JPH0655746A - Printing head - Google Patents

Abstract

PURPOSE:To ensure that a stopper part and an armature become less abraded by making T-shaped an area which comes in contact with the armature of the stopper part for determining the return position of the armature. CONSTITUTION:An armature 2 which is attracted by a coil assembly 1 returns to a home position by force of a spring 8, if the assembly is shut off from an electric current supply. In this case, the rear of the armature 2 runs into the stopper part 5, thus causing the armature to come to a stop. The stopper part 5 is T-shaped so that the area which comes in contact with the armature 2 becomes large. Since the armature 2 comes in contact with the T-shaped part 7, the stopper part and the armature are less abraded, if they collide with each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a print head for a dot impact serial printer.

[0002]

2. Description of the Related Art A conventional print head of a dot impact serial printer has an armature having a print wire fixed to its tip, and a coil assembly which is provided corresponding to the armature and which attracts the armature by supplying an electric current. The coil assembly is provided with a spring that returns the armature that is sucked, and a stopper that determines the return position of the armature when returned by the spring.The stopper is made of plate material and its thickness Is very thin, 0.2 mm, so that the contact area between the stopper portion and the armature is small, and the contact surface is a fracture surface due to press working, so that it is easily worn by collision with the armature.

[0003]

As described above, the conventional print head of the dot impact serial printer is
The stopper part is made of a thin material by press working, and its fracture surface is in contact with the armature, so the stopper part and the armature are easily worn due to collision with the armature. However, this wear reduces the life of the printhead.

[0004]

The print head of the present invention comprises:
An armature having a print wire fixed to the tip, and a coil assembly provided corresponding to the armature to attract the armature by supplying an electric current;
In a print head of a dot impact serial printer, comprising: a spring for returning the armature sucked by the coil assembly; The portion that comes into contact with the "T" shape is formed, and a film sheet is attached to the surface of the "T" shape portion.

[0005]

Embodiments of the present invention will now be described with reference to the drawings.

FIG. 1 is a perspective view showing details of the stopper portion of the embodiment of FIG. 2, and FIG. 2 is a sectional view showing an embodiment of the present invention.

In the embodiment shown in FIG. 2, an armature 2 having a print wire 3 for printing fixed to its tip and a corresponding armature 2 are provided, and a coil assembly for attracting the armature 2 by supplying an electric current. The solid 1 is provided with a spring 8 for returning the armature 2 attracted to the coil assembly 1, and a stopper portion 5 for determining a returning position of the armature 2 when the armature 2 is returned by the spring 8.

The armature 2 attracted to the coil assembly 1 returns to its original position by the force of the spring 8 when the supply of the electric current to the coil assembly 1 is cut off. At this time, the back surface of the armature 2 is a stopper. It collides with the part 5 and stops.

As shown in FIG. 1, the stopper portion 5 increases the area of the portion in contact with the armature 2,
It is formed in a "T" shape. Since the armature 2 comes into contact with the “T” -shaped portion 7, wear of the stopper portion and the armature due to collision is reduced.

Further, when the film sheet 6 is adhered to the surface of the "T" -shaped portion 7, the collision between the metal members is avoided, so that the wear of the stopper portion and the armature is reduced,
Noise during a collision is also reduced.

[0011]

As described above, in the print head of the present invention, the stopper portion and the armature that are in contact with the armature of the stopper portion, which determines the armature return position, have a "T" shape so that the stopper portion and the armature are not worn. The effect is that it can be reduced, and therefore the life of the print head can be extended.

[Brief description of drawings]

FIG. 1 is a perspective view showing details of a stopper portion of the embodiment of FIG.

FIG. 2 is a sectional view showing an embodiment of the present invention.

[Explanation of symbols]

 1 Coil Assembly 2 Armature 3 Print Wire 5 Stopper 6 Film Sheet 7 “T” Shape 8 Spring

Claims (2)

[Claims] 1. An armature having a print wire fixed to a tip thereof, a coil assembly provided corresponding to the armature to attract the armature by supplying an electric current, and the armature attracted to the coil assembly. In a print head of a dot impact serial printer that includes a spring that returns the armature and a stopper that determines the return position of the armature when the spring returns, a portion of the stopper that contacts the armature is a "T" shape. A print head characterized in that 2. An armature having a print wire fixed to a tip thereof, a coil assembly provided corresponding to the armature to attract the armature by supplying an electric current, and the armature attracted to the coil assembly. In a print head of a dot impact serial printer that includes a spring that returns the armature and a stopper that determines the return position of the armature when the spring returns, a portion of the stopper that contacts the armature is a "T" shape. The print head is characterized in that a film sheet is attached to the surface of the "T" -shaped portion.