| 摘要 |
PROBLEM TO BE SOLVED: To improve an abrasion resistance of a spring disc by changing a shape of an armature spacer which functions as a fulcrum action to the spring disc formed inside a printing head. SOLUTION: An excitation coil 8, a printing wire 9 and an armature 4 constitute one set element. The printing wires 9 are arranged in two longitudinal arrays. 24 sets of the elements are arranged radially in the printing head. Moreover, an end face of a leading end part of an armature spacer 2 at the side in contact with a spring disc 1 is rounded by a predetermined curvature in a sectional direction. In other words, the armature spacer 2 is subjected to press working, and then an outer circumferential face in the sectional direction is rounded 5 from a corner by barrel polishing or the like. The operation of the spring disc 1 at an edge face of the armature spacer 2 is thus eliminated. The armature spacer 2 accordingly functions as a fulcrum part 3 of the spring disc 1.
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