| 摘要 |
PURPOSE:To improve surface coarseness by applying pressure force to each armature resisting the elastic force of an elastic member, holding it in the same condition as when it is not actuated and creep-grinding the surface of the armature fitted to a stopper member. CONSTITUTION:A work 3 is inserted from under a main jig unit 31 until the circumferential part of a front yoke 13 of said work comes into contact with a protrusion 32. Next, a wire pushup plate 34 is introduced along a groove 33 and fixed to the main jig unit 31 with stepped screws 36. As a result, a printing wire 22 is pushed up to hold an armature in the same condition as when it is not actuated. If a grinder is driven in this condition, a grinding chuck 37 rotates at low speed and a grinding wheel 40 at high speed both in the same direction, and the grinding wheel 40 moves downward, grinding the fitted surface 20a of the armature 20. Thus the coarsness of the fitted surface of the armature is improved by creep-grinding, resulting in a reduction in the abrasion value of a stopper member. This in turn contributes toward a longer life of the printing head. |
