GB470767A - Improvements in electromagnetic machines with longitudinally moving armatures - Google Patents

Abstract

470,767. Dynamo-electric machines. SANDOR, N. Feb. 20, 1936, No. 5093. [Class 35] [Also in Group XXXIII] Apparatus for catapulting aircraft comprises a stator a in the form of a continuous laminated iron core with a squirrel cage winding disposed along a track and a movable laminated armature d with a polyphase winding constituting a carriage for the aircraft, the resistance of the winding over the length of the track being varied to impart acceleration to the armature, and a gap l being provided in the live rails i disposed adjacent the track with a polyphase auto-transformer interposed in the gap, to reduce and reverse the voltage supplied to the live rails beyond the gap whereby the armature is retarded in its travel over this portion of the track. Polyphase current is supplied to the armature through live rails i and the track rails c from a motor alternator set or engine driven alternator m coupled with a flywheel o having sufficient kinetic energy to provide the initial peak current during the accelerating period. An overload circuit breaker q may be interlocked with a switch on the live rails for switching off the supply at some predetermined position of the armature. The armature current is controlled by a rheostat r in the alternator field. circuit. The gap l may be closed and another provided at the starting end so that the apparatus may function in the reverse direction. In modifications, the stator and armature are in two portions, the portions of one element being disposed laterally and externally of the portions of the other element.