GB313584A - Improvements in or relating to magnetic materials - Google Patents

Abstract

313,584. Electrical Research Products, Inc., (Assignees of Elmen, G. W.). June 15, 1928, [Convention date]. Cables with inductances. - A composite magnetic body comprises a number of materials in juxtaposition, one material having a higher permeability at low magnetizing forces and also lower coercivity than iron known under the registered Trade Mark "Armco," another material having very high coercivity. The free poles of the materials react upon one another. Separate portions may comprise hard steel and an iron nickel alloy, the nickel content being 30 to 80 per cent of the whole, or the nickel content of one of the materials can be 75 to 85 per cent and iron 15 to 25 per cent. In one construction, Fig. 1, a conductor comprises a core of piano wire 20 having a surrounding tube 21 of permalloy about 0.006 inch in thickness. Alternatively, a bundle of piano wire and permalloy wire bound with tape, varnish or material known under the registered Trade Mark as " Bakelite " can be employed. In another construction, Fig. 3, a laminated core comprises alternate sheets of different material about 0.014 inch in thickness. One or more airgaps 25 may be provided and these may be arranged in staggered formation. In another construction, Fig. 4, the materials are powdered, insulated, mixed together, and pressed into rings. Specifications 188,688; and 273,638, [Class 82 (i), Metals, Extracting &c.], are referred to.