JPH04163055A - Impact dot head - Google Patents

Abstract

PURPOSE:To improve assembling properties of a printing head by a method wherein a spring holder is provided with a slit part having a step for guiding a lever. CONSTITUTION:A coil spring 2 is inserted to a hole of a spring holder 1. Furthermore, a lever 6 formed integrally with a wire 7 is set to a slit part 16 of the spring holder from above. The spring holder is provided with the slit 16 with a gap (g), which is too large to position the lever when the setting of the lever in a vertical direction of a head is completed but sufficient to stably dispose the lever on the upper end surface of a coil spring 2. The position of the set lever 6 is regulated in a circumferential direction (x) by the slit 16. In this manner, there is no failure in assembly that the lever 6 may interfere with an adjacent lever or bind the coil spring 2, and operability is remarkably improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an impact dot head for an impact dot printer.

[Conventional technology]

Conventionally, as shown in FIG. 12, a lever 6 integrated with an armature 8 pressed against a damper 12 by a coil spring 2 during printing standby energizes an electromagnet 11 having a core 13, which is an iron core. Armature 8
When a magnetic attraction force is generated and the lever 6 rotates around the fulcrum a, the wire 7 fixed to the tip of the lever 6 protrudes and connects with the armature 8 in the print head of an impact dot printer that prints. The integrated lever 6 is positioned by a fulcrum guide groove 4 and a guide die 3 provided in a spring holder 1 that accommodates a plurality of coil springs 2 corresponding to the lever 6.

[Problem to be solved by the invention]

However, when assembling, as shown in FIG. 13, if the free height of the coil spring 2 is set to an excessively long length, its upper end surface will be higher than the upper surface height of the guide die 3, and the lever fulcrum will become roughly Since the lever 6 is not guided to the fulcrum guide groove 4 by the fulcrum spring 10, the position of the lever 6 in the circumferential direction shown by X in the figure is not defined. For this reason,
If the lever 6 is misaligned in the circumferential direction of the spring holder 1, the lever 6 may become entangled with an adjacent lever (not shown) or bite the coil spring during the process of assembling the damper 12, spacer 14, and lever holder 9. There were many assembly defects caused by the assembly being put away, which significantly reduced work efficiency.

Furthermore, if the free length of the coil spring is shortened so that its upper end surface is lower than the height of the upper surface of the guide protrusion 3, the displacement of the spring will become smaller, so in order to obtain the necessary return force, the spring of the coil spring 2 must be The constant becomes very large, which not only makes machining the return spring difficult but also causes an increase in cost.

The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide an impact dot head that is inexpensive and has excellent assemblability while ensuring printing quality.

[Means to solve the problem]

In order to solve the problems of the prior art, the impact dot head of the present invention includes a coil spring for returning the lever and a spring holder for housing the coil spring, and the spring holder includes: The device is characterized in that a slit portion with a step for guiding the lever is provided, and a convex portion is provided in the slit portion.

(Example) Next, examples of the present invention will be specifically described.

FIG. 1, FIG. 2, and FIG. 3 are embodiments of item (1) of the present invention. The coil spring 2 is held by the spring holder 1 and applies a return force p to the lever 6 when the lever 6 returns after the printing operation is completed. The lever holder 9 has a fixed spring 1
The head is pressed against the upper surface of the spring holder 1 by spring force 7, thereby positioning the head in the axial direction y. The damper 12 absorbs the impact when the lever 6 returns, and together with the spacer 14 defines the stroke of the reciprocating movement of the lever, thereby achieving stabilization of the printing operation. The position of the lever 6 in the circumferential direction is defined by a fulcrum guide groove 4 and a guide protrusion 3 provided on the spring holder 1.

As shown in FIG. 2, the order of assembling the head is to insert the coil spring 2 into the hole 18 of the spring holder 1, and then assemble the lever 6 integrated with the wire 7 into the slit portion 16 of the spring holder from above. As shown in Fig. 3, the spring holder has a spacing g that is within a range that allows the lever to be stably placed on the upper end surface of the coil spring 2 in the state shown in Fig. 2, although it will not be positioned when the head is installed in the vertical direction. A slit 16 is provided.

The position of the assembled lever 6 in the circumferential direction X is defined by the slit 16. This eliminates assembly defects such as the lever 6 getting tangled with an adjacent lever (not shown) or biting the coil spring 2. This not only significantly improves work efficiency, but also frees up the lever to prevent the coil spring 2 from biting. Since it is no longer necessary to use a spring with a short length and a very large spring constant, it is also possible to reduce processing costs for the spring and realize cost reductions.

Figures 4, 5, and 6 are shown in Section 1 of Section (2) of the present invention.
This is an example. Here, since the protrusion 15 is provided in the slit 16 of the spring holder 1, in addition to the effect described in item 1, the protrusion 15 can be the only part that defines the circumferential direction X of the lever during assembly. , the interval g' between the protrusions 15
By setting the value of to a range in which the lever 6 is stably placed on the upper end surface of the coil spring 2, it is no longer necessary to process the entire surface of the slit 16 to the distance g as in the first item, and the spring holder 1 is Processing costs can be significantly reduced.

FIG. 7 shows a second embodiment of item (2) of the present invention.

By providing the chamfered portion 18 on the top/surface of the convex portion 15, the term (
In addition to the effect of the first cold embodiment described in 2), in the process of assembling the lever 6 into the slit of the spring holder, it becomes possible to improve the ease of inserting the lever into the slit, which further improves the ease of assembly. This makes it possible to improve performance and reduce costs.

FIG. 8 shows a third embodiment of item (2) of the present invention.

By providing the convex portion 15 only on the upper surface of the slit, the lever 6 does not come into contact with the convex portion 15 after assembly.
In addition to the effects of the second embodiment, during actual printing,
It becomes possible to eliminate the sliding resistance between the convex portion 15 and the lever 6, and it is possible to reduce the shading between dots and improve the printing quality.

9, 10, and 11 show fourth, fifth, and sixth embodiments of item (2) of the present invention. As shown in these embodiments, the effect of the present invention is not affected by the shape, position, or number of the protrusions 15 as long as they are attached to the slits 16, and even if these are changed, the effect of item (2) is still achieved. The same effects as in the first embodiment can be expected.

(Effect of the invention) According to the present application as described in 2, with a relatively simple configuration,
The ease of assembling the print head can be greatly improved, and as a result, the yield rate can be greatly improved, making it possible to provide print heads with stable quality at low cost. In addition, with the structure of the present invention, there is no need to process a spring with a very large spring constant to shorten the spring length, so it is possible to reduce the cost of the print head and improve printing quality. It became.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an impact dot head showing an embodiment of the ring (1) of the present invention. FIG. 2 is a partially exploded perspective view of FIG. 1. FIG. 3 is a partially exploded perspective view of FIG. 1. FIG. 4 is a perspective view showing a first embodiment of the ring (2) of the present invention. FIG. 5 is a partially exploded perspective view of FIG. 2. FIG. 6 is a partially exploded perspective view of FIG. 2. FIG. 7 is a perspective view showing a second embodiment of the ring (2) of the present invention. FIG. 8 is a perspective view showing a third embodiment of the ring (2) of the present invention. FIG. 9 is a perspective view showing a fourth embodiment of the ring (2) of the present invention. FIG. 10 is a perspective view showing a fifth embodiment of the ring (2) of the present invention. FIG. 11 is a perspective view showing a sixth embodiment of the ring (2) of the present invention. FIG. 12 is a sectional view of a conventional impact dot head. FIG. 13 is a perspective view showing a conventional example. 1... Spring holder 2... Coil spring 3... Guide protrusion 4... Fulcrum guide groove 5... Frame 6... Lever, 7... Wire 8... Armature 9... Lever holder 10... Fulcrum holding spring 11... Electromagnet 12, damper 1 core 14, spacer 15, assembly guide convex 16, slit 17, fixing spring 18° coil spring insertion hole or more Applicant Seiko Epson Corporation Representative Patent Attorney Kizobe Suzuki and 1 other person No. 31! l Figure 4 Figure 5 Illustration 6 Figure 7 Figure 8 Figure 459 Figure '>yote Figure 11-12 section

Claims (2)

[Claims] (1) In an impact dot head having a coil spring for returning the lever and a spring holder for storing the coil spring, the spring holder is provided with a slit portion with a step for guiding the lever. The impact dot head is characterized by: (2) The impact dot head according to claim 1, wherein a convex portion is provided in the slit portion.