Abstract: In order to realize a stabilized pivotal movement of an armature to thereby obtain pivotal force required for high-speed printing, a pivot shaft is held such that an armature having an attracted face that is in contact with a core, that has a coil wound therearound and has a pole face, and the pivot shaft is opposed to the core, whereby the armature becomes pivotable. An attracting direction of attraction force F acted on the attracted face by the core and the moving direction in which the attracted face moves due to the attraction force F are made substantially equal to each other.

Abstract: In order to realize a stable rocking operation of the armature for performing high-speed printing, between the armature spacer for accommodating and holding the support shaft of the armature which supports the printing wires, and the yoke for holding the support shafts of the plurality of armatures together with this armature spacer, there is provided the abrasion preventing member formed of material having higher magnetic permeability than that of the yoke, and hardened by surface hardening processing.

Abstract: In order to realize a stable rocking operation of the armature for performing high-speed printing, between the armature spacer for accommodating and holding the support shaft of the armature which supports the printing wires, and the yoke for holding the support shafts of the plurality of armatures together with this armature spacer, there is provided the abrasion preventing member formed of material having higher magnetic permeability than that of the yoke, and hardened by surface hardening processing.

Abstract: In order to enhance magnetic characteristic to realize a stabilized pivotal movement of an armature and to obtain magnetic characteristic required for high-speed printing, an armature according to the present invention has a magnetic circuit forming member formed by laminating plural plates to be provided on an arm, that supports a printing wire, for forming a magnetic circuit.

Abstract: In order to restrain a flux loss for obtaining magnetic characteristic required for high-speed printing, a wire dot printer head has armature 4 having a pivot shaft serving as a center of a pivot and pivotably provided so as to oppose to plural cores formed on a yoke and an armature spacer provided on the yoke for forming a side magnetic path with respect to the armature, wherein, supposing that each of the saturated magnetic fluxes of the yoke, the armatures and the armature spacer is defined as A, B and C in this order, these components are formed to establish a relationship of A?B?C.

Abstract: In order to restrain a flux loss for obtaining magnetic characteristic required for high-speed printing, a wire dot printer head has armature 4 having a pivot shaft serving as a center of a pivot and pivotably provided so as to oppose to plural cores formed on a yoke and an armature spacer provided on the yoke for forming a side magnetic path with respect to the armature, wherein, supposing that each of the saturated magnetic fluxes of the yoke, the armatures and the armature spacer is defined as A, B and C in this order, these components are formed to establish a relationship of A?B?C.

Abstract: In order to realize a weight saving and prevent a concentration of stress to thereby obtain durability endurable for high-speed printing, an armature of the present invention has an arm that is formed into a long-sized plate-like shape and holds a printing wire at its end section and a magnetic circuit forming member that is positioned at the other end at the side of the printing wire and has a projecting section projecting from the arm toward the direction in which the printing wire extends, wherein a first inclined surface that gradually inclines toward the projecting section in the direction in which the printing wire extends and a concave-shaped first curved surface that communicates with the first inclined surface and bends inward with a predetermined curvature to reach the projecting section are formed at a first end face of the arm at the side of the projecting section.

Abstract: In order to restrain the deterioration in assembling precision and prevent the formation of rust and deterioration in magnetic characteristics in a yoke to thereby obtain magnetic characteristics required for high-speed printing, a yoke having a core around which a coil is wound and a reference surface for assembly is made of permendur material, wherein the reference surface is polished so as to be flattened to complete the yoke. Accordingly, the reference surface of the yoke is precisely formed to be flat, thereby being capable of restraining the deterioration in assembling precision. The yoke is made of permendur material, so that the formation of rust on the yoke can be prevented. A plating layer that is a cause of magnetic resistance is not formed on the yoke, whereby the deterioration in magnetic characteristics at the yoke is prevented to thereby be capable of obtaining magnetic characteristics required for high-speed printing.

Abstract: In order to realize a stabilized pivotal movement of an armature to thereby obtain pivotal force required for high-speed printing, a pivot shaft is held such that an armature having an attracted face that is in contact with a core, that has a coil wound therearound and has a pole face, and the pivot shaft is opposed to the core, whereby the armature becomes pivotable. An attracting direction of attraction force F acted on the attracted face by the core and the moving direction in which the attracted face moves due to the attraction force F are made substantially equal to each other.

Abstract: In order to obtain joining force endurable for high-speed printing and realize an enhancement in magnetic characteristic, a plate-like arm for supporting a printing wire is laminated with a magnetic circuit forming member that is composed by laminating plural plates for forming a magnetic circuit, wherein a weld zone is formed on the laminated surface of the arm and plates with laser beam irradiation for fixing the arm and the magnetic circuit forming member with the weld zone.

Abstract: A wire dot printer head of the present invention has an armature that has an arm supporting a printing wire and pivotably provided at the position opposite to the core, and a coil spring that one end comes in contact with the arm for urging the armature in the direction away from the core, wherein the one end of the coil spring supported by the supporting member is brought into contact with the armature to apply return force to the armature. In order to prevent the breakdown of the armature due to a contact of the coil spring and to realize a stabilized urging operation of the coil spring, a winding end of the coil spring at the one end is located at the position inside of the coil spring and nearer to the supporting member from the contact position where the coil spring comes in contact with the armature.

Abstract: In order to realize a stable rocking operation of the armature for performing high-speed printing, between the armature spacer for accommodating and holding the support shaft of the armature which supports the printing wires, and the yoke for holding the support shafts of the plurality of armatures together with this armature spacer, there is provided the abrasion preventing member formed of material having higher magnetic permeability than that of the yoke, and hardened by surface hardening processing.

Abstract: In order to enhance magnetic characteristic to realize a stabilized pivotal movement of an armature and to obtain magnetic characteristic required for high-speed printing, an armature according to the present invention has a magnetic circuit forming member formed by laminating plural plates to be provided on an arm, that supports a printing wire, for forming a magnetic circuit.

Abstract: A wire dot printer head of the present invention is provided with an abrasion preventive member in a yoke. The abrasion preventive member encloses the outer periphery of the armature support shafts. The yoke, together with an armature spacer having a plurality of cutouts for holding the armature support shafts, holds the armature support shafts. The armature support shafts do not directly contact the yoke because of the use of the abrasion preventive member. It is therefore possible to restrain abrasion of the yoke surface and accordingly to prevent deterioration in printing quality.

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, 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, 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 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.