JPH02273244A - Printing head for serial printer - Google Patents

Abstract

PURPOSE:To reduce the number of components, and to obtain a printing head adapted for inexpensively printing at a high speed by composing an armature unit for driving a printing wire of an armature block, and an armature arm secured at one end to one end of the wire and at its lower end to a spacer via the hole of a leaf spring. CONSTITUTION:When a print command is received, a current flows to a coil 6 to generate a magnetic force opposite to that by a permanent magnet 1 in a yoke 3. Accordingly, the magnetic force by the magnet 1 is cancelled, and an armature block 4 is separated from the yoke by elastic energy stored a deflected leaf spring 7 and at the end 12a of the armature arm 12. Thus, a printing wire 13 coupled to the block 4 via the arm 12 is operated in a direction of an arrow X to print a dot via an ink ribbon on a printing sheet. Since the lower end 12a of the arm 12 is secured to a spacer 8 having sufficient rigidity, the block 4 released from the yoke 3 is restricted to move in the X direction of the block 4 to accelerate the returning motion (Y direction) of the wire 13.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a print head for a serial printer, and more particularly to a print head for a serial printer suitable for use in a dot matrix printer.

[Conventional technology]

FIG. 3 is a sectional view showing an example of a print head of a conventional serial printer.

As shown in FIG. 3, a permanent magnet 21 of a conventional print head
is one end of the “C”-shaped yoke 23 and the yoke 2
The excitation coil 6 is wound around the other end of the yoke 23. The leaf spring 27 is
It has a hole 34 approximately in the center thereof, and its lower end is held between the spacer 28 and the two to form a cantilevered structure. Spacers 28 and 29 are fixed to frame 31 together with leaf spring 27 by screws 20. The free end of the leaf spring 27 (
The armature block 24 is located at the upper end in FIG.
is fixed, and the armature arm 32 is inserted into the slit provided on the upper surface of the armature block 25.
is inserted and fixed by brazing. One end of the printing wire 13 is coupled to the upper end of this armature arm 32. A round bar-shaped spring 35 is coupled to the lower end of the armature block 24.
The tip end of the plate spring 27 passes through a hole 34 provided in the leaf spring 27 and is coupled to the spacer 8 . An armature system configured in this way is usually called a cross spring type armature system.

Next, the operation of the conventional print head configured as described above will be explained.

When inactive, the armature block 24 is connected to the permanent magnet 2
The leaf spring 27 and the spring 35, which are attracted to the yoke 23 by the magnetic force of 1 and have their free ends connected to the armature block 34, are both bent. When current is applied to the excitation coil 26 as necessary, the magnetic force of the permanent magnet 21 is canceled, and the armature block 24 is separated from the yoke 23 by the elastic energy stored in the bent leaf spring 27 and spring 35. , operates the printing wire 33 connected to the armature block 24 via the armature arm 32, and prints the printing paper (not shown).
Dots are printed on the paper using an ink ribbon. Even after completing the dot printing operation, the armature block 24 released from the yoke 23 continues to move forward due to inertia.
(to the left in Figure 3). However, spring 35
Since the movement of the armature block 24 is restricted by this, the printing operation is stabilized.

[Problem to be solved by the invention]

The conventional print head having a cross spring type armature system as described above has the advantage of being suitable for high-speed printing because the operation of the armature system is stable.
On the other hand, it has a disadvantage that it has a complicated structure and therefore has a large number of parts, and as a result, it is not possible to manufacture a low-cost print head.

[Means to solve the problem]

The print head of the serial printer of the present invention includes a plurality of print wires, a plurality of armatures that individually drive the print wires, and a leaf spring that securely holds the armature at the upper end and has a hole in the center. The permanent magnet is held between a spacer that clamps and holds the lower end of the leaf spring, a U-shaped yoke that holds the permanent magnet at the lower end, and the U-shaped yoke. a second yoke for fixing the spacer at an end face thereof; and an excitation coil for driving the armature wound around the upper end of the U-shaped yoke, the armature being connected to the excitation coil. an armature block disposed opposite to the upper end of the yoke around which a and an armature arm that protrudes from the plate spring, passes through the hole of the leaf spring, and is fixed to the spacer.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view showing one embodiment of the present invention.

The embodiment shown in FIG. 1 includes a frame 11 having a wire guide hole 11b provided for guiding a printing wire 13 in a nose portion 11a formed by projecting the upper end thereof, and a lower end portion of the frame 11 facing opposite to the nose portion 11a. A permanent magnet 1 is fixed to the lower end of the yoke 3, and a yoke 2 is fixed so as to sandwich the permanent magnet 1. .These yoke 3, yoke 2, and permanent magnet 1 create a “co” with a built-in permanent magnet.
A letter-shaped yoke is formed. An excitation coil 6 is wound around the other end of the yoke 3 (upper side in FIG. 1). A leaf spring 7 having a hole 14 in the center has its lower end held between spacers 8 and 9, and the leaf spring 7 and spacers 8 and 9 are fixed to the lower end of the frame 11 with screws 20. At the upper free end of the leaf spring 7,
An armature 5 for driving the printing wire 13 is mounted.

This armature 5 is connected to the yoke 3 as shown in FIG.
An armature block 4 is disposed opposite to the upper end and is fixed to the free end of the leaf spring 7, and one end of the printing wire 13 is fixed to the tip, and the lower end is connected to the armature block 4. The leaf spring 7 is made to protrude in the right angle direction.
The armature arm 12 is fixed to the upper part of the spacer 8 by passing through the hole 14 of the spacer 8.

The tip of the printing wire 13 is attached so that it can slide inside the wire guide hole 11b. The printing wire driving means including the armature 5 includes printing wires 1 provided in the number necessary for forming characters by dots.
The number corresponding to 3 is equipped.

Next, the operation of the above embodiment will be explained.

When not in operation, the armature block 4 has a permanent magnet 1
The lower ends of the leaf spring 7 and the armature arm 12, whose free ends are connected to the armature block 4, are bent by the magnetic force of the yoke 3. When a printing command is received, a current flows through the coil 6 and the permanent magnet l
Since a magnetic force in the opposite direction to the magnetic force due to is generated in the yoke 3,
The magnetic force of the permanent magnet 1 is canceled out, and the elastic energy stored in the bent leaf spring 7 and the tip 12a of the armature arm 12 causes the armature block 4 to leave the yoke. As a result, the printing wire 13 connected to the armature block 4 via the armature arm 12 moves in the direction of arrow X, printing dots on printing paper (not shown) through the ink ribbon. The armature block 4 is released from the yoke 3.
Even after the above-described dot printing operation is completed, the dot tries to move forward (in the X direction) due to inertia, but since the lower end 12a of the armature arm 12 is fixed to the spacer 8 with sufficient rigidity, the armature Block 4 X
The movement in the direction is restricted and the return movement of the printing wire 13 (
Y direction).

That is, the lower end 12a of the armature arm 12 is
Acts as a cross spring type vertical spring.

〔Effect of the invention〕

As explained above, in the print head of the present invention, the armature system that drives the print wire is fixed to the armature block and one end of the print wire, and the lower end protrudes at right angles to the armature block. By constructing the armature arm which is fixed to the spacer by passing through the spring hole, there is an effect that the number of parts can be reduced and an inexpensive print head suitable for high-speed printing can be obtained.

- A perspective view showing the relationship with a mature arm; FIG. 3 is a sectional view showing an example of a print head of a conventional serial printer;

1.21... Permanent magnet, 2.3.22.23... Yoke, 4.24... Armature block, 5.25
... Armature, 6.26 ... Excitation coil, 7
・27... Leaf spring, 8, 9, 28, 29... Spacer, 11, 31... Frame, lla... Knob section, 11b... Wire guide hole, 12, 32... Armature Arm, 12a... Tip of armature arm, 13, 33... Printing wire, ]4, 34...
Hole, 35... spring, 40... screw.

Claims (1)

[Claims] A plurality of printing wires, a plurality of armatures that individually drive the printing wires, a leaf spring that firmly holds the armature at its upper end and has a hole in its center, and a lower end of the leaf spring that is held in place. a spacer that holds the permanent magnet at its lower end; a U-shaped yoke that holds a permanent magnet at its lower end; and a spacer that holds the permanent magnet between the U-shaped yoke and fixes the spacer on its end face. a second yoke, and an excitation coil for driving the armature wound around the upper end of the U-shaped yoke, wherein the armature is connected to the upper end of the yoke around which the excitation coil is wound. an armature block disposed opposite to the plate spring; one end of the printing wire is fixed to the tip, the lower end is fixed to the armature block, and the tip protrudes perpendicularly to the armature block; A print head for a serial printer, comprising an armature arm that passes through a hole and is fixed to the spacer.