JPS6232858Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in dot printer heads.

A conventional dot printer head has a structure as shown in FIG. 1, for example. That is, the head body 1
A plurality of electromagnets 2 are arranged at equal intervals on the same circumference on the outer periphery of the rear end side. As is well known, the electromagnet 2 includes a bobbin 5 around which a coil 4 is wound around a core 3, and the bobbin 5 is surrounded by a U-shaped frame 6. A front plate 7 is fixed to the front surface of the head body 1, and a rear plate 8 is fixed to the rear surface thereof. The front plate 7 is provided with a plurality of linear or staggered guide holes for positioning and guiding the tips of a plurality of wires 9 disposed inside the head body 1, respectively. Wire pins 10 are provided at the rear ends of the plurality of wires 9, respectively.
The rear ends of the wires 9 are arranged on the circumference in correspondence with the plurality of electromagnets 2, respectively, and the wires 9 are biased toward the rear plate 8 by wire springs 11. One end of the wire pin 10 is in contact with the other end of an armature 12 which is rotatably attached to the electromagnet 2, and an armature spring 13 is hung on the end of the armature 12 on the one end side. 12 is urged in a direction away from the core 3.
The back surface of the armature 12 on the wire pin 10 side comes into contact with a fixed position stopper 14 fixed to the rear plate 8, and is held in a fixed position. Further, as shown in FIG. 2, the rotation fulcrum structure of the armature 12 is such that a protrusion 6a formed protruding from the end of the frame 6 engages with a notch groove 12a formed on both sides of the armature 12. It becomes. In addition, in FIG. 1, only one electromagnet 2, wire 9, armature 12, etc. are shown for convenience of illustration.

Next, its effect will be explained. When the core 3 is energized, the armature 12 is pulled by the core 3 and activated, thereby pushing the rear end of the wire pin 10 and causing the wire 9 to protrude from the front plate 7 to perform dot printing. When the core 3 is deenergized, the armature 12 is moved back by the action of the armature spring 13, and the wire 9 is moved back by the action of the wire spring 11.

In this way, in the conventional structure, the armature 12 is biased by the armature spring 13, which is a coil spring disposed on the electromagnet 2 side. It is in a state of being very mobile. Therefore, the fulcrum 12b of the armature 12 moves up and down and is not fixed at one location, resulting in unstable operation of the armature 12 and large friction loss.

The present invention was devised in view of the above-mentioned drawbacks of the prior art, and an object of the present invention is to provide a dot printer head that can stabilize the operation of the armature.

Hereinafter, the present invention will be explained with reference to illustrated embodiments.

FIG. 4 is an enlarged cross-sectional view of essential parts showing an embodiment of the dot printer head according to the present invention, and FIG. 5 is a view taken from the direction of arrow C in FIG. 4. In addition, the first
The same members as those in the figures are given the same reference numerals and their explanations will be omitted. In the present invention, the armature spring 20 is formed by a plate spring, one end of which is clamped and fixed between the rear plate 8 and the positioning stopper 14, and the other end is a sloped portion 20a that presses the end of the armature 12 on the rotation fulcrum side from an oblique direction. will be established. In this way, the force of the inclined portion 20a of the armature spring 20 causes the armature 1 to
2 is always urged in the axial direction of the head body 1, so the fulcrum 12b of the armature 12 is always
This stabilizes the operation of the armature 12.

As is clear from the above description, according to the dot printer head of the present invention, the operation of the armature is stable and friction loss is reduced, so that printing speed can be improved.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a conventional dot printer head, Fig. 2 is a view taken from the direction of arrow A in Fig. 1, Figs. FIG. 4 is an enlarged cross-sectional view of essential parts showing an embodiment of the dot printer head according to the present invention, and FIG. 5 is a view taken from the direction of arrow C in FIG. DESCRIPTION OF SYMBOLS 1... Head body, 2... Electromagnet, 9... Wire, 12... Armature, 20... Armature spring, 20a... Inclined part.

Claims (1)

[Scope of utility model registration request] An armature whose notched groove or hole formed at one end is rotatably engaged with a protrusion of the frame with play, an electromagnet that attracts the armature, and an electromagnet that attracts the armature in a direction opposite to the direction of attraction of the electromagnet. It includes an armature spring that biases the armature, and a wire that comes into contact with the other end of the armature and is slidably provided on the head body, and the armature is attracted by the electromagnet, thereby causing the wire to move in its axial direction. In a dot printer head that prints by moving, the armature spring is a leaf spring having an inclined portion that presses an end of the armature on the side remote from the wire side so as to bias the armature in the axial direction of the head main body. A dot printer head characterized by: