| 摘要 |
PURPOSE:To enable to obtain a large armature-attracting force, by fixing an auxiliary yoke to a core frame of a driving electromagnet for a printing wire in parallel with an armature, in a dot-matrix printer. CONSTITUTION:The printing wire 1 collides against a platen 17 in accordance with a movement of the armature 19, thereby printing. The axuiliary yoke 18 is fixed to an end face of the core frame 4, and the armature 19 is supported thereabove by a cover spring 9 and a rear cover 11 through a rubber support 5 embedded in a stopping plate 8. The auxiliary yoke 18 and the armature 19 are placed to be substantially parallel with each other, and come closer to each other as a support end part of the armature 19 approaches, so that the magnetic resistance at the supported end is reduced, and the cross-sectional area of the base of the armature corresponding to a desired magnetic flux can be reduced. Accordingly, a large armature-attracting force can be obtained even with such an armature construction wherein the moment of inertia is small. |
