JPH0513747U - Wire dot print head - Google Patents

Abstract

(57) [Abstract] [Purpose] A structure is provided in which a force that causes the tip of the divided guide nose 12 of the wire dot print head to separate is prevented from occurring, and the tip guide 11 does not loosen. [Structure] Protrusions 12a and 12b are provided on a clamp portion of a guide nose 12 of a divided wire dot print head, or a warp is provided below a bottom surface of the guide nose 12. [Effect] The position of the wire dot will not shift,
It is possible to obtain a wire dot print head with high print quality.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to the structure of a dot print head in a serial printer.

[0002]

[Prior Art]

 FIG. 5 shows a sectional view of a conventional wire dot print head. This is for a spring charge type printhead. The mechanism and operation will be described below. In the figure, the base of the print wire 15 is fixed to the tip of the armature 16. The armature 16 is supported on the tip of the biasing leaf spring 4. A base 8, a permanent magnet 7, a magnet yoke 6, a magnetic spacer 5, a bias leaf spring 4, an armature yoke 3, a stopper 2, and a guide nose 12 are provided between the guide frame 1 and the cap 10 as a clamp spring. It is fixed sequentially through 9.

In the non-printing state, the magnetic flux of the permanent magnet 7 forms a magnetic circuit composed of the base 8, the core 17, the armature yoke 3, and the magnet yoke 6, whereby the armature 16 resists the elasticity of the leaf spring. Is sucked by the core 17. On the other hand, when printing is performed, the electromagnet 18 is excited to generate a magnetic flux opposite to the magnetic flux of the permanent magnet 7. Then, the suction of the armature 16 is released, and the elastic reaction force of the leaf spring moves the armature 16 around the other end thereof, and at the same time, drives the printing wire 15 attached to the free end.

Printing on a medium is performed between the print wire 15 and the medium 13 via the ink ribbon 14, and by selectively operating the plurality of print wires, a character or a graphic having a dot structure is formed on the medium. The pattern is printed. The guide nose 12 used here is divided into two parts and is used in combination by fitting the press-fitting portions of the guide nose 12R and 12L shown in FIG.

[0005]

[Problems to be solved by the device]

 However, in the print head having the above structure, the partial guide noses 12R and 12L divided into two are used in combination as shown in FIG. 6, but the bottom surface of the guide nose 12 shown in FIG. The temperature of the resin is not well balanced with the bottom surface, and the bottom surface is easy to cool, and the A portion is difficult to cool. Therefore, the place that should be horizontal tends to warp upward. Therefore, when the guide nose 12 is clamped by the guide frame 1, the tip of the combined guide nose 12 acts as a moment to separate as shown by the arrow, and the tightening of the tip guide 11 is loosened, which causes guide play. there were.

It is an object of the present invention to provide a wire dot print head that reduces the looseness of the tip guide described above and has high printing quality.

[0007]

[Means for Solving the Problems]

 According to the present invention, in the wire dot print head, the guide nose is provided with a protrusion on the clamp part or the bottom face of the guide nose is provided with a downward warp, so that the tightening force by the clamp at the tip of the guide nose is strengthened. It is the one that was set to. In the wire dot print head, the present invention also provides a notch on the facing surface of the divided guide nose to strengthen the tightening force between the tip guide and the tip guide at the pressure contact portion of the guide nose, and further to mount on the carriage. In this case, the tightening force of the carriage-head clamp spring at the tip of the guide nose is strengthened.

[0008]

[Action]

 Since the present invention is configured as described above, the tip of the partial guide nose is not separated in any of the inventions, and the tip guide can be reliably gripped. As a result, the tip guide is not loosened.

[0009]

【Example】

 FIG. 1 is a sectional view of a wire dot print head for explaining the first embodiment of the present invention. In the figure, the wire dot print head includes a guide frame 1, a stopper 2, an armature yoke 3, a bias leaf spring 4, a magnetic spacer 5, a magnet yoke 6, a permanent magnet 7, a base 8, a clamp spring 9, a cap 10, and a tip. It is composed of an end guide 11, a guide nose 12, a print wire 15, an armature 16, a core 17 and an electromagnet 18.

The components other than the guide nose can be configured in the same manner as in the prior art, and therefore the same numbers are used and will not be described in detail. The guide nose 12 has a protrusion 12a near the center above the clamp portion and a protrusion 12b near the outer periphery below the clamp portion. This will be described in more detail with reference to FIG. First, as shown in FIG. 2, circular protrusions 12b are provided on the bottom surface of the clamp portion of the conventional guide nose 12, and further, on the top surface of the clamp portion, on the line drawn from the protrusion provided on the bottom surface toward the center, This is a case where a round protrusion 12a is provided near the edge of the guide frame at a position close to the center.

When the guide nose 12 is clamped by the guide frame 1 as described above, a force for pushing the bottom surface projection 12b upward and a force for pushing the top surface projection 12a downward work, so that the tip end of the guide nose 12 is It becomes the force to tighten the tip guide 11, and the force becomes larger than the conventional one. Although the circular protrusion has been described here, the same effect can be obtained by providing the linear protrusions 12a 'and 12b' as shown in FIG. The same applies to the case where only the bottom surface of the protrusion is provided.

Further, as another embodiment, the method shown below is one in which the effect is obtained without providing the guide nose 12 with a protrusion. As described above, the bottom surface of the conventional guide nose 12 is often warped horizontally or upward. Therefore, in the present invention, the warp is directed downward as shown in FIG. Even when such a guide nose 12 is used, the same effect as the above method can be obtained. That is, a downward pushing force acts at the contact point between the guide frame 1 and the clamp portion of the guide nose 12 that warps downward, and the tip end portion of the guide nose 12 serves as a force to tighten the tip guide 11. As described above, by improving the shape of the bottom portion of the guide nose 12, the force for tightening the tip guide 11 is increased, but depending on the shape of the guide nose 12, problems may still remain. That is, as shown in FIG. 8, the tip guide 11 and the guide nose 12 are abutted at the pressure contact portion and pressed by the guide frame 1, and the guide nose 12 facing each other is in contact at the pressed portion. The upper part has a slope so that a gap is opened. As shown in FIG. 9, when mounting the print head on the printer, the clamp part of the guide nose 12 is placed on the carriage 21 and the carriage-head clamp is installed. By being supported by the spring 22, a force is applied to the clamp portion of the guide nose in the direction of arrow A shown in FIG. As a result, the tightening force of the tip guide 11 is further strengthened at the tip 12 of the guide nose, and the rattling of the tip guide 11 is eliminated, but in reality, as shown in FIG. Since it is a molded product made of resin, the portion of the guide nose 12 that faces the guide nose tends to warp in the vertical direction around the center of the face due to the rigidity balance of the guide nose 12. The divided guide nose 12 comes into contact near the center of the facing surface, and the tip guide 11 cannot be abutted at the pressure contact portion of the guide nose 12. The guide nose 12 is vertically displaced with the facing surface as the center. Therefore, the bottom of the guide nose 12 is not horizontal, and the guide frame 1 presses the guide nose 12 so that the guide nose 12 is separated from the guide nose 12. Since the clamp portion of the guide nose is about to contact at this stage, the effect of increasing the tightening force applied to the tip of the guide nose 12 when the guide nose is placed on the carriage 21 and supported by the carriage-head clamp spring 22 is obtained. Decrease. In order to solve such a problem, the guide nose 12 of the wire dot print head may be configured as in the second embodiment described below. FIG. 11 shows a wire dot print head according to the second embodiment of the present invention. Here, the other parts except the guide nose 12 are the same as those in the first embodiment. As shown in FIG. 12, the guide nose 12 of the embodiment is supported by the carriage-head clamp spring 22 from the vicinity of the central portion where it is considered that the two guide noses are in contact with each other due to warping on the opposing surfaces of the guide nose. The notch 30 is provided so as to cover the holding portion. By doing so, even if the guide nose 12 is warped in the vertical direction from the central portion of the facing surface of the guide nose 12 due to the rigidity balance of the guide nose 12, the notch is provided when the guide nose 12 is opposed. Since the contact due to the warp is eliminated, it is possible to firmly press the tip guide 11 into the press contact portion at the tip of the guide nose 12. Further, when the print head is mounted on the printer, only the portion of the guide nose 12 which is pressed by the guide frame 1 is in contact with the guide nose 12 and the upper portion thereof is separated, so that the carriage-head clamp spring 22 supports the print head. The force applied when the force is applied acts on the pressure-contacting portion at the tip of the guide nose 12 in the direction in which the tip guide 11 is tightened, so that the pressure can be firmly pressed. By providing the projection 12a or 12b according to the first embodiment on the guide nose 12 in the same manner, the tip guide 11 can be fixed more reliably.

[0013]

[Effect of the device]

 As described in detail above, according to the present invention, a protrusion is provided near the outer periphery of the bottom surface of the clamp portion of the guide nose, or on the upper surface and the bottom surface, or the clamp portion of the guide nose is provided with a downward warp. As a result, the tightening force of the tip guide at the tip of the guide nose is increased, and it is possible to provide a print head with good print quality without fear of guide play. The present invention also provides a notch from the central portion of the opposing surface of the guide nose divided into two to the clamp portion of the guide nose, so that the tightening force of the wire guide at the pressure contact portion of the tip guide and the guide nose is strengthened, When the print head is mounted, the tightening force at the tip of the guide nose also becomes strong. Although the spring charge type print head has been described above, according to the present invention, the same effect can be obtained in the clapper type print head.

[Brief description of drawings]

FIG. 1 is a sectional view of a wire dot print head according to a first embodiment of the present invention.

FIG. 2 is a top view and a bottom view of a guide nose with a round protrusion.

FIG. 3 is a top view and a bottom view of the guide nose with linear protrusions.

FIG. 4 is a sectional view of a guide nose according to another embodiment of the first embodiment of the present invention.

FIG. 5 is a sectional view of a conventional wire dot print head.

FIG. 6 is an enlarged view of a fitting portion of the guide nose.

FIG. 7 is a sectional view illustrating a clamped state of a conventional guide nose.

FIG. 8 is a sectional view for explaining the problems remaining in the first embodiment of the present invention.

FIG. 9 is a perspective view of a wire dot print head when the printer is installed.

FIG. 10 is a cross-sectional view showing a state when the guide nose is clamped.

FIG. 11 is a sectional view of a wire dot print head according to a second embodiment of the present invention.

FIG. 12 is a sectional view of a guide nose according to a second embodiment of the present invention.

[Explanation of symbols]

 1 guide frame 2 stopper 3 armature yoke 4 bias leaf spring 5 magnetic spacer 6 magnet yoke 7 permanent magnet 8 base 9 clamp spring 10 cap 11 tip guide 12 guide nose 12a protrusion 12b protrusion 15 print wire 16 armature 17 core 18 electromagnet 22 carriage -Clamp spring 30 Notch

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Koichi Ando 1-7-12 Toranomon, Minato-ku, Tokyo Inside Oki Electric Industry Co., Ltd. (72) Masahiro Tachikami 1-7-12 Toranomon, Minato-ku, Tokyo Oki Electric Industry Co., Ltd.

Claims (2)

[Scope of utility model registration request] 1. A guide nose having a clamp portion clamped by a guide frame on an outer periphery of a bottom portion, and a grip portion for fitting and gripping a tip guide for guiding a tip of a printing wire at a tip portion, the guide nose extending from the tip portion to the bottom portion. A wire dot print head having a guide nose configured by combining partial guide noses divided into a plurality of surfaces, characterized in that the vicinity of the outer periphery of the bottom surface of the clamp portion of the guide nose projects below the inner surface. Wire dot print head to be. 2. A guide nose having a clamp portion clamped by a guide frame on an outer periphery of a bottom portion, and a grip portion for fitting and gripping a tip guide for guiding a print wire tip at a tip portion, the guide nose extending from the tip portion to the bottom portion. In a wire dot print head having a guide nose configured by combining partial guide noses divided into a plurality of surfaces, a notch is provided in the vicinity of the central portion of the facing surface where the partial guide noses are combined. Wire dot printing head.