摘要 |
An improved bi-stable electromagnetic actuator is provided having an armature linkage moveable between two stable positions either manually or through the application of an appropriate electrical pulse. The actuator includes a permanent magnet which maintains the actuator armature in a first stable position. It also includes a coil which reduces the magnetic flux used to restrain the armature and allows a compression spring to advance the armature to a second stabled position. In moving from the first to the second positions, the armature engages a stop on the linkage and drives the linkage in the same direction. The linkage, thus, transmits the mechanical action of the armature. The user may manually advance the linkage from the first to the second stable position. This linkage includes a rod of magnetically impermeable material in sliding engagement with the armature and a sleeve disposed around this rod at one end of the rod. This sleeve is made from soft magnetic material. The sleeve always lies within the magnetic field created by the permanent magnet. This allows the permanent magnet to pull the sleeve and, accordingly, the linkage in the direction of the permanent magnet and in abutting relation with the armature.
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