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: In the wire dot printer head of the present invention, there is provided an armature stopper against which an armature having pivoted from a printing position to a stand-by position comes into abutment, the armature stopper being formed by bonding an elastic plate and a hard plate with each other into an integral combination and thereafter punching the integral combination from the hard plate side. By this punching work the armature stopper is warped so that the hard plate side is convex in shape. With this warp, when the armature having pivoted to the stand-by position comes into abutment against the armature stopper, the armature stopper deflects in a direction to eliminate the warp. With this deflecting motion, an impact force induced upon mutual abutment of the armature and the armature stopper is diminished and deformation or chipping of the hard plate are suppressed, further, the durability of the armature stopper is improved and the printing accuracy is kept high over a long period.

Abstract: In the wire dot printer head of the present invention, an armature adapted to move pivotally between a printing position and a stand-by position is provided with a pivot shaft serving as a fulcrum, and the pivot shaft is pinched and supported by a pair of support members from both sides in the pivoting direction of the pivot shaft. In at least one support member is formed a concave support groove into which an outer periphery surface of the pivot shaft is inserted in a state of surface contact with the groove. When the armature moves pivotally in a printing operation, the surface of contact increases because the pivot shaft and the pivot groove are in surface contact with each other, thus preventing the occurrence of a local concentration of a strong force on the contact portion between the pivot shaft and the support groove.

Abstract: In the wire dot printer head of the present invention, there is provided an armature stopper against which an armature having pivoted from a printing position to a stand-by position comes into abutment, the armature stopper being formed by bonding an elastic plate and a hard plate with each other into an integral combination and thereafter punching the integral combination from the hard plate side. By this punching work the armature stopper is warped so that the hard plate side is convex in shape. With this warp, when the armature having pivoted to the stand-by position comes into abutment against the armature stopper, the armature stopper deflects in a direction to eliminate the warp. With this deflecting motion, an impact force induced upon mutual abutment of the armature and the armature stopper is diminished and deformation or chipping of the hard plate are suppressed, further, the durability of the armature stopper is improved and the printing accuracy is kept high over a long period.

Abstract: In the wire dot printer head of the present invention, an armature adapted to move pivotally between a printing position and a stand-by position is provided with a pivot shaft serving as a fulcrum, and the pivot shaft is pinched and supported by a pair of support members from both sides in the pivoting direction of the pivot shaft. In at least one support member is formed a concave support groove into which an outer periphery surface of the pivot shaft is inserted in a state of surface contact with the groove. When the armature moves pivotally in a printing operation, the surface of contact increases because the pivot shaft and the pivot groove are in surface contact with each other, thus preventing the occurrence of a local concentration of a strong force on the contact portion between the pivot shaft and the support groove.

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.