Arrangement in joining electric insulated multi-core cables

Claim 1

Arrangement for forming a detonation joint for an insulated electric multi-core cable, comprising a connecting tube of an elastomeric material, said tube having an axial bore of a diameter correspOnding to the outer diameter of the cable to be joined and extending inwardly from each end of said connecting tube to a predetermined depth, said tube further having a number of axial bores extending parallel to the axis of the connecting tube inter-connecting said end bores and having diameters adapted to each receive a respective phase conductor with the insulation thereon from opposite ends thereof, a copper tube positioned centrally in each of said connecting bores and having a length shorter than that of said connecting bore, said copper tubes each having an inner diameter adapted to receive exposed end portions of said opposite phase conductors, a metal tube encompassing the peripheral surface of the connecting tube and forming an outer casing for the joint, an external layer of an explosive being positioned about said metal tube, and a sleeve of elastic material being positioned between said metal tube and the layer of explosive, the arrangement being such that in response to detonation of the explosive the metal tube is adapted to be compressed and the compression transferred radially inwards through the connecting tube, to the copper tubes, said tubes being pinched about the conductors to form a firm electrical and mechanical contact, and between the insulation of the conductors and the cable ends.