JPS6160787B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a print lever for use in a newly configured moving coil type print head.

Recently, various types of print heads that adopt the moving coil system have been proposed for impact-type dot printers, but the conventional moving coil print head has many unresolved technological issues in terms of responsiveness and reliability. It had some problems. For example, with a moving coil type print head, it is difficult to obtain a large driving force compared to print heads with other drive methods such as a spring charge type, so the inertia of the print lever is required to be as small as possible. It is conceivable to make the print lever even lighter by using a thin plate (leaf plate) with spring properties. However, if the print lever is simply formed using a thin plate with spring properties, the print lever is likely to be twisted or deflected, resulting in poor responsiveness.

Therefore, the present invention prevents unnecessary twisting or bending of the printing lever even when the printing lever is formed of a thin plate having spring properties in order to reduce the inertia or weight of the printing lever. The aim is to be able to obtain responsiveness. One embodiment will be described below with reference to the drawings.

In FIGS. 1 and 2, the support plate 1 has an L-shaped side surface, and its vertical bent portion 2 is attached to a carriage (not shown), which is used for recording. The paper 3 is scanned in a direction perpendicular to the paper feeding direction (arrow 4). A holder 5, which is an example of a holding member, is fixed to the lower front surface of the support plate 1 via screws 6, 6. In the opposite direction (to the right in Fig. 2) at an appropriate angle (in this example, approximately 5
It is inclined at a certain angle (degree). The holding portion 7 is fitted into a square hole 8 formed in the support plate 1, and the base 10 of the printing lever 9 is fixed to this inclined holding portion 7 via caulking pins 11, 11. There is. As shown in FIG. 3, the printing lever 9 has spring leg pieces 12, 12 integrally formed extending from the base 10, and a spring leg piece 3 integrally connected to each spring leg piece 12, 12. It is composed of a square lever part 13. The printing lever 9 is made of a thin plate having spring properties in order to reduce its weight, and the lever portion 13 has vertically bent portions 14, 14 formed on both sides to increase its rigidity. Therefore, the printing lever 9 has a spring leg piece 12,
12 and can be bent and deformed. The lever portion 13 has a printing hammer 15 at its tip (free end) as an example of a printing element. The printing hammer 15 is sandwiched between the tip ends of the vertically bent portions 14, 14 in the form of a sandwich, and is fixed by adhesive, spot welding, or the like. From the bottom of the lever part 13, the tongue part 1
6 is integrally formed extending toward the base 10 between the spring leg pieces 12, 12, and a reinforcing member 17 is fixed onto this tongue portion 16. Holes 18, 18 through which caulking pins 11, 11 (first illustration) can pass are bored in the base 10, and the lever part 1
3, there is a bobbin holder 19 shown in the second figure.
A hole 20 is drilled in which a is attached. Further, the tongue portion 16 and the reinforcing member 17 are provided with a hole portion 22 through which a pin 21 as a support member shown in the second figure can loosely pass, and a hole portion 24 into which a board holder pin 23 is fixed. In FIG. 2, the arm-like member 25 is fixed to the holder 5 via a caulking pin 26, and the pin 21 is fixed to the tongue portion 16 by the method described below.

That is, the pin 21 is pushed into the arm-like member 2 by the spring force of the coil spring 27 inserted into the rear part of the pin 21.
In this state, adhesive is poured onto the lower surface of the pin 21, and the pin 21 is fixed by hardening of the adhesive. In this way pin 21
By fixing the arm-shaped member 25
Even if the positional accuracy of the pin 21 is somewhat poor, the pin 21 is always tightly fixed to the arm-shaped member 25. Therefore, no position adjustment of the pin 21 or the arm-like member 25 is required. Further, the contact position of the pin 21 with respect to the arm-shaped member 25 is
The position is approximately 1/3 from the base 10 with respect to the entire length of the base 10. The effect of such a configuration on the operation of the print lever 9 will be clearly understood from the explanation below. A bobbin holder 19 fixed in the hole 20 (FIG. 3) has a bottomed cylindrical bobbin 29 around which a moving coil 28 is wound.

The magnetic flux generating means is sandwiched between an annular outer yoke 30 and a cylindrical center yoke 31, both of which are made of a magnetic metal material with high magnetic permeability, and a rear disk portion of the center yoke 31 and the outer yoke 30 in a sandwich-like manner. It is composed of an annular permanent magnet 33 inserted therein.

The inner peripheral surface of the outer peripheral yoke 30 and the center yoke 3
A moving coil 28 is inserted into the gap between the outer peripheral surfaces of the moving coil 2 and the magnetic flux generated in the gap in the radial direction by the permanent magnet 33 is transferred to the moving coil 2.
8 crosses it. The permanent magnet 33 is connected to the disk portion 32, and the outer yoke 30 is connected to the permanent magnet 3.
3, each is fixed via adhesive,
The entire magnetic flux generating means is fixedly disposed on the back surface of the support plate 1 by screwing screws 34, 34 shown in FIG. 1 into the outer yoke 30 through the support plate 1. In this embodiment, the permanent magnet 33 is a rare earth magnetic anisotropic magnet (a typical example of which is a samarium cobalt magnet) that can obtain a high magnetic flux density, but is not limited to this. Further, the rear part of a stopper screw 35, which is an example of a regulating member, is screwed into the center of the center yoke 31 so that its position can be adjusted.
The rear part of the holder 19 is designed to abut against a flange 36 that is integrally formed with the holder 1, and the rest position of the printing lever 9 is determined by this flange 36. The print lever 9 has a slanted position as described above because the holding portion 7 of the holder 5 is tilted.
In the rest position, the spring leg pieces 12, 12 are deformed into a slight arch, and are therefore locked against the collar 36 with a preload applied thereto.
Further, a nut 37 is screwed onto the front part of the stopper screw 35 so that its position can be adjusted, and the overswing of the print lever 9 is restricted by this nut 37.

Furthermore, an air escape hole 38 is formed at the bottom of the center yoke 31 and communicates with the lower part of the gap.
Further, an air escape hole 39 is provided through the bobbin 29 and its holder 19 and communicates with a space formed hermetically between the bobbin 29 (bobbin holder 19) and the center yoke 31. Behind the printing hammer 15 is a ribbon guide 4 fixed to the outer yoke 30 via screws 40, 40 shown in the first diagram.
1 is located. The ribbon guide 41 has a recess 42 in the longitudinal direction at the center thereof, and a bottom surface 43 thereof.
It also has the role of a stopper that lightly contacts the upper end of the print lever 9 and determines the rest position of the print lever 9. The ribbon guide 41 has guide grooves 44, 44 formed on both front sides of the recess 42,
An ink ribbon 45 placed between the recording paper 3 and the printing hammer 15 is guided by the guide grooves 44 , 44 . The end of a well-known flexible flat cable 46 is inserted into the pin 23 (which is caulked into the hole 24 shown in the first figure) through a nut 48, with a receiving plate 47 glued to the back surface of the cable. installed. Lead wires 51 and 52 of the moving coil 28 are connected to terminals 49a and 50a of the thin plate conductors 49 and 50 of the cable 46, respectively. The platen 53 is disposed opposite the printing hammer 15, and has a plurality of protrusions 54 protruding at equal pitches on its outer peripheral surface in parallel in the axial direction (the scanning direction of the printing head). There is. The front end surface of the printing hammer 15 is curved in an arc shape, and the radius of curvature is approximately equal to the radius from the center of the platen 53 to the outer end of the protrusion 54. The center of the radius of curvature is located at a position offset from the center of the platen 53 by the swinging angle of the print lever 9 when the print lever 9 is in the rest position shown in the second figure.
That is, in FIG. 2, the center of the radius of curvature is located above the center of the platen 53. The print lever 9 is driven to swing and displace, and when the print hammer 15 collides with the projection 54 of the platen 53, the center of the radius of curvature is set to substantially coincide with the center of the platen 53.

In the above embodiment, all the parts except the outer yoke 30, the center yoke 31, and the permanent magnet 33 are made of non-magnetic materials such as stainless steel, phosphor bronze, brass, or plastic.

Next, the operation of the print head of this embodiment constructed as described above will be explained.

When a pulsed current is applied to the movable coil 28 in the rest state, the magnetic flux in the air gap between the outer yoke 30 and the center yoke 31 cooperates with the current to cause the movable coil 28 to An instantaneous displacement force acts on the other side. Due to this displacement force, the spring leg pieces 12, 12 of the printing lever 9 are elastically curved and deformed against their own spring force, and the printing lever 9 is swung to the left in FIG. Lever part 13 is vertically bent part 1
4 and 14, and the pin 21 fixed to the tongue portion 16 and its reinforcing member 17 is brought into contact with the arm-shaped member 25 as described above, so that printing is not possible. Lever 9 is pin 2
1 as the fulcrum, that is, in Fig. 3 -
The printing hammer 15 swings as shown by 9' in FIG. 5 with the position of the line as a fulcrum as a fulcrum, and the printing hammer 15 performs a nearly complete circular motion about the fulcrum.

The printing hammer 15 causes the ink ribbon 45 to impact the recording paper 3, and the printing hammer 15 and the platen 53
A rectangular dot (not shown) obtained by overlapping the projections 54 is formed on the recording paper 3.
Immediately after the printing hammer 15 collides with the protrusion 54, the central part of the lever part 13 (the part to which the bobbin 29 around which the movable coil 28 is wound via the holder 19 is attached) is still damaged due to inertia. Although a deforming force acts to the left, the front end surface of the holder 19 comes into contact with the nut 37, and deformation due to inertia is restricted. Therefore, the printing lever 9 is subjected to unreasonable force (deformation).
You will not receive any. The printing lever 9 then returns to the rest position shown in the second figure by its own spring force. The platen 53 of this embodiment is connected to the arrow 5 in FIG. 2 via a pulse motor (not shown) or the like.
It is designed to rotate continuously in five directions, and as the platen 53 rotates and the printing head scans, the position where the printing hammer 15 and the protrusion 54 overlap moves vertically and horizontally. Therefore, by driving the printing lever 9 at appropriate timing, arbitrary characters, figures, etc. can be formed in the form of dots. Since this character forming operation is not directly related to the present invention, a detailed explanation thereof will be omitted in the main text, but for details, please refer to Japanese Patent Application No. 119506/1983 filed by the present applicant entitled "Impact Type Dot Printer" (filing date: 1972). (September 17, 2016).

The characteristic effects of the above-mentioned support structure (tongue 16, reinforcing member 17, pin 21, alarm 25) of the printing lever 9 will be clearly understood from the following explanation. Temporarily, the tongue portion 16, the reinforcing member 17 (not an essential component), the pin 21, and the arm-shaped member 25
Assuming that the printing lever 9 is not provided, when the printing lever 9 receives the instantaneous and sudden displacement force, the spring leg pieces 12, 12 will momentarily move due to the influence of the inertia of the printing hammer 15, etc. 5, and then the lever portion 13 is displaced to the left. Therefore, the displacement of the printing hammer 15 is delayed, and the responsiveness of the printing lever 9 is different from that of the present configuration. In other words, the pin 21 and arm The above-mentioned abnormal deflection of the spring leg pieces 12, 12 is suppressed by the shaped member 25, and as a result, the printing lever 9
It has become possible to stabilize the operation of the printer, provide quick response, and reliably transmit printing force.

Also, during the above printing operation, the air release hole 3
8 and 39 are the center yoke 31 and the bobbin 2, respectively.
9 and its holder 19 as described above, when the moving coil 28 is displaced in the gap between the center yoke 31 and the outer yoke 30, it is not subjected to air resistance, and therefore the moving coil 28 is sensitive. In response, high-speed driving is possible.

Also, a terminal 49 to which the lead wires 51 and 52 are connected
The flexible flat cable 46 having the movable coil 28 and the flexible flat cable 46 is mounted on the printing lever 9 via the pin 23 so as to be displaced together with the printing lever 9. There is no relative movement between the terminals and the lead wires 51, 52.
No stress is applied repeatedly to the wire, and even if the print lever 9 is driven repeatedly at high speed over a long period of time, there is almost no risk of the wire breaking.

Furthermore, in this embodiment, the bottom surface 43 of the ribbon guide 41 also acts as a stopper member for the printing lever 9, so that the tip portion (printing hammer 15) is not required when the printing lever 9 returns to the rest position. This prevents it from moving to the right. At this time, if the ribbon guide 41 is made of soft plastic or the like, the impact when the print lever 9 returns to the rest position is softened, the vibration of the print lever is immediately attenuated, and the drive noise becomes quiet. Further, in order to quieten the drive noise and dampen the vibrations of the print lever 9, a damping member such as rubber or sponge may be provided between the collar portion 36 and the holder 19.

Further, in this embodiment, a plate-shaped printing hammer 15 is used as the printing element, but a wire may be used instead. In this case, the platen 53 would be fixedly installed, and the surface facing the wire would be formed flat.

Although the holder 5 can be integrated with the support plate 1, it is better to detachably attach it to the support plate 1 as a separate component, as in the sentence structure.
This is advantageous in terms of assembly and maintenance of the printing lever 9 and the like.

Further, the pin 21 may be fixed to the arm-shaped member 25, and the pin 21 may be brought into contact with the tongue portion 16 at the position on the above-mentioned line of the spring leg pieces 12, 12, and the fixing structure of the pin 21 may also be the same as that of the above embodiment. It is not limited to.

According to the printing lever for a moving coil type printing head according to the present invention described in detail above, it is possible to obtain a printing lever that is lightweight and has high rigidity, and the twisting and bending of the printing lever are small, so that the printing lever can be used as desired. It is possible to ensure the responsiveness of printing, to reliably transmit the printing force, and to form clear dots.
Furthermore, the printing element can be securely and easily held and fixed at the tip of the vertically bent portion, and especially when the printing element is a plate-like member as in the above embodiment, it can be held and fixed with high precision.

[Brief explanation of the drawing]

The drawings relate to an embodiment of the moving coil type printing head according to the present invention, in which Fig. 1 is a front view thereof, Fig. 2 is a sectional view taken along the line of Fig. 1, and Fig. 3 is a front view of the printing lever. , FIG. 4 is a sectional view taken along the line of FIG. 3, and FIG. 5 is an explanatory diagram for explaining the displacement operation of the printing lever. 9...Printing lever, 10...Base, 12...Spring leg piece, 13...Lever portion, 14...Vertical bending portion, 15...Printing element.

Claims (1)

[Claims] 1. A base fixed to a holding member, a plurality of spring leg pieces extending symmetrically from one end surface of the base, and a movable coil connected to the spring leg pieces at the center of the plate. A tapered triangular lever part is attached to receive force in the thickness direction, and vertical bent parts are formed on both sides of this lever part and hold the printing element at the tip.
A printing lever for a moving coil type printing head, characterized in that it is integrally formed of a thin plate having spring properties. 2. A printing lever for a moving coil type printing head according to claim 1, wherein the printing element is a plate-like member. 3. In claim 2, the printing element, which is the plate-like member, has a surface facing the platen that is an arcuate surface with a radius of curvature approximately equal to the radius of rotation of the outer end of the projection provided on the platen. Print lever for a moving coil type print head. 4 In claim 3, the center of the radius of curvature of the arcuate surface is at an eccentric position approximately corresponding to the swing angle of the printing lever with respect to the rotation center of the platen when the printing lever is in the rest position. can be,
A printing lever for a moving coil type printing head, which is set so that the center of the radius of curvature and the center of rotation of the platen substantially coincide with each other when the printing lever collides with the platen.