JPS61148070A - Printing head - Google Patents

Abstract

PURPOSE:To contrive a smaller printer, by a construction wherein a driving hammer is set into a biased state by a permanent magnet, a stopper plate is provided for restricting a returned position of a dot plate, and the hammer is released from the biased state by canceling the magnetic field of the permanent magnet by a solenoid. CONSTITUTION:Split pieces 6b of the driving hammer 6 not operated for printing are maintained in a biased state under the magnetic field of the permanent magnet 12, with movable yokes 13 attracted to an iron core 15. At the time of printing, the solenoid 16 is momentarily excited to cancel the magnetic field of the magnet 12, thereby releasing the hammer 6 from the biased state, so that the hammer 6 strikes the dot plate 4, and a dot is printed by the projected dot plate. After printing, the yokes 13 are again attracted to the iron core 15, and the split pieces 6b are set into the biased state. Simultaneously, the dot plate 4 on completing printing is returned to an initial position thereof by the split pieces 6b of a return spring 5, and the entire body of the printer using the dot plate can be reduced in size, and can be inexpensively manufacture.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a printer head for forming characters, symbols, etc. using dots in dot printers and the like.

[Conventional technology]

Conventional printer heads are made by dividing a disc-shaped leaf spring into a plurality of pieces centripetally so that the outer circumferential surface of the spring is connected in a ring shape, and printing wire is fixed to one end of each of the divided pieces (for example, a special type of printer head). 154178).

In addition, for printers that use a dot plate instead of print wires, a protrusion is integrally provided on the side of the thin flat dot plate, and the drive end of the armature is locked to this protrusion. Those that print by driving with a driving lens (for example, Japanese Patent Application Laid-open No. 5
7-58166, Japanese Patent Application Laid-open No. 127723/1983) are known.

[Problem that the invention seeks to solve]

However, in the former conventional example, the printed wire had to be fixed to the leaf spring, which increased the assembly process and increased manufacturing costs.

Furthermore, the latter conventional example has the disadvantage that the dot plate driving means is disposed on the side of the dot plate, making the structure of the compact printer itself large.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a printer head which is configured to print using a dot plate and which is effective in reducing the size and cost of printers.

[Means for solving the problem] A plurality of dot plates 4. are attached to the head frame 1 via a guide plate 3t. ...The dot plate is fully slidably supported, and the tip of this dot plate is fully formed with a dot protrusion 4a, and the rear end is formed with vertical bent portions 4b, 40'j&: for being driven, and this vertical bending... A restoring leaf spring 5 is brought into elastic contact with the front end of the section, and a driving hammer 6 can be brought into contact with the rear end of the vertically bent section. The drive hammer 6 is set in an even-odd state by a permanent magnet 12, and a stopper plate 7 is provided for regulating the return position of the dot plate.
VC is obtained by providing an electromagnetic device that cancels and releases the magnetic field of the permanent magnet by excitation of the magnet coil 16.

[For production]

The driving hammer 6 that does not print is placed in an even-odd state by the permanent magnet 12, or during printing, the magnet coil 16 is excited to cancel the magnetic field of the permanent magnet 12, thereby releasing the driving hammer 6 from the even-odd state. The vertically bent portion 4b of the dot grating 4 is struck. Therefore, the dot plate 4 prints with its dot protrusion 4a against the spring force of the return leaf spring 5. Immediately after printing, the magnet coil 16 is energized, and the driving hammer returns to the even-odd state due to the magnetic field of the permanent magnet 12. At the same time, the dot plate 4 returns to its original position by the return spring 5, but this return position is controlled by the stopper plate 7. Regulated.

〔Example〕

The embodiments of the present invention will be fully explained based on the drawings.

In FIG. 1, a head frame 1 is integrally molded from synthetic resin such as carbon graphite, and has a guide hole 1a in its front end surface through which a dot plate 4 moves forward and backward. Note that the paper guide 1b is attached to the head frame 1.
It is formed in an upright position facing upward from the lower front end of the platen (not shown).

A hollow part 2 with an opening at the lower end is formed in the front half of the head frame 1, and a hammer guide 3, which is a guide means, is formed from the opening at the lower end. ... are inserted in parallel. The concrete shape of the hammer guide 3 is as shown in the second figure, and includes a driver (staggered guide holes 3a for guiding the plate 4 are bored, elastic arms 31 on both sides of the lower end of the guide), which will be described later. 3b is formed, and locking claws 5a+3afr are formed on the outer lower ends of both arms. Therefore, in order to insert the hammer guide 5 into the head frame 1, it is inserted along the guide groove formed in advance in the hollow part 2, and the locking pawl 6c fits into the locking groove of this guide groove and is fixed. It is something that The guide hole 5hVC of each hammer guide 5 has nine dot plates 4. ... is slidably inserted.

and dot plate 4. As shown in the third diagram, the dot protrusion 4a protrudes from the tip, and the rear end has a first vertically bent portion 4b and a stepped portion that protrudes from the vertically bent portion. The second vertically bent portion 4C is integrally curved. and dot plate 4. ... are arranged in a staggered manner by the guide holes 3a of the hammer guide 5 as described above, but the dot projections 4a4C1 of each dot plate
They are supposed to form a line.

Next, the printing drive mechanism of the dot plate 4 will be explained.

A return leaf spring 5 is in elastic contact with the front end of the first vertically bent portion 4b of the dot plate 4, and a drive hammer 6 is in contact with the rear end.
A stopper plate 7 can come into contact with the rear end of the second vertically bent portion 4c, and is adapted to restrict the return position of this dot plate.

The specific shape of the return spring 5 is as shown in FIG. 4, the outer peripheral part 5a of a disc-shaped leaf spring is ring-shaped, and a plurality of divided pieces 5b are integrally formed centripetally from this outer peripheral part. is,
Each of the divided pieces is in elastic contact with the first bent portion 4b of the dot plate 4 as shown in the fifth figure.

Further, the specific shape of the drive hammer 6 is as shown in FIG. Each of these divided pieces can face the first vertically bent portion 4b of the dot plate 4.

As shown in the first figure, a spacer 8 is interposed between the return spring 5 and the stopper grate 7.

Further, the outer peripheral portion 6a of the drive hammer 6 is supported by a support plate 9, and a yoke grating 11 and a permanent magnet 12 are arranged on the rear surface of the support plate with a spacer 10 in between.

Here, the configuration of the electromagnet device will be explained.

The yoke plate 11 is provided with through holes corresponding to each of the dot plates 4.degree., and a movable yoke 13 is fitted into each through hole. The small diameter portion of the tip of this movable yoke 13 is press-fitted into the divided piece 6a of the drive hammer 6, and the rear end surface of this movable yoke is connected to the tip surface of the iron core 15, which is press-fitted and fixed to the yoke 14 constituting the magnetic path. The yoke is in contact with the permanent magnet 12. A magnet coil 16 is wound around the iron core 15, and the rear end of this coil is located within a coil bobbin 17 that is fixed to the yoke 14.

As mentioned above, dot grade 4. ... are arranged in a staggered manner by the guide holes 5tL of the hammer guide 5 shown in the second figure, but as shown in the seventh figure, the vertical bent portion 4b is formed at the rear end of this dot plate by changing the bending angle. The return spring 5 and the drive hammer 6 each have a split piece 5.
Since b and 6b are formed centripetally, they can be arranged centrally in the center of the printer head, resulting in excellent space efficiency.

Here, we will explain the printing drive using an electromagnetic device.
As shown in the lower part of FIG. 5, the movable yoke 15 of the divided piece 6b of the drive hammer 6 that does not perform printing is attracted to the iron core 15 by the electric field of the permanent magnet 12, and therefore is in an even-odd state. However, when printing, the entire magnet coil 16 is momentarily excited, thereby canceling the magnetic field of the permanent magnet 12.
W; As shown in the upper part of FIG. 5, the driving hammer 6 is released from its even-odd state, so that the driving hammer hits the entire dot plate 4, and the protruding dot plate prints. After printing, the movable yoke 13 is again attracted to the iron core 15, and the divided pieces 6b of the driving hammer 6 are in an even-odd state. At the same time, the dot plate 4, which has finished printing, releases the return spring 50.
The split piece 6b returns to the original position, and this return position is regulated by the stopper plate 7.

Furthermore, the divided pieces 6b of the driving hammer 6 are in an even-odd state due to the magnetic field of the permanent magnet 12 as shown in the lower part of FIG.
It is desirable to provide a minute gap (■) between the two. That is, when the even-odd state of the divided piece 6b is released during printing, the ability to activate the divided piece to the released state, that is, the responsiveness of printing is further improved.

The coil 16 is surrounded by a mold 18 made of highly thermally conductive resin, and the yoke 14 is surrounded by heat radiation fins 19.
are fitted, and a screw is inserted through the hole to attach the head frame, and the tip of this screw is screwed into this fin.

The end of each magnet coil 16 is connected to a coil bobbin 17.
It is connected to a flexible cable 21 via a piece 20 that protrudes further to the rear, and this cable connection surface is covered by a shield cover 22.

Note that 25 and 24 are nonwoven fabrics (felt) completely impregnated with lubricating oil to reduce contact friction between the dot plate and the drive spring and return spring, and to prevent rust.

〔Effect of the invention〕

Since the present invention has the above configuration, the entire structure of the printer using the dot plate can be downsized and manufactured at a lower cost.

[Brief explanation of the drawing]

Figure 1 is a sectional view, Figure 2 is an enlarged front view of the hammer guide, Figure 3 is an enlarged front view of the dot plate, Figure 4 is a front view of the return spring, Figure 5 is a front view of the main parts, FIG. 6 is a front view of the driving hammer, and FIG. 7 is a sectional view taken along the line ■-■ in FIG. 1. 4... Dot plate, 4a... Protrusion for dot, 4b, 4c... Elevated part for driven, 5... Spring for return, 5b... Divided piece, 6... For driving Hammer, 6b...divided piece, 7...φ stopper plate, 12...permanent magnet, 13...movable yoke, 14...
・Yoke, 15... Iron core, 16... Magnet coil. that's all

Claims (3)

[Claims] (1) A dot plate having a dot protrusion at its leading end and a vertically bent portion for being driven at its rear end, a stopper plate that regulates the return position of this dot plate, and the vertically bent portion of the dot plate. a return leaf spring that is in elastic contact with the front end of the dot plate; a drive hammer that faces the rear end of the vertically bent part of the dot plate and is biased by a permanent magnet; and the eccentric state of the drive hammer. A printer head comprising an electromagnet device that cancels and releases the magnetic field of the permanent magnet by excitation of a magnet coil. (2) The printer head according to claim 1, characterized in that there is a minute gap between the vertically bent portion of the dot plate and the drive hammer. (3) In claim 1, the dot plates are arranged in a staggered manner, and the return leaf springs and the drive hammer are arranged in a plurality of disc-shaped leaf springs so that the outer peripheral surfaces of the disc-shaped leaf springs are connected in a ring shape. A printer head characterized in that centripetal divided pieces are formed.