JPH0354630B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a printer head that forms characters or symbols using dot matrix.

(Prior Art) Conventionally, printer heads have been divided into two types: those using print wires and those using dot plates. It is divided centripetally into a plurality of pieces so that the outer peripheral surfaces thereof are connected in a ring shape, and a printed wire is fixed to one end of each divided piece (for example, Japanese Patent Application Laid-open No. 154178/1983).

In addition, for printers that use dot plates, there is a dot on the side of the thin flat dot plate.
A type in which both forward (printing) and return protrusions are integrally protruded, the drive end of the armature is locked to this protrusion, and the armature is driven by a drive solenoid to print (e.g. (Japanese Patent Application Laid-open No. 57-38166, Japanese Patent Application Laid-open No. 49-127723)
It has been known.

(Problems to be Solved by the Invention) However, in the former conventional example, the printed wire must be fixed to the leaf spring, which increases the assembly process and increases the manufacturing cost.

Further, in the latter conventional example, the armature of the drive means for the dot plate must be disposed around the side of the dot plate, which has the disadvantage of increasing the size of the structure of the printer head itself.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a printer head which employs a configuration in which printing is performed using a tot plate, which is effective in reducing the size and cost of the printer, and which has excellent printing responsiveness.

(Means for Solving the Problems) The features of the present invention include a dot plate, a stopper plate for regulating the return position of the dot plate, an armature for driving the dot plate for printing, and a return plate for the dot plate. spring and
It consists of a permanent magnet that biases the armature, and an electromagnetic device that releases the eccentric state of the armature. The vertically bent portions are arranged substantially radially, and the restoring leaf spring has a plurality of centripetally arranged tongues, each of which includes: The armature is in elastic contact with the front end of the vertically bent portion of the dot plate, and the armature has a plurality of tongues arranged centrially, and each of the tongues of the armature is connected to the dot plate. It faces the rear end of the vertically bent portion with a very small distance therebetween, and this very small distance is within the limit required to start printing under no-load conditions.

(Function) Therefore, when no current is applied, the drive spring 6 of the armature is in an eccentric state due to the permanent magnet 12, but when printing, by exciting the magnet coil 16 and canceling the magnetic field of the permanent magnet 12, In order to release the eccentric state of the armature, this armature strikes the vertically bent portion 4b of the dot plate 4. Therefore, the dot plate 4 moves forward against the spring force of the tongue piece 5b of the return leaf spring 5, and prints using the dot projection 4a. Furthermore, since the armature faces the dot plate 4 at a very small distance V, it can be started without any load. Immediately after printing, the excitation of the magnet coil 16 ends, so the armature drive spring 6 returns to its eccentric state due to the magnetic field of the permanent magnet 12, and at the same time, the dot plate 4 is returned to its original position by the return leaf spring 5. However, this return position is regulated by the stopper plate 7.

(Example) Embodiments of the present invention will be described based on the drawings.

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

A hollow portion 2 with an opening at the lower end is formed in the front half of the head frame 1, and three hammer guides 3 serving as guide means are inserted in parallel through the opening at the lower end. The concrete shape of the hammer guide 3 is as shown in the second figure, with staggered guide holes 3a for guiding a dot plate 4 (described later), and elastic arms 3 on both sides of the lower end of the guide.
b, 3b are formed, and locking claws 3c, 3c are formed on the outer lower ends of both arms. Therefore,
To insert the hammer guide 3 into the head frame 1, it is inserted along a guide groove previously formed in the hollow portion 2, and the locking pawl 3c is fitted into the locking groove of this guide groove and fixed. It is something. Nine dot plates 4 are slidably inserted into the guide hole 3a of each hammer guide 3 in the direction perpendicular thereto, as described above. The dot plate 4... has a dot projection 4a protruding from its tip as shown in the third figure, and a first vertically bent portion 4b and a stepped portion from this vertically bent portion only at its rear end. A second vertically bent portion 4c that protrudes is integrally formed. As described above, the dot plates 4 are arranged in a staggered manner by the guide holes 3a of the hammer guide 3, and the dot projections 4a of each dot plate are arranged in a single row.

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, an armature drive spring 6 is in contact with the rear end, and a stopper is in contact with the rear end of the second vertically bent portion 4c. A dot plate 7 can be brought into contact with the dot plate to regulate the return position of the dot plate.

As shown in FIG. 4, the specific shape of the return leaf spring 5 is such that the outer periphery is a ring-shaped portion 5a, and a plurality of tongues 5b are integrally formed centrially from this outer periphery. Each of the tongues 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 spring 6 of the armature is such that the outer peripheral part is a ring-shaped part 6a as shown in FIG. , each of the tongues 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 leaf spring 5 and the stopper plate 7. Further, the ring-shaped portion 6a of the drive spring 6 is connected to the support plate 9.
A yoke plate 11 and a permanent magnet 12 are disposed on the rear surface of this 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, and a movable yoke 13, which forms an armature together with the drive spring 6, is fitted into each through hole. This movable yoke 1
3 is press-fitted and fixed to the tongue piece 6a of the drive spring 6, and the rear end surface of the movable yoke 13 is magnetically connected to the tip surface of the iron core 15 press-fitted and fixed to the yoke 14 forming the magnetic path. It can be freely attached and detached. and iron core 1
A magnetic coil 16 is wound around the yoke 5, and the rear end of this coil is located in a coil bobbin 17 fixed to the yoke 14.

Note that, as mentioned above, the dot plate 4 is
They are arranged in a staggered manner by the guide holes 3a of the hammer guide 3 shown in the figure, but as shown in Figure 7, the rear end of this dot plate has vertical bent portions 4b and 4c with different bending angles. The upright portions are arranged substantially radially. The return leaf spring 5 and the armature 6 are provided with tongue pieces 5b and 6b, respectively.
Since they are formed centrially, they can be centrally arranged in the center of the printer head, resulting in excellent space efficiency.

Here, printing drive by the electromagnetic device will be explained.

The tongue piece 6b of the drive spring 6 of the armature is the fifth
As shown in the lower part of the figure, the movable yoke 13 is attracted to the iron core 15 by the electric field of the permanent magnet 12, and is therefore in an eccentric state.

During printing, the magnetic coil 16 is momentarily excited, thereby canceling the magnetic field of the permanent magnet 12, and as shown in the upper part of FIG. 5, the drive spring 6 is released from its eccentric state. The dot plate 4 is struck by the dot plate 4, and printing is performed by the dot projection 4a of the dot plate. After printing, the movable yoke 13 is again attracted to the iron core 15, and the tongue piece 6b of the drive spring 6 becomes eccentric. At the same time, the dot plate 4 is returned to its original position by the tongue piece 6b of the return leaf spring 5, and this return position is regulated by the stopper plate 7.

Further, the tongue piece 6b of the armature drive spring 6
is in an eccentric state due to the magnetic field of the permanent magnet 12 as shown in the lower part of FIG. 〓V is provided. During this time, when the eccentric state of the tongue 6b is released during printing due to 〓V, the activation of the tongue into the released state is started in a no-load state, so that the responsiveness of printing is significantly improved.

Further, the periphery of the magnet coil 16 is molded 18 with a highly thermally conductive resin, and a heat dissipation fin 19 is fitted around the yoke 14, and a screw is inserted through a mounting hole in the head frame. The tip is screwed into the fin 19.

Further, the end of each magnet coil 16 is connected to a flexible cable 21 via a terminal 20 projecting rearward from the coil bobbin 17, and this cable connection surface is covered by a head cover 22.

Note that 23 and 24 are nonwoven fabrics (felt) impregnated with lubricating oil to reduce contact friction between the dot plate and the drive spring and the return spring, and to prevent rust.

(Effects of the Invention) In the present invention, the vertically bent portions of the dot plate are arranged substantially radially, and the return leaf spring has a plurality of tongues arranged centripetally, and the armature has multiple tongues arranged centripetally, and these structures are organically combined, making the overall structure of a printer using a dot plate smaller, and as a result, cheaper to manufacture. can. Further, since there is a small distance between each tongue of the armature and the rear end of the rising portion of the dot plate, the responsiveness of printing is good.

[Brief explanation of drawings]

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 armature, and FIG. 7 is a sectional view taken along the line of FIG. 1. 4... Dot plate, 4a... Dot protrusion,
4b, 4c... Vertical bent portion for driven, 5... Leaf spring for return, 5b... Tongue piece, 6... Armature (drive spring), 6b... Tongue piece, 7... Stopper plate, 12... ...Permanent magnet, 13... Armature (movable yoke), 14... Yoke, 15... Iron core,
16...Magnetic coil.

Claims (1)

[Scope of Claims] 1. A plurality of dot plates, a stopper plate that regulates the return position of each of the dot plates, an armature that drives the dot plates for printing, and a return leaf spring for the dot plates, The dot plate includes a permanent magnet that biases the armature, and an electromagnetic device that releases the eccentric state of the armature by canceling the magnetic field of the permanent magnet by excitation of a magnetic coil. The striking protrusion has a vertical bent portion for being driven only at the rear end, and the vertical bent portions are arranged substantially radially, and the return leaf spring is arranged centripetally. The armature has a plurality of tongues arranged in a centripetal manner, each of the tongues being in elastic contact with the front end of the vertically bent portion of the dot plate, and the armature having a plurality of tongues arranged centripetally. Each of the tongue pieces of the armature faces the rear end of the vertically bent portion of the dot plate with a very small gap, and this small gap prevents the armature from starting printing. A printer head characterized in that it is of a limit necessary to perform under load conditions. 2. In claim 1, the dot plates are arranged in a staggered manner, and each tongue of the return leaf spring and each tongue of the armature are each integrally connected to a ring-shaped portion on the outer periphery. ing. A printer head characterized by: