JPH053324Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an impact type dot printing head used in printers and the like.

A conventional dot printing head of this kind will be explained with reference to Fig. 1. In the figure, 1 is a plate spring whose base is fixed, and an armature 3 having a printing wire 2 at the tip is attached to the free end of this plate spring 1. As the armature 3 is attracted to the core 5 of the electromagnet by the magnetic flux of the permanent magnet 4, the leaf spring 1 is bent toward the core 5.

Therefore, if this state is set as a standby state and the electromagnetic coil 6 is energized during printing, the permanent magnet 4
The magnetic flux of the armature 3 is canceled out and the armature 3 is released from the core 5, so the leaf spring 1
Due to the restoring force, the tip of the printing wire 2 protrudes from the guide hole 8 of the wire guide 7 and printing is performed.
Thereafter, the armature 3 is again attracted to the core 5, and one printing operation is completed.

In addition, in FIG. 1, 9 is a yoke.

By the way, in the above-mentioned dot printing head, the printing wire bends in a complicated manner and undergoes high-order vibration during the printing operation, which causes damage to the printing wire itself and the wire guide, as well as impeding high-speed printing. It was hot.

Conventionally, an intermediate guide was installed inside the head to suppress the above-mentioned high-order vibrations, but in order to make the dot printing head smaller and cheaper, the length of the printing wire was shortened and multiple printing Since it is necessary to arrange the wires closely together, the guide hole of the intermediate guide must be formed into a plurality of shapes, and the work of setting the intermediate guide in a predetermined position and gluing it is difficult and takes a lot of man-hours. It was hot.

The present invention aims to solve these drawbacks.

To achieve this objective, the present invention consists of a plurality of leaf springs arranged in a circular shape with their free ends facing inside the head, a base attached to an armature supported by the free end of each leaf spring, and a tip end connected to a wire. Printing wires are arranged in a straight line through guide holes at the tip of the guide, and the portion between the tip and the base is passed through the hollow part of the wire guide, an electromagnet provided to face each leaf spring, and the armature. In a dot printing head, which is equipped with a permanent magnet that attracts the core of an electromagnet, and performs printing by causing the tip of the printing wire to protrude from the guide hole of the wire guide by the restoring force of a deflected leaf spring, the guide of the tip of the wire guide is used. A cloth material such as felt placed so as to sandwich the row of printing wires from the outside from the vicinity of the hole to the middle of the hollow part of the wire guide, and a press that presses this cloth material with appropriate pressure so that it contacts each printing wire. It is characterized by having a means.

Examples of the present invention will be explained below with reference to the drawings.
FIG. 3 is an enlarged sectional view of the main part showing an embodiment of the present invention, and FIG. 4 is a sectional view taken along line A-A in FIG. 3. In the figure, 1 is a leaf spring, 2 is a printing wire, This printing wire 2 is attached to the tip of an armature 3 provided at the free end of the leaf spring 1.

Here, a plurality of leaf springs 1 are arranged in a circular shape with their free ends facing inward and their bases facing outside. The printing wire 2 is
Each wire guide 7 is inserted into a guide hole 8 provided at the tip of the wire guide 7 through a hollow portion thereof.

Therefore, in this embodiment, as shown in FIG. 3, a soft cloth material 10 such as felt is placed in the hollow part of the wire guide 7 for each printing wire 2 from the vicinity of the guide hole 8 to the middle of the hollow part. are arranged so as to sandwich them from the outside, and furthermore, a pressing plate spring 11 as a pressing means is provided on the outside thereof, and the printing wire 2
The above pressure is applied to the printing wire 2.
to the extent that it does not interfere with the printing operation.

Note that other components such as the permanent magnet 4 and electromagnets are
Since it is similar to the figure, the explanation will be omitted.

According to the dot printing head of this embodiment configured in this way, each printing wire 2 moves back and forth while rubbing the cloth material 10 during the printing operation, so that the secondary vibration generated in each printing wire 2 after printing is absorbed by the cloth material 10. 10 and can be absorbed.

In particular, since the cloth material 10 sandwiches the printing wire 2 from the vicinity of the guide hole 8 of the wire guide 7 to the middle of the hollow part as described above, the area where the maximum amplitude of the secondary vibration of the printing wire 2 occurs is cloth material 10
This has a great effect on suppressing higher-order vibrations.

Note that if the cloth material 10 is impregnated with oil, the friction with the printing wire 2 can be reduced.

Additionally, if ink from an ink ribbon (not shown) travels along the printing wire 2 and enters between the armature 3 and the core 9 during printing, the operating speed of the armature 3 will slow down, causing variations in printing density, or However, in this embodiment, since the ink can be absorbed by the cloth material 10, ink can be prevented from entering between the armature 3 and the yoke 9.

5a and 5b are a front view and a side view showing an example of the shape of the pressing leaf spring 11 in FIGS. 3 and 4,
This leaf spring 11 has a protrusion 12 formed at the top of one end, and a tongue piece 13 whose top part is cut out in a curved shape by punching or the like is formed at the center part, and this tongue piece 13 protrudes from one side. The base is bent so that the cloth material 10 can be pressed.

FIG. 6 is a perspective view showing a method of loading the cloth material 10 and the pressing leaf spring 11 into the hollow part of the wire guide 7. After inserting the two cloth materials 10 , a pressing leaf spring 11 can be placed in the hollow portion between the cloth materials 10 and the inner wall of the wire guide 7 .

FIG. 7 shows the cloth material 10 and the pressing leaf spring 1 as described above.
FIG. 8 is an enlarged side sectional view of the wire guide 7 loaded with the printing wire 2, the cloth material 10, and the pressing plate spring 1.
This is a diagram showing the relationship between the pressing leaf spring 1 and the loaded pressing leaf spring 1.
1 includes a protrusion 12 and a protrusion 12 as shown in FIG.
Since the lower portions of the sides abut against the edges 15 and 16 of the opening 14 and their movement is restricted, they do not move downward, and the tongue pieces 13 of the two pressing plate springs 11 have a reverse taper. Since the cloth material 10 is pressed by the user and one side of the cloth material 10 is brought into contact with the edge 16, the cloth material 10 also does not move downward.

Since the top of each tongue piece 13 is cut out in a curved shape so as to correspond to the row of printing wires, all the printing wires 2 can be uniformly pressed through the cloth material 10 as shown in FIG. Pressure can be applied, so that the frictional force between each printing wire 2 and the cloth material 10 is constant.

According to the embodiment described above, the wire guide 7
Since the cloth material 10 is brought into contact with each printing wire 2 with appropriate pressure by the tongue piece 13 of the pressing plate spring 11 in the hollow part, high-order vibrations of the printing wire 2 are suppressed and the printing operation is stabilized. As a result, damage to the printing wire 2 can be significantly reduced, and the life of the wire guide 7 can be greatly extended.

In addition, loading and replacing the cloth material 10 and the pressing plate spring 11 into the wire guide 7 can be easily performed through the opening 14 provided in the wire guide 7, compared to the conventional intermediate guide which is difficult to attach. This has the advantage that the number of installation steps can be reduced, and that it can also be applied to small dot printing heads that cannot use intermediate guides.

In addition, since the printing force of the printing wire 2 is stabilized by the action of the cloth material 10, it is possible to reduce uneven density of printing, and also to achieve the effect of being able to print at a higher speed. Since the cloth material 10 is used, it is inexpensive, and the cloth material 10 is impregnated with oil to make the operation of the printing wire 2 smooth, and the cloth material prevents the ink of the ink ribbon from penetrating into the inside. In addition, since the opening 14 is closed by loading the cloth material 10, it is possible to prevent noise from leaking from inside the head through the opening 14 and to prevent dust from entering.

Next, other embodiments will be described. FIG. 9 is an enlarged sectional view of the main part showing another embodiment of the present invention, and FIG. 10 is a sectional view taken along the line B-B in FIG. one part
In a compressed state, the cloth material 10 of about
4 into the hollow part, and the cloth material 10 is brought into contact with the printing wire 2 with appropriate pressure by utilizing the restoring force of the cloth material 10 to return to its original thickness.

In this case, as shown in FIG. 10, the inner walls 7a and 7b of the hollow part of the wire guide 7 are formed into a curved shape so as to correspond to the arrangement shape of the printing wires 2 in the hollow part. inner wall 7a,
The tongue piece 13 of the leaf spring 11 is used as a pressing means 7b.
Similarly, all the printing wires 2 are connected through the cloth material 10.
It is designed so that a uniform pressing force can be applied to the

Also in this embodiment, since one side of the cloth material 10 is brought into contact with the edge 16 (see FIG. 7) of the opening 14, the cloth material 10 will not move downward either.

Therefore, in this embodiment as well, the same effects as in the previous embodiment can be obtained, and at the same time, since the pressing leaf spring 11 is not required, the structure is simpler and the cost can be reduced by the amount of the pressing leaf spring 11. It has the advantage of being able to

As explained above, the present invention uses a cloth material such as felt, which is arranged to sandwich the printing wire row from the outside from the vicinity of the guide hole at the tip of the wire guide to the middle of the hollow part of the wire guide, and Since the structure is equipped with a pressing means that presses each printing wire so that it comes into contact with a certain amount of pressure, it is possible to press down with the cloth material the part where the maximum amplitude of high-order vibration of the printing wire occurs, and this makes it possible to print with complex shapes. Since high-order vibration of the printing wire can be suppressed without using an intermediate guide having a guide hole, it is possible to achieve the effect of simplifying the structure and reducing the size.

In addition, by providing an opening on one side of the hollow part of the wire guide, fabric materials can be easily loaded and replaced from the opening of the wire guide, reducing assembly man-hours and assembly time. In addition, since the opening is closed by loading the cloth material, noise can be reduced and dirt and the like will not enter through the opening, and one side of the cloth material is in contact with the edge of the opening. Since the dots are arranged in the same direction, there is an effect that no misalignment occurs, and it can be used in a dot print head that prints by driving a print wire.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of the main parts of a conventional dot printing head, Fig. 2 is a sectional view showing its operation, Fig. 3 is an enlarged sectional view of the main parts of an embodiment of the present invention, and Fig. 4 is a sectional view of the main parts of a conventional dot printing head. A sectional view taken along the line A-A in FIG. 3, FIGS.
Figure 6 is an overall perspective view showing how to load the cloth material and pressing plate spring, Figure 7 is an enlarged sectional view of the wire guide showing the state after loading, and Figure 8 is the printing wire, cloth material, and pressing leaf spring. Fig. 9 is an enlarged sectional view of the main part showing the relationship with the leaf spring, Fig. 9 is an enlarged sectional view of the main part showing another embodiment of the present invention, and Fig. 10 is a sectional view taken along line B-B in Fig. 9. . 1... Leaf spring, 2... Printing wire, 3... Armature, 4... Permanent magnet, 5... Core, 6...
Coil, 7...Wire guide, 7a, 7b...Inner wall, 8...Guide hole, 9...Yoke, 10...Cloth material, 11...Press plate spring, 12...Protrusion, 13
... tongue piece, 14 ... opening, 15, 16 ... edge.

Claims (1)

[Claims for Utility Model Registration] (1) A plurality of leaf springs arranged in a circular shape with their free ends facing inside the head, and a base attached to an armature supported by the free end of each leaf spring, and a wire with a tip end. Printing wires are arranged in a straight line through guide holes at the tip of the guide, and the portion between the tip and the base is passed through the hollow part of the wire guide, an electromagnet provided to face each leaf spring, and the armature. In a dot printing head that is equipped with a permanent magnet that attracts the core of an electromagnet and prints by causing the tip of the printing wire to protrude from the guide hole of the wire guide by the restoring force of a deflected and deformed leaf spring, the guide of the tip of the wire guide is provided. A cloth material such as felt is arranged to sandwich the row of printing wires from the outside from the vicinity of the hole to the middle of the hollow part of the wire guide, and a pressing force is used to press this cloth material with appropriate pressure so that it comes into contact with each printing wire. A dot printing head characterized in that it is equipped with a dot printing head. (2) Registration of a utility model characterized in that an opening is provided on one side of the wire guide, a cloth material is inserted into the hollow part through this opening, and one side of the wire guide is brought into contact with the edge of the opening. A dot printing head according to claim (1). (3) A pair of leaf springs each having a tongue piece with a curved cutout at the top protruding diagonally from one side so that the curved part corresponds to the row of printing wires in the hollow part of the wire guide. 2. The dot printing head according to claim 1, which is a utility model, and is characterized in that the pressing means is arranged between the inner wall of the hollow part of the guide and the cloth material. (4) Utility model registration claim (1) characterized in that the inner wall of the hollow part of the wire guide is formed into a curved shape so as to correspond to the row of printing wires in the hollow part to serve as a pressing means. Dot printing head as described.