JPH026147A - Impact dot type printing head - Google Patents

Abstract

PURPOSE:To prevent the displacement of the position of a fulcrum, and to improve the accuracy of printing by forming a protruding section for engaging an armature to a supporting material. CONSTITUTION:When a signal is input to a magnetic coil 12, electromagnetic force is generated in the magnetic coil 12, and an armature 7 is attracted to a yoke attracting surface 11a while using a rear section 7b as the center of revolution. Consequently, a wire 2 fitted at the nose 7a of the armature is introduced by guide plates 3-6, and the tip of the wire strikes an ink ribbon and printing is conducted. When the signal to the magnetic coil 12 is interrupted, the magnetic force of the magnetic coil 12 disappears, and the armature 7 is pushed back to a stopper plate 14 by the resiliency of a coil spring 13, and returned to an original position. Printing is performed by the repetition at high speed of the attraction and return, but the protruding section 8a of a supporting rubber holds down movement in the centripetal direction of the armature, thus reproducing repetition at high speed at the same position at all times, then allowing stable printing.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an impact dot type print head, and particularly to an impact dot type print head suitable for high precision printing.

[Prior Art] Conventionally, an impact dot print head uses a magnetic coil to attract an armature with its electromagnetic force, and a return spring returns the armature to its original position, thereby causing a reciprocating motion in the wire. It has a structure for printing. As shown in FIG. 3, the armature is a rod-shaped member whose outer end 51a of the print head is held down by a support rubber 52 with a rectangular cross section as a fulcrum, and whose other end is a point of action for printing. At times, the electromagnetic coil attracts the force point 51b located in the middle, and after printing, the spring coil returns to the original position.

Further, as a method for fixing the fulcrum so that it can rotate freely, there is also a method such as drilling a hole in the armature and using a bottle.

[Problem to be solved by the invention]

However, in the above conventional example, the fulcrum of the armature is simply held down from above by a support rubber with a rectangular cross section that is easy to manufacture and easy to manufacture, so the movement of the fulcrum in the axial direction of the armature is not sufficiently restrained. It had not been done. As a result, the fulcrum often moves when the entire armature moves up and down, which is caused by the wire-attached side of the armature being attracted to the magnetic coil or returning to its original position. As a result, the armature cannot return to its normal position, and the up-and-down movement during printing becomes unstable, resulting in misalignment of dots and the like, resulting in a situation in which highly accurate printing cannot be expected.

Further, there have been problems in that the ink ribbon gets caught on the printing wire that is striking the ink ribbon, and excessive force is applied to the printing wire, causing damage.

On the other hand, there is also a structure in which a hole is made in the armature using a bottle and the armature is fixedly supported, but the structure is complicated and expensive, resulting in poor productivity.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide an impact dot type print head which can improve the disadvantages seen in the conventional example and is capable of printing with high precision.

[Means to solve the problem]

In the present invention, a wire section that strikes an ink ribbon to print, an armature that transmits a driving force to this wire section,
It includes a support member that presses one end of the armature on the outer circumferential side of the print head and forms the center of the reciprocating rotational movement, and a drive unit that applies a driving force to the armature.

Furthermore, the above-mentioned support material is equipped with a protrusion for locking the armature. This aims to achieve the above-mentioned purpose.

[Function] When a print signal is input to the magnetic coil (driver) for driving the armature, the armature is attracted by the electromagnetic force of the magnetic coil, using the end pressed by the support rubber as a fulcrum. Next, when the printing signal to the magnetic coil is interrupted, the electromagnetic force disappears and the return spring pushes it back to its original position. As a result, during the reciprocating rotational movement of the armature, the deviation of the fulcrum in the centripetal direction, which conventionally occurs, is restrained by the protrusion provided on the support rubber.
The armature can always rotate back and forth at the same position.

On the other hand, the wire portion protrudes from the end of the armature opposite to the fulcrum and reciprocates according to the movement of the armature, striking the ink ribbon when the armature is attracted by the magnetic coil to print.

[Embodiment of the Invention] An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

FIG. 1 shows a half-sectional view of the entire print head.

Inside the protrusion la of the head frame 1 having a convex cross section, there is a
It is equipped with a plurality of printing wires 2 that are capable of reciprocating movement and a guide plate 3.4.5.6 that guides the movement of the wires 2.

The wire 2 has one end fixed to the tip 7a of the armature 7, and has small holes 3a and 4a in which guide plates exist.

5a and 6a, and the printing position is determined by this.

The armature 7 is arranged such that its other end is pressed against the ring yoke 9 by a support rubber 8, and its end 7b is pressed against the armature guide 10 so that it can rotate reciprocally as a fulcrum. At the same time, the protrusion 8a of the support rubber 8 restrains the armature from moving in the centripetal direction. Further, the armature 7 includes a yoke 11, a ring yoke 9 and a magnetic coil 1.
2 forms a magnetic circuit, and is disposed so as to face the attracting surface 11a of the yoke 11.

Further, the return spring 13 is arranged so as to push the armature 7 back toward the stopper plate 14 in the opposite direction to the attraction by the electromagnetic force.

In the impact dot print head configured as described above, when a signal is input to the magnetic coil 12, the magnetic coil 12 emits electromagnetic force, and the armature 7 is attracted to the yoke suction surface 11a with the rear part 7b as the center of rotation. As a result, the wire 2 attached to the tip 7a of the armature is guided to the guide plates 3, 4, 5.degree.6, and its tip hits the ink ribbon to perform printing.

Next, when the signal to the magnetic coil 12 is interrupted, the magnetic force of the magnetic coil 12 disappears, and the armature 7 is moved to the stopper plate 14 by the repulsive force of the coil spring 13.
It is pushed back towards and returns to its original position.

Printing is performed by repeating this suction and return at high speed, but since the protrusion 8a of the support rubber prevents the armature from moving in the centripetal direction, the high speed repetition is always reproduced at the same position, making it very difficult to print. Stable printing is now possible.

(Effects of the Invention) Since the present invention is configured and functions as described above, the fulcrum position does not shift as in the conventional example, and
Therefore, it is possible to provide an impact dot type print head that is unprecedentedly effective and can provide stable printing and avoid damage to printing wires, ink ribbons, etc.

[Brief explanation of the drawing]

FIG. 1 is a half sectional view of an overall diagram showing one embodiment of the present invention, FIG. 2 is a detailed explanatory view showing a part of FIG. 1, and FIG. 3 is an explanatory view showing a conventional example. DESCRIPTION OF SYMBOLS 1... Head frame, 2... Wire, 7... Armature, 8... Support rubber, 10... Armature guide, 11... Yoke, 12... Coil,
l3... Return spring, 14... Stopper plate. Patent applicant: Japan Electric Co., Ltd. Agent Patent attorney Isamu Takahashi Figure 1 Figure 3 (coil) 51a 52 (punch rubber)

Claims (1)

[Claims] (1) a wire section that prints by striking an ink ribbon;
An armature that transmits a driving force to the wire section, a support member that holds down one end of the armature on the outer periphery of the print head and forms the center of rotational movement, and a drive section that applies a driving force to the armature. An impact dot type print head comprising: The support material is equipped with a protrusion for locking the armature.