JPH04263959A - Wire dot type printing head - Google Patents

Abstract

PURPOSE:To prevent the damage of printing paper and the buckling or breakage of a printing wire by preventing the action of excessive force on the printing wire by connecting the leading end member having the printing wire and a rear end member having an armature attracting surface by a leaf spring. CONSTITUTION:The armature 8 of a printing head is formed so as to be divided into a leading end member 9 having a printing wire 1 attached thereto and a rear end member 10 having the armature attracting surface 8a opposed to a yoke attracting surface 6b formed thereto and both of the leading end member 9 and the rear end member 10 are connected by a leaf spring 11. In order to prevent the vibration due to the bending of the leaf spring generated when the printing wire 1 strikes a printing surface, a projection 12 prescribing the leaf spring 11 so as to bend the same only in one direction is formed to the leaf spring 11.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wire dot type print head that prints by selectively driving a plurality of print wires.

0002

2. Description of the Related Art Conventionally, an armature 51 of this type of print head is formed of one piece as shown in FIG. A printed wire 52 is attached to one end of this armature 51, and a support rubber 53 is attached to the other end.
It is urged toward the ring yoke 54 by. A yoke core 56 having a coil 55 around it is disposed facing the armature 51. Also armature 51
The distal end side of is biased toward the rear cover 58 side by a return spring 57. Then, by applying a current to the coil 55, the armature 51 is attracted and rotated counterclockwise, and with this rotation, the print wire 52 is projected from the head frame 59 and hits the printed surface. It is configured to perform printing.

0003

[Problems to be Solved by the Invention] However, in the above-mentioned conventional print head, the armature is formed of one piece, so when a current is applied to the coil and the armature is attracted, the inertial force of the armature causes It may rotate more than necessary. Therefore, when printing, the tip of the print wire hits the printing surface with excessive force, causing damage to the printing paper.

[0004] Further, due to excessive rotation of the armature, excessive stress is applied to the printed wire, causing problems such as buckling and bending.

An object of the present invention is to provide a wire dot type which does not damage the printing paper even if the armature rotates more than necessary due to the inertia of the armature, and prevents excessive stress from being applied to the print wire. The purpose is to provide a print head.

[0006]

[Means for Solving the Problems] The wire dot print head of the present invention is configured to drive a print wire by selective rotational movement of a plurality of armatures, and perform printing by striking a print surface with the print wire. In the wire dot type print head, the armature is divided into a leading end member having a print wire and a trailing end member having an armature suction surface, and the leading end member and the trailing end member are connected by a leaf spring. It is.

Further, in the wire dot type print head, it is preferable that a protrusion is provided on the tip member of the armature for regulating the direction of deflection of the leaf spring, and it is more preferable that a buffer member is provided at the tip of this protrusion.

[0008]

Embodiments Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a half-sectional explanatory diagram of a wire dot type print head (hereinafter referred to as "print head") according to an embodiment of the present invention, and FIG. 2 is an enlarged explanatory diagram of the main parts.

A plurality of print wires 1 are arranged in the print head, and a driving section corresponding to each print wire 1 is configured. The printer is configured so that printing can be performed by selectively operating a predetermined drive unit to drive the print wire 1 in accordance with print information. Hereinafter, in this embodiment, a typical print wire 1 will be explained, but this explanation applies to all print wires 1 constituting a print head.

The print wire 1 is guided by guide holes 2a to 4a formed in guides 2, 3, and 4 so as to be able to move back and forth, and the print wire 1 and guides 2 to 4 are connected to the head frame. It is stored inside 5.

A driving section for driving the printed wire 1 is composed of a yoke 6 having a yoke suction surface 6b formed at the tip of a yoke core 6a, a coil 7 provided around the yoke core 6a, and an armature 8. ing.

The armature 8 is divided into a tip member 9 to which the printed wire 1 is attached, and a rear end member 10 forming an armature suction surface 8a facing the yoke suction surface 6b. 9 and a rear end member 10 are connected by a leaf spring 11. Front side of the tip member 9 relative to the leaf spring 11 (left side in the figure)
At a position facing the rear end member 10, in order to prevent the generation of vibrations due to the deflection of the leaf spring 11 when the printed wire 1 hits the printed surface, there is provided a plate so that the leaf spring 11 is bent only in one direction. A defining protrusion 12 is formed. Further, a cushioning material 13 such as rubber is provided at the tip of the protrusion 12 with a slight gap between it and the rear end member 10.

Therefore, even if a force is applied to the leaf spring 11 that causes the tip member 9 to rotate counterclockwise, the cushioning material 13 immediately comes into contact with the rear end member 10, so that the leaf spring 11 is rotated counterclockwise. No deflection occurs. That is, the leaf spring 11
is regulated by the protrusion 12 so that the deflection occurs only in the clockwise direction. Further, by providing a cushioning material 13 at the tip of the protrusion 12, vibration of the tip member 9 can be prevented.

The armature 8 is set at a predetermined position by a mounting plate 14 in which a positioning groove (not shown) is formed. Rear end member 10 forming armature 8
The lower end, that is, the end opposite to the side where the tip member 9 is attached, is pressed against the ring yoke 16 by the support rubber 15, and the upper end is always urged in the return direction by the return spring 17, so that the rear cover 18
It is held in that position by being pressed.

In the print head configured as described above, when the coil 7 is selectively energized according to print information, a magnetic force is generated by this energization, and the yoke core 6a attracts the armature attraction surface 8a. At this time, the armature 8 rotates counterclockwise around the lower end of the rear end member 10 pressed against the ring yoke 16 by the support rubber 15. As the armature 8 rotates,
Printing is performed by the print wire 1 attached to the tip member 9 protruding from the head frame 5 and hitting the printing surface.

When the print wire 1 hits the printed surface, a force corresponding to the impact force acts on the print wire 1. When an excessive force is applied to the printed wire 1, this force is transmitted to the leaf spring 11 via the printed wire 1 and the tip member 9, causing the leaf spring 11 to deflect clockwise. That is, by absorbing an excessive force acting on the print wire 1 with the leaf spring 11, it becomes possible to always apply an appropriate force to the print wire 1. Therefore, it is possible to prevent damage from occurring without applying excessive force to the printing paper.

Furthermore, even if the armature 8 rotates excessively due to inertia, the excessive stress that may be applied to the printed wire 1 is absorbed by the leaf spring 11, so that the printed wire 1 is always It becomes possible to apply an appropriate amount of force.

After printing is completed, when the coil 7 is de-energized, the magnetic force disappears and the armature 8 is rotated clockwise by the biasing force of the return spring 17 and returns to its original position by coming into contact with the rear bar 18. do. As the armature 8 rotates, the print wire 1 separates from the printing surface and returns to its original position. This series of operations completes the predetermined printing.

[0020]

As explained above, the print head of the present invention is constructed using an armature in which the front end member having the print wire and the rear end member having the armature suction surface are connected by a leaf spring. If an excessive force is applied, this force can be absorbed by the leaf spring.

Furthermore, by providing a protrusion on the tip member constituting the armature for regulating the direction of deflection of the leaf spring, if the armature rotates more than necessary, this rotation may act on the printed wire. Excessive stress can be absorbed by the leaf spring.

Therefore, excessive force is not applied to the printing surface, and damage to the printing paper can be prevented. Further, the tip member constituting the armature does not rotate more than necessary, and excessive stress does not act on the printed wire. Therefore, occurrence of buckling, bending, etc. of the printed wire can be prevented.

[0023] Further, by providing a cushioning material at the tip of the protrusion, there is an effect that vibration of the tip member constituting the armature can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a half-sectional explanatory diagram of a wire dot type print head according to an embodiment of the present invention.

FIG. 2 is an enlarged explanatory diagram of the main part of FIG. 1;

FIG. 3 is a half-sectional explanatory diagram of a conventional print head.

[Explanation of symbols]

1 Printed wire 2, 3, 4 Guide 5 Head frame 6 York 6a Yoke core 7 Coil 8 Armature 9 Tip member 10 Rear end member 11. Leaf spring 12 Protrusion 13 Cushioning material 14 Seokji Plate 15 Support rubber 16 Ring yoke 17 Return spring 18 Rear cover

Claims (3)

[Claims] 1. A wire dot type print head configured to drive a print wire by selective rotational movement of a plurality of armatures, and perform printing by striking a print surface with the print wires, wherein the armature is connected to the print wire. What is claimed is: 1. A wire dot type print head comprising: a front end member having an armature suction surface; and a rear end member having an armature suction surface. 2. The wire dot type print head according to claim 1, wherein a protrusion is provided on the tip member of the armature for regulating the direction of deflection of the leaf spring. 3. The wire dot type print head according to claim 2, wherein a buffer member is provided at the tip of the projection.