JPH02155749A - Printing head for wire dot printer - Google Patents

Abstract

PURPOSE:To minimize the bending of printing wire and accelerate printing speed by arranging printing levers aligned to meet guide holes positioned near the end and between adjacent other printing levers, away from the projection center of the guide hole so that a spacer large enough to avoid the mutual interference of the printing wires. CONSTITUTION:Adjacent printing levers 10B, 10B are arranged to maintain a space delta and are also positioned so that their tips come between the correspond ing guide holes 8A, 8A with a constant distance (l) maintained like other levers 10.... Consequently the angle between the axial lines 10a, 10a of these printing levers 10A, 10A and the axial projection line of printing wire fixed to the tip of the printing lever is misaligned. However, the projection distance (l) of print ing wire, that is, the bending amount of printing wire 12 between the connection point (c) of the printing lever 10A and a printing end (d) can be reduced to the same lever as that of other printing levers 10. Therefore, a printing action under the same conditions is ensured.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a print head used in a wire dot printer.

(Prior Art) Wire dot printers, which form patterns such as characters on recording media using printing wires, are required to perform faster printing operations as computer terminals, like other printers.

U.S. Patent No. 4,669,898 or Japanese Unexamined Patent Publication No. 1983
The print head disclosed in Publication No. 29681 was developed to meet this type of demand, and as shown in Figure 3, each print lever a... is arranged in a row at the nose end. By arranging them radially toward each guide hole, and positioning their tips on an elliptical line along the wire arrangement direction, the printing wire b is connected from the connection point C between the printing wire b and the printing lever a. The projection distance β to the printing end d is shortened, the bending of the printing wire b is reduced to reduce the friction between the printing wire b and the guide hole, and the overall length of the printing wire b is shortened to reduce its inertia to increase speed. It was designed to achieve this.

However, when the tip of the printing lever a is concentrated in an elliptical shape at the center of the head in this way, in the part with large curvature near the long axis end of the ellipse, as shown in the circled part in Figure 3, As a result of the printing wires b and b being extremely close to each other, it is not only impossible to achieve the intended purpose of bringing the tip of the printing lever a close to the projection center of the guide hole, but also This may lead to inconveniences such as contact between adjacent printing wires, or an unnecessarily high manufacturing cost even though the processing accuracy and assembly accuracy of the parts should be improved.

(Problems to be Solved by the Invention) The present invention was made in view of these inconveniences, and its purpose is to reduce the bending of the printing wire as much as possible without significantly increasing the accuracy of parts and assembly. An object of the present invention is to provide an improved print head for a wire dot printer, which can increase the printing speed while reducing the number of printheads.

(Means for Solving the Problems) That is, the present invention provides a print head for a wire dot printer to achieve the above problems, and is provided with a print head located near an end of a plurality of guide holes arranged in a row at the nose end. The printing lever arranged in correspondence with the guide hole should be placed away from the projection center of this guide hole, and with a sufficient gap between it and other adjacent printing levers to avoid interference between the printing wires. This is what I did.

(Example) Therefore, the illustrated embodiment will be described below.

FIG. 2 shows an example of a printing mode to which the present invention is applied. In the figure, reference numeral 1 denotes a large number of stepped cores on one surface of an annular magnetic plate 2, and each of these cores 1 Plungers 11 fixed to the printing lever 10 are located opposite to each other on the end face, and when not printing, each plunger 11 is moved against the elasticity of the leaf spring 5 by the magnetic flux from the permanent magnet 3 attached to one side of the magnetic plate 2. At the time of printing, the electromagnetic coil 4 wound around the core 1 is selectively energized to release the attraction of the plunger 11, and the elastic force of the leaf spring 5 causes the printing wire 12 provided at the tip of the printing lever 10 to be drawn. is configured to be printed by protruding from the tip of the nose 6.

By the way, FIG. 1 shows the arrangement position M of the printing lever 10 and the printing wire 12, which are the characteristic parts of the present invention, and for ease of understanding, a plan view of FIG. 2 seen from the left side is shown. It is exaggeratedly drawn.

In this figure, reference numeral 7 indicates a guide plate fixed to the tip of the nose 6, and there are many guide holes 8 and 7.
... are drilled in two rows, and the print lever 1o...
It is configured to guide the printing end of each printing wire 12 fixed to the tip of.

Of these guide holes 8..., guide holes 8A, 8A at both ends! In the other guide holes 8..., a group of printing levers 1o... located opposite to each core on the annular magnetic plate 2 are located along the axis 10a18: the projection of the corresponding guide hole 8. The printing wires 12 at the tips of the levers 1o are arranged radially in a concentrated manner so as to be aligned with the center, and each tip is positioned a certain distance β outward from the position directly above the guide hole 8. They are arranged with a distance 6 of, for example, 0.2 mm between them so that they do not come into contact with each other.

On the other hand, the respective printing levers 10A, 104 corresponding to the guide holes 8A, 8A at both ends have their axes 10a, 1
0a is removed inward from the projection center of each corresponding guide hole 8A, 8A at both ends, and roughly two rows of guide holes 8 are formed.
By using the space between the rows of , at least the above-mentioned distance 6 is created between the adjacent printing levers 10B, 10B.
In addition, its tip is positioned so as to maintain a constant distance Mβ between the corresponding guide hole 8A and the corresponding guide hole 8A, similar to the other levers 10...'.

As a result, the axis 1 of these print levers 10A, 10A
Although an angular deviation occurs between 0a, 10a and the projection axis 12a of the printing wire 12 fixed at the tip, the projection distance Mβ of the printing wire, that is, the printing lever 1 in FIG.
The amount of deflection of the printing wire 12 between the connection point C with 0A and the printing end d can be reduced to the same amount as that of the other printing levers 10, and the original printing operation can be ensured under the same conditions. be able to.

Note that in the embodiment described above, the printing levers 10 located at both ends are
A, only the IOA is removed from the projection center of the corresponding guide hole 8A, and the required gap 6 is provided between it and the adjacent printing lever 10B, but both ends of the guide hole row in the longitudinal direction If the arrangement density of the printing levers 10 is high and considerable processing precision or assembly precision is required to secure the required gap 6 between the printing levers 10, printing on both ends may be difficult. Not only the lever 10A but also the printing lever 10 in the vicinity thereof can be shifted from the normal position to form a required gap 6 between the printing lever 1o and the adjacent printing lever 1o.

(Effects) As described above (according to the present invention), the gap between the guide hole located near the end of the guide hole row and the corresponding print lever is moved away from the projection center of the guide hole. Since the necessary gap is formed between the two printing levers, the tips of these levers can be moved while maintaining the necessary gap between the printing levers that are clustered together near the ends, without significantly increasing the precision of processing or assembly of the parts. Position H as close to the position directly above the guide hole as possible.
It is possible to keep the bending of the printing wire to the minimum necessary and reduce the friction between it and the wire guide member.
In addition to improving the durability of the print head, the overall length of the print wire can be made as short as possible to further increase the printing speed.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the arrangement relationship between a printing lever and printing wires showing an embodiment of the present invention, Fig. 2 is a sectional view showing an example of a printing head to which the invention is applied, and Fig. 3 is a conventional device. It is a diagram showing the arrangement relationship between the printing lever and the printing wire. 1...Core 3...Permanent magnet 6...
...Nose 7...Guide plate 8...
・・Guide hole 9・・Spacer 10・・・・
Printing lever 11... Plunger 12... Printing wire Applicant Seiko Epson Co., Ltd. Agent Patent attorney Haruto Nishikawa Katsuhiko Kimura Figure 2

Claims (1)

[Claims] The axis of the print lever disposed corresponding to the guide hole located near the end of the plurality of guide holes arranged in a row at the nose end is removed from the projection center of the guide hole, and the print lever is placed adjacent to the guide hole. A print head for a wire dot printer, characterized in that the print head is arranged with a sufficient gap between the print lever and the print wire to avoid interference between print wires.