Demagnetising device for workpiece held magnetically on machine tool - has ring-shaped permanent magnet in plastics casing rotated for alternating field

摘要

The demagnetising device is mounted on a machine tool to demagnetise work pieces retained in a magnetic clamping plate. The demagnetisation is produced by an alternating field. The device consists of permanent magnets coupled to a drive to produce a rotating field. The permanent magnet (3) is ring-shaped and mounted in a plastic casing (1). The permanent magnet is rotated close to the surface of the workpiece to produce a relative angular motion between the two. The plastic mounting is fitted with a coupling pin (2) which links it to the drive. The permanent magnet can be disc or cone-shaped.