| 摘要 |
PURPOSE:To reduce the inertia of an armature, thereby increase the operating speed, contrive to enhance rigidity and reduce wear by a method wherein an armature rotatably fitted to a fixed iron core is formed in a specified shape. CONSTITUTION:The shape of the armature 15 is so set that a rear part A is wider than the fixed core 12, whereas the width of a front part B is smaller than the plate thickness, and preferably, the plate thickness is uniform at the entire part. In addition, an armature-type printing head 11 is composed of the core 12, a field coil 13, a yoke 14, the armature 15, a return spring 16 and a printing wire 17. The armature 15 is attracted to the core 12 side by supplying a current to the coil 13 to excite it, whereupon the wire 17 fitted to the tip end of the armature 15 is moved downward and its tip produces a printed dot. Incidentally, when the width of the tip end of the armature 15 is set to be equal to the outside diameter (d) of the wire 17, a positioning process is facilitated and workability is enhanced. |
