JPH0696321B2 - Printer - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer, and more particularly to a printer including a drive mechanism that applies a rotational drive force to a member supported by a carriage that reciprocates.

[Summary of Disclosure] This specification and the drawings show, in a printer, a carriage capable of reciprocating in a predetermined direction, a first gear portion having external teeth, and an outer periphery of the first gear portion coaxial with the first gear portion. A second gear portion provided with an internal tooth facing the first gear portion, the drive switching gear member reversing the rotation direction according to the change in the moving direction of the carriage, and the drive switching gear. Depending on the position of the drive switching gear member on the carriage, the shaft supporting means for supporting the carriage while allowing the member to move in the direction along the moving direction of the carriage and the member supported by the carriage. A gear that meshes with the first gear portion or the second gear portion,
The drive switching gear member is displaced on the carriage in accordance with the change in the moving direction of the carriage, and the first gear portion or the second gear portion meshes with the gear, so that the drive switching gear member is irrespective of the moving direction of the carriage. By adopting a configuration in which the gears are driven in the same rotation direction, the number of parts is small, the structure is extremely simple, compact, and low-cost, and the rotation drive force is the same in the same rotation direction regardless of the carriage movement direction. The technology that enables the user to obtain is disclosed.

[Prior Art] In a printer in which an ink ribbon cassette is detachably provided on a carriage, a drive source for winding the ink ribbon must be provided on the carriage side.

The simplest drive source is to mount a motor for winding the ink ribbon on the carriage side, but this requires an extra motor, which increases the cost and the size of the apparatus.

Therefore, a structure has been proposed in which the ink ribbon is taken up by another driving means without using the motor.

Two examples are shown in FIGS. 5 and 6. The example shown in FIG. 5 uses a so-called pendulum gear.

That is, the reference numeral 1 in FIG. 5 is a carriage, which is reciprocated along the guide shaft 2 in parallel with a platen (not shown).

On the other hand, reference numeral 3 is an ink ribbon cassette, and a winding shaft (not shown) is housed in the ink ribbon cassette, and a knob 3a is exposed integrally with the winding shaft on the upper surface side thereof.

A shaft 4 is rotatably projected on the carriage 1,
The spline portion 4a at the tip thereof is fitted into the fitting portion having a shape complementary to the spline 4a formed at the lower end of the winding shaft (not shown) from the opening formed in the lower side of the ink ribbon 3. .

The shaft 4 has a gear 5 at its lower end, and gears 6 and 7 having small diameters mesh with the gear 5, and one gear 7 meshes with a gear 8.

By the way, the reference numeral 10 designates an operating gear, which is rotatably supported on the carriage 1 via a shaft 10a.

A pulley 14 is coaxially fixed to the upper surface of the operating gear 10, and a wire 12 stretched between the side plates 13, 13 of the device in parallel with the guide shaft 2 has a left-handed winding. It is wound once in the state.

In addition, a spring 12 is provided between one end of the wire 12 and the side plate 13.
a is interposed, and the wire 12 is always given a constant tension.

On the other hand, one end of a rotating lever 11 is rotatably supported on the rotating shaft 10a.

A pendulum gear 9 is rotatably supported on the other end of the rotary lever 11 via a shaft 9a.

The pendulum gear 9 is always in mesh with the operating gear 10 and is in a position where it can selectively mesh with the gears 6 and 8.

When the carriage 1 moves in the direction of arrow A in FIG. 6 based on the above structure, the operating gear 10 is rotated clockwise in the figure.

Then, the pendulum gear 9 meshing with the pendulum gear 9 is rotated counterclockwise in the figure, and tries to revolve clockwise around the operating gear 10 like a planetary gear, and the rotating lever 11 is also rotated clockwise. , Immediately meshes with the gear 8 and rotates it clockwise. As a result, the gear 7 meshed therewith is rotated counterclockwise, the gear 5 and the shaft 4 integral therewith are rotated clockwise, and the rotary shaft of the ink ribbon cassette and the knob 3a integral therewith are clockwise. The ink ribbon is rotated and wound up.

On the other hand, when the carriage 1 is rotated in the direction of arrow B in FIG. 5, the operating gear 10 is rotated counterclockwise, and the pendulum gear 9 also revolves counterclockwise, contrary to the above. It meshes with the gear 6.

At this time, the pendulum gear 9 is rotating clockwise, so the gear 6
Is rotated counterclockwise and gear 5 is rotated clockwise,
The winding shaft of the ink ribbon cassette 3 is rotated clockwise to wind the ink ribbon.

In this way, it is possible to wind the ink ribbon as the carriage reciprocates, without requiring a drive source such as a motor.

As a result, when the carriage reciprocates, the ink ribbon can be wound and reciprocal recording can be performed.

In the example shown in FIG. 5, if a certain friction is provided between the rotary lever 11 and the pulley 14 or between the rotary lever 11 and the pendulum gear 9, the switching operation of the pendulum gear 9 is surely performed. Becomes

On the other hand, in the conventional example shown in FIG. 6, a one-way clutch is used.

That is, the reference numerals 5 and 4 in FIG. 6 are gears and shafts similar to those in the example shown in FIG. 5, and are also rotatably supported on the carriage.

On the carriage, the pulley 15 is provided near the gear 5.
Is rotatably supported, and one wire 12 similar to the above-described example is wound around the shaft.

A gear 16 is fixed on the pulley 15, and a gear 18 is rotatably supported by a shaft 19 coaxially therewith via a one-way clutch 17 exemplified as a spring clutch. The gear 18 meshes with the gear 5.

On the other hand, a gear 20 meshing with the gear 16 is rotatably supported on the carriage, and the gear 20 has a one-way clutch.
The gear 22 is rotatably supported by the shaft 23 via the 21,
The gear 22 meshes with the gear 5.

With the above structure, when the carriage moves in the direction of arrow A, the pulley 15 and the gear 16 rotate clockwise, but at this time, the inward clutch 17 becomes free, and the rotation is not transmitted to the gear 18. The gear 5 is not rotated by the gear 18.

On the other hand, since the gears 16 and 20 mesh with each other, the gear 20 is rotated counterclockwise, and this rotation is transmitted to the gear 22 via the one-way clutch 21 which is ON, and the gear 5 rotates clockwise. Then, the ink ribbon is wound up.

On the other hand, when the carriage advances in the direction of arrow B in FIG. 6, the pulley 15 is rotated counterclockwise, and the gear 18 is rotated counterclockwise via the one-way clutch 17 in the ON state.
The gear 5 is rotated clockwise to wind up the ink ribbon.

At this time, the other one-way clutch 21 is free, so that the gear 22 does not rotate and the rotational force is not transmitted.

[Problems to be Solved by the Invention] However, when the pendulum gear structure as shown in FIG. 5 is used, many gears and parts are required, and not only the number of assembling steps increases and the cost increases, but also these members are required. There is a drawback that the space occupied on the carriage becomes large, the size of the entire apparatus becomes large, and a certain amount of friction must be given to the rotary lever 11, which increases the load.

Further, if the structure shown in FIG. 6 is adopted, the space becomes compact, but the height direction becomes large, the carriage becomes high, and the cost is increased because an expensive clutch is required.

If a spring clutch is used as the clutch, a loosening torque will always be generated in either one of the clutches, so not only power loss will occur, but also wear of the drum around which the spring is wound and fall of the spring will be prevented. For this reason, the clearance in the thrust direction of the spring needs to be adjusted, which is a disadvantage in that it becomes expensive as a whole.

[Means for Solving Problems] According to the printer of the present invention in order to solve the above problems, a carriage that can reciprocate in a predetermined direction, a first gear portion having external teeth, and the first gear. A second gear portion provided on the outer circumference of the portion coaxially with the first gear portion and having internal teeth facing the first gear portion, and reversing the rotation direction according to a change in the moving direction of the carriage. A drive switching gear member, a shaft supporting means for supporting the drive switching gear member in a direction along the moving direction of the carriage while supporting the carriage, and a member supported by the carriage, A gear that meshes with the first gear portion or the second gear portion depending on the position of the drive switching gear member on the carriage, and the drive switching gear member is mounted on the carriage according to a change in the moving direction of the carriage. The first gear portion or the second gear portion meshes with the gear so that the gear is driven in the same rotation direction regardless of the moving direction of the carriage.

[Operation] According to such a configuration, the drive switching gear member is displaced on the carriage according to the change in the moving direction of the carriage, and the first gear portion or the second gear portion of the drive switching gear member meshes with the gear. As a result, the gears are driven in the same rotation direction regardless of the moving direction of the carriage. That is, the drive switching gear member axially supported by the carriage by the shaft support means, and the gear provided on the member supported by the carriage,
With a drive mechanism with a small number of parts and an extremely simple structure,
It is possible to obtain the rotational driving force in the same rotation direction regardless of the moving direction of the carriage. Further, since the drive switching gear member is displaced and directly meshes with the gear, it is possible to reliably transmit the driving force without loss.

[Examples] Hereinafter, details of the present invention will be described based on Examples shown in the drawings.

[First Embodiment] FIGS. 1 and 2 are for explaining a first embodiment of the present invention. In the drawings, reference numeral 30 is a carriage, and one end of the carriage is partly protruded to the outside. In this state, the switching wheel 31 is rotatably supported.

The support shaft 31a of the switching wheel 31 has a long hole (not shown) formed in a predetermined length along the platen on the carriage 30 side.
It is slidably and rotatably supported inside.

The switching wheel 31 has a gear 31b formed on the outer peripheral surface thereof.

Further, the switching wheel 31 has a large-diameter internal gear 32 and a small-diameter external gear 33 arranged concentrically with the internal gear 32, and is formed in a dish shape as a whole.

The internal gear 32 is located one step higher than the external gear 33.

On the other hand, what is indicated by reference numeral 34 is a support plate, one end of which is a screw 35.
It is fixed to the carriage 30 side by the, but the free end side bends and extends on the switching wheel 31, and the support shaft is attached to the tip end thereof.
An elongated hole 34a is formed in which 31a is slidably and rotatably fitted.

Although not shown, the elongated hole 34a has the same shape as the aforementioned elongated hole provided on the carriage 30 side.

On the other hand, the rack plate 36 is arranged parallel to the platen in a state of meshing with the gear 31b on the outer peripheral surface of the switching wheel 31.

The rack plate 36 is provided horizontally between the left and right side plates 37, 37 of the printer main body, and a rack gear 36a is formed at the side edge on the carriage side thereof, and meshes with the gear 31b.

Two upper and lower projecting pieces 30a are projected from the end edge of the carriage 30. The two projecting pieces 30a, 30a sandwich the rack plate 36 from above and below to prevent the carriage from rotating and to prevent the carriage from rotating. Holds the linear movement of.

On the other hand, what is indicated by reference numeral 38 is an ink ribbon cassette, which has a large diameter integral with the winding shaft in a state of protruding from the lower end of the ink ribbon cassette so as to be located between the internal gear 32 and the external gear 33. A gear 39 and a small diameter gear 40 are provided.

Further, the reference numeral 41 is a knob that is integrally formed with the ink ribbon take-up shaft and protrudes on the upper surface of the cassette.

Next, the operation of this embodiment configured as described above will be described.

First, as shown in FIG. 2 (A), when the carriage 30 advances in the direction of arrow A, the support shaft 31a of the switching wheel 31 meshing with the rack gear 36a moves in the elongated hole 34a and is opposite to the carriage moving direction. Stop at the end of.

Then, since the position of the take-up shaft on the ink ribbon cassette side does not change, the external gear 33 has a small diameter gear located on the lower side.
Mates with 40.

When the carriage 30 advances in the direction of arrow A in this state, the switching wheel 31 and the external gear 33 are rotated in the direction of arrow B, that is, counterclockwise.

As a result, the small diameter gear 40 is rotated clockwise, and this rotation is transmitted to the winding shaft on the ink ribbon cassette side, and the ink ribbon is wound up.

On the other hand, as shown in FIG.
When it is moved in the direction, the switching wheel 31 is rotated in the direction of arrow D, that is, in the clockwise direction.

At this time, the support shaft 31a moves in the elongated hole 34a in the direction opposite to the traveling direction of the carriage.

As a result, this time the internal gear 32 and the large diameter gear 39 on the upper side
Meshes with.

When the carriage 30 moves in the direction of arrow C in this state, the switching wheel 31 rotates in the direction of arrow D, and the large diameter gear 39 also rotates in the clockwise direction.

Therefore, the winding force of the ink ribbon in the winding direction is transmitted through the gear 39 as in the case shown in FIG.

Since the present embodiment is configured as described above, the simple structure of the switching wheel, the winding shaft on the ink ribbon cassette side, the large and small gears, and the rack plate is used to reliably transmit the ink ribbon winding force. can do. still,
Instead of dividing into the large diameter gear 39 and the small diameter gear 40, one gear may mesh with the inner teeth and the outer teeth of the switching wheel 31.

Second Embodiment By the way, in the above-described first embodiment, the support shaft of the switching wheel 31 is a long hole formed on the carriage 30 side and a support plate.
Although the structure in which it is fitted in the long hole 34a formed on the 34 side is adopted, a mounting structure as shown in FIG. 3 may be adopted.

That is, if the notch 30c is provided outward in the middle of the long hole 30b provided on the carriage 1 side, and the spindle 31a is fitted into the long hole 30b from the notch 30c, it is attached. Since the other end of the switching wheel 31 can be meshed with the rack gear, the switching wheel 31 can be prevented from falling off and can be mounted extremely easily.

If such a structure is adopted, the same effects as those of the above-described embodiment can be obtained, and further, the support plate 34 and the screws 35 described above can be omitted, so that the structure can be simplified and the cost can be further reduced.

[Third Embodiment] FIG. 4 illustrates a third embodiment of the present invention. In this embodiment, a pulley type wheel is used as a switching wheel instead of a gear type wheel. It uses a wound structure.

Even if such a structure is adopted, the switching wheel 31 can be driven and the same effect as that of the above-described embodiment can be obtained.

The reference numeral 42a indicates a spring for applying a tension to the wire 42.

Even if such a structure is adopted, the same effect as that of the above-described embodiment can be obtained only by using the pulley type switching wheel and the wire as the driving means.

By the way, in the above-mentioned embodiment, when it is desired to remove the slack of the ink ribbon of the ink ribbon cassette, it is sufficient to rotate the knob 41.

When the knob 41 is rotated, the switching wheel is rotated in either direction in the meshed state of the respective gears, but at this time, since the support shaft 31a rotates while escaping through the elongated hole 34a, the slack remains with the ink ribbon cassette attached. Can take

[Effect] As is apparent from the above description, according to the printer of the present invention, the carriage that can reciprocate in the predetermined direction, the first gear portion having the external teeth, and the outer periphery of the first gear portion A second gear portion provided coaxially with the first gear portion and having internal teeth facing the first gear portion; and a drive switching gear member which reverses a rotation direction according to a change in the moving direction of the carriage. When,
The carriage of the drive switching gear member, which is provided in a member supported by the carriage and a shaft supporting means for rotatably supporting the drive switching gear member in a direction along the moving direction of the carriage, and a member supported by the carriage. A gear that meshes with the first gear portion or the second gear portion depending on an upper position, and the drive switching gear member is displaced on the carriage in accordance with a change in the moving direction of the carriage, and the first gear portion is moved. Since the gear portion or the second gear portion meshes with the gear to drive the gear in the same rotation direction regardless of the moving direction of the carriage, the number of parts is small and the structure is extremely simple. Therefore, the compact, lightweight, and low-cost drive mechanism required for the carriage provides the same rotation speed regardless of the carriage movement direction. It is possible to obtain a rotational driving force in the direction. Further, there is an excellent effect that the driving force can be surely transmitted without loss.

[Brief description of drawings]

1 and 2 are for explaining the first embodiment of the present invention. FIG. 1 is a perspective view, FIGS. 2 (A) and 2 (B) are plan views for explaining the operation, and FIG. FIG. 4 is a plan view illustrating a second embodiment of the present invention, FIG. 4 is a perspective view illustrating a third embodiment of the present invention, and FIGS. It is a perspective view. 30 …… Carriage, 31 …… Switching wheel 32 …… Internal tooth gear, 33 …… External tooth gear 36 …… Rack plate, 36a …… Rack gear 38 …… Ink ribbon cassette 39 …… Large diameter gear, 40 …… Small diameter Gear 41 ... Knob, 42 ... Wire

Claims (2)

[Claims] 1. A carriage capable of reciprocating in a predetermined direction, a first gear portion having external teeth, and an outer periphery of the first gear portion which is arranged coaxially with the first gear portion and faces the first gear portion. A second gear portion having internal teeth for rotating the drive switching gear member that reverses the rotation direction according to a change in the moving direction of the carriage; and the drive switching gear member along the moving direction of the carriage. And a first gear portion or a second gear depending on the position of the drive switching gear member on the carriage, which is provided on a member supported by the carriage. A gear that meshes with the portion, the drive switching gear member is displaced on the carriage in response to a change in the moving direction of the carriage, and the first gear portion or the second gear portion meshes with the gear. so, Printer, characterized in that said gear irrespective of the direction of movement of the serial carriage are driven in the same rotational direction. 2. The drive switching gear member includes a third gear portion provided on an outer peripheral portion of the drive switching gear member, and a rack gear arranged parallel to a moving direction of the carriage, thereby meshing the carriage. The printer according to claim 1, wherein the rotation direction is reversed according to the change in the movement direction.