JPH0541016Y2 - - Google Patents

Description

[Detailed explanation of the idea]

【0001】

[Field of Industrial Application] The present invention relates to an impact type printer head that prints characters, symbols, etc. in a dot matrix.

【0002】

[Prior Art] Conventionally, a printer head has a ring-shaped yoke plate and has a large number of comb-like tongues inside, and a print lever is disposed in the gap between these tongues. The base of the shape is
The width of the print lever hinge is very close to the width of the print lever, and the base portion functions as a lateral guide for the print lever, and these tongues are located close to the sides of the print lever. It is known that since then, it has also functioned as a side magnetic path to increase magnetic efficiency.

【0003】

[Problem to be solved by the invention] However, in the conventional printer head of this type,
Since the outer end of the printing lever was supported inside the yoke plate, a yoke plate with a large outer diameter was required, which was an obstacle to miniaturization (Japanese Patent Laid-Open Nos. 57-20367, 1983). -145462, Japanese Patent Application Publication No. 56-37176).

[0004] An object of the present invention is to provide a printer head that can be downsized by reducing the outer diameter of the yoke plate.

[0005]

[Means for Solving the Problems] The printer head according to the present invention is characterized by a plurality of printing elements biased rearward via a return spring, and printing elements arranged radially around their outer ends. a printing lever supported so as to be rotatable toward the printing lever; and a yoke having a plurality of iron cores around which driving coils are wound and arranged to face each printing lever in front of each printing lever. The frame is formed into a ring shape and is joined to the yoke frame, and a plurality of tongue-like portions are formed on the inner circumference thereof and extend centripetally between each of the print levers so as to be close to and opposite to the print levers. A yoke plate is provided, and a support portion for supporting the outer end of the print lever is formed at the outer edge of the yoke plate.

[0006]

[Function] According to the printer head according to the present invention, since the outer end of the printing lever is supported on the outer edge of the yoke plate, the outer diameter of the yoke plate can be set small, making it possible to downsize.

[0007]

[Example] Hereinafter, an example of the present invention will be described based on the drawings. In FIG. 1, a head frame 1 is integrally molded from a synthetic resin such as carbon graphite, and has a guide plate supporting portion 1a projecting from the center of its front half. A hollow part 2 with an opening at the lower end is formed inside the guide plate support part 1a, and a window 1c communicating with the hollow part 2 is provided in the front wall 1b of this support part.
is drilled there. On the peripheral wall of the front end of the hollow part 2,
A groove 2a is formed in the upper and lower directions, and a distal end guide 3 is inserted into this groove from below. Tip guide 3
A protruding portion 3a protruding toward the front of the head frame 1 fits into the window 1c, and the front surface of this protruding portion and the front wall 1b of the head frame 1 are flush with each other. Guide holes 3b into which the front ends of a plurality of printing elements 4 such as printing wires (24 in this example) are slidably inserted are arranged in two staggered rows in the protrusion 3a. It has been set up. A groove 2b is formed in the peripheral wall of the rear end of the hollow part 2 in the vertical direction in parallel with the groove 2a, and the intermediate guide 5 is inserted into the guide groove 2b from below. The intermediate guide 5 has 24 guide holes 5a through which intermediate portions of the printing elements 4 can slide freely.
The holes are arranged in a vertically elongated oval shape.

[0008] The head frame 1 is provided with a rear end guide 1d of the printing element 4 at a predetermined distance rearward from the hollow portion 2, and a wedge-shaped connecting portion extends from the center of the rear end guide. 1e protrudes rearward. The rear end guide 1d is provided with 24 concentric guide holes 1f, through which the rear end of the printing element 4 is slidably inserted. A return spring 6 is fitted to the rear end portion of the printing element 4 that projects rearward from the rear end guide 1d, thereby biasing each printing element rearward.

[0009] The drive mechanism of the printing element 4 will be explained. In the rear half of the head frame 1, there is a cylindrical yoke frame 7 (FIG. 2) in which the iron core 7a is circumferentially protruded in a number corresponding to each printing element 4 (24 pieces) toward the back side.
It is integrally formed. A driving coil 8 (FIGS. 3 and 4) is wound around each iron core 7a, and terminal pins 9a and 9b protrude toward the front side of the yoke frame 7. A flexible cable 10 is connected to the terminal pins 9a and 9b. Radiation fins 7b are integrally formed on the outer peripheral surface of the yoke frame 7. The connecting portion 1e passes through the center of the yoke frame 7 and projects toward the rear.

[0010] The side wall of the head cover 11 (FIG. 5) is
It is provided so as to face the rear end surface of the side wall of the yoke frame 7, and 24 notch grooves 11a are provided in this side wall. At the center of the head cover 11, there is a connecting portion 1e.
A center hole 11b is provided through which the guide projections 11c pass, and 24 guide protrusions 11c are provided around this center hole. A pressing spring 12 (FIG. 6) is housed in the inner surface of the head cover 11, and the inner peripheral surface of the ring-shaped portion 12a of this pressing spring is connected to the guide protrusion 11c.
24 spring pieces 12b... extend radially from this ring-shaped portion, and the tips of these spring pieces extend into the notched groove 11a of the head cover. Inside the guide protrusion 11c...
A ring-shaped damper 13 is housed. Twenty-four printing levers 14 (FIGS. 7 and 8) are opposed to the front surface of each spring piece 12b of the pressing spring 12.

[0011] The printing lever 14 is punched out of a plate-like material in the shape as shown in FIG. The rear end portions of each printing element 4 are opposed to each other, and the outer end portion 14b thereof is inserted into the notch groove 11a. Furthermore, a protrusion 14c is formed in the middle of the printing lever 14, and this protrusion can come into contact with the iron core 7a as shown in FIG.

[0012] As shown in FIG. 9, the yoke plate 15 is formed in a ring shape, and has a support portion 24 formed at an outer edge 15a that is joined to the rear end surface of the side wall of the yoke frame 7, corresponding to the notch groove 11a of the head cover 11. A notch 15b is provided, and the outer end 14b of the print lever 14 is positioned and supported within the notch groove and the notch. Tongue pieces 15c radially extend from the outer edge 15a toward the center with parallel gaps.
. . . are formed, and the inner sides of the tongues are parallel, and as shown in FIG. 10, they closely face the entire surface of both sides of each protrusion 14c of the print lever 14 .

[0013] The positioning protrusion 11d of the head cover 11 shown in FIG. 5 engages with the positioning groove 7c of the yoke frame 7 of FIG.
It engages with the positioning groove 15d of the yoke plate 15. Further, the positioning protrusion 12c between the head cover 11 shown in FIG. 6 and the guide protrusion 11 in FIG.
It engages in the gap between c.

[0014] The head cover 11 has a pressing spring 12,
After storing the printing lever 14 and joining the rear surface of the outer edge 15a of the yoke plate 15 to the front end surface of the side wall of the head cover and assembling it into the state shown in FIG. 10, the front surface of the outer edge 15a of the yoke plate 15 and the yoke frame 7 and the fixed spring plate 16
The peripheral edge of the head cover 11 is brought into elastic contact with the back surface of the head cover 11, and the male screw 17 is passed through the fixed spring plate 16 to connect the connecting portion 1e.
screw together. Therefore, the rear end surface of each printing element 4 comes into contact with the front end surface of the inner end 14a of the printing lever 14, and the rear end surface of the outer end 14b of this printing lever is pressed by the spring piece 12b of the presser spring 12. The front end surface of the outer end portion 14b comes into elastic contact with the rear end surface of the side wall of the yoke frame 7, so that the printing lever 14 is rotatably received in a direction along the plate surface about the outer end portion.

[0015] While the drive signal is not supplied to the drive coil 8, as shown in FIG. They are in elastic contact, and the iron core 7a and the protrusion 14c are separated. When a drive signal is supplied to the coil 8 and the iron core 7a is excited, the protrusion 14c of the printing lever 14 is attracted to this iron core and joins as shown in FIG. 11, so that the inner end 14a of the printing lever 14 Move forward to push the printing element 4 forward. The magnetic flux from the iron core 7a is transferred to the printing lever 1.
4, passes through the outer end 14b of the protrusion 14c, returns to the core 7a through the yoke frame 7, and at the same time, passes from the core 7a through the protrusion 14c of the print lever 14 to the tongue-shaped portion 15c of the yoke plate 15 on both sides. It passes through the outer edge portion 15a, passes through the yoke frame 7, and returns to the iron core 7a. For this reason, even if the printing lever 14 is plate-shaped and does not have a sufficient cross-sectional area, the printing lever 14 is driven by a sufficiently large magnetic attraction force, and the printing element 4 is driven.

[0016] In the printer head configured as described above, the outer end 14b of the print lever 14 is supported by the outer edge 15a of the yoke plate 15, so the outer diameter of the yoke plate can be set small.
Miniaturization becomes possible.

[0017] Note that the support structure of the print lever 14 according to the technical idea of the present invention is not limited to the above embodiment, and other embodiments are shown in FIGS. 12 to 1.
6, various support structures or forms can be employed.

In the example of FIG. 12, a small protrusion 14d is formed at the outer end of the print lever 14, and this small protrusion 14d is inserted into the receiving hole 1 at the outer edge of the yoke plate 15.
5d, this printing lever is rotatably supported.

In the example of FIG. 13, the receiver 15f for receiving the small protrusion 14d is made as a separate part and the yoke plate 15 is
It is fixed to the outer end of the

[0020] In the example of FIG. 14, the yoke plate 15
A vertically bent portion 15g is integrally formed on the outer edge of the printing lever 14, and is brought into contact with the V-groove 14e at the outer end of the printing lever 14.

[0021] In the example of FIG. 15, the yoke plate 15
This is an example in which the printing lever 14 is rotatably supported by fitting the edge 15h into the V-groove 14f formed in the printing lever 14 without bending the outer edge thereof.

16, a protrusion 14g at the outer end of the print lever 14 is brought into contact with the outer peripheral surface of the yoke frame 7, and the print lever 14 is supported so as to be rotatable about the protrusion 14g. The outer end of the print lever 14 is fitted into a groove 15j at the outer edge of the yoke plate 15 and positioned.

[0023]

[Effects of the invention] According to the invention, since the outer end of the printing lever is supported on the outer edge of the yoke plate, the outer diameter of the yoke plate can be set small, resulting in an excellent effect that miniaturization is possible. has.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway side view of the main part.

FIG. 2 is a rear view of the yoke frame.

FIG. 3 is a rear view of the coil.

FIG. 4 is a right side view of FIG. 3;

FIG. 5 is a front view of the head cover.

FIG. 6 is a front view of the pressing spring.

FIG. 7 is a side view of the print lever.

FIG. 8 is a front view of the print lever.

FIG. 9 is a front view of the yoke plate.

FIG. 10 is a partially cutaway front view showing the assembled state.

FIG. 11 is a cross-sectional view of the main parts showing the driving state of the print lever.

FIG. 12 is a sectional view of a main part showing another support structure of the printing lever.

FIG. 13 is a sectional view of a main part showing another support structure of the print lever.

FIG. 14 is a sectional view of a main part showing another support structure of the print lever.

FIG. 15 is a sectional view of a main part showing another support structure of the print lever.

FIG. 16 is a sectional view of a main part showing another support structure of the print lever.

[Explanation of symbols]

4...Printing element 6...Return spring 7...Yoke frame 7a... Iron core 8... Drive coil 11...Head cover 11a...notch groove 12...If you press it 12b...Spring piece 14...Print lever 14b...outer end 14c...protrusion 15...Yoke plate 15a... Outer edge 15b...Notch (supporting part) 15c...tongue.

Claims (1)

[Scope of utility model registration request] Claim 1: A plurality of printing elements biased rearward via a return spring, and a plurality of printing elements arranged radially and supported so as to be rotatable about their outer ends toward the printing elements. a printing lever; a yoke frame having a plurality of iron cores around which driving coils are wound; and a yoke frame arranged in front of each printing lever to face each printing lever; and a yoke frame formed in a ring shape a yoke plate joined to the yoke plate and having a plurality of tongue-shaped portions formed on the inner circumference extending centripetally between each of the printing levers so as to closely oppose the printing lever; A printer head characterized in that a support portion for supporting an outer end of the printing lever is formed on an outer edge of the yoke plate.