Cable joint coverings, devices for applying such coverings and joints obtained therewith

Claim 2

An electrical cable joint covering adapted to be stored in a radially stretched condition on a rigid tubular support comprising at least a first sleeve and a second sleeve, each sleeve being formed of a cross-linked, polymeric compound and each sleeve being elastically expandible in the direction radially of the axis thereof and having an axially extending bore, said first sleeve being disposed within and co-axial with said second sleeve and at least part of the radial thickness of said first sleeve being an electrically insulating, cross-linked, polymeric compound, said second sleeve, separate from said first sleeve and without stress thereon, having a bore diameter smaller than the diameter of the exterior surface of said first sleeve separate from said second sleeve and without stress thereon and said second sleeve being elastically shrinkable without the application of heat, whereby with said first sleeve within said second sleeve, said second sleeve exerts radially inward pressure on said first sleeve.

Claim 3

An electrical cable joint covering as set forth in claim 1 wherein at least part of said second sleeve is formed by a polymeric compound having a residual deformation less than 35% when subjected to an elongation of 50% applied thereto for 500 hours at a temperature of 100° C.

Claim 4

An electrical cable joint covering as set forth in claim 1 wherein said first sleeve comprises a radially innermost tubular layer and a further tubular layer radially outward of said innermost layer, the polymeric compound of said innermost tubular layer having a dielectric constant ε at least equal to 6 and said further tubular layer being an electrically insulating polymeric compound, and wherein said second sleeve comprises a radially outermost tubular layer and a further tubular layer radially inward of said outermost layer, the polymeric compound of said outermost layer having a residual deformation less than 35% with an imposed elongation of 50% applied for 500 hours at 100° C. and said further tubular layer of said second sleeve is semi-conductive.

Claim 5

An electrical cable joint covering as set forth in claim 1 wherein the polymeric compound of said second sleeve has a percentage ultimate elongation at least equal to 300% and the polymeric compound of said first sleeve has a percentage ultimate elongation at least equal to 150%.

Claim 6

An electrical cable joint covering as set forth in claim 1 wherein the modulus E of the polymeric compound of said second sleeve is at least equal to 0.2 MPa and the modulus E of the polymeric compound of said first sleeve is in the range from 0.2 MPa to 20 MPa.

Claim 7

An electrical cable joint covering comprising at least a first sleeve and a second sleeve, each sleeve being formed of a cross-linked, polymeric compound and each sleeve being elastically expandible in the direction radially of the axis thereof and having an axially extending bore, said first sleeve being disposed within and co-axial with said second sleeve and said first sleeve comprising a radially innermost tubular layer, a radially outermost tubular layer and a radially intermediate tubular layer, the polymeric compound of said innermost tubular layer having a dielectric constant ε at least equal to 6, the polymeric compound of said outermost tubular layer being semi-conductive and the polymeric compound of said intermediate layer being electrically insulating, the polymeric compound of said second sleeve having a residual deformation less than 35% when subjected to an elongation of 50% for 500 hours at 100° C. and said second sleeve, separate from said first sleeve and without stress thereon, having a bore diameter smaller than the diameter of the exterior surface of said first sleeve separate from said second sleeve and without stress thereon, whereby with said first sleeve within said second sleeve, said second sleeve exerts radially inward pressure on said first sleeve.

Claim 8

An electrical cable joint covering comprising at least a first sleeve and a second sleeve, each sleeve being formed of a cross-linked, polymeric compound and each sleeve being elastically expandible in the direction radially of the axis thereof and having an axially extending bore, said first sleeve being disposed within and co-axial with said second sleeve and said first sleeve comprising a radially innermost tubular layer, a radially outermost tubular layer and a radially intermediate tubular layer, the polymeric compound of said innermost tubular layer having a dielectric constant ε at least equal to 6, the polymeric compound of said outermost tubular layer being semi-conductive and the polymeric compound of said intermediate layer being electrically insulating, the polymeric compound of said second sleeve having a residual deformation less than 35% when subjected to an elongation of 50% for 500 hours at 100° C. and said second sleeve, separate from said first sleeve and without stress thereon, having a bore diameter smaller than the diameter of the exterior surface of said first sleeve separate from said second sleeve and without stress thereon, whereby with said first sleeve within said second sleeve, said second sleeve exerts radially inward pressure on said first sleeve.

Claim 9

An electrical cable joint covering as set forth in claim 6 further comprising at least one electrically conductive metallic element intermediate said first sleeve and said second sleeve and extending beyond the axial ends of said first sleeve and said second sleeve.

Claim 10

An electrical cable joint covering as set forth in claim 7 wherein there are a plurality of metallic elements intermediate said first sleeve and said second sleeve, said elements being disposed in circumferentially spaced relation with respect to each other.

Claim 11

An electrical cable joint covering as set forth in claim 8 wherein said elements comprise copper wires, aluminum wires, plaited copper wires, plaited aluminum wires, braided copper wires or braided aluminum wires.

Claim 12

An electrical cable joint covering as set forth in claim 6 wherein said second sleeve has an axial length greater than the axial length of said first sleeve and has end portions extending beyond the axial ends of said first sleeve,

Claim 13

An electrical cable joint covering as set forth in claim 10 wherein each of said end portions has an axial length at least equal to 10% of the axial length of said first sleeve.

Claim 14

An electrical cable joint covering as set forth in claim 10 wherein each of said end portions is turned back on the radially outermost surface of said second sleeve.

Claim 15

An electrical cable joint covering comprising at least a first sleeve and a second sleeve, each sleeve being formed of a cross-linked, polymeric compound and each sleeve being elastically expandible in the direction radially of the axis thereof and having an axially extending bore, said first sleeve being disposed within and co-axial with said second sleeve and at least part of the radial thickness of said first sleeve being an electrically insulating, cross-linked, polymeric compound, said second sleeve, separate from said first sleeve and without stress thereon, having a bore diameter smaller than the diameter of the exterior surface of said first sleeve separate from said second sleeve and without stress thereon, the ratio of said diameter of said exterior surface of said first sleeve to said bore diameter of said second sleeve being at least 1.2, whereby with said first sleeve within said second sleeve, said second sleeve exerts radially inward pressure on said first sleeve.

Claim 16

An electrical cable joint covering comprising at least a first sleeve and a second sleeve, each sleeve being formed of a cross-linked, polymeric compound and each sleeve being elastically expandible in the direction radially of the axis thereof and having an axially extending bore, said first sleeve being disposed within and co-axial with said second sleeve and at least part of the radial thickness of said first sleeve being an electrically insulating, cross-linked, polymeric compound, said second sleeve, separate from said first sleeve and without stress thereon, having a bore diameter smaller than the diameter of the exterior surface of said first sleeve separate from said second sleeve and without stress thereon, the ratio of said diameter of said exterior surface of said first sleeve to said bore diameter of said second sleeve being at least 1.2, whereby with said first sleeve within said second sleeve, said second sleeve exerts radially inward pressure on said first sleeve.

Claim 17

An electrical cable joint covering as set forth in claim 4 wherein said first sleeve comprises a radially innermost tubular layer and a further tubular layer radially outward of said innermost layer, the polymeric compound of said innermost tubular layer having a dielectric constant ε at least equal to 6 and said further tubular later being an electrically insulating polymeric compound, and wherein said second sleeve comprises a radially outermost tubular layer, a radially innermost tubular layer and an intermediate tubular layer, the polymeric compound of said outermost layer having a residual deformation less than 35% with an imposed elongation of 50% applied for 500 hours at 100° C., the polymeric compound of the innermost layer of said second sleeve is electrically insulating and the polymeric compound of said intermediate layer is semi-conductive.

Claim 18

An element for applying a covering to electrical cable joint, said element comprising at least a first sleeve and a second sleeve mounted in elastically expanded condition on a rigid tubular support, each sleeve being formed of a cross-linked, polymeric compound and each sleeve being elastically expandible in the direction radially of the axis thereof and having an axially extending bore, said first sleeve being disposed within and co-axial with said second sleeve and at least part of the radial thickness of said first sleeve being an electrically insulating, cross-linked, polymeric compound, said second sleeve, separate from said first sleeve and without stress thereon, having a bore diameter smaller than the diameter of the exterior surface of said first sleeve separate from said second sleeve and without stress thereon and said second sleeve being elastically shrinkable without the application of heat, whereby with said first sleeve within said second sleeve, said second sleeve exerts radially inward pressure on said first sleeve and when the tubular support is removed, causes the bore of said first sleeve to reduce to a predetermined diameter without the application of heat.

Claim 19

An element for applying a covering to electrical cable joint, said element comprising at least a first sleeve and a second sleeve mounted in elastically expanded condition on a rigid tubular support, each sleeve being formed of a cross-linked, polymeric compound and each sleeve being elastically expandible in the direction radially of the axis thereof and having an axially extending bore, said first sleeve being disposed within and co-axial with said second sleeve and at least part of the radial thickness of said first sleeve being an electrically insulating, cross-linked, polymeric compound, said second sleeve, separate from said first sleeve and without stress thereon, having a bore diameter smaller than the diameter of the exterior surface of said first sleeve separate from said second sleeve and without stress thereon and said second sleeve being elastically shrinkable without the application of heat, whereby with said first sleeve within said second sleeve, said second sleeve exerts radially inward pressure on said first sleeve and when the tubular support is removed, causes the bore of said first sleeve to reduce to a predetermined diameter without the application of heat.

Claim 20

An element as set forth in claim 15 wherein at least part of said second sleeve is formed by a polymeric compound having a residual deformation less than 35% when subjected to an elongation of 50% applied thereto for 500 hours at a temperature of 100° C.

Claim 21

An element as set forth in claim 15 wherein said first sleeve comprises a radially innermost tubular layer and a further tubular layer radially outward of said innermost layer, the polymeric compound of said innermost tubular layer having a dielectric constant ε at least equal to 6 and said further tubular layer being an electrically insulating polymeric compound, and wherein said second sleeve comprises a radially outermost tubular layer and a further tubular layer radially inward of said outermost layer, the polymeric compound of said outermost layer having a residual deformation less than 35% with an imposed elongation of 50% applied for 500 hours at 100° C. and said further tubular layer of said second sleeve is semi-conductive.

Claim 22

An element as set forth in claim 15 wherein the polymeric compound of said second sleeve has a percentage ultimate elongation at least equal to 300% and the polymeric compound of said first sleeve has a percentage ultimate elongation at least equal to 150%.

Claim 23

An element as set forth in claim 15 wherein the modulus E of the polymeric compound of said second sleeve is at least equal to 0.2 MPa and the modulus E of the polymeric compound of said first sleeve is in the range from 0.2 MPa to 20 MPa.

Claim 24

An element for applying a covering to electrical cable joint covering comprising at least a first sleeve and a second sleeve mounted in elastically expanded condition on a rigid tubular support, each sleeve being formed of a cross-linked, polymeric compound and each sleeve being elastically expandible in the direction radially of the axis thereof and having an axially extending bore, said first sleeve being disposed within and co-axial with said second sleeve and said first sleeve comprising a radially innermost tubular layer, a radially outermost tubular layer and a radially intermediate tubular layer, the polymeric compound of said innermost tubular layer having a dielectric constant ε at least equal to 6, the polymeric compound of said outermost tubular layer being semi-conductive and the polymeric compound of said intermediate layer being electrically insulating, the polymeric compound of said second sleeve having a residual deformation less than 35% when subjected to an elongation of 50% for 500 hours at 100° C. and said second sleeve, separate from said first sleeve and without stress thereon, having a bore diameter smaller than the diameter of the exterior surface of said first sleeve separate from said second sleeve and without stress thereon, whereby with said first sleeve within said second sleeve, said second sleeve exerts radially inward pressure on said first sleeve.

Claim 25

An element for applying a covering to electrical cable joint covering comprising at least a first sleeve and a second sleeve mounted in elastically expanded condition on a rigid tubular support, each sleeve being formed of a cross-linked, polymeric compound and each sleeve being elastically expandible in the direction radially of the axis thereof and having an axially extending bore, said first sleeve being disposed within and co-axial with said second sleeve and said first sleeve comprising a radially innermost tubular layer, a radially outermost tubular layer and a radially intermediate tubular layer, the polymeric compound of said innermost tubular layer having a dielectric constant ε at least equal to 6, the polymeric compound of said outermost tubular layer being semi-conductive and the polymeric compound of said intermediate layer being electrically insulating, the polymeric compound of said second sleeve having a residual deformation less than 35% when subjected to an elongation of 50% for 500 hours at 100° C. and said second sleeve, separate from said first sleeve and without stress thereon, having a bore diameter smaller than the diameter of the exterior surface of said first sleeve separate from said second sleeve and without stress thereon, whereby with said first sleeve within said second sleeve, said second sleeve exerts radially inward pressure on said first sleeve.

Claim 26

An element as set forth in claim 20 further comprising at least one electrically conductive metallic element intermediate said first sleeve and said second sleeve and extending beyond the axial ends of said first sleeve and said second sleeve.

Claim 27

An element as set forth in claim 21 wherein there are a plurality of metallic elements intermediate said first sleeve and said second sleeve, said elements being disposed in circumferentially spaced relation with respect to each other.

Claim 28

An element as set forth in claim 22 wherein said elements comprise copper wires, aluminum wires, plaited copper wires, plaited aluminum wires, braided copper wires or braided aluminum wires.

Claim 29

An element as set forth in claim 20 wherein said second sleeve has an axial length greater than the axial length of said first sleeve and has end portions extending beyond the axial ends of said first sleeve.

Claim 30

An element as set forth in claim 24 wherein each of said end portions has an axial length at least equal to 10% of the axial length of said first sleeve.

Claim 31

An element as set forth in claim wherein 24 each of said end portions is turned back on the radially outermost surface of said second sleeve.

Claim 32

An element for applying a covering to electrical cable joint covering comprising at least a first sleeve and a second sleeve mounted in elastically expanded condition on a rigid tubular support, each sleeve being formed of a cross-linked, polymeric compound and each sleeve being elastically expandible in the direction radially of the axis thereof and having an axially extending bore, said first sleeve being disposed within and co-axial with said second sleeve and at least part of the radial thickness of said first sleeve being an electrically insulating, cross-linked, polymeric compound, said second sleeve, separate from said first sleeve and without stress thereon, having a bore diameter smaller than the diameter of the exterior surface of said first sleeve separate from said second sleeve and without stress thereon, the ratio of said diameter of said exterior surface of said first sleeve to said bore diameter of said second sleeve is at least 1.2, whereby with said first sleeve within said second sleeve, said second sleeve exerts radially inward pressure on said first sleeve.

Claim 33

An element for applying a covering to electrical cable joint covering comprising at least a first sleeve and a second sleeve mounted in elastically expanded condition on a rigid tubular support, each sleeve being formed of a cross-linked, polymeric compound and each sleeve being elastically expandible in the direction radially of the axis thereof and having an axially extending bore, said first sleeve being disposed within and co-axial with said second sleeve and at least part of the radial thickness of said first sleeve being an electrically insulating, cross-linked, polymeric compound, said second sleeve, separate from said first sleeve and without stress thereon, having a bore diameter smaller than the diameter of the exterior surface of said first sleeve separate from said second sleeve and without stress thereon, the ratio of said diameter of said exterior surface of said first sleeve to said bore diameter of said second sleeve is at least 1.2, whereby with said first sleeve within said second sleeve, said second sleeve exerts radially inward pressure on said first sleeve.

Claim 34

An element as set forth in claim 27 wherein said first sleeve comprises a radially innermost tubular layer and a further tubular layer radially outward of said innermost layer, the polymeric compound of said innermost tubular layer having a dielectric constant at least equal to 6 and said further tubular layer being an electrically insulating polymeric compound, and wherein said second sleeve comprises a radially outermost tubular layer, a radially innermost tubular layer and an intermediate tubular layer, the polymeric compound of said outermost layer having a residual deformation less than 35% with an imposed elongation of 50% applied for 500 hours at 100° C., the polymeric compound of the innermost layer of said second sleeve is electrically insulating and the polymeric compound of said intermediate layer is semi-conductive.

Claim 35

An electrical cable joint between a pair of cables, said cables having conductors mechanically and electrically interconnected within said joint and having insulation around said conductors, said joint having a covering surrounding the connection between said conductors and said covering comprising at least a first sleeve and a second sleeve, each sleeve being formed of a cross-linked, polymeric compound and each sleeve being elastically expandible in the direction radially of the axis thereof and having an axially extending bore, said first sleeve being disposed within and co-axial with said second sleeve and at least part of the radial thickness of said first sleeve being an electrically insulating, cross-linked, polymeric compound and said first sleeve engaging and applying radially inward pressure on said insulation of said cables, said second sleeve, separate from said first sleeve and without stress thereon, having a bore diameter smaller than the diameter of the exterior surface of said first sleeve separate from said second sleeve and without stress thereon, whereby said second sleeve exerts radially inward pressure on said first sleeve and causes said first sleeve to exert a predetermined radially inward pressure on said insulation of said cables.

Claim 36

An electrical cable joint between a pair of cables, said cables having conductors mechanically and electrically interconnected within said joint and having insulation around said conductors, said joint having a covering surrounding the connection between said conductors and said covering comprising at least a first sleeve and a second sleeve, each sleeve being formed of a cross-linked, polymeric compound and each sleeve being elastically expandible in the direction radially of the axis thereof and having an axially extending bore, said first sleeve being disposed within and co-axial with said second sleeve and at least part of the radial thickness of said first sleeve being an electrically insulating, cross-linked, polymeric compound and said first sleeve engaging and applying radially inward pressure on said insulation of said cables, said second sleeve, separate from said first sleeve and without stress thereon, having a bore diameter smaller than the diameter of the exterior surface of said first sleeve separate from said second sleeve and without stress thereon, whereby said second sleeve exerts radially inward pressure on said first sleeve and causes said first sleeve to exert a predetermined radially inward pressure on said insulation of said cables.

Claim 37

An electrical cable joint as set forth in claim 29 wherein at least part of said second sleeve is formed by a polymeric compound having a residual deformation less than 35% when subjected to an elongation of 50% applied thereto for 500 hours at a temperature of 100° C.

Claim 38

An electrical cable joint as set forth in claim 29 wherein said first sleeve comprises a radially innermost tubular layer and a further tubular layer radially outward of said innermost layer, the polymeric compound of said innermost tubular layer having a dielectric constant ε at least equal to 6 and said further tubular layer being an electrically insulating polymeric compound, and wherein said second sleeve comprises a radially outermost tubular layer and a further tubular layer radially inward of said outermost layer, the polymeric compound of said outermost layer having a residual deformation less than 35% with an imposed elongation of 50% applied for 500 hours at 100° C. and said further tubular layer of said second sleeve is semi-conductive.

Claim 39

An electrical cable joint between a pair of cables, said cables having conductors mechanically and electrically interconnected within said joint and having insulation around said conductors, said joint having a covering surrounding the connection between said conductors and said covering comprising at least a first sleeve and a second sleeve, each sleeve being formed of a cross-linked, polymeric compound and each sleeve being elastically expandible in the direction radially of the axis thereof and having an axially extending bore, said first sleeve being disposed within and co-axial with said second sleeve and said first sleeve comprising a radially innermost tubular layer, a radially outermost tubular layer and a radially intermediate tubular layer, the polymeric compound of said innermost tubular layer having a dielectric constant ε at least equal to 6, the polymeric compound of said outermost tubular layer being semi-conductive and the polymeric compound of said intermediate layer being electrically insulating, the polymeric compound of said second sleeve having a residual deformation less than 35% when subjected to an elongation of 50% for 500 hours at 100° C. and said second sleeve, separate from said first sleeve and without stress thereon, having a bore diameter smaller than the diameter of the exterior surface of said first sleeve separate from said second sleeve and without stress thereon, whereby with said first sleeve within said second sleeve, said second sleeve exerts radially inward pressure on said first sleeve.

Claim 40

An electrical cable joint between a pair of cables, said cables having conductors mechanically and electrically interconnected within said joint and having insulation around said conductors, said joint having a covering surrounding the connection between said conductors and said covering comprising at least a first sleeve and a second sleeve, each sleeve being formed of a cross-linked, polymeric compound and each sleeve being elastically expandible in the direction radially of the axis thereof and having an axially extending bore, said first sleeve being disposed within and co-axial with said second sleeve and said first sleeve comprising a radially innermost tubular layer, a radially outermost tubular layer and a radially intermediate tubular layer, the polymeric compound of said innermost tubular layer having a dielectric constant ε at least equal to 6, the polymeric compound of said outermost tubular layer being semi-conductive and the polymeric compound of said intermediate layer being electrically insulating, the polymeric compound of said second sleeve having a residual deformation less than 35% when subjected to an elongation of 50% for 500 hours at 100° C. and said second sleeve, separate from said first sleeve and without stress thereon, having a bore diameter smaller than the diameter of the exterior surface of said first sleeve separate from said second sleeve and without stress thereon, whereby with said first sleeve within said second sleeve, said second sleeve exerts radially inward pressure on said first sleeve.

Claim 41

An electrical cable joint as set forth in claim 32 wherein said cables have metal screens around said insulation thereof and further comprising at least one electrically conductive metallic element intermediate said first sleeve and said second sleeve and extending beyond the axial ends of said first sleeve and said second sleeve, said element being conductively connected to said screens.

Claim 42

An electrical cable joint as set forth in claim 33 wherein there are a plurality of metallic elements intermediate said first sleeve and said second sleeve, said elements being disposed in circumferentially spaced relation with respect to each other.

Claim 43

An electrical cable joint as set forth in claim 34 wherein said elements comprise copper wires, aluminum wires, plaited copper wires, plaited aluminum wires, braided copper wires or braided aluminum wires.

Claim 44

An electrical cable joint as set forth in claim 32 wherein said second sleeve has an axial length greater than the axial length of said first sleeve and has end portions extending beyond the axial ends of said first sleeve.

Claim 45

An electrical cable joint as set forth in claim 36 wherein each of said end portions has an axial length at least equal to 10% of the axial length of said first sleeve.

Claim 46

An electrical cable joint as set forth in claim 36 wherein said cables have sheaths and wherein each of said end portions overlies said sheaths.

Claim 47

An electrical cable joint between a pair of cables, said cables having conductors mechanically and electrically interconnected within said joint and having insulation around said conductors, said joint having a covering surrounding the connection between said conductors and said covering comprising at least a first sleeve and a second sleeve, each sleeve being formed of a cross-linked, polymeric compound and each sleeve being elastically expandible in the direction radially of the axis thereof and having an axially extending bore, said first sleeve being disposed within and co-axial with said second sleeve and at least part of the radial thickness of said first sleeve being an electrically insulating, cross-linked, polymeric compound, said second sleeve, separate from said first sleeve and without stress thereon, having a bore diameter smaller than the diameter of the exterior surface of said first sleeve separate from said second sleeve and without stress thereon, the ratio of said diameter of said exterior surface of said first sleeve to said bore diameter of said second sleeve being at least 1.2.

Claim 48

An electrical cable joint between a pair of cables, said cables having conductors mechanically and electrically interconnected within said joint and having insulation around said conductors, said joint having a covering surrounding the connection between said conductors and said covering comprising at least a first sleeve and a second sleeve, each sleeve being formed of a cross-linked, polymeric compound and each sleeve being elastically expandible in the direction radially of the axis thereof and having an axially extending bore, said first sleeve being disposed within and co-axial with said second sleeve and at least part of the radial thickness of said first sleeve being an electrically insulating, cross-linked, polymeric compound, said second sleeve, separate from said first sleeve and without stress thereon, having a bore diameter smaller than the diameter of the exterior surface of said first sleeve separate from said second sleeve and without stress thereon, the ratio of said diameter of said exterior surface of said first sleeve to said bore diameter of said second sleeve being at least 1.2.

Claim 49

An electrical cable joint as set forth in claim 39 wherein said first sleeve comprises a radially innermost tubular layer and a further tubular layer radially outward of said innermost layer, the polymeric compound of said innermost tubular layer having a dielectric constant ε at least equal to 6 and said further tubular layer being an electrically insulating polymeric compound, and wherein said second sleeve comprises a radially outermost tubular layer, a radially innermost tubular layer and an intermediate tubular layer, the polymeric compound of said outermost layer having a residual deformation less than 35% with an imposed elongation of 50% applied for 500 hours at 100° C., the polymeric compound of the innermost layer of said second sleeve is electrically insulating and the polymeric compound of said intermediate layer is semi-conductive.

Claim 50

An electrical cable joint as set forth in claim 39 wherein the polymeric compound of said second sleeve has a percentage ultimate elongation at least equal to 300% and the polymeric compound of said first sleeve has a percentage ultimate elongation at least equal to 150%.

Claim 51

An electrical cable joint as set forth in claim 39 wherein the modulus E of the polymeric compound of said second sleeve is at least equal to 0.2 MPa and the modulus E of the polymeric compound of said first sleeve is in the range from 0.2 MPa to 20 MPa.

Claim 52

An electrical cable joint between a pair of cables, said cables having conductors mechanically and electrically interconnected within said joint and having insulation around said conductors, said joint having a covering surrounding the connection between said conductors and said covering comprising at least a first sleeve and a second sleeve, each sleeve being formed of a cross-linked, polymeric compound and each sleeve being elastically expandible in the direction radially of the axis thereof and having an axially extending bore, said first sleeve being disposed within and co-axial with said second sleeve and said first sleeve comprising a radially innermost tubular layer and a further tubular layer radially outward of said innermost layer, the polymeric compound of said innermost tubular layer having a dielectric constant ε at least equal to 6 and said further tubular layer being an electrically insulating polymeric compound, said second sleeve comprising a radially outermost tubular layer, a radially innermost tubular layer and an intermediate tubular layer, the polymeric compound of said outermost layer having a residual deformation less than 35% with an imposed elongation of 50% applied for 500 hours at 100° C. the polymeric compound of the innermost layer of said second sleeve being electrically insulating and the polymeric compound of said intermediate layer being semi-conductive and said second sleeve, separate from said first sleeve and without stress thereon, having a bore diameter smaller than the diameter of the exterior surface of said first sleeve separate from said second sleeve and without stress thereon, whereby with said first sleeve within said second sleeve, said second sleeve exerts radially inward pressure on said first sleeve.

Claim 53

An electrical cable joint between a pair of cables, said cables having conductors mechanically and electrically interconnected within said joint and having insulation around said conductors, said joint having a covering surrounding the connection between said conductors and said covering comprising at least a first sleeve and a second sleeve, each sleeve being formed of a cross-linked, polymeric compound and each sleeve being elastically expandible in the direction radially of the axis thereof and having an axially extending bore, said first sleeve being disposed within and co-axial with said second sleeve and said first sleeve comprising a radially innermost tubular layer and a further tubular layer radially outward of said innermost layer, the polymeric compound of said innermost tubular layer having a dielectric constant ε at least equal to 6 and said further tubular layer being an electrically insulating polymeric compound, said second sleeve comprising a radially outermost tubular layer, a radially innermost tubular layer and an intermediate tubular layer, the polymeric compound of said outermost layer having a residual deformation less than 35% with an imposed elongation of 50% applied for 500 hours at 100° C. the polymeric compound of the innermost layer of said second sleeve being electrically insulating and the polymeric compound of said intermediate layer being semi-conductive and said second sleeve, separate from said first sleeve and without stress thereon, having a bore diameter smaller than the diameter of the exterior surface of said first sleeve separate from said second sleeve and without stress thereon, whereby with said first sleeve within said second sleeve, said second sleeve exerts radially inward pressure on said first sleeve.

Claim 54

An electrical cable joint between a pair of cables, said cables having conductors mechanically and electrically interconnected within said joint and having insulation around said conductors, said joint having a covering surrounding the connection between said conductors and said covering comprising at least a first sleeve and a second sleeve, each sleeve being formed of a cross-linked, polymeric compound and each sleeve being elastically expandible in the direction radially of the axis thereof and having an axially extending bore, said first sleeve being disposed within and co-axial with said second sleeve and at least part of the radial thickness of said first sleeve being an electrically insulating, cross-linked, polymeric compound, the polymeric compound of said second sleeve having a percentage ultimate elongation at least equal to 300% and the polymeric compound of said first sleeve having a percentage ultimate elongation at least equal to 150%, and said second sleeve, separate from said first sleeve and without stress thereon, having a bore diameter smaller than the diameter of the exterior surface of said first sleeve separate from said second sleeve and without stress thereon, whereby with said first sleeve within said second sleeve, said second sleeve exerts radially inward pressure on said first sleeve.

Claim 55

An electrical cable joint between a pair of cables, said cables having conductors mechanically and electrically interconnected within said joint and having insulation around said conductors, said joint having a covering surrounding the connection between said conductors and said covering comprising at least a first sleeve and a second sleeve, each sleeve being formed of a cross-linked, polymeric compound and each sleeve being elastically expandible in the direction radially of the axis thereof and having an axially extending bore, said first sleeve being disposed within and co-axial with said second sleeve and at least part of the radial thickness of said first sleeve being an electrically insulating, cross-linked, polymeric compound, the polymeric compound of said second sleeve having a percentage ultimate elongation at least equal to 300% and the polymeric compound of said first sleeve having a percentage ultimate elongation at least equal to 150%, and said second sleeve, separate from said first sleeve and without stress thereon, having a bore diameter smaller than the diameter of the exterior surface of said first sleeve separate from said second sleeve and without stress thereon, whereby with said first sleeve within said second sleeve, said second sleeve exerts radially inward pressure on said first sleeve.

Claim 56

An electrical cable joint between a pair of cables, said cables having conductors mechanically and electrically interconnected within said joint and having insulation around said conductors, said joint having a covering surrounding the connection between said conductors and said covering comprising at least a first sleeve and a second sleeve, each sleeve being formed of a cross-linked, polymeric compound and each sleeve being elastically expandible in the direction radially of the axis thereof and having an axially extending bore, said first sleeve being disposed within and co-axial with said second sleeve and at least part of the radial thickness of said first sleeve being an electrically insulating, cross-linked, polymeric compound, the modulus E of the polymeric compound of said second sleeve being at least equal to 0.2 MPa and the modulus E of the polymeric compound of said first sleeve being in the range from 0.2 MPa to 20 MPa and said second sleeve, separate from said first sleeve and without stress thereon, having a bore diameter smaller than the diameter of the exterior surface of said first sleeve separate from said second sleeve and without stress thereon, whereby with said first sleeve within said second sleeve, said second sleeve exerts radially inward pressure on said first sleeve.

Claim 57

An electrical cable joint between a pair of cables, said cables having conductors mechanically and electrically interconnected within said joint and having insulation around said conductors, said joint having a covering surrounding the connection between said conductors and said covering comprising at least a first sleeve and a second sleeve, each sleeve being formed of a cross-linked, polymeric compound and each sleeve being elastically expandible in the direction radially of the axis thereof and having an axially extending bore, said first sleeve being disposed within and co-axial with said second sleeve and at least part of the radial thickness of said first sleeve being an electrically insulating, cross-linked, polymeric compound, the modulus E of the polymeric compound of said second sleeve being at least equal to 0.2 MPa and the modulus E of the polymeric compound of said first sleeve being in the range from 0.2 MPa to 20 MPa and said second sleeve, separate from said first sleeve and without stress thereon, having a bore diameter smaller than the diameter of the exterior surface of said first sleeve separate from said second sleeve and without stress thereon, whereby with said first sleeve within said second sleeve, said second sleeve exerts radially inward pressure on said first sleeve.

Claim 58

An electrical cable joint covering comprising at least a first sleeve and a second sleeve, each sleeve being formed of a cross-linked, polymeric compound and each sleeve being elastically expandible in the direction radially of the axis thereof and having an axially extending bore, said first sleeve being disposed within and co-axial with said second sleeve and said first sleeve comprising a radially innermost tubular layer and a further tubular layer radially outward of said innermost layer, the polymeric compound of said innermost tubular layer having a dielectric constant ε at least equal to 6 and said further tubular layer being an electrically insulating polymeric compound and said second sleeve comprising a radially outermost tubular layer and a further tubular layer radially inward of said outermost layer, the polymeric compound of said outermost layer having a residual deformation less than 35% with an imposed elongation of 50% applied for 500 hours at 100° C. and said further tubular layer of said second sleeve being semi-conductive, and said second sleeve, separate from said first sleeve and without stress thereon, having a bore diameter smaller than the diameter of the exterior surface of said first sleeve separate from said second sleeve and without stress thereon, the ratio of said diameter of said exterior surface of said sleeve to said bore diameter of said second sleeve being at least 1.2, whereby with said first sleeve within said second sleeve, said second sleeve exerts radially inward pressure on said first sleeve.

Claim 59

An electrical cable joint covering comprising at least a first sleeve and a second sleeve, each sleeve being formed of a cross-linked, polymeric compound and each sleeve being elastically expandible in the direction radially of the axis thereof and having an axially extending bore, said first sleeve being disposed within and co-axial with said second sleeve and said first sleeve comprising a radially innermost tubular layer and a further tubular layer radially outward of said innermost layer, the polymeric compound of said innermost tubular layer having a dielectric constant ε at least equal to 6 and said further tubular layer being an electrically insulating polymeric compound and said second sleeve comprising a radially outermost tubular layer and a further tubular layer radially inward of said outermost layer, the polymeric compound of said outermost layer having a residual deformation less than 35% with an imposed elongation of 50% applied for 500 hours at 100° C. and said further tubular layer of said second sleeve being semi-conductive, and said second sleeve, separate from said first sleeve and without stress thereon, having a bore diameter smaller than the diameter of the exterior surface of said first sleeve separate from said second sleeve and without stress thereon, the ratio of said diameter of said exterior surface of said sleeve to said bore diameter of said second sleeve being at least 1.2, whereby with said first sleeve within said second sleeve, said second sleeve exerts radially inward pressure on said first sleeve.

Claim 60

An electrical cable joint covering comprising at least a first sleeve and a second sleeve, each sleeve being formed of a cross-linked, polymeric compound and each sleeve being elastically expandible in the direction radially of the axis thereof and having an axially extending bore, said first sleeve being disposed within and co-axial with said second sleeve and at least part of the radial thickness of said first sleeve being an electrically insulating, cross-linked, polymeric compound, the polymeric compound of said second sleeve having a percentage ultimate elongation at least equal to 300% and the polymeric compound of said first sleeve having a percentage ultimate elongation at least equal to 150% and said second sleeve, separate from said first sleeve and without stress thereon, having a bore diameter smaller than the diameter of the exterior surface of said first sleeve separate from said second sleeve and without stress thereon, the ratio of said diameter of said exterior surface of said first sleeve to said bore diameter of said second sleeve being at least 1.2, whereby with said first sleeve within said second sleeve, said second sleeve exerts radially inward pressure on said first sleeve.

Claim 61

An electrical cable joint covering comprising at least a first sleeve and a second sleeve, each sleeve being formed of a cross-linked, polymeric compound and each sleeve being elastically expandible in the direction radially of the axis thereof and having an axially extending bore, said first sleeve being disposed within and co-axial with said second sleeve and at least part of the radial thickness of said first sleeve being an electrically insulating, cross-linked, polymeric compound, the polymeric compound of said second sleeve having a percentage ultimate elongation at least equal to 300% and the polymeric compound of said first sleeve having a percentage ultimate elongation at least equal to 150% and said second sleeve, separate from said first sleeve and without stress thereon, having a bore diameter smaller than the diameter of the exterior surface of said first sleeve separate from said second sleeve and without stress thereon, the ratio of said diameter of said exterior surface of said first sleeve to said bore diameter of said second sleeve being at least 1.2, whereby with said first sleeve within said second sleeve, said second sleeve exerts radially inward pressure on said first sleeve.

Claim 62

An electrical cable joint covering comprising at least a first sleeve and a second sleeve, each sleeve being formed of a cross-linked, polymeric compound and each sleeve being elastically expandible in the direction radially of the axis thereof and having an axially extending bore, said first sleeve being disposed within and co-axial with said second sleeve and at least part of the radial thickness of said first sleeve being an electrically insulating, cross-linked, polymeric compound, the modulus E of the polymeric compound of said second sleeve being at least equal to 0.2 MPa and the modulus E of the polymeric compound of said first sleeve being in the range from 0.2 MPa to 20 MPa and said second sleeve, separate from said first sleeve and without stress thereon, having a bore diameter smaller than the diameter of the exterior surface of said first sleeve separate from said second sleeve and without stress thereon, the ratio of said diameter of said exterior surface of said first sleeve to said bore diameter of said second sleeve is at least 1.2, whereby with said first sleeve within said second sleeve, said second sleeve exerts radially inward pressure on said first sleeve.

Claim 63

An electrical cable joint covering comprising at least a first sleeve and a second sleeve, each sleeve being formed of a cross-linked, polymeric compound and each sleeve being elastically expandible in the direction radially of the axis thereof and having an axially extending bore, said first sleeve being disposed within and co-axial with said second sleeve and at least part of the radial thickness of said first sleeve being an electrically insulating, cross-linked, polymeric compound, the modulus E of the polymeric compound of said second sleeve being at least equal to 0.2 MPa and the modulus E of the polymeric compound of said first sleeve being in the range from 0.2 MPa to 20 MPa and said second sleeve, separate from said first sleeve and without stress thereon, having a bore diameter smaller than the diameter of the exterior surface of said first sleeve separate from said second sleeve and without stress thereon, the ratio of said diameter of said exterior surface of said first sleeve to said bore diameter of said second sleeve is at least 1.2, whereby with said first sleeve within said second sleeve, said second sleeve exerts radially inward pressure on said first sleeve.

Claim 64

An element for applying a covering to electrical cable joint covering comprising at least a first sleeve and a second sleeve mounted in elastically expanded condition on a rigid tubular support, each sleeve being formed of a cross-linked, polymeric compound and each sleeve being elastically expandible in the direction radially of the axis thereof and having an axially extending bore, said first sleeve being disposed within and co-axial with said second sleeve and comprising a radially innermost tubular layer and a further tubular layer radially outward of said innermost layer, the polymeric compound of said innermost tubular layer having a dielectric constant ε at least equal to 6 and said further tubular layer being an electrically insulating polymeric compound, said second sleeve comprising a radially outermost tubular layer and a further tubular layer radially inward of said outermost layer, the polymeric compound of said outermost layer having a residual deformation less than 35% with an imposed elongation of 50% applied for 500 hours at 100° C. and said further tubular layer of said second sleeve being semi-conductive and said second sleeve, separate from said first sleeve and without stress thereon, having a bore diameter smaller than the diameter of the exterior surface of said first sleeve separate from said second sleeve and without stress thereon, the ratio of said diameter of said exterior surface of said first sleeve to said bore diameter of said second sleeve being at least 1.2, whereby with said first sleeve within said second sleeve, said second sleeve exerts radially inward pressure on said first sleeve.

Claim 65

An element for applying a covering to electrical cable joint covering comprising at least a first sleeve and a second sleeve mounted in elastically expanded condition on a rigid tubular support, each sleeve being formed of a cross-linked, polymeric compound and each sleeve being elastically expandible in the direction radially of the axis thereof and having an axially extending bore, said first sleeve being disposed within and co-axial with said second sleeve and comprising a radially innermost tubular layer and a further tubular layer radially outward of said innermost layer, the polymeric compound of said innermost tubular layer having a dielectric constant ε at least equal to 6 and said further tubular layer being an electrically insulating polymeric compound, said second sleeve comprising a radially outermost tubular layer and a further tubular layer radially inward of said outermost layer, the polymeric compound of said outermost layer having a residual deformation less than 35% with an imposed elongation of 50% applied for 500 hours at 100° C. and said further tubular layer of said second sleeve being semi-conductive and said second sleeve, separate from said first sleeve and without stress thereon, having a bore diameter smaller than the diameter of the exterior surface of said first sleeve separate from said second sleeve and without stress thereon, the ratio of said diameter of said exterior surface of said first sleeve to said bore diameter of said second sleeve being at least 1.2, whereby with said first sleeve within said second sleeve, said second sleeve exerts radially inward pressure on said first sleeve.

Claim 66

An element for applying a covering to electrical cable joint covering comprising at least a first sleeve and a second sleeve mounted in elastically expanded condition on a rigid tubular support, each sleeve being formed of a cross-linked, polymeric compound and each sleeve being elastically expandible in the direction radially of the axis thereof and having an axially extending bore, said first sleeve being disposed within and co-axial with said second sleeve and at least part of the radial thickness of said first sleeve being an electrically insulating, cross-linked, polymeric compound, the polymeric compound of said second sleeve having a percentage ultimate elongation at least equal to 300% and the polymeric compound of said first sleeve having a percentage ultimate elongation at least equal to 150% and said second sleeve, separate from said first sleeve and without stress thereon, having a bore diameter smaller than the diameter of the exterior surface of said first sleeve separate from said second sleeve and without stress thereon, the ratio of said diameter of said exterior surface of said first sleeve to said bore diameter of said second sleeve being at least 1.2, whereby with said first sleeve within said second sleeve, said second sleeve exerts radially inward pressure on said first sleeve.

Claim 67

An element for applying a covering to electrical cable joint covering comprising at least a first sleeve and a second sleeve mounted in elastically expanded condition on a rigid tubular support, each sleeve being formed of a cross-linked, polymeric compound and each sleeve being elastically expandible in the direction radially of the axis thereof and having an axially extending bore, said first sleeve being disposed within and co-axial with said second sleeve and at least part of the radial thickness of said first sleeve being an electrically insulating, cross-linked, polymeric compound, the polymeric compound of said second sleeve having a percentage ultimate elongation at least equal to 300% and the polymeric compound of said first sleeve having a percentage ultimate elongation at least equal to 150% and said second sleeve, separate from said first sleeve and without stress thereon, having a bore diameter smaller than the diameter of the exterior surface of said first sleeve separate from said second sleeve and without stress thereon, the ratio of said diameter of said exterior surface of said first sleeve to said bore diameter of said second sleeve being at least 1.2, whereby with said first sleeve within said second sleeve, said second sleeve exerts radially inward pressure on said first sleeve.

Claim 68

An element for applying a covering to electrical cable joint covering comprising at least a first sleeve and a second sleeve mounted in elastically expanded condition on a rigid tubular support, each sleeve being formed of a cross-linked, polymeric compound and each sleeve being elastically expandible in the direction radially of the axis thereof and having an axially extending bore, said first sleeve being disposed within and co-axial with said second sleeve and at least part of the radial thickness of said first sleeve being an electrically insulating, cross-linked, polymeric compound, the modulus E of the polymeric compound of said second sleeve being at least equal to 0.2 MPa and the modulus E of the polymeric compound of said first sleeve being in the range from 0.2 MPa to 20 MPa and said second sleeve separate from said first sleeve and without stress thereon, having a bore diameter smaller than the diameter of the exterior surface of said first sleeve separate from said second sleeve and without stress thereon, the ratio of said diameter of said exterior surface of said first sleeve to said bore diameter of said second sleeve being at least 1.2, whereby with said first sleeve within said second sleeve, said second sleeve exerts radially inward pressure on said first sleeve.

Claim 69

An element for applying a covering to electrical cable joint covering comprising at least a first sleeve and a second sleeve mounted in elastically expanded condition on a rigid tubular support, each sleeve being formed of a cross-linked, polymeric compound and each sleeve being elastically expandible in the direction radially of the axis thereof and having an axially extending bore, said first sleeve being disposed within and co-axial with said second sleeve and at least part of the radial thickness of said first sleeve being an electrically insulating, cross-linked, polymeric compound, the modulus E of the polymeric compound of said second sleeve being at least equal to 0.2 MPa and the modulus E of the polymeric compound of said first sleeve being in the range from 0.2 MPa to 20 MPa and said second sleeve separate from said first sleeve and without stress thereon, having a bore diameter smaller than the diameter of the exterior surface of said first sleeve separate from said second sleeve and without stress thereon, the ratio of said diameter of said exterior surface of said first sleeve to said bore diameter of said second sleeve being at least 1.2, whereby with said first sleeve within said second sleeve, said second sleeve exerts radially inward pressure on said first sleeve.

Claim 70

An electrical cable joint between a pair of cables, said cables having conductors mechanically and electrically interconnected within said joint and having insulation around said conductors, said joint having a covering surrounding the connection between said conductors and said covering comprising at least a first sleeve and a second sleeve, each sleeve being formed of a cross-linked, polymeric compound and each sleeve being elastically expandible in the direction radially of the axis thereof and having an axially extending bore, said first sleeve being disposed within and co-axial with said second sleeve and said first sleeve comprising a radially innermost tubular layer and a further tubular layer radially outward of said innermost layer, the polymeric compound of said innermost tubular layer having a dielectric constant ε at least equal to 6 and said further tubular layer being an electrically insulating polymeric compound, and said second sleeve comprising a radially outermost tubular layer and a further tubular layer radially inward of said outermost layer, the polymeric compound of said outermost layer having a residual deformation less than 35% with an imposed elongation of 50% applied for 500 hours at 100° C. and said further tubular layer of said second sleeve being semi-conductive, said second sleeve, separate from said first sleeve and without stress thereon, having a bore diameter smaller than the diameter of the exterior surface of said first sleeve separate from said second sleeve and without stress thereon, the ratio of said diameter of said exterior surface of said first sleeve to said bore diameter of said second sleeve being at least 1.2, whereby with said first sleeve within said second sleeve, said second sleeve exerts radially inward pressure on said first sleeve.

Claim 71

An electrical cable joint between a pair of cables, said cables having conductors mechanically and electrically interconnected within said joint and having insulation around said conductors, said joint having a covering surrounding the connection between said conductors and said covering comprising at least a first sleeve and a second sleeve, each sleeve being formed of a cross-linked, polymeric compound and each sleeve being elastically expandible in the direction radially of the axis thereof and having an axially extending bore, said first sleeve being disposed within and co-axial with said second sleeve and said first sleeve comprising a radially innermost tubular layer and a further tubular layer radially outward of said innermost layer, the polymeric compound of said innermost tubular layer having a dielectric constant ε at least equal to 6 and said further tubular layer being an electrically insulating polymeric compound, and said second sleeve comprising a radially outermost tubular layer and a further tubular layer radially inward of said outermost layer, the polymeric compound of said outermost layer having a residual deformation less than 35% with an imposed elongation of 50% applied for 500 hours at 100° C. and said further tubular layer of said second sleeve being semi-conductive, said second sleeve, separate from said first sleeve and without stress thereon, having a bore diameter smaller than the diameter of the exterior surface of said first sleeve separate from said second sleeve and without stress thereon, the ratio of said diameter of said exterior surface of said first sleeve to said bore diameter of said second sleeve being at least 1.2, whereby with said first sleeve within said second sleeve, said second sleeve exerts radially inward pressure on said first sleeve.

Claim 72

An element for applying a covering to electrical cable joint covering comprising at least a first sleeve and a second sleeve mounted in elastically expanded condition on a rigid tubular support, each sleeve being formed of a cross-linked, polymeric compound and each sleeve being elastically expandible in the direction radially of the axis thereof and having an axially extending bore, said first sleeve being disposed within and co-axial with said second sleeve and said first sleeve comprising a radially innermost tubular layer and a further tubular layer radially outward of said innermost layer, the polymeric compound of said innermost tubular layer having a dielectric constant ε at least equal to 6 and said further tubular layer being an electrically insulating polymeric compound, and said second sleeve comprising a radially outermost tubular layer, a radially innermost tubular layer and an intermediate tubular layer, the polymeric compound of said outermost layer having a residual deformation less than 35% with an imposed elongation of 50% applied for 500 hours at 100° C., the polymeric compound of the innermost layer of said second sleeve being electrically insulating and the polymeric compound of said intermediate layer being semi-conductive, and said second sleeve, separate from said first sleeve and without stress thereon, having a bore diameter smaller than the diameter of the exterior surface of said first sleeve separate from said second sleeve and without stress thereon, whereby with said first sleeve within said second sleeve, said second sleeve exerts radially inward pressure on said first sleeve.

Claim 73

An element for applying a covering to electrical cable joint covering comprising at least a first sleeve and a second sleeve mounted in elastically expanded condition on a rigid tubular support, each sleeve being formed of a cross-linked, polymeric compound and each sleeve being elastically expandible in the direction radially of the axis thereof and having an axially extending bore, said first sleeve being disposed within and co-axial with said second sleeve and said first sleeve comprising a radially innermost tubular layer and a further tubular layer radially outward of said innermost layer, the polymeric compound of said innermost tubular layer having a dielectric constant ε at least equal to 6 and said further tubular layer being an electrically insulating polymeric compound, and said second sleeve comprising a radially outermost tubular layer, a radially innermost tubular layer and an intermediate tubular layer, the polymeric compound of said outermost layer having a residual deformation less than 35% with an imposed elongation of 50% applied for 500 hours at 100° C., the polymeric compound of the innermost layer of said second sleeve being electrically insulating and the polymeric compound of said intermediate layer being semi-conductive, and said second sleeve, separate from said first sleeve and without stress thereon, having a bore diameter smaller than the diameter of the exterior surface of said first sleeve separate from said second sleeve and without stress thereon, whereby with said first sleeve within said second sleeve, said second sleeve exerts radially inward pressure on said first sleeve.

Claim 74

An electrical cable joint covering comprising at least a first sleeve and a second sleeve, each sleeve being formed of a cross-linked, polymeric compound and each sleeve being elastically expandible in the direction radially of the axis thereof and having an axially extending bore, said first sleeve being disposed within and co-axial with said second sleeve and said first sleeve comprising a radially innermost tubular layer and a further tubular layer radially outward of said innermost layer, the polymeric compound of said innermost tubular layer having a dielectric constant ε at least equal to 6 and said further tubular layer being an electrically insulating polymeric compound, and said second sleeve comprising a radially outermost tubular layer, a radially innermost tubular layer and an intermediate tubular layer, the polymeric compound of said outermost layer having a residual deformation less than 35% with an imposed elongation of 50% applied for 500 hours at 100° C., the polymeric compound of the innermost layer of said second sleeve being electrically insulating and the polymeric compound of said intermediate layer being semi-conductive, and said second sleeve, separate from said first sleeve and without stress thereon, having a bore diameter smaller than the diameter of the exterior surface of said first sleeve separate from said second sleeve and without stress thereon, whereby with said first sleeve within said second sleeve, said second sleeve exerts radially inward pressure on said first sleeve.

Claim 75

An electrical cable joint covering comprising at least a first sleeve and a second sleeve, each sleeve being formed of a cross-linked, polymeric compound and each sleeve being elastically expandible in the direction radially of the axis thereof and having an axially extending bore, said first sleeve being disposed within and co-axial with said second sleeve and said first sleeve comprising a radially innermost tubular layer and a further tubular layer radially outward of said innermost layer, the polymeric compound of said innermost tubular layer having a dielectric constant ε at least equal to 6 and said further tubular layer being an electrically insulating polymeric compound, and said second sleeve comprising a radially outermost tubular layer, a radially innermost tubular layer and an intermediate tubular layer, the polymeric compound of said outermost layer having a residual deformation less than 35% with an imposed elongation of 50% applied for 500 hours at 100° C., the polymeric compound of the innermost layer of said second sleeve being electrically insulating and the polymeric compound of said intermediate layer being semi-conductive, and said second sleeve, separate from said first sleeve and without stress thereon, having a bore diameter smaller than the diameter of the exterior surface of said first sleeve separate from said second sleeve and without stress thereon, whereby with said first sleeve within said second sleeve, said second sleeve exerts radially inward pressure on said first sleeve.