A swing-type actuator having: (a) an upper yoke made of a ferromagnetic material, (b) a permanent magnet assembly constituted by a lower yoke made of a ferromagnetic material and opposing the upper yoke and a flat permanent magnet attached to the lower yoke; (c) a base member made of a thermoplastic...http://www.google.se/patents/US5576583?utm_source=gb-gplus-sharePatent US5576583 - Swing-type actuator
