POLARIZED ELECTROMAGNETIC ACTUATOR DEVICE

摘要

A polarized electromagnetic actuator device advantageous for single-stable armature operation comprises an armature pivotally supported for movement between two different angularly displaced positions about a pivot axis and an electromagnet with a pair of opposed pole members extending toward the ends of the armature on either side of the pivot axis. Disposed between the free ends of the opposite pole members is a bar-shaped three-pole magnetized permanent magnet which is magnetized to have end poles of the same polarity at the longitudinal ends and a center pole of the opposite polarity intermediate the ends, producing first and second flux paths opposing to each other and extending between the respective end portions of the permanent magnet and the adjacent end portions of the armature. The center pole is offset from the pivot axis of the armature to provide at a correspondingly offset portion therefrom between the armature and the permanent magnet a common flux path through which the first and second flux paths extend in the same direction, whereby producing a torque on the armature tending it to rotate about the pivot axis toward the one of the two angularly displaced positions.