GB682818A - Improvements in or relating to magnetos - Google Patents

Abstract

682,818. Ignition magnetos. BENDIX AVIATION CORPORATION. Sept. 15, 1950 [Sept. 28, 1949], No. 22764/50. Class 35. The rotor 10 of a magneto has permanent magnets 35, 36, 37; pole-pieces 34 and a non- magnetic spacer 38 separating two of the polepieces arranged in such a manner that when the rotor is rotating the direction of the flux through the stator core 15 is reversed only twice during each revolution of the rotor. The stator and rotor pole-shoes are equally angularly spaced and when the magneto is used for a 2-cylinder engine two identical stators are used as shown in Fig. 1. The contacts of the make-and-break 17 are arranged to be opened by the cam 11 when the flux in the stator changes abruptly from a positive maximum to a negative maximum, i.e. between 180 and 270 degrees. Fig. 8 (not shown), and this occurs during the 90 degrees of the rotor movement during which the magnet 37, Fig. 6, leaves its shown position and its position is taken by the non-magnetic spacer 38, Fig. 7. The second flux reversal takes place during the next 90 degrees rotor movement and, although a voltage 43, Fig. 8 (not shown), may be generated in the stator coil, there is little likelihood of a spark to take place owing to the prevailing condition of the gases at that instant in the cylinder of the engine.