THREE POSITION ELECTROMAGNETIC INDICATOR

摘要

A three-position indicating device including an indicator member having localized magnetic poles and rotatably mounted for positioning in any one of three positions by an electromagnetic structure. The electromagnetic structure essentially comprises (1) a movable pole piece which is adapted to lock the indicator member in an intermediate "center" position or to unlock the indicator member so that it may be moved to either of two limit positions each determined by engagement of said indicator member with said pole piece, and (2) one or two coils for establishing magnetic fields to effect movement of the pole piece to unlock said indicator member and also to effect movement of the indicator member to one or the other of its two limit positions by interaction of said electromagnetic fields with the localized magnetic poles of said indicator member.