Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
241 words
A method of manufacturing an electric cable comprising at least one cable core having a substantially moisture-impermeable multi-wire electric conductor, which method comprises causing a flexible elongate core of metal or metal alloy to travel continuously in the direction of its length; helically winding around the advancing metal core at least one layer of wires to form a flexible multi-wire conductor; extruding over the multi-wire conductor at least one fluid-impermeable layer of plastics material to form an electric cable core; winding the cable core around the hub of a cable drum in such a way that each end of the wound cable core is exposed and accessible; sealing the end of the multi-wire conductor at one exposed end of the wound cable core and evacuating air from the interstices bounded by the wires of the multi-wire conductor from the other exposed end of the wound cable core; connecting a source of semi-conductive moisture-impermeable compound in a liquid or semi-liquid state to the end of the multi-wire conductor at one exposed end of the wound cable core and filling the interstices with moisture-impermeable compound by allowing moisture-impermeable compound to be drawn into and to flow along the interstices throughout the length of the multi-wire conductor until the interstices are substantially filled throughout the length of the conductor and permitting or causing the moisture-impermeable compound in said interstices to thicken to such an extent that it will not readily flow from the conductor.
Claim 2
Independent Claim
241 words
A method of manufacturing an electric cable comprising at least one cable core having a substantially moisture-impermeable multi-wire electric conductor, which method comprises causing a flexible elongate core of metal or metal alloy to travel continuously in the direction of its length; helically winding around the advancing metal core at least one layer of wires to form a flexible multi-wire conductor; extruding over the multi-wire conductor at least one fluid-impermeable layer of plastics material to form an electric cable core; winding the cable core around the hub of a cable drum in such a way that each end of the wound cable core is exposed and accessible; sealing the end of the multi-wire conductor at one exposed end of the wound cable core and evacuating air from the interstices bounded by the wires of the multi-wire conductor from the other exposed end of the wound cable core; connecting a source of semi-conductive moisture-impermeable compound in a liquid or semi-liquid state to the end of the multi-wire conductor at one exposed end of the wound cable core and filling the interstices with moisture-impermeable compound by allowing moisture-impermeable compound to be drawn into and to flow along the interstices throughout the length of the multi-wire conductor until the interstices are substantially filled throughout the length of the conductor and permitting or causing the moisture-impermeable compound in said interstices to thicken to such an extent that it will not readily flow from the conductor.
Claim 3
Dependent Claim
50 words
A method as claimed in claim 1 in which the electric cable core is to constitute the core of a single core electric cable, wherein before the cable core is wound around the hub of the cable drum, the method further comprises applying a cable sheath to the cable core.
Claim 4
Dependent Claim
81 words
A method as claimed in claim 1 in which the electric cable core is to constitute one core of a multi-core electric cable, wherein, before the cable core is wound around the hub of the cable drum, the method further comprises laying-up the cable core with at least one other cable core of similar construction, applying a cable sheath to the assembled cores to form a multi-core electric cable, and winding the electric cable around the hub of the cable drum.
Claim 5
Dependent Claim
44 words
A method as claimed in claim 3, wherein the method further comprises evacuating the multi-wire conductors of the cable cores of the wound multi-core cable and drawing moisture-impermeable compound in a liquid or semi-liquid state into the evacuated interstices of the multi-wire conductors concurrently.
Claim 6
Dependent Claim
27 words
A method as claimed in claim 1, wherein the method further comprises evacuating substantially all air from the interstices of the multi-wire conductor during the evacuating step.
Claim 7
Dependent Claim
55 words
A method as claimed in claim 1, wherein, before semi-conductive moisture-impermeable compound in a liquid or semi-liquid state is drawn into the interstices of the conductor, the method further comprises heating the multi-wire conductor of the wound core to prevent premature cooling and thickening of the compound as it is being drawn into the interstices.
Claim 8
Dependent Claim
20 words
A method as claimed in claim 6, wherein said heating is effected by passing an appropriate current along the conductor.
Claim 9
Dependent Claim
36 words
A method as claimed in claim 1, wherein the method further comprises evacuating air from the interstices of the multi-wire conductor of the wound cable core at the exposed leading end of the wound cable core.
Claim 10
Dependent Claim
43 words
A method as claimed in claim 8, wherein the method further comprises feeding the leading end of the wound cable core through a hole in a flange of the cable drum so that the leading end of the wound cable core protrudes therethrough.
Claim 11
Dependent Claim
74 words
A method as claimed in claim 1, wherein the method further comprises detachably connecting a vacuum pump to the end of the multi-wire conductor at the exposed end of the wound cable core, which vacuum pump incorporates means for temporarily sealing the end of said multi-wire conductor with respect to the vacuum pump, and evacuating air from the interstices of the multi-wire conductor of the wound cable core by means of said vacuum pump.
Claim 12
Dependent Claim
44 words
A method as claimed in claim 1, wherein the method further comprises detachably connecting to the end of said multi-wire conductor at the exposed trailing end of the wound cable core a source of said semi-conductive, moisture-impermeable compound in a liquid or semi-liquid state.
Claim 13
Dependent Claim
36 words
A method as claimed in claim 11, wherein the method further comprises effecting a temporary seal between said multi-wire conductor and the source of semi-conductive, moisture-impermeable compound whilst the interstices of said conductor are being evacuated.
Claim 14
Dependent Claim
39 words
A method as claimed in claim 11, wherein the method further comprises heating the source of semi-conductive, moisture-impermeable compound to maintain compound in the source at such a temperature that the compound is in said liquid or semi-liquid state.
Claim 15
Dependent Claim
77 words
A method as claimed in claim 1, wherein the method further comprises selecting a semi-conductive, moisture-impermeable compound which, when heated to a temperature of above approximately 150° C., is sufficiently liquified for the compound to be drawn into evacuated interstices of said multi-wire conductor of the wound cable core and which, when permitted to cool to a temperature below approximately 130° C., thickens to such an extent that the compound will not readily flow from the conductor.