GB1245197A - Improvements in iron cores for inductive electrical apparatus - Google Patents

Abstract

1,245,197. Inductors. ALLMANNA SVENSKA ELEKTRISKA A.B. 4 March, 1970 [5 March, 1969], No. 10296/70. Heading HIT. An iron core for inductive electric apparatus comprises at least one substantially circular core element built from a number of concentrically arranged rings each manufactured from a basic element 1 comprising a flexible carrier member 2 and a number of plates 3, of equal size, of magnetic material attached by one edge to the carrier member with the width of the basic element equal to the length of the plates, and its thickness equal to the sum of the width of a plate and the thickness of the carrier member. The rings may be manufactured from basic elements having the same thickness. In a further embodiment the rings situated nearest the centre of the core element are manufactured from basic elements which are thinner than those forming the outer rings (see Fig. 3, not shown). The iron core is held together by a bandage or glass fibre tape 7. The core element is impregnated with a resinous binder not containing a solvent. The iron core may comprise two or more elements stacked on top of each other, spacers being arranged between the core elements or being made by shaping the resinous binder. The core element is manufactured by placing ring after ring of the prefabricated basic element into a mould having the desired outer dimension of the core element starting at its periphery. The core element may be finished with an insulating tube 5 around the central hole. Alternatively, the element may be finished by a cylindrical centre piece which is part of the mould. The carrier member 2 may consist of a strip of paper or tape.