| 摘要 |
<p>PURPOSE: To provide the printing wire of a dot printing head having longer life and easy to assemble. CONSTITUTION: A printing wire 24 is produced by subjecting a wire material being a printing wire material to annealing treatment to correct the same and cutting the treated wire material into a predetermined size and subsequently adapting a forging process to the cut wire material to form a head part 100 and applying electroless nickel plating 102 to at least the head part 100. The head part 100 is brought to two-step constitution of large and small diameter portions and a restoring spring 26 is fitted to the small diameter portion. The strength of the forged portion is extremely enhanced by the suppression of the crack caused by annealing treatment, nickel plating filling the crack and the two-step constitution and the hardness difference with an armature 18 is also eliminated and, as a result, life is extremely extended. Since rust-proofing is executed by plating, a rustproof agent is unnecessary and, since the printing wire is attached to a wire guide 22 in such a state that the spring 26 is incorporated, handling or assembling becomes easy.</p> |
