摘要 |
A releasable magnetic sweeping device 8 comprises a magnetically permeable base 16 located at one end of a hollow shaft 10. An elongate magnetic member 28, 34 is mounted adjacent to a base portion 22 such that it is movable between two positions relative to the said base portion. In the first position the magnetic member provides a more intense magnetic field at the base portion than that provided when the said member is at the second position. The said magnetic member 28, 34 is biased towards the first position by resilient means 30. A wire or cord 12 may be attached to the magnetic member 28, 34 and may be arranged to extend through the hollow shaft 10 to provide a mechanism to move the magnetic member between its two positions, thereby releasing metallic objects collected. The base 16 may be an enclosure formed from upper and lower box members made of non-ferrous material which may be joined together by a gasket or an adjustable screw arrangement to adjust the spacing between the members. The resilient means may be two symmetrically arranged V or U-shaped leaf springs. |