JPS5857971A - Printing head for dot printer - Google Patents

Abstract

PURPOSE:To enable to widen the width of a plate spring and to improve the durability thereof by preventing interference with each other in such manner that each plate spring for a print wire operation to be arranged in parallel is installed so that each adjacent plate spring does not come into contact with each other in the direction of the width. CONSTITUTION:In order to produce a movable member A by fixing a plate spring 2 which operates a print wire 1 onto a supporting member 4, a construction is made up in such manner that the distance H from the bottom end of the supporting member 4 to the top surface of the plate spring 2 is shorter than the distance H1 from the bottom end of the supporting member 4 to the bottom surface of the plate spring 2 of the adjacent movable member B, and the clearance obtained by subtracting H from H1 is sufficiently provided. These two kinds of movable member A and B constructed in such manner as described above are alternately installed so that each plate spring 2 partly laps over or under the adjacent plate spring 2. Thus the width of the plate spring 2 is made wider so as to improve the strength in comparison with the prior art.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a print head for a dot printer that is widely used in data communications, computer terminal equipment, and the like.

In recent years, as the demand for printers as terminal equipment has increased, dot printers have become popular due to their ability to print at high speed, high reliability, and versatility. A printhead has been proposed.

Among the print heads for this type of dot printer, those that use the so-called release printing method are biased by a permanent magnet such as a leaf spring, and the magnetism of the permanent magnet is activated by excitation of a drive coil corresponding to the print pattern. One type offsets the attraction force and releases the biasing force of the leaf spring to drive the print wire to print, while the other uses an electromagnet instead of a permanent magnet to bias the leaf spring and de-energizes the excitation coil of the electromagnet. In particular, it is known that printing is performed by releasing a leaf spring.

Figures 1 to 3 show conventional examples of print heads for dot printers using permanent magnets.This is briefly explained using the figures. 1 is a print wire, 2 is a leaf spring, and 3 is a print head made of magnetic material. This is a movable member having one end fixed to the leaf spring 2 and the base end of the printed wire 10 fixed to the other end, and these three members constitute the movable part 10. The leaf spring 2 is fixedly held by a support member 4, and this support member 4 is fixed to a substrate S. In this case, the print head requires seven print wires 1 when printing alphanumeric characters or katakana characters, and about 24 print wires 1 when printing kanji characters. The movable parts 10 are arranged radially at predetermined intervals as partially shown in FIG. It is inserted. The driving portions 11 disposed corresponding to the respective movable portions 10 are provided with permanent magnets 6. It consists of a magnetic pole piece T and a drive coil 8. When the movable member 10 is at rest, the movable member 3 is attracted to the magnetic pole piece 1 by the magnetic attraction force of the permanent magnet 6, thereby causing the leaf spring 2 to be attracted to the drive unit 11.
It is biased to the side.

When driving, it is driven so as to generate a magnetic flux in the opposite direction to the magnetic flux produced by the permanent magnet 6; when a current is passed through the permanent magnet 6, the permanent magnet 6
Since the magnetic attraction force caused by this cancels out, the movable part 10 is released from the drive part 11, and the movable member 3 moves in the direction of the substrate 5 due to the restoring force of the leaf spring 2, thereby causing the printed wire to fly out from the cylinder body 9. A paper surface (not shown) is struck with the tip of the dot 1 to record dots. Therefore, if the drive coil 8 of each drive unit 11 is selectively excited based on the print signal, the corresponding movable unit 10 is driven, and the print wire 1
By using the 0 combination, a desired character 9 pattern can be printed on the paper.

By the way, in such a print head for a dot printer, when the movable part 10 is driven, as shown in FIG.

It exhibits two types of vibrating rods as shown in Fig. In this case, in the impactful dot recording by the print wire 1,
Although the basic vibration mode shown in (a) of the figure is used exclusively, in reality, the secondary vibration mode shown in (b) of the figure often occurs with recording operations, and in high-speed vertical print heads. Often, the overstress caused by the latter mode is applied to the leaf spring 2, leading to its destruction. Ninth, the leaf spring 2 is required to have sufficient strength. In order to increase the strength of the leaf spring 2 and reduce the stress on the leaf spring 2, it is effective to set the width W of the leaf spring 20 large as shown in Figure tIX3, and in fact, the movable member 3 It is already known that the arm part 3a is integrally provided at the arm part 3a, and the leaf spring 2 is held by the arm part 31 of the arm part, and the plate width W is set considerably larger than the width dimension of the movable member 3. There is. However, even with such a structure, conventionally the slope springs 2 of the round can movable parts 1 are arranged in parallel and form one common plane, so when the plate width W is increased, the adjacent movable parts 10 The problem is that the leaf springs 1 of the two interfere with each other.

The present invention was made in view of the conventional inconveniences as described above, and the leaf springs of each movable part are arranged so that adjacent leaf springs are shifted from each other in the thickness direction to prevent mutual interference. Additionally, it is an object of the present invention to provide a print head for a dot printer in which the plate of the plate spring can be set to a large size and the plate spring is prevented from breaking due to excessive stress.

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

FIGS. 5(1) and 5(b) are perspective views of movable parts used in the print head for a dot printer according to the present invention, respectively. In the drawings, the same components as in FIGS. 1 to 4 are designated by the same reference numerals, and their explanations will be omitted. One of the movable parts A shown in FIG. below W
smaller than the distance H1 at t (H<Hl), and K1−
The structure is such that H is sufficiently large. First, the arm portion 3a of the movable portion M is joined to the lower surface of the leaf spring 2, while the arm portion 3& of the movable portion B is joined to the upper surface of the leaf spring 2. Furthermore, the plate springs 2 of each movable part M, B are sufficiently larger than the plate width (W) of the conventional plate spring shown in FIG.
W+α).

Configured in this way, the 92 types of movable parts M and B are arranged alternately as shown in FIG. Ru. As a result, the leaf springs 2 of each movable part M, B are arranged so that adjacent ones are shifted by a predetermined distance in the plate thickness direction due to the relationship H<Hl, so that the plate 11 (W+α) of the slope spring 2 is Even in the case where a part of the leaf spring on one side of the movable part 3, that is, the end part of the leaf spring 2 on the side of the other movable part 1, is set larger than the conventional one, As shown in FIG. 5, the movable parts M and B can be smoothly and reliably driven without interfering with each other.

That is, the present invention prevents mutual interference by arranging the leaf springs 2 of adjacent movable parts M and B so as to be alternately shifted in the thickness direction, and the width of the leaf springs 2 is set large. It is. This rounding increases the strength of the leaf spring 2 and prevents the leaf spring 2 from being destroyed or damaged due to excessive stress during dot recording.

FIG. 7 is a perspective view of a movable part showing another embodiment of the present invention. In this embodiment, the stress acting on the leaf spring 2 is rounded so that it is maximum at the connection part with the movable member S and the support member 4, and the width of both ends of the leaf spring 2 is set large, and the width of the central part is set small. This is the fourth day.

It goes without saying that the present invention is not limited to a print head using a nine-spring release printing method using a permanent magnet, but can also be applied to a print head using an electromagnet.

As explained above, the print head for a dot printer according to the present invention is configured such that the leaf springs arranged in parallel are arranged so that adjacent springs are shifted from each other in the thickness direction to prevent mutual interference. , the restrictions on the width of the leaf spring can be relaxed. Therefore, the width of the leaf spring can be set large and the strength can be increased, so that it will not break or break even under excessive stress, and its durability can be improved.

In addition, the structure is simple, and existing products can be easily discharged, so the effect is very large.

[Brief explanation of the drawing]

Figures 1 to 3 are cross-sectional views showing a print head for a conventional dot printer, a partially omitted cross-sectional view taken along the line I-I, and an enlarged perspective view of the movable part. Figures 4 (a) and (b) are the movable part. Figures 5(a) and 5(b) are respectively perspective views of the movable part used in the print head for a dot printer according to the present invention, and Figure 6 is a diagram for explaining the vibration mode of the present invention. FIG. 7, which is a diagram showing the arrangement of the movable parts, is a plan view of the movable parts showing another embodiment of the present invention.

Claims (1)

[Claims] A plurality of leaf springs that selectively actuate each printed wire are arranged in parallel so that adjacent springs are offset from each other in the thickness direction, and a portion of each leaf spring is placed above or below the adjacent leaf spring. A print head for a dot printer that is characterized by facing downward.