| 摘要 |
A lifter with electro-permanent magnets comprises an external bearing structure (2, 3) closed at the bottom by a plate (10), provided with a heat shield (9), and pole pieces (5) secured under the respective poles (1) and protruding from said bottom plate (10), each of the electro-permanent magnets being composed of a reversible magnet (6) arranged on top of one of said poles (1), of a fixed polarization magnet (7) formed by a plurality of blocks placed along the lateral faces of the pole (1) and of a coil (8) arranged around the reversible magnet (6) to cause the reversal of the polarization of the latter by means of an electrical pulse, an airtight air gap (12) between 1 and 4 mm high being formed between each pole piece (5) and the respective pole (1) through the interposition of a plate (4) of thermal insulation material that resists high temperatures provided at each pole (1) with a rectangular window slightly smaller in size than the pole itself, the top sides of the pole pieces (5) and/or the bottom sides of the poles (1) being provided with peripheral recesses suitable to act as seats for the positioning of said plate (4). |
