GB151162A - Improvements in magnetos - Google Patents

Abstract

151,162. Jackson, W. J. Mellersh-, (American Bosch Magneto Corporation). Oct. 3, 1919. Inductor machines.-In an ignition magneto of the type having a magnetic sleeve 5 rotating in the gap between the field-magnet and armature pole-pieces 2, 3, the trailing tips of the sleeve are arranged to leave the trailing tips of the fieldmagnet and armature pole-pieces at irregular angular intervals, and the interrupter is arranged to break the circuit of the primary generating winding 21 at substantially these irregular intervals. Magnetos, according to the invention, are adapted particularly for the ignition of multicylinder aeroplane engines, arranged in V-, fan, or circular formation. The drawings show a magneto for firing a 12-cylinder four-cycle engine having the cylinders arranged in two planes inclined at an angle of 45‹, the sleeve being driven at one and a half times the speed of the crank-shaft. The armature is displaced from its neutral position by an angle equal to half the difference between the adjacent irregular intervals. Figs. 2 and 3 show the trailing tips of the sleeve-members 5 leaving the trailing tips of the armature polepieces 3; at 67.5‹ later in the rotation, the trailing tips of the sleeve-members leave the trailing tips of the field-magnet pole-pieces 2, Fig. 5; at the end of a further angular interval of 112.5‹, the position of the parts is as shown in Fig. 6, and so on. At each of these ignition periods, the mechanical interrupter 27, Fig. 3, opens the circuit of the primary generating winding 21 and the high-tension voltage is directed in turn to the sparking-plugs 30 through the distributor 29.