| 摘要 |
<p>PURPOSE:To regulate the attracting force of an armature delicately in a wide range by a construction wherein a non-magnetic material is added to at least one of the magnetic poles of a permanent magnet forming a magnetic path. CONSTITUTION:A permanent magnet 2 is arranged so that its upper yoke side 1 is negatively polarized and a non-magnetic material 3 is interlockingly added to the other pole S through which a lower yoke 4 is arranged. A central piece 5a is provided with a U-shaped armature 5, so that side pieces 5b, 5c can be arranged in an air gap between both the ends of the lower yoke 4 and side plates 1b, 1c. The armature 5 is driven to the left and right according to the strength of the magnetic flux of the air gap at both the ends of side pieces 5b, 5c depending on the direction of the current flowing through a coil 6. At this time, because the magnetic flux in the magnetic path is weakened by the non-magnetic material 3, the attracting force of the armature can readily be regulated by obtaining the same effect as if the permanent magnet 2 were demagnetized.</p> |
