JPH0584931A - Printing head of wire dot printer - Google Patents

Abstract

PURPOSE:To save labor for repairing of warps of an armature one by one to manufacture a normal printing head. CONSTITUTION:A film 60 is placed between an end cap 16 and back stopper 18 on the basis of a decrease of a quantity of a stroke of a wire 36 by a warp of an armature 26, through which a distance (space) between a film 30 energized by a yoke 14 and a damper 54 energized by a back stopper 18 is extended and a quantity of a stroke of the wire 36 is increased.

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 wire dot printer.

[0002]

2. Description of the Related Art Conventionally, a wire dot printer is usually
A print head provided with a plurality of wires in two rows or two rows is moved in a certain direction at a predetermined pitch, and the wires are driven at appropriate times based on the print data to express a character corresponding to the print data. The dot matrix was formed on the paper. The basic structure of the print head 10 of such a wire dot printer is shown in FIG.

The print head 10 has a skeleton formed of a yoke 14, an end cap 16, and a back stopper 18 with the front frame 12 as a reference.

An iron core 22 constituting an electromagnet 20 and a coil 24 wound around the iron core 22 are attached to the yoke 14. The armatures 26 are arranged radially, and the outer ends 27 of the armatures 26 are biased by a leaf spring 28 through a film 30 against a part of the yoke 14. Then, the movable piece 32 forming a part of the armature 26 is attracted by the electromagnet 20, so that the free end 34 of the armature 26 is guided and rotated by the rib 68 formed on the end cap 16. The wire 36 is attached to the free end 34 of the armature 26.
And is actuated by the rotation of the armature 26, and moves in the direction of the ink ribbon 46 according to the guide of the guide plates 38, 40, 42, 44. At this time, the ink ribbon 46 is moved to the sheet 5 by the tip portion 48 of the wire 36.
Since it is pressed against 0, the ink of the ink ribbon 46 adheres to the paper 50 at that portion, and dots are printed.
When the movable piece 32 is no longer attracted by the electromagnet 20, the wire 36 that has moved toward the ink ribbon 46 is urged by the spring 52 supported by the guide plate 38 to cause the armature 26 to move.
Returns to the position supported by the back stopper 18 via the damper 54. Further, a film 56 is arranged between the armature 26 and the leaf spring 28 to suppress wear on the contact surface between the armature 26 and the leaf spring 28.

By the way, this wire 36 is used for the print head 1.
0 is assembled, the tip 48 of the guide plate 44
The stroke amount of the wire 36 (the maximum amount by which the tip end 48 of the wire 36 can jump out of the guide plate 44) is determined by the distance that the free end 34 of the armature 26 moves.

The print head 10 is usually composed of a plurality of wires 36. In this case, each wire 36 is independently driven by the above-mentioned structural unit to attach the ink of the ink ribbon 46 to the paper 50. Then, a dot matrix expressing characters is formed on the paper 50.

[0007]

However, in the conventional print head 10, when the armature 26 is manufactured, the armature 26 is warped, and the stroke amount of the reciprocating wire 36 becomes improper. The print quality sometimes deteriorated. In particular, armature 26
When the movable piece 32 is attached to the armature 26 by thermal staking, the armature 26 is moved in the direction in which the stroke of the wire 36 is reduced.
Was often warped. When the stroke amount of the wire 36 cannot be sufficiently obtained, the ink ribbon 46 cannot be sufficiently pressed against the paper 50 by the tip 48 of the wire 36, so that the print quality deteriorates. In the print head 10 in which the print quality is deteriorated in this way, the print head 10 that has been assembled once is disassembled, the warps of the armatures 26 are manually corrected, and then the print head 10 is reassembled. In order to manufacture the print head 10 as described above, there is a problem that it takes a very troublesome work of disassembling the print head 10 once assembled and correcting the warp of the armature 26 by hand.

The present invention has been made to solve the above-mentioned problems, and corrects the deviation of the stroke amount of the wire from the normal stroke amount due to the warp of the armature, which occurs when the armature is manufactured. Therefore, it is an object of the present invention to provide a print head of a wire dot printer that can save the trouble of individually correcting the warp of the armature.

[0009]

In order to achieve this object, a print head of a wire dot printer according to the present invention is provided with an electromagnet for changing the strength of a magnetic field, and a rotating head according to the change of the strength of the magnetic field by the electromagnet. An armature that moves and drives a wire by its rotation, a back stopper that determines a rest position of the rotation operation of the armature, a support portion that supports the armature, and urges the armature to the support portion. The armature is integrally formed with a leaf spring and a film interposed between the leaf spring and the armature, and is interposed between the support portion and the back stopper to change the fixed position of the back stopper with respect to the support portion. And a turning stroke amount adjusting member for changing the rest position of the turning operation.

[0010]

The armature of the present invention having the above structure is
The wire is driven to rotate according to the change in the strength of the magnetic field generated by the electromagnet. The back stopper determines the rest position of the pivotal movement of the armature. The support part supports the armature. The leaf spring biases the armature against the support. The rotary stroke amount adjusting member is interposed between the leaf spring and the armature, is integrally formed with a film that suppresses abrasion of the contact surface between the leaf spring and the armature, and is interposed between the support portion and the back stopper. , By changing the fixed position of the back stopper with respect to the support portion, the rest position of the pivotal movement of the armature is changed.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

1 and 2 illustrate an embodiment of the present invention. The same parts as those in FIG. 7 are designated by the same reference numerals and detailed description thereof will be omitted. As shown in FIG. 2, the movable piece 32 is attached to the armature 26 of the print head 58 of the present embodiment by a heat staking method, and the central portion of the armature 26 is closer to the yoke 14 (the stroke of the wire 36) than the both ends. The amount is decreasing). The amount of warp of the armature 26 varies depending on the conditions at the time of heat staking and is not constant. In addition, against the decrease in the stroke amount of the wire 36 due to the warp of the armature 26,
As shown in FIG. 1, by sandwiching the film 60 between the end cap 16 and the back stopper 18, the distance between the film 30 urged by the yoke 14 and the damper 54 urged by the back stopper 18 is increased. The (space) is widened to increase the stroke amount of the wire 36.

As shown in FIG. 3 (a), the film 60 has nine covering portions 60 formed radially at substantially equal intervals.
Stroke adjusting part 60 in which the radial center of the covering part 60a is formed in the same radial shape at substantially equal intervals at three positions between the a and the covering part 60a, and screw holes 62 are provided in the vicinity of the tip part thereof.
and b are integrally formed.

This film 60 has the armature 26 mounted on the armature mounting portion 64 formed by the ribs 68 of the end cap 16 shown in FIG. 4 (however, in FIG. 4, two armatures 26 are mounted). 9 are actually mounted in the print head 58 in which the end cap 16 shown in FIG. 4 is used.) The screw hole 66 and the film 60 provided in the end cap 16 from above. And the screw holes 62 of are fitted together. FIG. 5 shows the state at that time. In FIG. 5, the covering portion 60a of the film 60 is
It covers almost all of the armature 26 except near the free end 34. In addition, the stroke adjusting portion 60b of the film 60 covers most of the ribs 68a provided with the screw holes 66 among the ribs 68 of the end cap 16 forming the armature mounting portion 64.

Next, the leaf spring 28 is thus formed into the film 6
It is mounted from the state where 0 is mounted. FIG. 6 shows the state at that time. In FIG. 6, the covering portion 60 a of the film 60 is arranged at a position below the leaf spring 28 and covered with the leaf spring 28. The stroke adjusting portion 60b of the film 60 is not covered by the leaf spring 28 but covers most of the rib 68a provided with the screw hole 66.

Then, when the back stopper 18 is mounted from the state shown in FIG. 6 and the back stopper 18 is biased toward the end cap 16 by the screw 70, the rib 68a provided with the screw hole 66 is placed on the rib 68a. The stroke adjusting portion 60b of the film 60 thus arranged causes the end cap 16
It is sandwiched between the back cap 18 and the back stopper 18, and the position where the back stopper 18 is biased is pushed up toward the end cap 16.

In this way, the film 30 urged by the yoke 14 and the back stopper 18 are urged by the means for sandwiching the member for adjusting the stroke amount of the wire 36 between the end cap 16 and the back stopper 18. The stroke amount of the wire 36 is increased by increasing the distance (space) from the damper 54 and adjusting the stroke amount of the wire 36.

Here, the amount by which the stroke of the wire 36 is reduced corresponds to the amount of warp of the armature 26, and the amount of warp of the armature 26 is substantially determined by the attachment of the movable piece 32. Since the movable piece 32 is generally attached by a machine, the armature 26 manufactured at the same time is manufactured.
Then, the variation in the warp amount is small. Therefore, a warp of the armature 26 randomly selected from a fixed number of armatures 26 manufactured at the same time is examined, and a stroke adjusting portion 60b having a thickness for correcting the decrease in the stroke amount of the wire 36 due to the warp is provided. By sandwiching the film 60 between the end cap 16 and the back stopper 18, an appropriate stroke amount of the wire 36 is secured. As shown in FIG. 3, the film 60 has a plurality of coatings 60a having the same thickness, the stroke adjusting portion 60b being thinned by rolling or the like, and having different thicknesses.

As described above, in the print head 58 of the wire dot printer according to the present invention, it is not necessary to correct the warp of the armature 26 one by one, and an appropriate stroke amount of the wire 36 is secured, so that good printing can be performed. You can get quality.

[0020]

As is apparent from the above description, in the print head of the present invention, by correcting the deviation of the stroke amount of the wire from the normal state due to the warp of the armature, which occurs when the armature is manufactured, It is possible to save the trouble of individually correcting the warp of the armature when manufacturing the print head.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a state in which a film stroke adjusting unit used in a print head of the present invention is sandwiched between an end cap and a back stopper.

FIG. 2 is a cross-sectional view showing the configuration of the print head of the present invention.

FIG. 3A is a plan view showing the shape of a film having a stroke adjusting portion for adjusting the wire stroke amount of the print head of the present invention. FIG. 3B is a sectional view taken along the line AA of the film shown in FIG.

FIG. 4 is a plan view showing a state in which armatures are attached to two positions of an armature attachment portion of an end cap.

FIG. 5 is a plan view showing a state in which the film shown in FIG. 3 is attached to the state shown in FIG.

FIG. 6 is a plan view showing a state in which a leaf spring is attached to the state shown in FIG.

FIG. 7 is a cross-sectional view showing a configuration of a print head assembled by correcting a warp of a conventional armature.

[Explanation of symbols]

 14 Yoke (Support) 18 Back Stopper 20 Electromagnet 26 Armature 28 Leaf Spring 36 Wire 58 Print Head 60 Film 60a Cover 60b Stroke Adjuster (Stroke Adjusting Member)

Claims (1)

[Claims] 1. An electromagnet that changes the strength of a magnetic field, an armature that rotates in response to a change in the strength of the magnetic field generated by the electromagnet, and a wire that is driven by the rotation, and a pause in the rotation operation of the armature. A back stopper that determines the position, a support portion that supports the armature, a leaf spring that biases the armature with respect to the support portion, and a film that is interposed between the leaf spring and the armature are integrally formed. A rotary stroke amount adjusting member interposed between the support portion and the back stopper to change the fixed position of the back stopper with respect to the support portion to change the rest position of the rotary operation of the armature. Print head for wire dot printer.