JPH0985971A - Print head used for dot impact printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce frictional resistance by providing a wheel-shaped rubber ring formed of an expandable material in a concentric circular groove provided in the image area side bottoms of pillars of a stopper plate and a groove provided toward the center of rotation from the side face of an armature stopper plate. SOLUTION: A circular groove 1c which is concentric with the circumference of a stopper plate 1 is provided on the image area side bottoms of the pillars 1a, 1b of the stopper plate 1 and a groove 2b is cut in an armature 2 toward the center of rotation of the armature from the side of the stopper plate 1. A rubber ring 3 formed of a hooped expandable material is provided in the groove 1c. A printing action is performed when a coil is energized, the armature 2 is sucked to a yoke and print wires are driven. At such time, the armature 2 rotates while forced toward the enter of rotation by a tensile force. After energization ends, the armature 2 is pushed against the stopper plate 1 and stops.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a print head used in a dot impact printer.

[0002]

2. Description of the Related Art FIG. 5 is a sectional view showing the structure of a conventional print head. Referring to FIG. 5, this conventional print head has a magnetic circuit formed by a yoke 5, a coil 6 and an armature 10. Armature 10
The print wire 7 is brazed to its tip and positioned by the armature support 4. Further, a hold spring 11 that is a leaf spring formed corresponding to the plurality of armatures 10 that are installed concentrically is installed. The free end on the outer peripheral side of the hold spring 11 presses the armature 10 from a position facing the printing surface 12 so as to press the rotation center 10 a of the armature 10. At this time, at the contact portion between the armature 10 and the hold spring 11, the force applied to the armature 10 of the hold spring 11 due to the rotational movement of the armature 10 seems to be directed to the armature rotation center point 10a at any position. Is designed to.

Next, the printing operation of this conventional print head will be described. From the state where the armature 10 is pressed against the stopper plate 9 by the return spring 8, the armature 10 is magnetically attracted to the yoke 5 by the magnetic flux generated by the energized coil 6, and the print wire 7
Is driven. After energizing the coil 6, the armature 1
0 is pressed against the stopper plate 9 by the return force of the return spring 8 and stands still, completing one printing step.

[0004]

In the conventional print head of this type, since the armature 10 is pressed by the hold spring 11 of the leaf spring and the point 10a of the armature 10 is the center of rotation, the armature 10 is rotated during the rotational movement. Since there is friction at the contact portion between the holding spring 11 and the holding spring 11 and it is an operation resistance, a large amount of energy is required to be applied by energizing the coil 6. Further, along with that, it becomes worn, and it is difficult to extend the life. Further, since the restraining force of the hold spring 11 on the armature 10 is opposite to the magnetic attraction direction of the armature 10, there is a drawback that a large amount of energy is required to be applied by energizing the coil 6.

An object of the present invention is to provide a print head for use in a dot impact printer, which can reduce frictional resistance due to contact with other parts of the armature, can prolong life, and can reduce energy loss due to parts for pressing the armature rotation center.

[0006]

A print head used in a dot impact printer according to the present invention has a magnetic circuit composed of a yoke, a coil and an armature, and drives a print wire by the rotational movement of the armature. In a print head used for a dot impact printer that prints by striking the print surface through an ink ribbon, a first groove that is concentrically arranged on the outer periphery and extends in the print surface direction and is concentric on the bottom surface of the print surface. A disk-shaped stopper plate having a plurality of pillars each having a plurality of columns and installed at a position facing the print surface of the armature, and a second groove is cut from a surface facing the stopper plate toward its own center of rotation. When the armatures are arranged concentrically with the pillars alternately, and the stopper plate and the armature are assembled, the first armature Beauty and a rubber ring annular molded by extendable material that is disposed in the second groove.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a detailed view of a main part of this embodiment, and FIG. 3 (a) shows a relationship between a stopper plate and an armature. 3B is a sectional view taken along the line AA of FIG. 3A, FIG. 4A is a detailed top view of the armature, and FIG. 4B is a detailed side view of the armature.

Referring to FIGS. 1, 2, 3 and 4, the print head used in the dot impact printer of this embodiment has a magnetic circuit composed of a yoke 5, a coil 6 and an armature 2. The print head 7 prints by driving the print wire 7 by the rotational movement of the armature 2 and hitting the print surface 12 through the ink ribbon. The print head is arranged concentrically on the outer peripheral portion.
The first groove 1c which is concentric with the print surface 12 side bottom surface.
An armature 2 having a plurality of posts 1a and 1b having
Disk-shaped stopper plate 1 installed at a position facing the printing surface 12 of the column 1 and the second groove 2b is cut from the surface facing the stopper plate 1 toward the center of rotation of the column 1
An armature 2 arranged concentrically with a and 1b alternately, and a ring-shaped rubber formed of a stretchable material arranged in the first and second grooves 1c and 2b when the stopper plate 1 and the armature 2 are assembled. And a ring 3.

The print head of this embodiment has a yoke 5,
The armature 2 has a magnetic circuit formed of a coil 6 and an armature 2. A print wire 7 is brazed to the tip of the armature 2, and the armature 2 is positioned by an armature support 4. Further, columns 1a and 1b extending in the direction of the plurality of printing surfaces 12 are concentrically arranged on the outer peripheral portion of a disk-shaped stopper plate 1 installed at a position facing the printing surface 12 of the armature 2. The columns 1a and 1b are inserted between the armatures 2 arranged concentrically. Further, the pillars 1a and 1b of the stopper plate 1 have grooves 1c concentric with the outer circumference of the stopper plate 1 on the bottom surface of the pillar on the printing surface 12 side. The groove 1c has a shape in which the central side wall of the print head is inclined and the print surface side is widened. Armature 2 is stopper plate 1
A groove 2b is cut from the side surface toward the rotation center point 2a of the armature 2.

Stopper plate 1 and armature 2
Each of the grooves 1c and 2b has a rubber ring 3 formed of a ring-shaped expandable and contractible material arranged at the time of assembly. When assembling the print head, the yoke 5, the coil 6, the armature support 4, the armature 2, the rubber ring 3 and the stopper plate 1 are assembled in this order. On this occasion,
The rubber ring 3 is arranged in the groove 2b of the armature 2,
When the stopper plate 1 is assembled, the stopper plate 1
The groove 1c is guided by the inclined wall of the groove 1c and is assembled in the groove 2b of the armature 2 and the groove 1c of the stopper plate 1.

In the printing operation, the armature 2 is pressed against the stopper plate 1 by the return spring 8 and, after the coil 6 is energized, the magnetic flux generated in the coil 6 causes the armature 2 to be magnetically attracted to the yoke 5 to print. This is performed by driving the wire 7. At this time, the armature 2 makes a rotational movement while being pressed toward the center of rotation by the tension of the rubber ring 3. Then, after the coil 6 is energized, the armature 2 is pressed against the stopper plate 1 by the return spring 8 and stands still, completing one step.

[0013]

As described above, according to the present invention,
Since the center of rotation of the armature was changed from the hold spring to the rubber ring, the contact part between the armature and the hold spring was eliminated, and the friction between the armature and the hold spring was eliminated, which eliminated the operating resistance and the coil to the coil. The energy given by energization can be reduced. Further, similarly, since the contact portion between the armature and the hold spring is eliminated, it is possible to suppress the generation of wear debris, so that the service life can be extended. Further, since the restraining force that is applied to the armature rotation center of the hold spring and that opposes the magnetic attraction direction of the armature is eliminated, the energy provided by energizing the coil can be reduced.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is a detailed view of a main part of this one embodiment.

FIG. 3 is a diagram showing a relationship between a stopper plate and an armature. FIG. 3B is a sectional view taken along the line AA of FIG.

FIG. 4 (a) is a detailed top view of the armature,
FIG. 4B is a detailed side view of the armature.

FIG. 5 is a main detailed view of a conventional example.

[Explanation of symbols]

 1 Stopper plate 2 Armature 3 Rubber ring 4 Armature support 5 Yoke 6 Coil 7 Printing wire 8 Return spring 9 Stopper plate 10 Armature 11 Hold spring 12 Printing surface

Claims (1)

[Claims] 1. A dot impact that has a magnetic circuit composed of a yoke, a coil, and an armature, drives a printing wire by the rotational movement of the armature, and strikes the printing surface via an ink ribbon to perform printing. In a print head used in a printer, a plurality of pillars having concentric circular grooves arranged on the outer periphery and extending in the print surface direction and having a concentric first groove on the bottom surface of the print surface are provided at positions facing the print surface of the armature. A disk-shaped stopper plate installed on the base plate, the armature arranged in a concentric circle with the second groove cut from the surface facing the stopper plate toward the center of rotation of the armature, and the stopper A ring-shaped rubber ring formed of a stretchable material arranged in the first and second grooves when the plate and the armature are assembled A print head for use in a dot impact printer, characterized by comprising: