JPH0346911Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention attracts a leaf spring with a dot wire at its free end using the magnetic flux of a permanent magnet, and selectively excites the electromagnet. The present invention relates to a so-called spring charge type dot printing head that performs printing by canceling the magnetic flux of the permanent magnet and protruding the dot wire by the reaction force of the leaf spring.

[Conventional technology]

A conventional dot printing head will be explained based on FIG. 2. FIG. 2 is a side sectional view of the conventional example. In the figure, the magnetic flux of the permanent magnet 1 is transmitted through the base plate 2, the spacer 3, the leaf spring 4, the yoke 5, the armature 6, the core 7, and the base 8, forming a magnetic path returning to the permanent magnet 1. The armature 6 fixed to the free end side of the leaf spring 4 is attracted to the core 7.

Here, the electromagnet 9 is selectively excited and the core 7 is
When a magnetic flux is generated in the opposite direction to the magnetic flux of the permanent magnet 1 passing through it, the leaf spring 4 is released and the wire 10 fixed to the tip of the armature 6 is projected from the wire guide 11 to print a dot.

To assemble such a dot printing head,
Like the dot printing head described in Utility Model Application No. 58-093298, the plate spring 4 is sandwiched between the spacer 3 and the yoke 5 and welded together, eliminating the need for screws and securing the spring part and the magnet part together to the extent that they do not shift. Assembling.

As a method for the above-mentioned fixing, there is a method using a clamp spring shown in FIGS. 3 and 4 a and b. This clamp spring 12 has a ring-shaped main body 12a bent at right angles at several points on the outer periphery to extend the tongue-like portions 12b, and a portion of the main body 12a on both sides of each tongue-like portion 12b is bent to tilt the tongue-like portions 12b outward. let That is, bending portions 12c parallel to the surface of the tongue portion 12b are formed in the main body 12a portion on both sides of each tongue portion 12b to tilt the tongue portion 12b outward, and the elastic force of the bent portion 12c The tongue-shaped portion 12b can be tightened and locked onto the head body 13. Furthermore, the tip of the tongue-like portion 12b is bent inward so that it can be engaged with a groove 13a carved on the outer periphery of the lower portion of the head body 13.

The clamp spring 12 having such a configuration is
It is placed on the head body 13 as shown in FIG. 4a, and the tongue-shaped portion 12b is pressed in the direction of the arrow in FIG. 4a, and its tip is locked in the groove 13a of the main body 13 as shown in FIG. do.

[Problem that the invention attempts to solve]

However, with such a dot printing head, a force in the direction of arrow B is generated on the clamp spring at the same time as the clamping force A shown in FIG. There is. In addition, in this conventional example, the tip of the tongue is bent and locked in the groove of the head body, so it is difficult to maintain the positional accuracy of the tip P of the tongue as shown in Fig. 4a. There will be variations in the clamping force A due to the tongue-shaped portions, and further problems will occur, such as the bending portion shown at Q in FIG.

The present invention has been devised to solve the above-mentioned problems, and its purpose is to provide a dot printing head having a clamp spring that provides sufficient clamping force, is easy to install, and is difficult to detach.

[Means for solving problems]

In order to achieve the above-mentioned object, the present invention stacks the guide frame, yoke, bottom plate, etc., and extends the tongue-like portions by bending them from several points on the outer periphery of the main body of the clamp spring that maintains this stacked state. In the dot printing head, bending portions are formed on the main body portions on both sides so that the tongue portions are inclined outward, and the tongue portions are retained on the head body by the elastic force generated by the bending to maintain the laminated state. , the tongue is bent into a mountain shape between the bent part of the main body of the clamp spring and the tongue, and a locking hole is bored at the tip of the tongue, and the locking hole is It is characterized in that a locking portion for locking is formed protruding from the head body.

[Effect]

In the present invention having the above-mentioned characteristics, first, a clamp spring is placed on the head body, and when the flexure is pressed and stretched, the tongue-shaped portion of the clamp spring comes into contact with the outer peripheral portion of the head body and protrudes above the locking portion.
The locking portion and the locking portion of the tongue-shaped portion lock together. In this state, even if the pressing force is released, the elastic force of the mountain-shaped main body portion will not release the lock, and the head main body will be strongly tightened.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on FIGS. 1, 5, and 6 a, b, and c.

FIG. 1 is a perspective view of a clamp spring used in an embodiment of the dot printing head according to the present invention;
The figure is a plan view of Figure 1, and Figures 6a, b, and c are side views of the main parts explaining the process of attaching the clamp spring to the head body, where a is before installation, b is during installation, and c is after installation. show.

In FIG. 1, the clamp spring 14 is
It consists of a ring-shaped main body 15 and tongue-like parts 16 bent at right angles from several points on the outer periphery of the main body 15, and a locking hole 17 is bored at the tip of each tongue-like part 16. Further, the main body 15 on both sides of each tongue-like portion 16
The tongue portion 16 is formed by bending the portion to form the bent portion 18.
Tilt outward. That is, as shown in FIG. 5, the main body 15 is aligned so that the two-dot chain line H passing through the bent portion 18 and the two-dot chain line G passing over the surface of the tongue portion 16 are parallel to each other.
bend the part. Furthermore, the bent portion 18 of the main body 15
and the tongue-like portion 16 by bending it into a mountain shape to form the tongue-like portion 16.
lift up. That is, a step is provided by forming a first bent part 19 and a second bent part 20 in a direction perpendicular to the bent part 18 between the main body 15 and the bent part 17 at the base of the tongue part 16. Try to lift 16.

In FIGS. 6a, b, and c, the head main body 21 is assembled by laminating a guide frame, a yoke, a bottom plate, etc., and has an engaging hole on its lower outer circumference that engages with the locking hole 17 of the clamp spring 14. A plurality of stop portions 22 are formed to protrude.

Next, the operation of the above configuration will be explained. First, the 6th
When the clamp spring 14 is placed on the head body 21 as shown in FIG. The tongue-shaped portion 16, which has been inclined at this angle, comes into contact with the outer circumferential surface of the head body 21.

Furthermore, when the clamp spring 14 is pushed in the direction of the arrow E, the first
The bent portion 19 and the second bent portion 20 are bent, and the tongue portion 16
protrudes in the direction of arrow F in FIG. 6b, and as shown in FIG.
Even if the first bending portion 21 is locked and the pressing force in the direction of the arrow E is released in this state, the first bending portion 19
Due to the elastic force of the second bending portion 20 in the direction of arrow K shown in FIG. 6c, the locking hole 17 and the locking portion 21 do not come apart, and the head body 21 is tightened.

Since the bent portion 18 is bent to such an extent that the tongue portion 16 does not come into contact with the head body 21, no force is generated in the direction of the arrow L shown in FIG. 6c, that is, in the direction in which the clamp spring 14 comes off. Further, the force generated by the bending of the first bent portion 19 and the second bent portion 20 is only in the direction of the arrow K shown in FIG. Furthermore, in this embodiment, the locking portion 22
Although the locking portion is provided protrudingly on the fixing plate of the head body 21, this locking portion may be provided on the base plate or base of the head body 21.

[Effect of idea]

As described above, according to the wire dot printing head according to the present invention, the tongue is bent into a mountain shape between the bent portion of the main body of the clamp spring and the tongue to lift the tongue, and the tip of the tongue is A locking hole is drilled in the
By forming a protruding locking part on the head body that locks with the locking hole, a clamp spring is placed on the head body, and the locking hole drilled in the tongue-like part is extended by stretching the clamp spring onto the head body. Since the head body is locked by the locking portion of the head and the head body is tightened by the elastic force caused by the deflection, the following effects are achieved.

In other words, since the head body is tightened by the elastic force of the mountain-shaped bent portion of the clamp spring, a sufficient tightening force can be obtained, and the connection between the spring part and the magnet part of the dot printing head is maintained sufficiently, and the Misalignment is eliminated, and the characteristics of the dot printing head are stabilized and improved. Therefore, high printing quality can be obtained.

Further, since the locking portion of the head body is inserted and locked into the locking hole of the clamp spring, there is an effect that the clamp spring will not be broken and will not come off.

[Brief explanation of drawings]

Fig. 1 is a perspective view of a clamp spring used in an embodiment of the present invention, Fig. 2 is a sectional view of main parts of a conventional example, Fig. 3 is a perspective view of a clamp spring used in a conventional example, and Fig. 4 is a clamp spring. FIG. 3 is a side view of a main part illustrating the installation process, in which a shows a state before mounting and b shows a state after mounting. 5 is a plan view of FIG. 1, and FIG. 6 is a side view of a main part illustrating the process of attaching the clamp spring to the head body, in which a shows the clamp spring before mounting, b shows the process during mounting, and c shows the state after mounting. 14... Clamp spring, 15... Main body,
16... tongue-shaped part, 17... locking hole, 18... bending part, 19... first bending part, 20... second bending part,
21... Main body, 22... Locking portion.

Claims (1)

[Scope of claim for utility model registration] The guide frame, yoke, bottom plate, etc. are laminated,
The body of the clamp spring that maintains this stacked state is bent at several points on the outer periphery to extend the tongue-like portions, and bent portions are formed on the main body on both sides of each tongue-like portion to make the tongue-like portions slope outward. In the dot printing head, in which the tongue-like part is locked to the head main body by the elastic force of While lifting the shape part,
A dot printing head characterized in that a locking hole is formed at the tip of the tongue-shaped portion, and a locking portion that is locked by the locking hole is formed protruding from the head body.