavi Pirelli S.p.A.
InventorAlberto Giussani
Estimating the term…
An oil-filled, multi-core, electric cable having three cores within a metal sheath. Each core has a conductor surrounded by insulation and has substantially the same outer dimensions as the other cores. One conductor is made of copper and has a central oil duct. The other conductors are made of stranded aluminum wires in side-by-side and contacting relation and the ratio of the cross-sectional area of the metal of the copper conductor to the cross-sectional area of the metal of each aluminum conductor is the reciprocal of the ratio of the electrical conductivities thereof.
An oil-filled, multi-core, electric cable comprising a metal sheath surrounding a plurality of cores, each of said cores comprising a metal conductor covered with oil-permeable insulation impregnated with a fluid, insulating oil, the conductor of at least one, but less than all, of said cores being made of a metal having an electrical conductivity higher than the electrical conductivity of the metal of the conductor of at least one other of said cores, each conductor made of a metal of higher conductivity having a longitudinal duct therein for the movement of said fluid, insulating oil along the duct and each conductor made of a metal of a lower conductivity being a compact strand of metal wires which substantially fill the space within a circle containing the periphery of said strand.
Dependencies are inferred from the claim text.
No related US applications are recorded in the indexed filing history.
Drawings are temporarily unavailable. Open the PDF at USPTO
Gas-pressure cables; Oil-pressure cables; Cables for use in conduits under fluid pressure: oil-pressure cables
Cables
Term ended 18 Jun 2004 (estimated)
USPTO file history isn’t available for this patent, so only indexed dates are shown.
The present invention relates to an oil-filled, multi-core cable and more particularly to an oil-filled, multi-core cable especially suitable for use as a submarine cable.
The known oil-filled, multi-core cables are made up with a plurality of cores laid-up together and are enclosed within a metal sheath, and fillers, impregnated with an insulating, fluid oil, are interposed in the interstices existing between the cable cores and between these latter and the metal sheath. Each core comprises a conductor covered with an insulation, constituted at least by a winding of a tape of material selected from cellulose, synthetic or mixed material and impregnated with an insulating, fluid oil.
To enable the insulating, fluid oil impregnating all the cable elements encased within the sheath to move along the cable itself, ducts must be provided in this latter for the longitudinal movement of the oil. Different types of oil-filled, multi-core cables are known.
Other objects and advantages of the present invention will be apparent from the following detailed description of the presently preferred embodiments thereof, which description should be considered in conjunction with the accompanying drawings in which:
FIG. 1 is a cross-sectional view of an oil-filled, multi-core cable according to the present invention omitting, however, the cable parts outside the metal sheath, and
FIG. 2 is a longitudinal, cross-sectional view of the embodiment shown in FIG. 1 taken along the line I--I shown in FIG. 1.
FIGS. 1 and 2 show cross-sections of a preferred embodiment of an oil-filled, three-core cable according to the present invention which is the simplest case of an oil-filled, multi-core cable to which the present invention refers, but it is to be understood that the invention is applicable to multi-core cables having a different number of cores.
Further, the sections shown in the figures do not illustrate the usual longitudinal coverings, metallic reinforcement, armors which generally are placed around the cable sheath since they are per se known.
As shown in FIGS. 1 and 2, within a metal sheath 1, for example, of lead, of aluminum, there are housed three cores 2, 3 and 4 which are later described in detail. Said cores have in substance all the same outer diametral dimensions.