Abstract: In a wire dot printer head of the present invention, an armature is formed by coupling a magnetic circuit formation member having a supported piece with one end inserted into a cavity formed on a surface of a yoke to an arm coupled to a wire. The supported piece of the armature is rotatably supported by a support point, thereby a side surface of the cavity and a side surface of the supported piece, and a bottom surface of the cavity and an end surface of the supported piece can be set in the proximity. Accordingly, magnetic resistance between the magnetic circuit formation member and the yoke can be reduced.

Abstract: The present invention is a wire dot printer head wherein a spacer is inserted between a yoke block and a head holder. The yoke block has yokes opposed to plural armatures, coils wound respectively round plural cores whose one ends are opposed to the armatures, and fulcrum portions which hold the armatures so that the armatures can rise and fall with respect to end faces of the cores. The spacer is adapted to move under the action of an external force, thereby changing the spacing between the yoke block and the head holder.

Abstract: An impact dot printer head having one or plural heat conductive members. The heat conductive member, with a part in the proximity of armature stopper of the impact dot printer head while another part guided to the outside a housing of the impact dot printer head, conducts heat inside the housing to the outside. Accordingly, as the heat conductive member first conducts heat of the armature stopper to a heat radiation unit outside the housing, degradation of hardness of the armature stopper due to heat can be prevented, and a return position of the armature can be determined in a stable manner.