Patent ID: 6369479
Filing Date: 2002-04-09
Classification: H01F,H02K

Abstract:
A hybrid-type magnet comprising:an electromagnet including a U-shaped core made of a magnetic material, said core comprising a core body having outer ends and a pair of opposing arms extending upwardly from the outer ends of said core body, wherein each said opposing arm includes an upper end having an end surface; a bar-like engagement member comprising a permanent magnet having a direction of magnetization, said permanent magnet being disposed between magnetic members, wherein the magnetic members are closely joined to the respective end surfaces of said arms and the magnetic members define outer surfaces opposite the end surfaces of said arms, said permanent magnet being positioned between said arms of said core, wherein the end surfaces of said opposing arms extend in a direction substantially parallel with the direction of magnetization of the permanent magnet and a ratio between a width of said permanent magnet in the direction of magnetization thereof and a sum of widths of said magnetic members is within a range between 1:1 and 1:15; and an excitation coil wound on said core, wherein when current is fed to said excitation coil, it generates a magnetic flux in a direction opposite the direction of magnetization of said permanent magnet thereby generating an attractive force through the outer surfaces of the magnetic member to attract a movable member to the outer surfaces of the magnetic members.