PURPOSE: To resttain a strsas from acting on a welded point and prevent a spring from being broken by a method wherein the welding point between an armature and the spring is set near the central point of the impact force of the armature.
CONSTITUTION: The welding point a' between the armature 8, driven magnetically by a magnet, and the spring 6 supporting the armature is coincided with the central point C of the impact force of the printing wire 10 and both of them are fixed. According to this method, loads will not be concentrated on the welded point a' and the shock thereof is absorbed near the lowest end of the armature 8, thus, the spring 6 may keep a long life. If a distance from the fixed end e of the spring 6 to the welded point a', that means the length of the spring, is shorter than a distance 12 to the central point C of the impact, the life of the spring may be shortened remarkably.
NAKAMURA KEIJI
HORIUCHI TAKAO
KODAMA TADASHI
SHIBUYA ATSUSHI
NIPPON TELEGRAPH & TELEPHONE