JPH049166Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a support device for a printing element in a dot-type printer, such as a dot matrix printer, in which characters, symbols, etc. are represented by a plurality of dots.

(Prior Art) In the prior art, in order to fix a guide plate that slidably supports a printing element such as a printing wire, an adhesive is applied in advance to the outer peripheral end surface of the guide plate.
It was glued to a predetermined location on the inner wall of the hollow part of the head frame. Unless the guide plate is installed at a predetermined location with extremely high precision, the printing accuracy of the printer will be reduced, and the installation work is complicated and requires skill.

Therefore, in order to make the installation of the guide plate easier and faster and to improve the printing accuracy, the applicant first formed a guide groove having an engagement groove on the inner wall of the head frame and engaged the guide plate with the engagement groove. It was proposed to form an elastic arm having a mating engagement claw and insert it into the guide groove (Utility Model Application No. 112935/1983).

(Problem that the invention aims to solve) However, with this configuration in which guide grooves are formed on the inner wall of the head frame, the mold for plastic molding becomes complicated, which increases manufacturing costs, and also increases wall thickness. Since there are some parts and thin parts, there is a problem that sink marks occur and deformation easily occurs.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a support device for a printing element that can simplify the shape of a mold for a head frame, prevent deformation due to sink marks, and facilitate the assembly of a guide plate for a printing element. It is in.

(Means for Solving the Problems) The features of the present invention include a head frame, a plurality of guide plates inserted into the head frame, and a plurality of guide plates attached to the back side of the head frame and arranged above the guide plates. and a stopper plate that prevents the head frame from coming off backward, the head frame having a hollow part and a window opened in the front thereof, and facing the hollow part of the head frame. A plurality of step portions are formed at predetermined intervals in the depth direction on the inner wall, and a guide hole into which the printing element is slidably inserted, a positioning surface, and a spacer piece are formed on the plurality of guide plates. The positioning surface of the guide plate is in contact with the surface of each stepped portion of the head frame, and the spacer piece of the guide plate extends toward an adjacent guide plate and contacts the guide plate. Further, the stopper plate is in contact with the guide plate located at the rearmost position of the head frame.

(Function) Therefore, each guide plate is sequentially inserted into the hollow part of the head frame from below or from the rear, and its positioning surface is brought into contact with the surface of the stepped part, and in this state, the stopper plate is attached to the back part of the head frame. The guide plate can be inserted into the head frame just by attaching it. When the guide plates are inserted, the spacer pieces ensure that the distance between adjacent guide plates is maintained.

(Embodiment) In FIGS. 1 and 2, a head frame 1 is integrally molded from a synthetic resin such as carbon graphite, and constitutes a support portion for a printing element.
Specifically, the head frame 1 is provided with a hollow portion 1a, and a window 1b is opened in the front surface. A plurality of step portions 1c, 1d, 1e, 1f are provided at predetermined intervals in the depth direction on the opposing inner walls of the hollow portion 1a.
It has been formed. Inside the hollow part 1a, a guide plate 2,
3, 4, and 5 are arranged at predetermined intervals.

As shown in the third to sixth figures, each guide plate 2 to 5 has a plurality of printing wires 6 as an example of printing elements...
Guide holes 2a..., 3a..., 4a that guide the
..., 5a... and positioning surfaces 2b, 3b, 4
b, 5b, and spacer pieces 3c, 4c, 5c. Positioning surfaces 2b, 3b, 4b, 5b
are formed on the side edges of guide plates 2 to 5,
These are the step portions 1c and 1d of the head frame 1,
It can come into contact with the surfaces 1e and 1f. Further, the spacer pieces 3c, 4c, and 5c extend from the guide plates 3, 4, and 5 toward the adjacent guide plates, and are in contact with the adjacent guide plates. Note that the spacer piece 3c,
4c and 5c are provided so as to protrude forward in this example, but these spacer pieces may be provided so as to protrude rearward, or they may be provided so as to protrude forward and rearward, and the end faces of adjacent spacer pieces at each end face are It may also be provided so as to be in contact with.

Guide plate 2 at the tip of guide plates 2, 3, 4, and 5
is a protrusion 2d that protrudes forward and fits into the window 1b.
A guide hole 2a is provided in this protrusion 2d.
...is provided. The rear ends of the printing wires 6 protrude into the recesses on the back surface of the guide plate 5, and return springs 7 fit into each wire 6, and the printing pins 6a are fixed to the rear ends of each wire 6. It has become impossible to fall off due to... Further, among the guide plates 2 to 5, the rear end surface of the last guide plate 5 is located on the same plane as the rear opening of the head frame 1, and the stopper plate 8 is in contact with the rear end surface of this guide plate. This prevents each guide plate from coming off to the rear of the head frame.

When assembling, insert the guide plate 2, which should be located at the most extreme position, through the lower opening of the hollow part 1a, push it forward, fit the protruding part 2d into the window 1b, and bring the positioning surface 2b into contact with the stepped part 1c. Let them come into contact with you. Next, insert the guide plate 3 to be positioned next from the lower opening and push it forward, so that the positioning surface 3b is aligned with the stepped portion 1.
d. Similarly, the guide plate 4 is inserted into the hollow part 1.
a, and align the positioning surface 4b with the stepped portion 1.
Let it come into contact with e. Note that the guide plates 2, 3, and 4 may be inserted sequentially from the back of the head frame 1 toward the front. The guide plate 5 is inserted from the back side of the head frame 1, and its positioning surface 5b is brought into contact with the stepped portion 1f. In this state, the spacer pieces 3c to 5c of the guide plates 3 to 5 are in contact with adjacent guide plates, respectively.

Thereafter, each printing wire 6 is returned to fit the spring 7, and each printing wire 6 is inserted into the guide hole 5a, 4a, 3a, 2a at a predetermined position from the back side of the guide plate 5, respectively. The tip of each wire 6 is located in the guide hole 2a, and when the rear end surface of each printing pin 6a is pushed, the return spring 7 is compressed and projected to print.

On the back of the head frame 1, printing wires 6...
A drive unit is provided. That is, as shown in the first and second figures, a stopper plate 8, a drive spring 9, and a spacer 12 are sequentially stacked on the back surface of the head frame 1. As shown in FIG. 7, the drive spring 9 is provided with arms 9a in a number equal to the number of printing wires 6 (12 in this example) at equal intervals toward the center. A driving hammer 10 is attached to the intermediate portion of each arm 9a. Drive hammer 1
0 has its tip extending closer to the center than the tip of the arm 9a, and its rear end is located in the middle of the arm 9a, so the arm 9a and the driving hammer 10 extend from the middle of the arm 9a to the tip. Even the parts overlap. The tip of the arm 9a is spot welded to the drive hammer 10 to increase its rigidity. A movable yoke 11 is attached to the intermediate portion of the arm 9a, and in this example, the movable yoke 11 is connected by passing through the overlapping driving hammer 10 and the arm 9a. Each printing pin 6 of the printing wire 6 is attached to the front of the tip of the driving hammer 10.
The end face of a is in elastic contact with the spring force of the return spring 7. The movable yoke 11 is driven by an electromagnet device 13, which will be described later. The stopper plate 8 is provided with stopper pieces 8a . . . extending toward the center within the space between the drive hammer 10. Both sides of the stopper piece 8a are provided with an engagement surface 9 of the arm between the tip of the arm 9a and the rear end of the drive hammer 10, which is created by making the drive hammer 10 narrow and the arm 9a wide.
b overlaps the front of... The stopper plate 8 overlaps the drive spring 9 from the middle part to the outer peripheral part of the arm 9a.

The movable yoke 11 is usually an electromagnet device 13 which will be described later.
, the spring portion outward from the intermediate portion of the arm 9a is flexibly bent and displaced rearward, and the tip of the drive hammer 10 is in the retreated position. For this reason, the printing wire 6 is retracted by the return spring 7, and its tip does not protrude from the head frame 1. During printing, the magnetic field that had attracted the movable yoke 11 is canceled out, and the movable yoke becomes free and returns to its original position due to the spring force of the drive spring 9. This return is caused by the arm 9
Since the rigidity is increased by overlapping with the drive hammer 10 from the middle part to the tip of a, the information is reliably transmitted to the drive hammer 10, and the drive hammer 10
The leading end of the printing wire 6 moves forward, causing the printing wire 6 to advance. When the arm 9a moves forward, it gradually comes into contact with the stopper plate 8 from the outer periphery of the arm 9a toward the distal end, and finally its return is stopped when the engagement surface 9b comes into contact with the stopper piece 8a. When two members that are separated from each other momentarily collide and stop, a large impact sound is emitted at the time of stopping, but this is caused by the contact area gradually increasing from the outer periphery of the arm 9a. The impact noise is extremely small.

The electromagnet device 13 that drives the movable yoke 11 will be described. Front yoke 14 behind spacer 12
are superimposed. As shown in the first figure, the front yoke 14 has a through hole 1 into which the movable yoke 11 is loosely fitted.
4a is provided. A permanent magnet 15 is provided at the center of the back surface of the front yoke 14, and a rear yoke 16 is provided at the back surface of the permanent magnet 15. As shown in the first and eighth figures, three positioning pins 17 are press-fitted into the front yoke 14, and these pins position the permanent magnet 15 at the center position. Further, adhesive is injected through a through hole 14b provided in the center of the front yoke 14 to fix the permanent magnet 15 at the center position. A plurality of iron cores 18 are located on the outer periphery of the permanent magnet 15 and are fixed to the rear yoke 16. Each core 18
faces each movable yoke 11 at its front end surface. The coil terminal plate 19 has a donut shape, and has a plurality of through holes 19a through which the iron core 18 can pass.
is provided. A coil 20 is fixed concentrically to the front surface of the through hole 19a. The terminal pin 2 is inserted outside the coil 20 and passes through the coil terminal plate 19.
1... is stuck. Both ends of each coil 20 are connected to the end of each terminal pin 21 projecting forward from the coil terminal plate 19, thereby forming a coil assembly. When assembling, adhesive is injected into the recess 16a at the center of the front surface of the rear yoke 16, and the permanent magnet 15 is placed and fixed. Next, the coil terminal plate 19 is disposed on the front surface of the rear yoke 16 while the coils 20 are fitted into the iron cores 18 . Next, attach the front yoke 14 to the positioning pin 1
7, the permanent magnet 15 is positioned and placed in the center, and the permanent magnet 15 is fixed by injecting an adhesive through the through hole 14b. front yoke 14
Three positioning pins 22 (shown in Figures 1 and 10) are press-fitted toward the front. Therefore, the positioning pin 22 is connected to the positioning hole 12 of the spacer 12.
c. The positioning hole 9c of the drive spring 9 and the positioning hole 8c of the stopper plate 8 (shown in FIG. 7) are fitted and overlapped one after another, and then the printing element 6 is
. . . into the positioning hole 1g of the head frame 1 supporting the head frame 1. Finally, screw in the fixing screws 23 from the front side of the head frame 1 toward the front yoke 14 to complete the assembly.

In addition, each terminal pin 21 is connected to a predetermined position of a flat cable (not shown) on the back side. Furthermore, heat dissipation fins (not shown) are disposed on the outer periphery surrounding the plurality of coils 20.

(Effects of the invention) As described above, in the present invention, since the guide plate is positioned by providing a stepped portion on the inner wall of the hollow part of the head frame, the construction of the mold for the head frame can be easily completed.
There is no need to worry about deformation due to sink marks. Insert each guide plate into the hollow part of the head frame one after another, bring the positioning surface into contact with the surface of the stepped part, and in this state simply attach the stopper plate to the back of the head frame, and the guide plate into the head frame can be inserted into the head frame. Since the guide plate can be inserted and attached, the guide plate can be assembled extremely easily and quickly, and the positional accuracy of the guide plate can also be ensured. Therefore, the accuracy of the installation position of the printing element guided by the guide hole of the guide plate is improved, and the printing of the printer becomes beautiful. Furthermore, the protrusion of the guide plate at the tip fits into the window so that its front surface and the front surface of the head frame are flush with each other, so there is no recess around the tip of the printing element, which prevents dirt from forming. It does not stick and is effective in making printing clear.

[Brief explanation of the drawing]

Figure 1 is a longitudinal sectional view, Figure 2 is a sectional view taken along the line of Figure 1, Figures 3 to 6 are enlarged front views showing guide plates, and Figure 7 is a portion taken along the line of Figure 1. Fig. 8 is a cross-sectional view taken along the line of Fig. 1; Fig. 9 is a partially cut-away sectional view taken along the line of Fig. 1;
Figure 0 is a rear view. 1...Head frame, 1a...Hollow part, 1b
...window, 1c, 1d, 1e, 1f...step,
2, 3, 4, 5... Information board, 2a, 3a, 4a,
5a... Guide hole, 2b, 3b, 4b, 5b...
Positioning surface, 2d...Protrusion, 3c, 4c, 5c
...Spacer piece, 6...Printing element (printing wire),
8...Stotsupa plate.

Claims (1)

[Claims for Utility Model Registration] 1. A head frame, a plurality of guide plates inserted into the head frame, and a device attached to the back surface of the head frame to prevent the guide plates from coming off to the rear of the head frame. The head frame has a hollow part and a window is opened in the front thereof, and inner walls of the head frame opposite to each other in the hollow part are provided at predetermined intervals in the depth direction. A plurality of step portions are formed, and the plurality of guide plates are formed with a guide hole into which the printing element is slidably inserted, a positioning surface, and a spacer piece, and the positioning surface of the guide plate is formed with: The stopper plate is in contact with the surface of each stepped portion of the head frame, the spacer piece of the guide plate extends toward and abuts on the adjacent guide plate, and the stopper plate is A support device for a printing element, characterized in that the device is in contact with the guide plate located at the rear end of the head frame. 2. In claim 1 of the claims for utility model registration, the guide plate at the tip of the plurality of guide plates has a protrusion that fits into a window on the front side of the head frame and forms the same plane as the front side of the head frame. A printing element support device characterized in that the protruding portion is provided with the guide hole.