JP2560681B2 - Wire dot printer with switchable printing modes - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wire dot printer capable of switching print modes.

[0002]

2. Description of the Related Art Conventionally, a plurality of printing wires are electromagnetically driven and a dot matrix recording is formed on a recording medium on a platen via an ink ribbon at the tip of the printing wires. There is a print head that does. In recent years, high density printing has been required, and the number of printing wires has increased accordingly. For example, 24 printing wires are arranged in two rows in a direction substantially orthogonal to the moving direction of the print head. . The tip portion of each print wire penetrates a predetermined guide hole of the tip guide.

As the arrangement of the print wires, there are a parallel arrangement in which two wires which are adjacent to each other in the moving direction of the print head are located at the same level, and a staggered arrangement in which the positions are deviated from each other by half a pitch. High-speed printing (Dra
Suitable for ft mode) and zigzag arrangement for high density printing (NLQ
(Near Letter Quality) mode)
Suitable for

The prior art discloses a configuration in which the parallel arrangement and the staggered arrangement can be arbitrarily switched as needed.

As a first example , US Pat.
No. 5 (Japanese Examined Patent Publication No. 57-60950), as one specific means, a wire guide that supports one row of printing wires is fixed, and a wire guide that supports the other rows of printing wires.
The guide can be moved up and down by a solenoid, and both guides are adjacent to each other. When the movable wire guide is raised, it is in a staggered arrangement, and when it is lowered, it is in a parallel arrangement. As another specific means, one wire guide is made to support all the printing wires, and this wire guide is configured to be slightly rotatable in the clockwise direction or the counterclockwise direction. When the print wires are aligned in the lower left tilt by the clockwise rotation, the staggered arrangement is provided, and when the print wires are aligned in the lower right tilt by the counterclockwise rotation, the staggered arrangement is provided.

As a second example , US Pat. No. 4,470,71
No. 3 (Japanese Patent Publication No. 2-29022) has 3 tip guides.
Two plates are formed adjacent to each other, two adjacent plates are fixed guide plates, and the other plates are movable guide plates. In the fixed guide plate, the guide hole has semi-circular recesses formed opposite to each other on opposite end surfaces thereof, and one row of the print wires on the fixed side are supported in the recesses. The print wires in the other rows are supported by the recesses provided in the end surfaces of the fixed guide plate and the movable guide plate that face each other. That is, a semi-circular recess is formed on the end face of the movable side guide plate to position the print wires in other rows, and the recess is formed on the end face of the fixed side guide plate to allow the print wires to be displaced by a half pitch. Has a small unevenness on the bottom surface. In addition, in order to regulate the stroke of the movable side guide plate, semicircular recesses are provided in the upper and lower movable side guide plates of the print wire row, and a shaft of the same diameter as the print wire is fixed in this, and the fixed side is fixed. In the guide plate of the above, at the position opposite to this axis, two arcs which are the same as the hole into which the print wire is fitted are adjacent and the center distance of the two arcs is half the center distance at the position where the print wire is fitted. To form a recess. Axis is 2
It is possible to selectively fit one of the two arcs and move up and down a half pitch. The guide plate on the movable side is fixed to the support body, and the support body is urged by the spring force toward the fixed side, and the finger-like pieces are erected on the front surface of the support body.
On the left and right side plates where the print head moves left and right,
There is provided an inclined surface, one of which is upwardly inclined and the other of which is downwardly inclined, which can be engaged with the finger-like piece. Therefore, when the fingers are engaged with the upper inclined surface, the movable guide plate is raised and the printing wires are arranged in a staggered manner, and when the fingers are engaged with the lower inclined surface, the movable guide plate is lowered and the printing wires are arranged. Are arranged in parallel.

As a third example , US Pat. No. 4,605,532.
In No. 3, two rows of printing wires are supported by separate guides, and both guides can be moved up and down separately. Both guides are mounted on a table that moves forward and backward by a solenoid, and the upper surface of this table is tilted between the side on which one guide is placed and the side on which the other guide is placed. Is the opposite. Therefore, when the table moves forward, one guide rises and the other guide descends, and when the table retracts, one guide descends and the other guide rises, which causes the two rows of print wires to move relative to each other. The target position can be switched to a staggered arrangement or a parallel arrangement.

As a fourth example , German Published Patent No. 320
In No. 8104, the tip guide is rotatable, and the tip guide is slightly rotated clockwise or counterclockwise,
Switch between a parallel arrangement in which the print wires are aligned in the lower left tilt and a staggered arrangement in which they are aligned vertically. As a mechanism for rotating the tip guide, the following is actually used.

That is, a slide bar is connected to the tip guide, and a solenoid is located outside the main plate of the printer. When the carrier stops near the main plate,
The slide bar protrudes from the main plate. Then, the solenoid is driven to cause the plunger to project and engage with the slide bar. When the print head is moved slightly in the direction of the ground plane or in the direction opposite to the ground plane, the tip guide is slightly rotated clockwise or counterclockwise via the slide bar, which causes the parallel arrangement and the staggered arrangement. Can be switched.

As a fifth example , Japanese Patent Application Laid-Open No. 63-99960.
The publication discloses an example in which two tip guides are provided, and the guide hole arrangements of the two tip guides are partly or wholly offset from each other so that the corresponding wires are skewed. Then, by changing the gap between the head and the platen, the dot formation position by the tip of the wire is changed, and the dot formation position corresponds to the parallel arrangement or the zigzag arrangement, so that high-speed printing and high-density printing can be switched. ing.

However, the above technique has the following drawbacks.

That is, in the above-mentioned first prior art, a solenoid is required to drive one wire guide up and down, so that the cost is increased. Also, in the case of rotating the tip guide, in both the parallel arrangement and the staggered arrangement,
Since the arrangement of the print wires is not perpendicular to the movement direction of the print head, the processing of print data for driving the wires is complicated, the memory is increased, the processing speed must be increased, and the control circuit becomes expensive.

In the second prior art described above, the print wire is supported in one row by opposing semicircular recesses, and in the other row by the semicircular recesses and small irregularities, both of which are complete holes. Since it is not, the print quality deteriorates. In addition, the above small irregularities are easily worn by use, the print wires in this row are not sufficiently supported, and the print quality is degraded. Further, ribbon dust, ink, dust of recording paper, etc. are likely to adhere to the concave portion of the guide plate on the fixed side, and the dust may adhere to the shaft of the guide plate on the movable side so that switching cannot be performed. is there. Further, since the finger-like pieces on the front surface of the support engage with the left and right side plates, a space must be provided around the tip guide, and a ribbon guide or the like cannot be provided, which causes a design restriction.

In the third prior art, the cost is increased because the solenoid is required to move both guides up and down.

In the fourth prior art described above, since the tip guide is rotated, the amount of twist of the printing wire is different between near and far from the center of rotation, which causes variation in the response characteristics of the wire. Further, a solenoid is required, which increases the cost. Further, when the print wires are arranged in a staggered arrangement or in a parallel arrangement, the arrangement pitch of the print wires in the vertical direction changes, so that the character size changes.

In the fifth prior art described above, since the printing wire is slanted by the two tip guides, the load applied to the wire is increased, and there are problems in response characteristics and durability. Further, since the wire strokes are different between the parallel arrangement and the zigzag arrangement, a difference in the printing characteristics is likely to occur.

Therefore, in order to solve the above problems, the present applicant has filed Japanese Patent Application No. 3-300583 (Japanese Patent Application Laid - Open No. 5-138902).
No.) "Wire dot printer with print mode switching" is submitted.

To explain the structure, the print head has a print head in which a plurality of print wires are aligned and supported by the nose portion of the head frame, and the nose portion has first and second print wires arranged in at least two rows. Second tip guides are provided opposite to each other in the drawing direction of the printing wire, and the first tip guide is fixed to the nose portion, while the second tip guide is attached to the nose portion of the tip of the printing wire. It is fixed to a tip guide frame that is movably provided in the alignment direction.

The tip guide frame is substantially movable at a stroke that is ½ of the tip alignment pitch of the printing wires.
In the first and second tip guides, a plurality of guide holes that determine the vertical position of each row and the printing wires of each row are bundled.
Align and print at least the length above the alignment direction
Long grooves which are longer by half the wire pitch are arranged in parallel, and the guide hole and the long groove of the first tip guide face the long groove and the guide hole of the second tip guide, respectively. ing.

On the head frame or a member fixed thereto, slide members that can slide substantially parallel to the moving direction of the print head are provided so as to project from both sides of the head frame.

Between the slide member and the tip guide frame,
Transmission switching means for displacing the tip guide frame in association with the displacement of the slide member is provided.

The operation is as follows :
The slide member is displaced by abutting a stationary member in the blinter when moved over a moving region that moves to. The transmission switching means displaces the tip guide frame in conjunction with the displacement of the slide member to move the second tip guide to switch between the staggered arrangement and the parallel arrangement.

Therefore, the arrangement of the print wires can be automatically switched only by moving the print head, the solenoid is not required, and the structure can be simplified. In addition, the change in the amount of bending of the printing wire due to the switching of the arrangement of the printing wire is minimized to stabilize the printing characteristics,
It is possible to prevent a difference in printing characteristics between the parallel arrangement and the zigzag arrangement. Further, since the slide members protruding from both sides of the head frame contact the stationary member to switch the printing mode, it is possible to mount a ribbon mask or the like without providing a space near the tip guide, and there is no restriction in design.

However, since the tip guide frame is movably provided on the nose portion, the first tip guide fixed to the nose portion must be smaller than the tip guide frame.
Therefore , there is a problem that it is difficult to manufacture.

Therefore, a first object of the present invention is to provide at low cost a printer which has a simple structure and can switch the printing mode which is easy to manufacture. The second object of the present invention is to
Stabilize the printing characteristics by minimizing the change in the amount of bending of the printing wires due to the switching of the printing wire layout, prevent the printing characteristics from being different between the parallel layout and the zigzag layout, and improve the durability. Is to let.

[0026]

In order to achieve the above object, a wire dot printer of the present invention is mounted on a carriage, moved in the width direction of a recording medium, and electromagnetically driven. In a wire dot printer having a print head in which a print wire is aligned and supported by a nose portion of a head frame, and a print mode can be switched between high-speed printing and high-quality printing, the nose portion has a tip portion of the print wire. A first tip gas aligning the at least two rows
The id and the second tip guide are juxtaposed with each other, the first tip guide is fixed to the nose portion, and the second tip guide is marked relative to the first tip guide at the nose portion . br /> character Ri wire tip alignment direction and movable in one stroke of half the tip alignment pitch of substantially the printing wires <br/> Ah of, the member in the head frame or a fixed relationship Is provided in such a state that a slide member that can slide substantially parallel to the moving direction of the print head projects from both sides of the head frame. Slide member state, and are not to be displaced by contacting with the stationary member in the printer when the print head is moved beyond the movement area to move during normal printing, the slide member and the second tip guide In between, transmission switching means for displacing the second tip guide in association with the displacement of the slide member is provided.

The transmission switching means includes a transmission lever that slides in a direction substantially orthogonal to the moving direction of the slide member in association with the displacement of the slide member, and a leaf spring whose both ends engage with the transmission lever. The slide member is provided so as to move integrally with the second tip guide and includes an engaging piece that engages with the central portion of the leaf spring . The slide member is long in the moving direction of the slide member and First and second positions that are displaced in a direction substantially orthogonal to the moving direction
And switching long groove, Yes and the inclined groove and in that the cam groove consists of coupling the two switching length groove is provided, preferably in the transmission lever is provided with a cam follower for mating with the cam groove,
A guide plate for guiding the second tip guide is provided on the nose portion, and one of the guide plate and the second tip guide is provided with a positioning protrusion and the other is provided with a positioning long groove so that they can be fitted to each other. The length of the positioning long groove in the vertical direction is set to be longer than that of the positioning protrusion by a half of the tip alignment pitch of the printing wire, and the cam follower is located above the first and second switching long grooves. , The transmission lever holds both end portions of the leaf spring so as to be positioned higher than the natural state with respect to the central portion of the leaf spring, and the cam follower has the lower long groove of the first and second switching long grooves. When in, the transmission lever holds both ends of the leaf spring below its natural position relative to its center.

More preferably, on the front surface of the tip guide of the print head, there is fixedly provided a holding plate having a plurality of rows of long grooves into which print wire rows can be inserted.

More preferably, the surface of the head frame opposite to the nose portion is provided with a concave portion or a convex portion for guiding the slide of the transmission lever and the slide member, and the slide member, the transmission lever, the leaf spring, and the engaging member. The pieces are attached to the surface side in a laminated manner.

[0030]

When the slide member moves together with the head and comes into contact with the stationary member in the printer and relatively moves in the direction opposite to the moving direction of the head, the transmission switching means is interlocked with the displacement of the slide member to move the second member. The tip guide is displaced and the row of print wires guided by it is moved a half pitch. Therefore, the arrangement of the print wires is switched between the staggered arrangement and the parallel arrangement.

[0031]

BRIEF DESCRIPTION along preferred embodiment showing details of the present invention with reference to the drawings.

As shown in FIG. 2, the print head A is provided with an iron core, a drive coil, a print lever, a return spring and the like (not shown) as an electromagnetic drive device. Twenty-four print wires W are fixed to the tip of the print lever, are attracted to the iron core, print when the print lever advances, and move backward by the spring force of the return spring. As shown in FIGS. 2 and 3, a head frame 1 is provided on the front surface of the print head A, and the print wire W penetrates through the nose portion 1d that projects forward from the head frame 1, and Aligned by the second two tip guides 10, 9.

As shown in FIG. 3, the guide plate 12 has a distal end guide pin 7 having a circular planar shape at the distal end, and a positioning protrusion 7.
a is press-fitted, and the two left end guide pins 7 are located in the two positioning holes 1 of the first end guide 10 in front of the guide plate 12.
It mates with 0a. Here, the upper positioning hole 10a is circular and the lower positioning hole 10a is a long groove, whereby the first tip guide 10 is positioned with respect to the guide plate 12.

The positioning protrusion 7a on the right side of the guide plate 12,
The tip guide pin 7 is fitted into the positioning long groove 9a and the positioning hole 9c of the second tip guide 9 in front of the guide plate 12. The vertical length of the positioning long groove 9a is set to be longer than that of the positioning protrusion 7a by a half of the tip alignment pitch of the print wires W, and the vertical length of the positioning hole 9c is set to be longer than that of the positioning long groove 9a. It is set longer than that. As a result, the second tip guide 9 can be moved by a distance of ½ of the tip alignment pitch of the print wires W.

As shown in FIG. 1, the guide plate 12 is fixed to the adhesive portion 1c provided on the nose portion 1d of the head frame 1. The tips of the positioning protrusion 7a and the tip guide pin 7 are fitted into the positioning holes of the holding plate 13 in front of the first and second tip guides 10 and 9, and the holding plate 13 is positioned with respect to the guide plate 12, and the holding plate is further held. Numeral 13 is fixed to the adhesive portion 1b provided on the nose portion 1d.

That is, as means for making the second tip guide 9 slidable in the vertical direction and determining its stroke,
It is performed by the positioning long groove 9a of the second tip guide 9 and the positioning protrusion 7a fixedly provided on the nose portion 1d, which is provided so as to be fittable with the positioning long groove 9a.

Therefore, the first tip guide 10 is fixed to the front end of the nose portion 1d, and the second tip guide 9 is arranged at the front end of the nose portion 1d in parallel to the right side of the first tip guide 10 and on the printing wire W. Is provided so as to be movable in the alignment direction by a stroke that is ½ of the tip alignment pitch of the print wires W.

Each of the first and second tip guides 10 and 9 has a row of guide holes. Each of the guide holes is composed of a plurality of 12 circular holes, through which the print wires W penetrate, one by one, and which are arranged in close proximity to each other in the vertical direction. These two rows of guide holes are arranged in parallel with each other.

As shown in FIG. 1, the holding plate 13 has two rows of long grooves 13a through which the rows of the print wires W can be inserted.

Since the sliding portion due to the vertical movement of the second tip guide 9 is behind the tip guide pressing plate 13, dust or the like generated near the tip portion of the printing wire W due to the printing operation is generated on this sliding portion. It does not adhere and prevents the operation from becoming unstable due to dust or the like.

In the present invention, the movement of the second tip guide 9 in the vertical direction switches the printing wires W between the parallel arrangement and the staggered arrangement. When the second tip guide 9 is raised, the two guide holes of the first and second tip guides 10 and 9 are displaced from each other by ½ of the tip alignment pitch of the printing wires, and The two rows are staggered.

Therefore, a structure for moving the second tip guide 9 up and down will be described below. As shown in FIG. 5, a slide bar (slide member) 2 is connected to a support portion on the lower side of the head frame 1. The slide bar 2 is provided with a guide long groove which is long in the moving direction.

As shown in FIG. 6, a roller is fitted to the head of the cylindrical protrusion (projection) 1a on the surface opposite to the nose portion 1d of the head frame 1, and the roller is fitted in the guide long groove. The support plate 18 at the protruding end of the head of the cylindrical protrusion 1a.
Is mounted and the columnar protrusion 1a and the support plate 18 are screwed to the slide bar 2 so that the slide bar 2 cannot be removed from the print head.

As shown in FIG. 5, the print head A is placed on the carriage 24 and is movable left and right. The slide bar 2 can be moved together with the head A, but can be moved in the left-right direction relative to the head A. Slide bar 2
Both end portions of the head protrude from the head A to the left and right.

As shown in FIG. 4, the slide bar 2 has a cam groove 2
a is provided. The cam groove 2a is for converting the horizontal movement of the slide bar 2 into the vertical movement of a transmission lever 3 which will be described later. Vertically (up and down) mutually offset position, slightly inclined lower first
A switching long groove 2a1 and an upper second switching long groove 2a2 are provided, and an inclined groove 2a3 connecting the two switching long grooves at the central portion.
Is provided. The length of the inclined groove 2a3 in the moving direction of the slide bar 2 is set to be smaller than the sliding amount of the slide bar 2.

As shown in FIG. 1, the slide member 2 and the second
The transmission switching means B for displacing the second tip guide 9 is provided between the tip guide 9 and the second tip guide 9. The transmission switching means B includes the transmission lever 3,
It is composed of a leaf spring 6 and an engaging piece 8. A roller pin (cam follower) 4 provided on the transmission lever 3 is fitted in the cam groove 2 a of the slide bar 2. That is, the roller pin 4 is crimped to the transmission lever 3, the roller 5 is fitted to the tip of the roller pin 4 as shown in FIG. 6, and the roller 5 is fitted to the cam groove 2a of the slide bar 2. There is.

As shown in FIG. 1, the upper ends of the left and right ends of the transmission lever 3 are bent in the protruding direction of the printing wire W to form a holding portion 3a for a leaf spring 6 which is a pressure spring.
A connection hole 3b for connecting with is formed.

As shown in FIG. 6, similarly to the slide bar 2, the transmission lever 3 is provided with a long groove 3c which is long in the vertical direction, and the long groove 3c is provided on the side opposite to the nose portion 1d of the head frame 1. It is fitted with the cylindrical protrusion 1a on the surface via a roller. By mounting the support plate 19 on the projecting end of the head of the columnar protrusion 1a and screwing the columnar protrusion 1a and the support plate 19 into the print head, the transmission lever 3 is incorporated in the print head so as not to come out of the print head, and the transmission is performed again. The lever 3 is held so that it can slide up and down.

As shown in FIG. 1, the leaf spring 6 penetrates the connecting holes 3b, 3b at both ends thereof, and the connecting hole 8a of an engaging piece 8 described later at an intermediate portion thereof, and the transmission lever 3 is Leaf spring 6
Is connected to the engagement piece 8 via. As shown in FIG. 1, the engagement piece 8 connects the second tip guide 9 and the leaf spring 6, and the tip 8b of the engagement piece 8 has a hole 9b formed in the second tip guide 9. And the engaging piece 8 is inserted into the second tip guide 9
Connected with. The connecting hole 8a is located on the opposite side of the nose portion 1d of the head frame 1.

As shown in FIG. 1, intermediate guides 14, 15, 16, 1 for guiding the print wire behind the guide plate 12 of the nose portion 1d and suppressing the vibration of the print wire during printing.
1 are provided in order, and as shown in FIG. 3, the intermediate guide 1
4, 15 and 16 have slits 14a that allow the engagement pieces 8 to escape.
15a and 16a are provided, whereby the intermediate guide 1
4, 15 and 16 do not hinder the vertical movement of the engagement piece 8.

The intermediate guides 14 and 15 near the first and second tip guides are divided into left and right. The positioning holes 14b and 15 are provided on the left and right of all the intermediate guide plate surfaces.
b, 16b, 11b are provided, and a pair of right and left common positioning pins can be inserted at the time of wire insertion, so that all the intermediate guides can be positioned. As a result, the guide holes of all the intermediate guides face each other, and the wire insertability is improved. The pair of positioning pins are removed after inserting the wire.

The intermediate guide 11 is fixed to the head frame 1, and the other intermediate guides are not fixed to the head frame 1 but are loosely fitted. Hole 11a of the intermediate guide 11
The rear end 8c of the engagement piece 8 can be inserted into the shaft, and the intermediate guide 11 can pivotally support the engagement piece 8.

As will be described later, when the slide bar 2 moves to the left or right with respect to the print head A, the roller pin 4 enters the first switching long groove 2a1 or the second switching long groove 2a2, at which time the transmission lever 3 slides. It moves up and down at right angles to the moving direction of 2. The transmission lever 3 moves the second tip guide 9 up and down via the leaf spring 6 and the engagement piece 8.

The slide bar 2 is stabilized at the high-speed printing position and the high-quality printing position by the positioning means C which will be described later. At this time, the roller pin 4 also has two long grooves 2a1 and 2a2.
Be stable in either. Two long grooves 2a1 and 2a2
The amount of vertical displacement of the roller pin 4 when inside is equal to the amount of vertical movement of the transmission lever 3. The amount of movement is set to be larger than one half of the tip alignment pitch of the print wires W. Further, a main plate 17 provided on both sides of the head moving region and constituting a support frame of the printer is provided.
The slide bar 2 can come into contact with a and b (stationary members).

As shown in FIG. 8, the print head A has a main plate 1
The area I having a length L0 between 7a and 17b is moved during normal printing. When the staggered arrangement is switched to the parallel arrangement, or when the parallel arrangement is switched to the staggered arrangement, the print head moves in the area J or K over the area I and moves to L1.
Alternatively, when L2 is moved, the slide bar 2 contacts the contact member 17a or 17b and the slide bar 7 moves a predetermined amount in the direction opposite to the moving direction of the head A.

The positioning means C for positioning the slide bar 2 and the transmission lever 3 is a transmission lever 3 and a cam groove 2.
a, a leaf spring 6. As shown in FIG. 4, the groove surface above the first switching long groove 2a1 and the groove surface below the second switching long groove 2a2 become higher toward the right, and the inclined groove of the groove surface above the first switching long groove 2a1. 2a3 and the second switching long groove 2a
Positioning projections 2a4 and 2a5 are provided in the vicinity of the inclined groove 2a3 on the groove surface below 2.

At the time of assembling the print head A, the guide plate 12, the first and second tip guides 10, 9 and the pressing plate 13 are attached to the nose portion 1d side of the head frame 1 so as to be opposite to the nose portion 1d of the head frame 1. Attach the engaging piece 8 from
The intermediate guides 14, 15, 16 and 11 are attached to the nose portion 1d.

After that, as shown in FIG. 6, the head frame 1
The transmission lever 3 to which the leaf spring 6 is attached is attached to the connecting hole 8a of the engaging piece 8 from the side opposite to the nose portion 1d, and the slide bar 2 is attached to the side opposite to the nose portion 1d. The transmission lever 3 is located in the recess 1e on the side opposite to the nose portion 1d of the head frame 1. Further, supporting plates 19 and 18 for the transmission lever 3 and the slide bar 2 are mounted thereon, and the supporting plates 19 and 18 are screwed to the head frame 1. After that, as shown in Fig. 7, the insulation sheet
Mount the yoke 21, the yoke frame 22, the drive coil, the electromagnetic drive device such as the yoke plate, the assembly 23 of the print wire W and the armature, etc. in a laminated form, and finally, the head cover 30. Then, the assembly of the print head A is completed.

[0059]

[Description of Operation] In the state of FIG. 5, the print head A moves from left to right in FIG.
When the slide wire 2 is moved to the right only, the slide bar 2 comes into contact with the contact member 17b and its movement is blocked, and the print wire W moves relatively to the left in the direction opposite to the moving direction of the head. The state in the middle of switching to the staggered arrangement suitable for high quality printing is shown.

That is, before moving the print head A, the wire rows were arranged in parallel and the roller pin 4 was positioned in the first switching long groove 2a1 of the switching groove 2a.
When the slide bar 2 moves to the left relative to the print head A, the roller pin 4 moves through the inclined groove 2a3 and into the second switching long groove 2a2. Since the second switching long groove 2a2 is located above the first switching long groove 2a1, the roller pin 4 moves upward and the transmission lever 3 moves upward. The transmission lever 3 and the engagement piece 8 are connected to each other via the leaf spring 6 and the second
And the tip guide 9 of is moved upward. Here, the second tip guide 9 is ½ of the tip alignment pitch of the print wires W.
The amount of movement of the transmission lever 3 in the vertical direction is set to be larger than the amount of movement of the second tip guide 9.

That is, as shown in FIG. 4, when the roller pin 4 moves from the first switching long groove 2a1 into the second switching long groove 2a2, the second tip guide 9 rises by a half of the tip alignment pitch of the print wires W. When the lower end of the positioning long groove 9a of the second tip guide 9 comes into contact with the lower end of the positioning projection 7a, the movement of the second tip guide 9 stops there. Therefore, the center portion of the leaf spring 6 also rises by only one half of the pitch at which the tips of the print wires W are aligned. However, the transmission lever 3 is raised by an amount larger than one half of the tip alignment pitch of the print wires W. Therefore, the transmission lever 3 holds both end portions of the leaf spring 6 so as to be positioned higher than the natural state with respect to the central portion thereof.

At this time, both ends of the leaf spring 6 are bent upward by the transmission lever 3, and the lower end of the positioning long groove 9a is attached to the lower end of the positioning projection 7a by the spring force of the leaf spring 6, and then the spring of the leaf spring 6 is pressed. A force is applied to the transmission lever 3 in the downward direction of the head A by both ends of the leaf spring 6 by the force. Therefore, the roller pin 4 is pressed against the groove surface below the second switching long groove 2a2. Also at this time, both ends of the leaf spring 6 are still bent upward by the transmission lever 3, and the lower end of the positioning long groove 9a is attached to the lower end of the positioning protrusion 7a to position the second tip guide 9.

For example, when the print head moves beyond the normal moving area I due to the displacement of the print head and is further moved to the right by L2 or more in FIG. 8, the slide bar 2 moves leftward from the state in FIG. At this time, the portion of the groove surface below the second switching long groove 2a2 on the right side of FIG. 4 faces the roller pin 4. The groove surface is higher toward the right,
The roller pin 4 is pressed downward by the leaf spring 6. Therefore, the slide bar 2 is returned to the right by the amount moved to the left from the state of FIG. 4 by the pressing force of the roller pin 4, the positioning protrusion 2a5 hits the roller pin 4, and the slide bar 2 and the transmission lever 3 are positioned. It
That is, the slide bar 2 and the transmission lever 3 are positioned by the leaf spring 6, the transmission lever 3, and the cam groove 2a.

The positioning of the slide bar 2 and the transmission lever 3 is the same as that described above when the roller pin 4 is in the first switching long groove 2a1.

When the second tip guide 9 moves upward,
Only the twelve print wires W penetrating the guide holes of the second tip guide 9, that is, only the twelve print wires in the right row move upward by a half pitch, and the twelve print wires in the left row are the first tip. Since the guide wires 10 are still restricted by the guide holes, the 24 print wires W are staggered.

The intermediate guides 14 and 15 are divided into left and right parts, which are close to the first and second tip guides 10 and 9. The intermediate guides 14 and 15 guide a portion of the print wire having a large amount of displacement at the time of mode switching, and the right side pieces thereof can move together with the 12 print wires in the right row. Therefore, it is possible to prevent excessive stress from acting on the wire from the intermediate guide, and it is possible to reduce the sliding load of the wire with the guide hole.

When the staggered arrangement is switched to the parallel arrangement suitable for high-speed printing, contrary to the case described above, as shown in FIG.
Print head A moves from right to left to move area I
It moves by moving L1 further to the left after moving over, and moving the slide bar 2 relatively to the right. Then, the roller pin 4 moves into the first switching long groove 2a1, the transmission lever 3 descends,
The engaging piece 8 and the second tip guide 9 are moved downward.
Also at this time, when the second tip guide 9 descends by a half of the tip alignment pitch of the printing wires W and the upper end of the positioning long groove 9a of the second tip guide 9 abuts the upper end of the positioning protrusion 7a, The movement of the tip guide 9 is stopped there. Therefore, the center portion of the leaf spring 6 also descends by only one half of the tip alignment pitch of the print wires W.

However, the transmission lever 3 descends by an amount larger than ½ of the tip alignment pitch of the print wires W. Therefore, the transmission lever 3 holds both end portions of the leaf spring 6 so as to be positioned below the natural state with respect to the central portion thereof. At this time, both ends of the leaf spring 6 are flexed downward by the transmission lever 3 and the upper end of the positioning long groove 9a is attached to the upper end of the positioning projection 7a by the spring force, and then the leaf spring 6 is pressed.
By the spring force of, the pressing force in the upward direction of the head A is applied to the transmission lever 3 by both ends of the leaf spring 6. Therefore, the roller pin 4 is pressed against the groove surface above the first switching long groove 2a1. Also at this time, both ends of the leaf spring 6 are bent downward by the transmission lever 3 and the upper end of the positioning long groove 9a is put on the upper end of the positioning protrusion 7a to position the second tip guide 9.

Further, the leaf spring 6, the transmission lever 3, the cam groove 2a
As a result, the positioning protrusion 2a4 contacts the roller pin 4, and the slide bar 2 and the transmission lever 3 are positioned.

Then, only twelve printing wires W passing through the guide holes of the second tip guide move downward by a half pitch. The 12 print wires in the left column are the first tip guide 1
Since it is still restricted by the 0 guide hole, the 24 printing wires W are arranged in parallel as a result.

Thus, except for when the carriage presses the slide bar 2 against the base plates 17a and 17b by the positioning long groove 9a, the positioning projection 7a, and the transmission switching means B, the spring force of the leaf springs 6 causes the springs to move in the respective arrangements. The second tip guide 9 has the effect of being positioned and held.

According to the present invention, since the tip guide is not rotated to switch the print wires to the zigzag arrangement and the parallel arrangement, the arrangement pitch of the print wires in the vertical direction does not change during the zigzag arrangement and the parallel arrangement, and the character size is changed. Hasn't changed much.

[0073] Referring now be described <br/> operation of the positioning means C, for example, when switching the parallel disposed in a staggered arrangement, print head A is moved from the left of FIG. 5 to the right, the deviation of the movement of the print head There is a case where the slide bar 7 is further moved to the right by L2 or more in FIG. 8 beyond the normal movement area I, but at this time, the slide bar 7 protrudes leftward from the print head A more than necessary. In this state, the print head A is moved to the moving area I.
If it moves inside and the full digit is printed, the left end of the slide bar 2 may come into contact with the abutting member 17a and damage the slide bar 2, or the staggered arrangement may be erroneously switched to the parallel arrangement during printing. The positioning protrusion C hits the roller pin 4 by the positioning means C to hold the slide bar 2 at a correct position with respect to the head and prevent the above. The same applies when the staggered arrangement is switched to the parallel arrangement.

Since the slide member 2 and the transmission switching means B are provided on the surface of the head frame opposite to the nose portion 1d, the slide member 2 and the transmission switching means B are prevented from being damaged by the force from the outside of the head. it can.

As a method of assembling the print head A, the slide bar 2, the leaf spring 6, and the transmission lever 3 are attached in a laminated manner on the surface of the head frame opposite to the nose portion 1d, and a yoke or the like is attached thereon. Assemble electromagnetic drive devices by stacking them. Since it is sufficient to sequentially stack the components and assemble them on one surface of the head frame 1 as described above, it is possible to reduce the step of turning over the head frame during the assembly of the head.
Easy to assemble, leading to cost reduction in the process.

Since the long groove 13a is for preventing the wire W from being caught by the ribbon and is not a guide when the printing wire is projected, the width may be set sufficiently larger than the diameter of the wire W.

The present invention is not limited to this embodiment, and the groove surfaces of the first switching long groove and the second switching long groove of the cam groove may be provided so as to extend completely parallel to the moving direction of the head. In this case, when the roller pin 4 is in the first switching long groove and the second switching long groove, the roller force is applied to these groove surfaces by the spring force of the leaf spring 6, thereby accurately positioning the transmission lever in the vertical direction. The transmission lever can be selectively stabilized between the high speed printing position and the high quality printing position.

[0078]

According to the structure of the present invention, the parallel arrangement and
Space for a simple structure of the mechanism for switching the staggered arrangement
Since it can be efficiently arranged and the slide members protruding from both sides of the head frame contact the stationary member to switch the printing mode, there is no need to provide a space near the tip guide, and there are no design restrictions on the installation of the ribbon mask. .

[Brief description of drawings]

FIG. 1 is a perspective view of a main part of a print head according to an embodiment of the present invention.

FIG. 2 is a side view of a main part of the above print head.

FIG. 3 is an explanatory diagram showing an assembling method of the wire guide of the above print head.

FIG. 4 is a front view of a main part of the above slide member.

FIG. 5 is a front view of the above print head.

FIG. 6 is an explanatory view showing an assembling method of the above print head.

FIG. 7 is an explanatory diagram showing a method of assembling the above print head.

FIG. 8 is an explanatory diagram showing a moving range of a print head.

[Explanation of symbols]

 1 Head frame 1a Convex part 1d Nose part 2 Slide bar (slide member) 2a Cam groove 2a1 1st switching long groove 2a2 2nd switching long groove 2a3 Inclined groove 3 Transmission lever 4 Roller pin (cam follower) 6 Leaf spring 7a Positioning protrusion 8 Engaging piece 9 Second tip guide 9a Positioning long groove 10 First tip guide 12 Guide plate 13 Holding plate 13a Long groove 17a, 17b Base plate (stationary member) 24 Carriage A Print head B Transmission switching means W Print wire

Claims (4)

(57) [Claims] 1. A print head mounted on a carriage, moved in the width direction of a recording medium, and having a plurality of electromagnetically driven print wires aligned and supported by a nose portion of a head frame, In a wire dot printer capable of switching the printing mode between high-speed printing and high-quality printing, the tip of the printing wire is reduced in the nose section.
The first tip guide and the second tip guide also aligned in two rows
Are provided side by side, the first tip guide is fixed to the nose portion, and the second tip guide is provided at the nose portion .
The head frame is fixed to the head frame or the head frame so as to be movable relative to the first tip guide in the alignment direction of the tips of the printing wires at a stroke substantially half the tip alignment pitch of the printing wires. The related members are provided with slide members slidable substantially parallel to the moving direction of the print head so as to project from both sides of the head frame. When printing
It is displaced by coming into contact with a stationary member in the printer when it is moved beyond the moving region to move, and between the slide member and the second tip guide,
The association with the displacement of the slide member Ri Ah provided with a transmitting switching means for displacing said second front guide, said transmission switching means, in conjunction with the displacement of the slide member
Which is substantially orthogonal to the moving direction of the slide member
Transmission lever that slides in the direction and both ends are the transmission lever
Move integrally with the leaf spring that engages with the second tip guide.
It is provided so as to move and engages with the central portion of the leaf spring.
And an engaging piece that engages in the moving direction of the slide member.
The position is long and in the direction substantially perpendicular to this moving direction.
Misaligned first and second switching long grooves and both switching
A cam groove consisting of an inclined groove connecting the long grooves is provided.
Yes, the transmission lever has a cam follower that fits in the cam groove.
A wire dot printer capable of switching print modes, characterized by being provided with . 2. The nose portion according to claim 1 , wherein
A guide plate for guiding the second tip guide is provided.
Position on one of the guide plate and the second tip guide.
Positioning protrusion and positioning long groove on the other can be fitted together
The vertical length of the positioning long groove is
The tip of the above-mentioned printing wire is aligned more than that of the positioning protrusion.
It is set to be half the pitch longer,
The lower is the upper long groove of the first and second switching long grooves.
When it is inside, the transmission lever is at both ends of the leaf spring.
Is located above the natural state with respect to its center
And the cam follower switches between the first and second switching positions.
If it is inside the lower long groove, the transmission lever
-The natural state of both ends of the leaf spring with respect to the center
A wire dot printer capable of switching the print mode, which is characterized in that the wire dot printer is held so as to be positioned lower than the above . 3. The printing mark according to claim 1 ,
The front of the tip guide on the
Fixed holding plate with multiple rows of long slots that can be inserted
Possible wire dot printer switches the print mode, characterized in that are. 4. The method according to claim 1, wherein
On the surface of the head frame opposite to the nose part,
A slide of the transmission lever and the slide member is proposed.
There is a concave part or a convex part inside, and the slide part
Material, the transmission lever, the leaf spring, the engaging piece are the surfaces
A wire dot printer capable of switching the print mode, which is characterized in that it is mounted on the side in a laminated form .