JPS6126052Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a print arm drive device used in a printer.

As shown in FIGS. 1 to 3, the conventional device includes a magnetic circuit structure 2 equipped with a permanent magnet 1, a print arm 5 having an armature 4 attracted to an iron core 3 of this structure 2, and a print arm 5 that is magnetically attached to the arm 5. A leaf spring 6 is cantilever-supported by the circuit structure 2 and urges the arm 5 toward the printing position, and a degaussing coil 7 is attached to the magnetic circuit structure 2 and generates magnetic flux in the opposite direction to the magnetic flux of the permanent magnet 1. It is formed. By the way, in order to reduce the size of the permanent magnet, it is necessary to make the passage of magnetic flux between the armature 4 and the facing portion of the magnetic circuit structure 2 as good as possible. Generally, the armature 4 is fitted into a U-shaped groove 2a provided in the magnetic circuit structure 2 with a small distance g between the inner surface thereof and the U-shaped groove 2a. Therefore, the armature 4 vibrates in the U-shaped groove 2a by being attracted to the iron core 3 and driving the arm by the urging force of the leaf spring 6.

However, since the leaf spring 6 in the prior art device is simply a horizontal plate configuration, it has very little effect on the tendency of the print arm 5 to rotate about its axis. Therefore, if the above-mentioned interval g is made small, the armature 4 may come into contact with the inner surface of the groove 2a and may not operate normally. Also,
In view of this, it is necessary to make the conventional leaf spring quite thick, which increases the inertia of the vibrating part (arm and leaf spring), which has the drawback of hindering high-speed printing.

This invention was devised based on the above circumstances, and its purpose is to make it possible to downsize the permanent magnet, to vibrate the print arm normally and reliably, and to achieve high-speed printing. A print arm driving device for a printer is sometimes provided, which is capable of achieving the following.

An embodiment of the present invention will be described below with reference to FIGS. 4 to 7.

11 in FIGS. 4 to 6 is a magnetic circuit structure.
This structure 11 includes a permanent magnet 12 and a permanent magnet 12.
It is formed from magnetic path members 13 and 14 provided on both sides of the magnetic body 13 and 14, and an iron core 15 and a magnetic path member 16 provided separately at the tips of these magnetic bodies 13 and 14, respectively. The distal end of the magnetic passage member 16 has a U-shaped groove 1
6a, and faces the tip of the iron core 15 with a distance therebetween. For example, an iron core 15 is wound around this magnetic circuit structure 11, and a degaussing coil 17 is attached thereto. This coil 17 is designed to generate a magnetic flux in the opposite direction to the magnetic flux of the permanent magnet 12 by its excitation.

Further, numeral 18 in the figure is a print arm. This arm 18 is formed by brazing an armature 20 to an arm body 19 formed by bending a single metal strip into a V-shape. A print wire 21 is fixed to the tip of the print arm 18. Furthermore, 22 in the figure is the print arm 1
This is a leaf spring for biasing the print arm 8 toward the printing position and for supporting the print arm 18 in a cantilever manner on the magnetic circuit structure 11. As shown in detail in FIG. 7, this leaf spring 22 includes a horizontal support portion 23 that is fixed flush to the horizontal portion of the armature 20 by brazing or the like, and a horizontal support portion 23 that is cut vertically from the support portion 23. The armature 20 has a vertical support portion 24 which is fixed to the vertical surface portion of the armature 20 by brazing or the like, and the side surface thereof is formed to have a substantially T-shape. One end of the horizontal support portion 23 of the leaf spring 22 is connected to the protrusion 1 of the magnetic circuit member 14.
4a by suitable means. This fixation allows the print arm 18 to be attached to its armature 20.
is opposed to the iron core 15 and is fitted into the U-shaped groove 16a so as to be supported in a cantilever manner.
Of course, this leaf spring 22 is provided to bias the print arm 18 away from the tip of the iron core 15 by its spring force. In addition,
In FIG. 4, A is the platen, B is the paper, C is the ink ribbon, D is the wire guide, and g in FIG. show.

However, in this drive device, the degaussing coil 1
When no current is passed through 7, the armature 20 is attracted to the iron core 15, and in this state, the horizontal support portion 23 and the vertical support portion 24 of the leaf spring 22 are bent. Therefore, when the magnetic flux of the permanent magnet 12 is canceled by passing current through the degaussing coil 17,
The armature 20 is pressed against the iron core 1 by the urging force of the leaf spring 22.
5, the print arm 18 is rapidly driven. Therefore, the tip of the print wire 21 collides with the platen A, resulting in dot printing. next,
When the power to the degaussing coil 17 is cut off, the armature 20 is attracted to the iron core 15 again and the leaf spring 22 is bent. That is, printing is performed repeatedly in this manner.

By the way, according to this drive device, the U-shaped groove 1
The distance g between the inner surface of the armature 6a and the armature 20 can be set as small as possible. That is,
Since the leaf spring 22 has a vertical support 24 to which the armature 20 is secured, the rigidity of the vertical support 24 counteracts the tendency of the print arm 18 to rotate about its axis. I can resist. Therefore, even if the distance g is made as small as possible, the armature 20 is prevented from coming into contact with and adsorbing to the inner surface of the U-shaped groove 16. Therefore, it is possible to reliably vibrate the print arm 18 and perform printing. Moreover, since the interval g can be made extremely small as described above, the magnetic flux from the permanent magnet 12 and the degaussing coil 17 can be passed through effectively, and the permanent magnet 12 can therefore be made smaller. Furthermore, the print arm 21 receives not only the urging force from the horizontal support part 23 but also the vertical support part 2 fixed to the vertical surface of the armature 20, which has not been done in the past.
It also receives biasing force from 4. Therefore, the necessary printing energy given to the print arm 21 can be sufficiently secured even if the thickness of the leaf spring 22 is made thin. Therefore, by making the leaf spring 22 thinner, the inertia of the entire vibrating section can be reduced, thereby enabling high-speed printing.

Although this embodiment is constructed as described above, in implementing the present invention, the magnetic circuit structure, permanent magnet U,
The specific structure, shape, position, etc. of the shape groove, degaussing coil, print arm, armature, leaf spring, horizontal support part, vertical support part, etc. are not limited to the above-mentioned example, and can be implemented in various configurations. Of course.

As explained above, according to the present invention, since the plate spring can be made thinner, high-speed printing is possible. Furthermore, since the distance between the armature and the inner surface of the U-shaped groove can be minimized, the passage of magnetic flux becomes effective, and the size of the permanent magnet can be reduced. Furthermore, even if the spacing is minimized, the vertical portion of the leaf spring can prevent contact and adsorption to the inner surface of the armature's U-shaped groove, allowing the print arm to vibrate normally and reliably. have

[Brief explanation of the drawing]

1 to 3 show a conventional device, FIG. 1 is a side view, and FIGS. 2 and 3 are respectively shown in FIG. 1.
FIG. Figure 4~
Figure 7 shows an embodiment of the present invention, Figure 4 is a side view, Figures 5 and 6 are sectional views taken along lines - and -, respectively, in Figure 4, and Figure 7 shows the main parts. It is an enlarged perspective view. 11...Magnetic circuit structure, 12...Permanent magnet, 1
5... Iron core, 16a... U-shaped groove, 17... Degaussing coil, 18... Print arm, 20... Armature, 22... Leaf spring, 23... Horizontal support part, 24... Vertical support part .

Claims (1)

[Scope of utility model registration request] A print arm having an armature that fits with a slight spacing into the inner surface of a groove provided in a part of a magnetic circuit structure including a permanent magnet is biased by a leaf spring and cantilevered on the magnetic circuit structure. In the print arm drive device, the armature is released from adsorption by excitation of a degaussing coil attached to the magnetic circuit structure, and the print arm is driven by the biasing force of a leaf spring. A printer characterized in that it is formed by having a horizontal support portion fixed to the armature, and a vertical support portion cut vertically from the horizontal support portion and fixed to the vertical surface portion of the armature. print arm.