GB382614A - Improvements in or relating to inductive loading coils for submarine electric signalling cables - Google Patents

Abstract

382,614. Inductances; cables. ELECTRICAL RESEARCH PRODUCTS, Inc., 195, Broadway, New York, U.S.A.-(Assignees of Buckley, O. E. ; 36, Clinton Avenue, Maplewood, New Jersey, U.S.A.) July 25, 1931, No. 21286. Convention date, July 25, 1930. Addition to 342,301. [Classes 36 and 37.] In a loaded submarine cable as claimed in the parent Specification, the loading coils are arranged in pairs, the coils 20, 21 of each pair being closely adjacent and having their convolutions wound in opposite directions so as to form astatic combinations. The coils are preferably wound with wire insulated by enamel or other non-hygroscopic material. The wire may be loosely wound, in order that the coils may be flexible. The cores are formed of fine wires or tapes of high permeability, e.g. formed from alloy containing iron, nickel, and cobalt, and may have a length of about ten times their diameter. The cores are vacuum impregnated with melted rubber or other insulating material. A magnetic circuit of low reluctance is provided by surrounding each coil with a layer of magnetic material, which may extend considerably beyond the ends of the coils to provide magnetic shielding, and which may be formed by bending over the core wires 13, 14 so as to touch or slightly overlap. The cable insulation 16 is extruded over the outsides of the loading coils and into the interstices between them. The Specification as open to inspection under Sect. 91 (3) (a) describes also the use of a single coil, which may either be constructed as described above, or may have a core comprising a number of axially aligned rings 31, Fig. 3 (Cancelled), of magnetic material, the winding 32 passing through the centre and around the outside so that each turn includes all the core rings. This subject-matter does not appear in the Specification as accepted.