GB760300A - Improvements in and relating to magnetic cores for electric induction apparatus - Google Patents

Abstract

760,300. Transformers and inductors. GENERAL ELECTRIC CO. Nov. 9, 1954 [Nov. 16, 1953], No. 32419/54. Class 38 (2). A method of making a magnetic core comprises spirally winding a strip of magnetic material into a multiple turn closed loop and sub-dividing it into sections by cuts which are displaced from one another. When the strip material has been wound to form a closed loop 10 a cut is made in the outer lamination 1 near the top of the left-hand side of the loop. The lamination 1 is then unwound and a cut is made in the next lamination 2 which cut is displaced downwardly from the cut in lamination 1. Lamination 2 is then unwound and a cut, displaced from that in lamination 2, is made in lamination 3. This procedure is repeated until a cut in a lamination occurs at the bottom of the left-hand side of the loop 10. The laminations 1 to 6 so cut and unwound thus form a section 13, each lamination of which is slightly longer than one turn of the loop. The cut in the next lamination of the loop 10 is made at the top of the left-hand side similarly to the cut in lamination 1, the sequence then being repeated. The loop is thus divided into four sections 13 ... 16. When assembling the core in an electric winding section 16 is sprung open and placed around the winding, the joints being disposed within the winding. Section 15 is now sprung around the - winding and similarly sections 14, 13 forming the complete core. In another embodiment the first cut is made at the bottom of the side of the loop, the succeeding cuts progressing upwardly. In this case each lamination is slightly shorter than one turn of the loop. Specification 624,137 is referred to.