Magnetically operated lifting device - has permanent magnets whose field is modified by movable pole piece and seal extending across gap between fixed pole pieces

摘要

The apparatus has spaced permanent magnets with adjacent and indentical inner poles in the space separating the magnets. Fixed pole pieces for connecting to a load are associated with outer poles. A movable pole piece in the space of separation from a load is able to modify the magnetic lift field available between the pole pieces and the load. A sealing element of non-magnetic substance prevents ingress of scrap. The sealing element extends across the space separating the fixed pole pieces. The permanent magnets are of high field strength.