JPS641077Y2 - - 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 leaf 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 leaf 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
Since the magnetic flux is canceled and the armature 3 is released from the core 5, the tip of the printing wire 2 protrudes from the guide hole 8 of the wire guide 7 due to the restoring force of the leaf spring 1, as shown in FIG. After that, armature 3 is sucked into core 5 again and 1
The printing operation ends.

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 more compact and cost-effective, it was necessary to shorten the length of the printing wire and to Since the printing wires need to be packed together, the guide hole of the intermediate guide must have a complicated shape, and the work of setting the intermediate guide in a predetermined position and gluing it is difficult and takes many man-hours. It was hot.

The present invention is aimed at solving these drawbacks, and is characterized in that a soft cloth material such as felt is placed in the hollow part of the wire guide and brought into contact with the dot printing wire with an appropriate pressure.

Examples of the present invention will be explained below with reference to the drawings.
Fig. 3 is an enlarged cross-sectional view of the main part showing one embodiment of the present invention, and Fig. 4 is a cross-sectional view taken along line A-A in Fig. 3. In the figure, 1 is a leaf spring, 2 is a printing wire, and The 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 wires 2 are each inserted into a guide hole 8 provided at the tip of the wire guide 7 through a hollow portion of the wire guide 7.

Therefore, in this embodiment, a soft cloth material 10 such as felt is arranged in the hollow part of the wire guide 7 so as to sandwich each printing wire 2, and a pressing leaf spring 11 is provided on the outside of the soft cloth material 10. The cloth material 10 is brought into contact with the printing wire 2 with an appropriate pressure, and the above pressure is set to a level that does not interfere with the printing operation of the printing wire 2. Note that other components such as permanent magnets and electromagnets are the same as those in FIG. 1, so explanations will be omitted.

According to the dot printing head of this embodiment configured in this way, each printing wire 2 is connected to the cloth material 1 during printing operation.
Since it moves back and forth while rubbing 0, secondary vibrations generated in each printing wire 2 after printing can be limited and absorbed by the cloth material 10.

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

Furthermore, 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 operation, the operating speed of the armature 3 will slow down, causing variations in printing density, or However, in this embodiment, the ink can be absorbed by the cloth material 10, so that 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. A tongue piece 13 is formed with a curved notch at the top by punching or the like,
The base of the tongue piece 13 is bent so as to protrude from one side, so that the tongue piece 13 can press the cloth material 10.

FIG. 6 is a perspective view showing a method of filling the cloth material 10 and the pressing plate spring 11 into the hollow part of the wire guide 7. An opening 14 is provided on one side of the hollow part. After inserting the two cloth materials 10 from
0 and the leaf spring 11 can be arranged within the hollow part.

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 plate 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 cloth material 10, the cloth material 10 also does not move downward.

Since the top of each tongue piece 13 is cut out in a curved shape, it is possible to apply a uniform pressing force to all the printing wires 2 through the cloth material 10, as shown in FIG. 2 and cloth material 10
The frictional force between the

According to the embodiment described above, the pressing plate spring brings the cloth material into contact with the printing wire with appropriate pressure within the hollow part of the wire guide, thereby suppressing the high-order vibration of the printing wire and performing the printing operation. This has the effect of significantly reducing damage to the printing wire and greatly extending the life of the wire guide.

In addition, loading the cloth material and pressing leaf spring into the wire guide can be easily done through the opening provided in the wire guide, reducing the number of installation steps compared to conventional intermediate guides that are difficult to install. This has the advantage 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 is stabilized by the action of the cloth material, it is possible to reduce unevenness in printing density, and it is also possible to print at a higher speed. Because it uses cloth material, it is inexpensive, and the cloth material can be impregnated with oil to make the printing wire operate smoothly, and the cloth material can prevent ink from penetrating into the ink ribbon. There is also.

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
The cloth material 10 is inserted into the hollow part in a compressed state, and the cloth material 10 is brought into contact with the printing wire 2 with an appropriate pressure by using the restoring force of the cloth material 10 to return to its original thickness. It was designed to do so.

Therefore, in this embodiment, the same effect as 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 has a structure in which a soft cloth material such as felt is placed inside the hollow part of the wire guide, and this cloth material is brought into contact with the printing wire with appropriate pressure. High-order vibrations of the printing wire can be suppressed without using an intermediate guide with
Since the fabric material can be easily loaded, the assembly man-hour and assembly time can be reduced, and it can be used in a dot printing head that prints by driving a printing wire.

[Brief explanation of drawings]

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 another embodiment of the present invention, and FIG. 10 is a sectional view taken along the line B--B in FIG. 9. 1... Leaf spring, 2... Printing wire, 3... Armature, 4... Permanent magnet, 5... Core, 6...
Coil, 7... wire guide, 8... guide hole,
9... Yoke, 10... Cloth material, 11... Pressing leaf spring, 12... Protrusion, 13... Tongue piece, 14... Opening, 15, 16... Edge.

Claims (1)

[Scope of utility model registration request] a plurality of printing wires each attached to the armature; a leaf spring supporting each armature at its free end; and an electromagnet facing each leaf spring;
In a dot printing head that is driven by a mechanism consisting of a permanent magnet and prints by making the tip of each printing wire protrude from a guide hole of a wire guide, a cloth material such as felt is arranged in the hollow part of the wire guide, A dot printing head characterized in that this cloth material is brought into contact with a printing wire under appropriate pressure.