| 摘要 |
A switchable permanent magnetic chuck including a housing which has one open end and a face plate which covers the open end of the housing. The face plate comprises a plurality of elongated magnetic pole members and a plurality of elongated non-magnetic members, both members being arranged in an alternately juxtaposed manner. The permanent magnetic chuck further included a plurality of first permanent magnets each disposed between adjacent magnetic pole members of the face plate so as to give alternately inverted magnetized directions in the transverse direction of the magnetic pole members. In the housing is enclosed a movable member which is movable in the transverse direction of the magnetic pole members, and on the movable member are disposed a plurality of second permanent magnets in a corresponding relation to the magnetic pole members. The permanent magnets on the movable member, which have pole faces slidably opposed to the magnetic pole members, are adapted to cooperate with the first permanent magnets for bringing the face plate selectively into magnetically excited and non-excited states.
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