GB303310A - Improvements in or relating to ignition magnetos for internal combustion engines - Google Patents

Abstract

303,310. Cardellino, M. M. March 28, 1928. Addition to 269,374. Magnetoelectric machines.-In the ignition magneto of the parent Specification the coil 10 is disposed in an axial plane of rotation and its core is connected symmetrically to two laminated pole pieces 6 between which the magnet 1 rotates. The magnet comprises a bundle of elliptical shaped cobalt-steel plates with truncated ends to which are secured laminated polepieces 3 of soft iron arranged not to project beyond the edges of the magnet and the whole is secured between non-magnetic members 4. The magnets have a central hole for the passage of a hollow shaft 2, and the magneto may be mounted in overhang on a shaft, for example, on an extension of the dynamo shaft. The rotor polepieces subtend an. angle of about 60‹, and the stator pole-pieces an angle of about 124‹. Connection between the core 9 and the fixed polepieces is effected by laminated members 8 which are so shaped by thinning down the laminae as to converge at the places of contact with the core 9. The winding 10 comprises a single coil of about 75,000 turns, earthed at one end and connected at the other end to a distributor. In order that the spark may be produced as nearly as possible at the instant when the trailing pole tips of the rotor are passing the stator pole tips, the air-gap should be kept small.