JPS6243877B2 - - Google Patents

Description

Detailed Description of the Invention Technical Field The present invention relates to a dot printer in which a plurality of printing wires are connected to each other and an armature is attracted and driven by an electromagnet so that the printing wires are moved to a driving position and printing is performed. This relates to the print head of the printer.

Prior Art Conventionally, this type of printing head has been provided with a plurality of stoppers corresponding to each armature.
Some devices are configured to stop the armature at a fixed position after returning from a driving position to a non-driving position. However, in this conventional structure, since the stoppers are provided separately, the structure is extremely complicated, the assembly work is troublesome, and the cost is high.

In order to eliminate such defects, print heads have been proposed in which one common stopper is provided for a plurality of armatures. and,
Some print heads have a stopper fixed to a wire holder at the center, while others have a stopper supported in a swingable manner.

However, in the former case, when the armature collides with the stopper, it rebounds and is not quickly transferred to the next drive standby state, making it impossible to perform high-speed printing, and the rebound of the armature causes the printing wire to be driven again. There was a risk that the printer would move to the wrong position and cause erroneous printing. In addition, in the latter case, when the armature that performs the printing operation collides with the stopper, the stopper is swung, so the armature located on the opposite side of the armature is knocked out by the swiveling of the stopper, causing an error. There was a risk that vine printing would occur.
Furthermore, when the same printing wire is driven continuously, the swinging of the stopper increases the gap between the armature and the core of the armature driving electromagnet, which may deteriorate the response characteristics.

Purpose This invention was made to solve the above-mentioned problems, and its purpose is to prevent the rebound of the armature and prevent the rebound from occurring, even though the structure is simple and can be manufactured at low cost. The object of the present invention is to provide a new print head that can prevent erroneous printing operations.

Embodiment Hereinafter, an embodiment embodying the present invention will be described with reference to the drawings. A wire holder 1 made of a heat-resistant and wear-resistant synthetic resin has a substantially cylindrical supporting tube portion 2 and its support tube portion 2. It consists of a protective cylinder part 3 that projects forward from the center, and a boss part 4 is formed projecting from the center of the interior of the support cylinder part 2. A substantially cylindrical support plate 5 made of a magnetic material is fixed to one side of the support tube 2 with a plurality of screws 6. On this support plate 5, as shown in FIG. 2, a plurality of electromagnets 7 are arranged concentrically with the support plate 5.

As shown in FIG. 1, each of the electromagnets 7 includes a yoke 8 formed separately on the outer peripheral edge of the support plate 5, and a core 9 screwed onto the yoke 8 in correspondence with the yoke 8.
, a cylindrical insulating member 10 fitted around the outer periphery of the core 9, and a coil 11 wound around the outer periphery of the insulating member 10. When the coil 11 is energized, the armature 19
is attracted to the core 9. Further, a substrate 13 is fixed to the side surface of the support plate 5 with a plurality of screws 12.

A plurality of through holes 14 are formed at equal intervals on the same circumference near the center of the support tube 2 so as to correspond to the electromagnets 7, and compression springs 15 are installed in these through holes 14. It is now accommodating.
A plurality of positioning protrusions 16 are protruded from one end surface of the support cylinder part 2 near the inside of each through hole 14 at equal intervals on the same circumference, and each positioning protrusion 16
A groove portion 17 in between corresponds to the through hole 14 .

The support cylinder portion 2 is located near the outside of each through hole 14.
A plurality of regulating protrusions 1 as regulating members are provided on one end surface.
8 are provided protrudingly at equal intervals and correspond to the positioning projections 16.

A plurality of armatures 19 arranged corresponding to the electromagnets 7 are formed of a magnetic material, and a printing wire 20 extending in a direction substantially perpendicular to the armature 19 is brazed to the tip thereof, and a printing wire 20 is brazed to the base end. is a leaf spring 21 extending in the same direction as the printing wire 20;
It is worn tightly. And this leaf spring 21
is fixed to the yoke 8 with screws 22. Further, the armature 19 is accommodated in the groove 17 between the positioning protrusions 16, and is urged outward by contacting the compression spring 15.

The printing wire 20 passes through a small hole 23 provided at the proximal periphery of the boss portion 4 and is extended to the distal end side of the protective cylinder portion 3, and is connected to the armature 1 by the electromagnet 7.
When the protective tube 9 is driven by suction, it is projected from the tip of the protective cylinder portion 3 and performs a printing operation.

A substantially disk-shaped stopper 24 is screwed onto the boss portion 4 at its central portion.
When the armature 19 is not driven, as shown by a solid line in the figure, a portion 24a that comes into contact with the armature 19 is made of synthetic resin having heat resistance and wear resistance, and a portion 24b on the opposite side is made of metal, Further, an elastic member 24c made of rubber or the like having damping properties is sandwiched between the two 24a and 24b. Further, when the armature 19 is in a non-driving state, the outer peripheral portion of the stopper 24 corresponds to the regulating protrusion 18, and a predetermined gap 25 is formed between the two 24 and 18, and as the armature 19 returns to its original position, a predetermined gap 25 is formed between the two. When colliding with the stopper 24, the boss portion 4 is displaced in any direction due to its own elasticity, and accordingly, the outer peripheral portion of the stopper 24 is displaced within the range of the gap 25, and then the boss portion 4 is displaced into the restricting protrusion 18. When engaged, its displacement is regulated.

Note that a cover 26 is screwed onto the support cylinder portion 2 so as to cover each of the members.

Next, the operation of the print head constructed as described above will be explained.

Now, when a predetermined printing signal is input to this printing head and any electromagnet 7 is excited, the corresponding armature 19 is attracted to the core 9, and the printing wire 20 attached to the armature 19 is moved as shown in FIG. Printing is performed by protruding to the drive position shown by the chain line in .

Thereafter, when the electromagnet 7 is demagnetized, the armature 19 is moved by the reaction force during printing and the urging force of the compression spring 15.
At the same time as the printing wire 20 returns to the non-driving position shown by the solid line in FIG. At this time, the kinetic energy of the armature 19 is the stopper 2
4, and a part of it is absorbed by the elasticity of the stopper 24 itself. The remaining kinetic energy is absorbed by slightly displacing the boss portion 4 due to its elasticity.
As a result, the outer periphery of the stopper 24 on the side opposite to the suction-driven armature 19 is displaced inward within the space 25, thereby being absorbed.
Therefore, the armature 19 is immediately stopped at the non-driving position without rebounding, and the amount of displacement of the stopper 24 is regulated, so that the armature on the opposite side of the driven armature 19 is brought to the driving position by the stopper 24. There is no need to be exposed.

Incidentally, in this embodiment, the vibrations generated during the printing operation are absorbed by the elastic member 24c and the metal portion 24b of the stopper 24, so that noise can be reduced.

Effects As detailed above, the present invention includes a substantially circular stopper which is provided in common to each armature, comes into contact with the armature when each armature is not driven, and whose center portion is fixed to the wire holder. In order to regulate the displacement of the stopper, a regulating member is provided at a position corresponding to the periphery of the stopper of the wire holder, so that erroneous printing operations caused by rebound of the armature are not performed, and printing can be performed immediately. It is possible to shift to a standby state for the next printing operation, making high-speed printing possible.

In addition, since the configuration for this purpose is simply provided with one stopper common to each armature and a regulating member corresponding to each armature, it is extremely simple and has an excellent effect of being able to be manufactured at low cost.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of a printing head embodying the invention, and FIG. 2 is a rear view showing the main parts thereof cut away. Wire holder...1, electromagnet...7, regulating projection as a regulating member...18, armature...19, printing wire...20, stopper...24.

Claims (1)

[Claims] 1. A plurality of printing wires 20, and a wire holder 1 that holds the printing wires 20.
and, corresponding to each of the printing wires 20, connected to one end of each printing wire 20, and connected to one end of each printing wire 20,
armatures 19 extending in a direction substantially perpendicular to the longitudinal direction of 0; and armatures 19 provided at intervals on the circumference corresponding to each of the armatures 19; An electromagnet 7 that drives the wire 20 in the longitudinal direction to perform printing, and an electromagnet 7 that is provided in common to each of the armatures 19 and comes into contact with the armature 19 when each armature 19 is not driven, and its center portion is fixed to the wire holder 1. and a regulating member 18 provided at a position where it can come into contact with the peripheral portion of the stopper 24 of the wire holder 1 in order to regulate the displacement of the stopper 24. Print head of dot printer. 2. The print head for a dot printer according to claim 1, wherein the wire holder 1 is made of synthetic resin. 3. A patent characterized in that the stopper 24 is composed of a synthetic resin portion 24a on the side that contacts the armature 19 when not driven and a metal portion 24b on the opposite side, with an elastic member 24c sandwiched therebetween. A print head for a dot printer according to claim 1.