GB541967A - Improvements in and relating to ignition magnetos provided with a rotary cylindricalmagnet - Google Patents

Abstract

541,967. Magnetos. BERNARD, J. June 3, 1940, No. 9642. Convention date, July 3, 1939. [Class 35] In a magneto having a rotary cylindrical magnet with field blocks of spiked form forming poles which act on the armature poles, the field blocks include solid magnetic members clamped against the ends of the magnet and of cylindrical external form to receive laminated flux distributers which are mounted on cylindrical rows of the blocks, the inner peripheries of the rims not being in contact with the magnet. In the form shown, the field blocks 3 are clamped, by a nut 6 and a flange 5 on the shaft, against the ends of the magnet 4 and taper inwardly at their cylindrical outer surfaces on which are mounted the flux distributers 8 in the form of rings having integral polar projections. These projections co-operate with pairs of similarly laminated armature poles 13, 14 cast into the frame and joined in pairs on both sides of the armature coil 21 by laminated bridges 19. The magnetic circuit is completed by the laminated armature core 22 at right-angles to the shaft. The various sets of laminae are secured together by insulated rivets and the armature assembly is secured by screws 23 passing through the core 22 and bridges 19 into the frame. Paper or other insulating sheet is inserted between the bridges and poles 8 or between the bridges and core 22, in which case the bridge plates are slit to preclude closed circuits around the core. The form shown has four polar projections on each ring 8, the two rings being displaced by 45 degrees from polar coincidence.