JPH06286257A - Printing apparatus - Google Patents

Abstract

PURPOSE:To provide a printing apparatus wherein a main body of a carriage is formed superior in terms of costs and manufacturing procedures in a simplified integral structure using a synthetic resin. CONSTITUTION:A main body 11 of a carriage is formed of a synthetic resin, consisting integrally of a cylindrical second leg part 11a outfitted to a front guide shaft 8 in a slidable manner in the right-and-left direction, a cylindrical first leg part 11b outfitted to a rear guide shaft 9 in a slidable manner in the right-and-left direction, and a coupling frame 11e which includes a first main wall 11c and a second main wall 11d coupling the first and second leg parts 11b and 11a and erected while faced in the front-and-rear direction. The coupling frame 11e is provided with a plurality of ribs for the purpose of reinforcement. The first main wall 11c generally in a U-shaped cross section is formed approximately at the central part of the main body 11 in the right-and-left direction, and the second main wall 11d generally in a U-shaped cross section is formed at the right end of the main body 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a type wheel type printing apparatus, and more particularly to a synthetic resin material having a simple structure for a carriage main body which is equipped with a plurality of driving mechanisms such as a printing mechanism and is driven to move along a platen. Related to the one that is integrally molded.

[0002]

2. Description of the Related Art A type wheel type electronic typewriter capable of printing and erasing characters by providing a printing hammer, a type wheel, a printing ribbon, an erasing ribbon, and a drive mechanism for them on a carriage body is well known. by the way,
The applicant of the present application discloses in JP-A-4-235082 that a position switching mechanism for a holder member on which a print ribbon is placed, a print hammer drive mechanism, a print ribbon take-up mechanism, an erase ribbon take-up mechanism, and a holder member are printed at a print position. And a position switching mechanism for switching between the erasing position and the erasing position are respectively driven by operatively interlocking with a cam body that is rotationally driven by one drive motor provided in a carriage body composed of a pair of left and right main frames. In this way, an electronic typewriter that can reduce the manufacturing cost and can make the carriage compact has been proposed.

In this electronic typewriter, from the viewpoints of compactness of the carriage main body and rigidity enough to receive a reaction force against the impact at the time of printing, a pair of thin plate-shaped members having a substantially rectangular shape in side view are provided. The metal may frame of the above is integrally formed with a plurality of spacers and screws in a rigid state to form the carriage body, while the rear end side of the carriage body is slidably attached to the guide shaft. The guide member, which is connected to the fitted support member and supported in the left-right direction on the front side of the carriage body, is engaged and supported by the swingable contact member provided at the front end of the carriage body. Is configured to. Therefore,
More than 10 parts are used for the carriage body and the carriage body supporting mechanism.

[0004]

As described above, in the electronic typewriter proposed by the applicant of the present application, the carriage main body is compact and has a rigidity enough to receive a reaction force against a hit at the time of printing. Since a pair of thin plate-like metal mayframes are integrated with a plurality of spacers and screws in a rigid state, a great deal of labor is required for the assembling work for assembling the carriage body, and There is a problem that the carriage main body and the carriage main body supporting mechanism require a large number of parts of 10 or more points, and the carriage main body becomes expensive.

SUMMARY OF THE INVENTION An object of the present invention is to provide a printing apparatus in which the structure of a carriage body is simplified and integrally formed of a synthetic resin material so that a carriage body which is advantageous in terms of cost and manufacturing can be constructed. .

[0006]

A printer according to claim 1 is
At least a platen extending in the left-right direction, a carriage body movably guided along the front side of the platen in the printing direction, a type wheel, and a printing mechanism including a printing hammer, a carriage body, A cylindrical first leg that is slidably fitted to the left and right on a guide shaft that guides and supports the lower portion of the rear part of the carriage body, and a left and right guide member that guides and supports the front part of the carriage body. A first leg part, a second leg part, and a connecting wall part; and a second leg part that is freely engaged, and one or a plurality of connecting wall parts that connect the first leg part and the second leg part. Is integrally formed of a synthetic resin material.

[0007]

In the printing apparatus according to the first aspect of the present invention, the carriage main body, which is guided movably in the printing direction along the front side of the platen extending in the left-right direction, has the guide shaft supporting the lower part of the rear portion of the carriage main body in the left-right direction. A cylindrical first leg that is slidably fitted to the outside, a second leg that is slidably engaged in the left-right direction with a guide member that guides and supports the front portion of the carriage body, and the first leg A simple structure composed of one or a plurality of connecting wall portions that connect the first portion and the second leg portion, and the first leg portion, the second leg portion, and the connecting wall portion are integrally formed of a synthetic resin material. Since it is configured, the number of parts can be reduced to one, and the assembling work is completely unnecessary, so that the carriage main body can be remarkably inexpensive.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. In this embodiment, a cam drive motor composed of a DC motor is used for an electronic typewriter which is designed to perform a printing operation, a printing ribbon winding operation associated therewith, an erasing operation and an erasing ribbon winding operation associated therewith. This is a case where the invention is applied. As shown in FIG. 1, side wall plates (machine frames) 2 are provided at the left and right ends inside the casing of the typewriter 1, respectively.
Is provided in the front-back direction, and the platen 3 disposed between the pair of side wall plates 2 is rotatably supported by the side wall plates 2 in the vicinity of both ends of the platen shaft 4.
It is rotationally driven by a line feed motor (not shown) via a driven gear (not shown) fixed to the left end portion of the platen shaft 4.

A rack 7 is further provided between the pair of side wall plates 2.
A pair of front and rear guide shafts 8 and 9 are arranged in parallel with the platen 3, and a carriage 10 supported by these guide shafts 8 and 9 so as to be movable in the left and right directions will be described. First, the carriage body 11 will be described with reference to FIGS. The carriage main body 11 includes a cylindrical second leg portion 11a fitted on the front guide shaft 8 so as to be slidable in the left-right direction.
And a cylindrical first leg portion 11b externally fitted to the rear guide shaft 9 so as to be slidable in the left-right direction, and the first and second leg portions 11
b and 11a are integrally formed of a synthetic resin material with a connecting frame 11e that includes a first main wall 11c and a second main wall 11d that are erected in the front-rear direction and are provided upright and that are provided with a plurality of ribs for reinforcement. It was done. Here, the first main wall 11c having a substantially U-shaped cross section is formed at a substantially central portion in the left-right direction of the carriage body 11, and the second main wall 11d having a substantially U-shaped cross section is formed at the right end portion thereof. .

As described above, the carriage body 11 guides and supports the lower portion of the rear portion of the carriage body 11.
Cylindrical first leg 1 that is slidably fitted to the outside in the left and right direction
1b and a second leg portion 11 slidably engaged in the left-right direction with a guide shaft 8 that guides and supports the front portion of the carriage body 11.
a and a connecting frame 11e connecting the first leg portion 11b and the second leg portion 11a with a simple structure. The first leg portion 11b, the second leg portion 11a, and the connecting frame 11 have a simple structure.
Since e is formed integrally with a synthetic resin material,
The number of parts of the carriage body 11 can be reduced to one, and the assembling work is not required at all, so that the carriage body 11 can be made much cheaper.

Next, the printing mechanism 15 will be described with reference to FIGS.
It will be explained based on. The first main wall 11 immediately in front of the rack 7
The cam body drive motor 16 is attached to the left side of c,
The drive shaft 16a of the cam body drive motor 16 has the first main wall 1
The pinion 17 having a small diameter is fixed to the tip of the pinion 1c extending rightward through the pin 1c. On the other hand, the cam body drive motor 1
On the diagonally upper rear side of 6, the left and right ends of a pivot shaft 18 parallel to the platen 3 are rotatably supported by both main walls 11c and 11d, respectively. As shown in the figure, a cam body 20 made of synthetic resin is integrally formed with a printing cam 21, a driven gear 22, a rotational position detecting disk 23, a ribbon feed cam 24, and a ribbon lift cam 25 from the cam body drive motor 16 side. Is fixed so that it cannot move left and right. The driven gear 22 is the pinion 1
7 is meshed. The pinion 17 and the driven gear 22
And constitute a reduction mechanism, and the gear ratio between the pinion 17 and the driven gear 22 is 1: 2.5. In this way, the printing cam 21, the driven gear 22, and the rotational position detecting disk 2
3. Since the ribbon feed cam 24 and the ribbon lift cam 25 are integrally formed, the phase adjustment work for matching the phases of these cams can be dispensed with and the cam body 20 can be omitted.
Can be manufactured easily and at low cost.

On the other hand, a turning lever 27 having a substantially inverted U-shape in side view.
Is fixed to a pivot shaft 28 rotatably supported by both main walls 11c and 11d corresponding to the position near the first leg 11b, and the printing cam 21 is provided at the middle portion in the height direction.
A cam follower 29 that abuts on the cam surface is rotatably pivotally mounted, and its upper end is bent backward to form a print hammer 27a. And this cam follower 2
A tension spring 30 is stretched over the rotation lever 27 and the pivot shaft 18 so that the print medium 9 always contacts the cam surface of the printing cam 21. Here, reference numeral 31 is a print ribbon PR
The reference numeral 35 denotes a holder member on which the ribbon cassette 31 is placed and which can be swung between the printing position shown in FIG. 1 and the raised erasing position shown in FIG.

As shown in FIG. 5 and FIG. 14, the printing cam 21 has a generally side view in a side view, and the curved cam surface on the outside of the printing cam 21 has a cam body 20 at the start of printing, that is, printing. The set normal phase start angle of the print cam 21 is 0 °, and in the print standby range from this phase angle 0 ° to about 60 °, the radii are equal and the radius is equal. The radius expansion rate increases from 60 ° to a phase angle of about 140 °.
After that, the radius expansion rate has become small. Moreover, the printing cam 2 is designed so that the cam follower 29 does not come off from the outer peripheral cam surface even after the printing hammer 27a is hit.
1, a curved cam is extendedly formed.

Here, as shown in FIG. 14, the cam follower 29 at the start of printing is located at any position in the print standby range. Then, by driving the cam body drive motor 16 in a predetermined rotation direction, the pinion 1
When the cam body 20, that is, the printing cam 21 is rotated in the clockwise direction in FIG. 6 at a high speed of, for example, about 180 ° via the 7 and the driven gear 22, the cam follower 29 causes the printing cam 2 to move.
Since it moves backward about 10 mm along the curved cam surface of No. 1, the rotation lever 27 is rapidly rotated in the counterclockwise direction about the pivot 28 as the center of rotation, and the print hammer 27a is
By turning the turning lever 27 backward, the type wheel 7 is moved.
The platen 3 via the second type 72a and the print ribbon PR.
It is strongly pressed and hit.

Here, the cam body 20 is driven via a reduction gear mechanism including a driven gear 22 formed on the cam body 20 and a pinion 17 fixed to a drive shaft 16a of the cam body drive motor 16. Therefore, the fluctuation of the rotation speed of the cam body drive motor 16 with respect to the fluctuation of the load acting on the cam body 20 not only decreases in accordance with this reduction gear ratio, but conversely the cam speed with respect to the fluctuation of the rotation speed of the cam drive motor 16 does not change. The fluctuation of the rotation speed of the body 20 also decreases corresponding to this reduction gear ratio, so that the printing operation by the printing hammer 27a becomes stable. In addition, the cam body 20 for driving the plurality of drive mechanisms and the cam body drive motor for driving the cam body 20 have a degree of freedom in arrangement, and the dimension of the carriage body 11 in the front-rear direction can be further reduced. Further, due to the moving speed of the print hammer 27a and the large inertial force of the cam body drive motor 16 generated from the reduction gear ratio between the pinion 17 and the driven gear 22, the print hammer 27a can be strongly pressed against the platen 3. The drive control of the cam body drive motor 16 can be simplified and good print quality can be obtained.

By the way, as shown in FIG. 6, the rotation center position of the rotation lever 27 is provided near the tangent line S1 at the striking point where the print hammer 27a strikes the platen 3 and near the first leg portion 11b. Moreover, since the center of rotation is provided below the cam follower 29 and the distance from the center of rotation to the print hammer 27a is increased, the impact direction of the print hammer 27a is orthogonal to the tangent line S1 from the impact point. Becomes the orthogonal direction S2 toward the center of the platen 3,
Since the type 27a is pressed evenly, the printing quality is improved.

Here, the detection disk 23 will be briefly described. As shown in FIGS. 9 and 14, assuming that the phase angle at the start of regular printing is 0 °, the detection disk 23 has an outer peripheral portion. The first notch 23a is formed from the phase angle 65 ° to the phase angle 160 °, and the second notch 23b is formed from 0 ° to −35 °. Then, as shown in FIG. 17, this detection disk 2
At the lower end of 3, the first and second notches 23a and 23
The photo sensor 36 for detecting b is the carriage body 1
It is fixed to 1. Then, as shown in FIG. 14, from the photo sensor 36, the first and second notches 23 are formed.
An "L" level position detection signal is output corresponding to a. 23b, and an "H" level position detection signal is output at times other than the first and second notches 23a and 23b.

Next, the holder member 35 will be described. As shown in FIGS. 1, 2, and 7, a plate-shaped support plate 35a for mounting and supporting the ribbon cassette 31, and an outer periphery of the support plate 35a. Provided on the outer peripheral wall portion 35b extending downward, a front wall portion 35c erected at a substantially front end portion of the support plate 35a for holding the front end portion of the ribbon cassette 31, and a portion near the front end of the support plate 35a. It is made of a synthetic resin integrally formed with a pair of hinge portions 35d having a substantially b-shaped side view. When the holder member 35 is swingably attached to the carriage body 11, as shown in FIGS. 7 and 8, the rear end portion of the holder member 35 is swung largely upward, and the holder member 35 is first swung. 35 and then to the right to move both hinge portions 35d to the second leg portion 11a.
A pair of pin portions 11h of the pin attachment portion 11g formed on the
And the holder member 35 is lowered until the holder member 35 reaches the print position. At this time,
The holder member 35 includes a pair of pin portions 11h and a hinge portion 35.
The abutment portion 35e formed on the right outer peripheral wall portion 35b of the holder member 35 is pivotally supported by the carriage main body 11 via the d and the pin attachment portion 11g on the right side.
Since they are in contact with each other from the right side, the pin portion 11h and the hinge portion 35d are not disengaged from each other when the printing operation or the erasing operation is performed.

Next, the print ribbon winding mechanism 4 for winding a predetermined amount of the print ribbon PR on the take-up spool for each printing operation.
0 will be described with reference to FIGS. 4, 7, and 9. At the lower left end of the holder member 35, a ratchet wheel 41 having a plurality of teeth is rotatably supported by a pin 42,
The third swinging member 43, which is rotatably supported by the pin 42 and provided with the feed claws 43a, is connected to the second swinging member 44, which is pivotally mounted on the holder member 35, via a connecting pin 45. The second swinging member 44 is elastically biased in the counterclockwise direction in FIG. 7 by the tension spring 46. The take-up spool 47 is fixed to the pin 42.

On the other hand, as shown in FIG. 9, the ribbon feed cam 24 is an eccentric cam having a substantially elliptical shape in side view, and has a lower end pivotally supported by the carriage main body 11 so that the lower end thereof is pivotally supported. The rear side surface of the member 48 near the upper end is in contact with the ribbon feed cam 24. Further, this first swing member 48
The right end of the second swinging member 44 is in contact with the front side surface of the upper end of the. Therefore, when the ribbon feed cam 24 is rotated in the printing direction P by the cam body drive motor 16, when the first swing member 48 moves forward due to the cam shape of the ribbon feed cam 24, the right end of the second swing member 44. The parts also move forward at the same time, the second rocking member 44 is rotated clockwise as shown by the chain double-dashed line in FIG. 7, and the third rocking member 4 is rotated.
3 rotates counterclockwise to rotate the ratchet wheel 41 by one tooth by the feed claw 43a, and the print ribbon PR is step-fed by a predetermined amount by the take-up spool 47 immediately before printing.

Next, the erasing mechanism 50 for raising the holder member 35 from the printing position to the erasing position so that the erasing ribbon CR faces the printing hammer 27a during character erasing will be described with reference to FIGS. The ribbon lift cam 25 has a reference cam 25a having an equal radius from the rotation center of the cam 25, a first inclined cam surface 25b continuously extending from the reference cam 25a in the radial expansion direction, and the first inclined cam. A second inclined cam surface 25c continuous with the surface 25b in the middle and continuous with the outer peripheral cam surface 25d is formed, and an outer peripheral wall 25e extends from the right end of the outer peripheral cam surface 25d in the radial expansion direction.

A part of the outer peripheral wall 25e is provided on the outer peripheral wall 25e.
e and the right protruding portion 21p of the right end surface of the first inclined cam surface 25b
In the left-right direction, that is, about 1/3 of the total movement amount (about 5 mm) of the driven pin 51 moving in the left-right direction, the outer peripheral wall 25e.
A shallow shallow bottom surface 21h is formed from the
An inclined surface 25i extending from h to the right end surface 25g is formed. The depth of the inner peripheral side of the inclined surface 25i is shallower by about 1/3 of the total movement amount than the depth of the outer peripheral side. Further, the advance side portion and the retard side portion of the shallow bottom surface 21h are respectively connected to the outer peripheral wall 25e by inclined surfaces.

Next, the driven pin 51, which comes into contact with the ribbon lift cam 25 from the right side, is supported by the lower end portion of the support member 52 attached to the outer peripheral wall portion 35b on the right side of the holder member 35 so as to be movable in the left-right direction. , Is always elastically biased to the left by a coil spring (not shown). This driven pin 51
At the start of printing, as shown in FIG. 10, the weight of the holder member 35 causes the pin tip of the holder member 35 to come into contact with the reference cam 25a from above to support the holder member 35 at the printing position shown in FIG. The right end surface 25g is elastically biased from the right side. That is, the vertical swing amount of the holder member 35 is determined by the vertical movement amount of the driven pin 51.

Therefore, when the ribbon lift cam 25 is rotated by a predetermined angle in the direction opposite to the printing direction P (referred to as the anti-printing direction) from the printing start phase angle shown in FIG. 14, the driven pin 51 moves. First inclined cam surface 25
Since the holder member 35 is moved upward by b, the holder member 35 is also swung upward according to the upward movement distance, and when the ribbon lift cam 25 is rotated in the printing direction P after that, the driven pin 5 is moved.
Since 1 reaches the outer peripheral cam surface 25d via the second inclined cam surface 25c, the holder member 35 swings further upward and is switched to the erasing position shown in FIG. At this time, the erasing ribbon CR is at a position facing the print hammer 27a.

Next, when erasing characters, the erasing ribbon winding mechanism 5 for winding a predetermined amount of the erasing ribbon CR on the winding spool.
5 will be described with reference to FIGS. 7 and 13. A supply spool 56 of the erasing ribbon CR is rotatably attached to the left outer peripheral wall 35b of the rear end of the holder member 35.
The take-up spool 57 of the erasing ribbon CR is rotatably and pivotally attached to the corresponding outer peripheral wall portion 35b on the right side. The take-up spool 57 is provided with a ratchet wheel 58 having a plurality of teeth.
On the front side of the carriage main body 11, a feed pawl 59 is attached to the carriage body 11 for contacting the ratchet wheel 58 and rotating it by one tooth.

That is, as described for the erasing mechanism 50, the set phase angle of the regular cam body 20 at the start of printing is 0 °.
And the ribbon lift cam 25 about 45 ° in the opposite printing direction.
When rotated (hereinafter referred to as -45 °), the driven pin 51
Is lifted along the first inclined cam surface 25b and then positioned on the second inclined cam surface 25c. At this time, the driven pin 51 is at a position raised by about 2 mm with respect to the position of the reference cam 25a. Then, here, the ribbon lift cam 25 moves in the printing direction P.
When the driven pin 51 rotates to the second inclined cam surface 25c.
After moving up, the outer peripheral cam surface 25d is reached. At this time, the driven pin 51 is at a position raised by about 5.5 mm with respect to the reference cam 25a, and the holder member 35 is moved to the erasing ribbon CR.
Is switched to the erasing position facing the print hammer 27a. Here, during this ascending, the currently engaged tooth of the ratchet wheel 58 is rotated downward by one tooth by the feed pawl 59, so that the erasing ribbon CR is wound onto the winding spool 57 by a predetermined amount. Step forward.

Next, the wheel drive mechanism 61 for driving the type wheel 72 will be described with reference to FIGS. The wheel drive motor 62, which is a stepping motor, is attached to the motor holder 63 with screws.
The motor holder 63 is screwed to the rear end wall portion 11f of the carriage body 11 from the rear side, and the wheel drive motor 6
The second drive shaft 62a extends through the rear end wall portion 11f and extends forward, and the drive gear 65 is fixed to the wheel housing portion 64 formed on the front side of the rear end wall portion 11f. That is,
The wheel drive motor 62 is located below the platen 3. The large-diameter wheel drive gear 66 meshed with the drive gear 65 has its rotation center position determined by the print hammer 27a.
The spindle unit 6 on the carriage body 11 at a position facing the
It is rotatably supported via 6a. Incidentally, reference numeral 67
Is an origin lever for setting the origin position of the wheel drive gear 66, and reference numeral 68 is a paper meter.

On the other hand, on the front side of the wheel accommodating portion 64,
As shown in FIG. 3, a flat plate-shaped wheel holding plate 69 having an operating portion 69a at the upper end thereof can press the type wheel 72 set in the wheel accommodating portion 64 from the front side, and at the lower end portion thereof, is attached to the carriage body 11. Axis 70 provided
It is pivoted back and forth via. Further, the pivot shaft 70 is provided with a winding spring 71 that elastically biases the wheel holding plate 69 rearward. A lower end portion of the wheel holding plate 69 is bent rearward to form a receiving portion 69b for receiving the type wheel 72.

When mounting the type wheel 72, first, as shown in FIG. 16, the type wheel 72 is accommodated in the wheel while the wheel holding plate 69 is rotated forward against the spring force of the winding spring 71. The receiving portion 69 in the portion 64
b, and then the wheel holding plate 69 is wound on the spring 7
The urging force of 1 swings backward. At this time, the spindle portion 66a is fitted in the engaging hole 72b formed in the center portion of the type wheel 72, and the center portion of the type wheel 72 is pressed against the front end surface of the wheel drive gear 66, so that the type wheel 72 is It is elastically sandwiched between the wheel drive gear 66 and the wheel holding plate 69 while being engaged with the portion 66a and positioned.

As described above, when the type wheel 72 is mounted, the type wheel 72 is accommodated in the wheel accommodating portion 64 and the wheel holding plate 69 is swung rearward by the urging force of the winding spring 71 to move the type wheel 72. Can be easily installed. Here, since the wheel drive motor 62 is disposed below the platen 3 and is fixedly mounted on the rear end wall portion 11f of the wheel housing portion 64, only the wheel drive motor 62 of the carriage body 11 is attached. Since the dimension in the front-rear direction can be reduced, a sufficient space can be secured for the electronic board for electronic control arranged on the front side of the carriage 10.

Next, a carriage drive mechanism 75 for moving the carriage body 11 in the left-right direction will be described with reference to FIGS. 1, 3, and 17. Here, as described above, the carriage body 11 has the cam body drive motor 1
6, a cam body 20, a rotating lever 27, a print ribbon winding mechanism 40, an erasing mechanism 50, an erasing ribbon winding mechanism 55, a holder member 35, a wheel drive mechanism 61, a wheel drive motor 62, and other numerous members and mechanisms are provided. The center of gravity G of the carriage 10 is set to the first main wall 1 as shown in FIG.
It is located immediately to the left of 1c and to the rear of rack 7. The carriage drive motor 76 is disposed immediately behind the center of gravity G of the carriage 10 and faces forward. That is, near the center of gravity G, the cam body 20 and the left and right symmetrical positions with respect to the carriage center line L corresponding to the print hammer 27a. And is configured to move and drive the carriage body 11 in the left-right direction by engaging with the rack 7 via a gear mechanism.

Regarding this gear mechanism, FIG. 1, FIG. 3, and FIG.
7, the carriage drive motor 76 is
The motor holder 77 is attached to a motor holder 77 having a substantially U shape in a plan view, and the motor holder 77 is pivotally supported on the carriage body 11 by a pin 78 at its lower end. The drive shaft 76a of the carriage drive motor 76 is inserted through the motor holder 77 and extends forward to fix the pinion 79, and a large-diameter driven gear 80 meshing with the pinion 79 is rotatably supported by the motor holder 77. A small-diameter contact gear 80a integrally formed with the driven gear 80 is meshed with teeth on the upper surface of the rack 7.

Further, auxiliary rollers 81, which come into contact with the lower side of the rack 7 and the front and rear sides thereof, are rotatably supported on the lower portion of the carriage body 11, and further, are supported on the upper end of the motor holder 77 and the first main wall 11c. Tension spring 82 stretched over
The elastic biasing of the contact gear 80a eliminates the backlash between the contact gear 80a and the teeth of the rack 7. When the carriage drive motor 76 is rotationally driven, the carriage body 11 is moved leftward or rightward by the engagement of the contact gear 80a and the teeth of the rack 7 via the pinion 79 and the driven gear 80. . At this time, the carriage drive motor 76 causes the carriage center line L corresponding to the print hammer 27a to be near the center of gravity of the carriage 10.
On the other hand, since the print mechanism 16 mainly composed of the cam body drive motor 16 and the cam body 20 is arranged at a position substantially symmetrical to the left and right, the carriage body 11 can be moved and driven at a position with a good weight balance. The main body 11 can be moved smoothly. Moreover, since the print hammer 27a is driven at a position corresponding to the carriage center line L with good weight balance, the print quality by the print hammer 27a can be improved.

The guide shaft may be replaced by a guide member having a rectangular cross section, and the second leg 11a may be slidably engaged with the guide member. The connecting frame 11e may be composed of a plurality of connecting wall portions.

[0035]

As described above, according to the printing apparatus of the first aspect, the carriage body has the cylindrical first leg portion, the second leg portion, and the first leg portion and the second leg portion. Since the first leg portion, the second leg portion, and the connecting wall portion are integrally formed of a synthetic resin material, they have a simple structure including one or a plurality of connecting wall portions that connect The number of the carriages can be one, and the assembling work is completely unnecessary, so that the carriage main body can be remarkably inexpensive.

[Brief description of drawings]

FIG. 1 is a side view of an internal mechanism of an electronic typewriter.

FIG. 2 is a plan view of a holder member.

FIG. 3 is a view on arrow A in FIG.

FIG. 4 is a partial front view of the internal mechanism of the electronic typewriter.

FIG. 5 is a vertical sectional side view of a main part of an internal mechanism of the electronic typewriter.

FIG. 6 is a view corresponding to FIG. 5 at the time of printing operation.

FIG. 7 is a view on arrow B of FIG.

FIG. 8 is a partial perspective view of the holder member and the carriage body when the holder member is attached to the carriage body.

FIG. 9 is a partial side view of the internal mechanism of the electronic typewriter.

FIG. 10 is a view corresponding to FIG. 9 illustrating an erasing mechanism.

FIG. 11 is an exploded perspective view of a ribbon lift cam and a driven pin.

FIG. 12 is a view corresponding to FIG. 9 at the erase position.

FIG. 13 is a view illustrating an erasing ribbon winding mechanism, which corresponds to FIG. 9.

FIG. 14 is a diagram showing motion curves of a driven pin and a cam follower.

FIG. 15 is a rear view of the main part of the internal mechanism.

16 is a view corresponding to FIG. 5 when the type wheel is attached and detached.

FIG. 17 is a vertical cross-sectional front view taken along the line C-C of FIG.

[Explanation of symbols]

 1 Electronic Typewriter 3 Platen 8 Guide Axis 9 Guide Axis 11 Carriage Main Body 11a Second Leg 11b First Leg 11e Connection Frame 15 Printing Mechanism 16 Cam Body Drive Motor 21 Printing Cam 27 Rotating Lever 27a Printing Hammer 29 Cam Follower 72 Type wheel

Claims (1)

[Claims] 1. A printing apparatus comprising at least a platen extending in the left-right direction, a carriage body movably guided in a printing direction along a front side of the platen, a type wheel, and a printing mechanism including a printing hammer. A first leg portion of the carriage body that is slidably fitted to the left and right on a guide shaft that guides and supports the lower portion of the rear portion of the carriage body; and a guide member that guides and supports the front portion of the carriage body. Second slidably engaged in the left and right direction
A leg portion and one or a plurality of connecting wall portions connecting the first leg portion and the second leg portion are provided, and the first leg portion, the second leg portion, and the connecting wall portion are integrally made of a synthetic resin material. A printing device characterized by being formed and configured.