GB523970A - Improvements in or relating to the magnetising of annular magnets - Google Patents

Abstract

523,970. Magnetizing permanent magnets. JURAK, L. Jan. 18, 1939, No. 1719. Convention date, Feb. 16, 1938. [Class 35] An annular magnet with inwardly extending polar projections has the projections progressively magnetized in groups in such a way that two diametrically opposite pairs of adjacent poles are simultaneously magnetized by the two pole-shoes of the magnetizing apparatus, one of these shoes bridging the two similar poles on one side of a diameter of the magnet and the'other shoe bridging the two similar poles (which are dissimilar to the first pair) on the other side of the diameter. In the form shown, the poles 1, 2, 6, 7 are magnetized simultaneously by the poleshoes 12, 13 extending from a U-shaped electromagnet so that the poles 1, 7 have the same polarity which is dissimilar to that of the poles 2, 6. The shoes 12, 13 are then moved through two pole-pitches and the pole pairs 3, 4, 8, 9 are magnetized, this operation being repeated until all poles are magnetized. Where, as shown, the ring has an odd number of pole pairs two of the poles are, in consequence, magnetized twice and to remove the resulting magnetic inequality the entire procedure may be repeated with a diminished magnet saturation.