GB439271A - Improvements in and relating to high frequency electric cables - Google Patents

Abstract

439,271. Cables. SIEMENS & HALSKE AKT.-GES., Siemensstadt, Berlin. Feb. 22, 1935, No. 5775. Convention date, March 28, 1934. [Class 36] In a high-frequency cable comprising one or more core groups, each core group, for the purpose of increasing its inductance, is surrounded by a sheath of magnetizable material which is subdivided to reduce eddy current losses. The sheath may be formed by winding a tape of magnetizable material around the cone group with the turns of the tape insulated from one another, or spaced apart. The tape may be applied in a number of layers which are insulated from one another. Alternatively, the sheath may consist of magnetizable particles which are mixed or sprayed with insulating adhesive material and secured to an insulating strip which is wrapped around the core group. In the construction shown, a single core group, comprising air-space insulated conductors 10, 11 stranded together and enclosed in an insulating sheath 15, is wound with a magnetizable tape 16 with spaced turns, over which is applied an insulating layer 17 and a lead sheath 18. The air-space insulation of the conductors 10, 11 is built up by winding on the conductors an insulating cord consisting of a thread 13 spun round a thread 12 and then applying over the cord winding a lapping of insulation 14. The insulation 13, 14, 15, 17 is preferably of polystyrol. In another construction a cable comprises a quad lapped with two open windings of magnetizable tape which are insulated from each other, whilst in a further embodiment the cable has three core groups which are individually wound, in overlapping turns, with the magnetizable tape, the tape being coated with varnish to insulate the turns from one another.