GB651939A - Improvements in or relating to the jointing of oil-filled electric cables - Google Patents

Abstract

651,939. Cable joints. PIRELLI-GENERAL CABLE WORKS, Ltd. Sept. 14, 1948, No. 24074. Convention date, June 11, 1940. [Class 38 (i)] [Also in Group XXII] In an oil-filled electric cable, a method of joining two hollow conductors by a soldering operation is provided, while a flow of oil is maintained through one or both conductors in which the flow of oil is diverted from passage through the point of junction during soldering. In an embodiment, Fig. 1, conductors 1, 1<SP>1</SP> formed by a single layer of wire have passage 4, 41 made therein by bending some of the wires towards the conductor axis to allow oil supplied by reservoirs at the remote ends of the conductors 1, 1<SP>1</SP> to flow from the conductors 1, 1<SP>1</SP> as indicated at 5, 5<SP>1</SP>. Solid core 6, 61 of aluminium if the conductors 1, 11 are of aluminium, are placed in the conductor ends and metal rings 7, 7<SP>1</SP> are compressed on the wires around the cores 6, 6<SP>1</SP> to prevent oil flow along the wires. A mould is placed about the wires at the junction point 8, into which molten aluminium is poured to effect the soldering of the conductors 1, 1<SP>1</SP> and cores 6, 6<SP>1</SP>. When soldering is complete an electrostatic screen is placed around the conductors 1, 1<SP>1</SP> so that oil flows from the passage 4 through the screen to the passage 4<SP>1</SP> to maintain oil flow through the cable. In a modification in which the conductor is formed of two wire layers, some wires are bent towards the axis and some away from it to provide the byepass passage. In a further embodiment in which a cable end is connected to a terminal, the conductor 19, Fig. 4, is provided with a passage 25 and an iron core 27 having a lateral hole 28 and a closing diaphragm 33 is entered into the conductor 19 while a ring 29 is compressed on the wires about the core 27. A sleeve 22 is placed over the core 27 so that a hole 23 therein corresponds with the hole 23 and soldering with molten aluminium at 30 takes place when the conductors are of aluminium. When soldering is complete and the passage 25 is closed by insulation 34 a bell 31 connected to an insulator 32 is placed about the conductors and the diaphragm 33 is punctured to establish communication between the hollow cable and the terminal chamber. If the conductor is made of strips, passages are formed by mating holes in one or more strips.