GB1239439A - - Google Patents

Abstract

1,239,439. Magnet cores. TELCON METALS Ltd. 10 Dec., 1969 [24 Dec., 1968], No. 61393/68. Heading H1P. Laminated magnetic cores, e.g. of spirated strip formation and toroidal, stadium shaped, oval or other non-circular configuration are protected mechanically from the imposition of extraneous forces impairing the magnetic permeability of the core material; the core 1 (Fig. 1) being shielded by cut or stamped insulating e.g. synthetic resin end members 4, 5 and circumferential wall members 2, 3 coiled from nonferromagnetic metal strip to diameters slightly less than the outer and slightly greater than the inner diameters of the core, with overlapping ends which are sprung into position; their edges abutting on the circumferential edges of the end members. The edges of the circumferential strip members may be turned inwardly and outwardly to retain the end members (Fig. 5, not shown), each having one turned edge and assembled by sliding in and over the core from opposite ends, or each strip member may be in two concentric overlying parts (Fig. 6, not shown) each having one turned edge and assembled by sliding in and over the core from opposite ends. The width of the circumferential strip members may slightly overlap the annular end face members, and additional annular end face members may be applied to abut the overlaps (Fig. 3, not shown), or the strip members may overlap the core ends and be overlain by an annular end member. Plural unit cores may be assembled coaxially and end on with annular spacing end members interposed between the cores with a circumferential strip member disposed inside and outside the core overlaying all the annular members (Fig. 4, not shown). The metallic strip may be low resistivity (e.g. aluminium) or high resistivity (e.g. nickelchromium). The assembly may be taped up, and the insulating material may be a curable synthetic resin.