| 摘要 |
PURPOSE:To conduct printing at high speed by a small-sized wire dot head by mounting a second coil attracting an armature in the direction of release besides a first coil demagnetizing the magnetic force of a permanent magnet attracting and holding the armature. CONSTITUTION:When a demagnetizing coil 3 is excited and the magnetic field of a permanent magnet 4 is cancelled, a leaf spring 2 under a deviated state is released. When an exciting coil 10 is excited at that time, magnetic flux passes through a core 9, a bypass yoke 8 and an armature 1, and the speed of collision of a printing wire 7 fixed at the nose of the armature 1 can be accelerated by the force of magnetic attraction of the coil 10. When printing is completed and the excitation of the demagnetizing coil 3 and the exciting coil 10 is ended, the leaf spring 2 under the deviated state is released while the magnetic flux of the permanent magnet 4 passes through a yoke 5, the bypass yoke 8, the armature 1 and a core 6, and the armature 1 is returned by the force of magnetic attraction of the permanent magnet 4. Accordingly, printing at high speed can be performed by a small-sized wire dot head. |
