JPH05185705A - Printing device - Google Patents

Abstract

PURPOSE:To provide a printing device, in which erasing ribbon is surely and stably arranged to an erasing position by a method wherein a first cam follower is surely engaged with a second cam. CONSTITUTION:In a supporting member 51, a second follower pin 54, which is parallel to a first follower pin 52, is protrusively formed toward a lifting cam 21. The second follower 54 engages with a fourth cam 21j, when the first follower pin 52 arrives the connecting part of a second sloping cam 21h with a second cam 21d. During the engagement, the first follower pin 52 parts slightly from the second cam 21d, resulting in surely engaging the edge face of the first follower pin 52 with the bottom face of a groove.

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, at the time of erasing characters, a holder member having a printing ribbon and an erasing ribbon mounted thereon is swung upward from a printing position for erasing, and at the end of erasing operation. The present invention relates to a device that swings downward.

[0002]

2. Description of the Related Art Conventionally, 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 these on a carriage is well known.

In this type of electronic typewriter, a holder member equipped with a printing ribbon or an erasing ribbon is placed at a printing position where the printing ribbon faces the printing hammer during printing and an erasing position where the erasing ribbon faces the printing hammer during erasing. The position switching mechanism for switching positions, the print hammer drive mechanism, and the print ribbon winding mechanism are each driven by a dedicated motor.

By the way, the applicant of the present invention filed Japanese Patent Application No. 3-129.
In the specification and the drawings attached to the application No. 49, the position switching mechanism of the holder member, the print hammer drive mechanism, the print ribbon winding mechanism and the erasing ribbon winding mechanism are driven by one motor provided in the carriage body. In this way, an electronic typewriter that can reduce the manufacturing cost and can make the carriage compact is proposed.

In this electronic typewriter, the drive shaft of the motor is integrally provided with a printing cam for driving the printing hammer and a raising cam for raising the holder member to the erasing position. A reference cam for holding the holder member at the printing position, a peripheral cam for holding the erasing position, and inclined first and second inclined cams connecting the reference cam and the peripheral cam surface are formed on the ascending cam. Further, a driven pin that slides on the lifting cam and is movable in the axial direction is attached to the holder member.

Then, the driven pin is slid on the reference cam by the forward rotation of the motor to hold the holder member at the printing position, and the printing hammer is operated to print through the printing cam, while the motor is driven. By moving the driven pin in the axial direction along the inclined portions of the first and second inclined cams by the reverse rotation and the forward rotation of a predetermined angle, the driven pins are slid on the cam surfaces and guided to the outer peripheral cam, Further, the holder member is slid on the outer peripheral cam to move from the printing position to the erasing position and is held at the erasing position, and the erasing operation is performed in that state.

[0007]

As described above, in the electronic typewriter proposed by the present applicant in the previous application, the driven pin is erased by sliding on the first and second inclined cams. The ribbon can be raised to the erase position,
When the driven pin is raised, the entire weight of the holder member, the print ribbon and the erasing ribbon is applied to the portion of the driven pin that slides on the first and second inclined cams. Friction resistance prevents the driven pin from moving smoothly in the axial direction.

Therefore, there is a problem that the driven pin does not move to the outer peripheral cam and returns to the reference cam again, the erasing ribbon does not rise to the erasing position, and the erasing operation cannot be performed.
In addition, the peripheral cam returns to the first or second inclined cam, and the erasing ribbon vibrates in the vertical direction, and the position of the erasing ribbon and the character to be erased is deviated, and a stable erasing operation cannot be performed. is there.

The present invention has been made in order to solve the above-mentioned problems, and surely and stably erases the erasing ribbon by reliably engaging the first cam follower with the second cam. An object of the present invention is to provide a printing device that can be arranged at a position.

[0010]

In order to achieve the above object, a printing apparatus according to the present invention is provided with a type wheel and a printing hammer in a carriage body which is reciprocally driven in the left-right direction along a platen. A holder member for mounting the printing ribbon and the erasing ribbon is mounted on the main body so that the position can be switched by rotating the erasing position where the rear end side lifts up to a predetermined height and the printing position where the rear end does not lift up. A first cam follower and a second cam follower are provided on the holder member, and the first cam follower slides on the peripheral surface of the holder member to hold the holder member at the printing position. When the first cam follower slides on the peripheral surface of the first cam follower, the holder member is held at the erasing position, and the first cam follower moves from the first cam by rotating the motor at least in the forward direction. To the second cam A cam body provided with a third cam therein, which is driven to rotate by a motor, is provided in the carriage main body, and the first cam follower moves from the third cam by rotating the motor at least in the forward rotation direction. The cam body is provided with a fourth cam that engages with the second cam follower when moving to the second cam and temporarily separates the first cam follower from the peripheral surface of the second cam.

[0011]

In the printing apparatus of the present invention having the above construction, during the printing operation, the first cam follower slides on the peripheral surface of the first cam and the holder member is held at the printing position. During the erasing operation, the first cam follower moves from the first cam to the second cam by the third cam due to the rotation of the motor in at least the forward direction.
You will be guided towards the cam. Then, when the first cam follower moves from the third cam to the second cam, the second cam follower provided on the holder member engages with the fourth cam. By this engagement, the first cam follower is temporarily separated from the peripheral surface of the second cam.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. In this embodiment, the present invention is applied to an electronic typewriter in which one DC motor performs a printing operation, a printing ribbon winding operation associated therewith, an erasing operation and an erasing ribbon winding operation associated therewith. It is a thing.

As shown in FIGS. 1 and 2, the typewriter 1
Side wall plates (machine frame) on both left and right sides inside the casing of
2 is provided, and the platen 3 disposed between the pair of side wall plates 2 is rotatably instructed to both side wall plates 2 near both ends of the platen shaft 4, and the platen shaft 4
It is rotationally driven by a platen drive motor and a platen drive mechanism (not shown) via a driven gear (not shown) fixed to the left end of the.

Between the pair of side wall plates 2, a guide shaft 5 and a guide member 6 which is substantially U-shaped in side view are further arranged in parallel with the platen 3. Next, the guide shaft 5 and the guides are arranged. The carriage 7 supported by the member 6 so as to be movable in the left-right direction will be described with reference to FIGS.

Between the guide shaft 5 and the guide member 6, a pair of plate-shaped and substantially rectangular main frames 8 are arranged in the front-rear direction with a predetermined distance in the left-right direction. Is an upper end portion of the first support portion 10 and the second support portion 11 of the support member 9 supported by the guide shaft 5 so as to be movable in the left-right direction and rotatably, and is inserted as a spacer between both main frames 8. Pins 12 and 13 are fixed from the outside to the upper ends of the two support parts 10 and 11, respectively. The pair of main frames 8 constitutes the carriage body 14.

Next, the printing mechanism 15 will be described.
A DC motor 16 is supported by the main frame 8 on the right side so as not to rotate itself, and a drive shaft 17 of this motor 16 is inserted through both main frames 8 and extends to the left,
The drive shaft 17 is located between the main frame 8 and the motor 16 side, and has a printing cam 18 having a generally side-viewed side view, and an encoder disk 1 having a plurality of slits formed on the outer peripheral portion thereof.
9, a ribbon supply cam 22 for stepwise feeding the print ribbon, and a raising cam 21 for raising and driving the holder member 32 to the erasing position are fixed to each other.

The print cam 18 and the ribbon supply cam 2 are provided.
The cam body 20 is composed of 2 and the raising cam 21, and the ribbon supply cam 22 and the raising cam 21 are integrally formed as the cam body 20. In addition, in FIG.
The print start position is indicated by a dotted line, and the origin setting position is indicated by a two-dot chain line.

At the upper ends of the rear ends of both main frames 8, the central part of a rotating lever 23 and the lower end of a link 24, which are generally V-shaped in side view, are pivoted by pins 25 and 26, respectively. The print hammer 27 which is supported and arranged in the front-rear direction so as to face the platen 3 is pivotally attached to the upper end of the link 24 at the rear end thereof, and is rotated at the center in the front-rear direction. It is pivotally attached to the upper end of the lever 23 so as to be rotatable.

Further, a cam follower 28 is rotatably attached to the front end of the rotating lever 23 so that the cam follower 2 can rotate.
A tension spring 29 is stretched between the upper end portion of the rotary lever 23 and the lower end portion of the link 24 so that 8 always contacts the cam surface of the printing cam 18.

Reference numeral 30 is a daisy wheel rotatably driven by a wheel drive motor and a wheel drive mechanism (not shown), reference numeral 31 is a ribbon cassette containing a print ribbon, and reference numeral 32 is a ribbon cassette 31 mounted thereon. In addition, it is a holder member that is vertically swingable via a support shaft 34 to an auxiliary frame 33 that is pivotally supported by the guide shaft 5 so as to be movable in the left-right direction. The carriage 7 is reciprocated in the left-right direction along the platen 3 via a drive wire by a carriage drive motor and a drive mechanism (not shown).

Therefore, the motor 16 causes the printing direction P in FIG.
When rotated by a predetermined angle, the cam follower 28 ascends along the cam surface of the printing cam 18, so that the rotating lever 23 rotates counterclockwise and the printing hammer 27 causes the daisy wheel 30 to print. The platen 3 is pressed through the print ribbon.

Adjustment plates 41 extending in the front-rear direction are provided outside the upper ends of both main frames 8, and oblong holes 8a formed in each main frame 8 at the front ends of both adjustment plates 41. The support shaft 42 inserted through is fixed,
Further, oval holes 41a are formed at the rear end portions of both adjusting plates 41, and both main frames 8 and both adjusting plates 41 have screws 4 inserted through these oval holes 41a.
It is screwed at 3. On the other hand, an engaging portion 44a that slidably engages with the rear end of the guide member 6 is provided at the front end of the contact member 44 whose rear end is rotatably supported by the support shaft 42. ing.

Next, an erasing mechanism 50 for raising the holder member 32 from the printing position to the erasing position so that the erasing ribbon faces the printing hammer 27 when erasing characters will be described with reference to FIG.
~ It demonstrates based on FIG.

The ascending cam 21 and the ribbon supplying cam 2
2 is formed as an integral cam body, and a raising cam 21 is formed on the left side of this cam body. A groove 2 having an equal radius from the center is formed on the outer peripheral portion of the cam 21.
1a is formed, and the shallow bottom portion 2 is formed in a part of the groove 21a.
1b is provided. The shallow bottom portion 21b is connected to the bottom surface of the groove 21a at a gentle slope. This groove 21
The inside of a is the second cam 21d. A first cam 21c having a smaller diameter and an equal radius than the second cam 21d is formed so as to project from the left end surface 21e of the second cam 21d.

The left end face 2 adjacent to the shallow bottom portion 21b
A part of 1e is cut out to form an inclined surface 21f that is inclined from the vicinity of the first cam 21c toward the shallow bottom portion 21b.

At a portion about 1/3 counterclockwise from the inclined surface 21f of the second cam 21d, the radius gradually increases from about 2/3 of the radius of the second cam 21d toward the outer periphery of the second cam 21d. A second inclined portion cam 21h that expands is formed. The second inclined cam 21h is provided with the groove 2 from the left end surface 21e.
It is gradually inclined toward the bottom surface of 1a to about 1/2.

The first cam 21c gradually projects from the vicinity of the inclined surface 21f in a counterclockwise direction to about ⅛ of the left end surface 21e to about ½ of the protrusion amount of the first cam 21d. A first inclined cam 21g is formed, and the first inclined cam 21g is also formed from the outer circumference of the first cam 21c to the second inclined cam 21c.
The radius gradually increases toward the inclined surface 21f to about 1/3 of the radius of the cam 21d, and is connected to the second inclined portion cam 21h. The first inclined cam 21g and the second inclined portion cam 21h form a third cam of the present invention.

The outer peripheral wall 21i of the ascending cam 21 projects counterclockwise from a position facing the connecting portion between the second inclined cam 21h and the second cam 21d by an amount corresponding to about 1/4 of the entire outer peripheral wall 21i. The outer surface of this protruding portion serves as a fourth cam 21j that engages with a second driven pin 54, which will be described later.

Further, the first driven pin 52, which comes into contact with the ascending cam 21 from the left side, is movable in the left-right direction to the lower end portion of the support member 51 whose upper end portion is fixed to the side wall 32a at the left end portion of the holder member 32. And is always elastically biased to the right by the winding spring 53. Incidentally, this first driven pin 52
Thus, the first cam follower of the present invention is formed.

At the start of printing, the first driven pin 52 has its tip end abutted against the first cam 21C from above as shown in FIG. 4 to move the holder member 32 to the printing position (reference swing) shown in FIG. Position) while supporting the end face 21f.
It is abutted from the left. That is, the swing amount of the holder member 32 is determined by the vertical movement of the first driven pin 52. Here, the printing cam 18 at the start of printing
The positional relationship between the ascending cam 21 and the first driven pin 52 is shown in FIG.

A second driven pin 54, which is parallel to the first driven pin 52, is formed on the support member 51 so as to project toward the raising cam 21. The second driven pin 54 engages with the fourth cam 21j with the rotation of the ascending cam 21, and during this engagement, the first driven pin 52 moves the second cam 21d.
The protruding position of the second driven pin 54 is determined so as to be slightly separated from the position. The second driven pin 54 forms a second cam follower.

Therefore, when the motor 16 rotates by a predetermined angle in the direction opposite to the printing direction P (hereinafter referred to as the anti-printing direction) from the phase angle at the start of printing shown in FIG. 4, the first driven pin 52 has the first inclination. Since the cam 21g moves upward, the holder member 32 also swings upward in accordance with the upward moving distance. After that, when the motor 16 is rotated in the printing direction P, the first driven pin 52 reaches the second cam 21d via the second inclined cam 21h, so that the holder member 32 swings further upward and switches to the erasing position. Be done.

By the way, when the first driven pin 52 reaches the connecting portion between the second inclined cam 21h and the second cam 21d,
The second driven pin 54 engages with the fourth cam 21j. While the second driven pin 54 and the fourth cam 21j are engaged, the first driven pin 52 is slightly separated from the second cam 21d (see FIG. 10). Due to this separation, the first driven pin 5
The end surface of 2 surely contacts the bottom surface of the groove 21a.

Therefore, even if the movement of the first driven pin 52 in the axial direction is not smoothly performed by the frictional resistance between the first driven pin 52 and the first inclined cam 21g and the second inclined cam 21h, Since the second driven pin 54 engages with the fourth cam 21j and the first driven pin 52 is slightly separated from the second cam 21d, the first driven pin 52 surely moves in the axial direction, and the first driven pin 52 moves. 52 does not return to the first inclined cam 21g or the second inclined cam 21h.

After the erasing operation is completed, when the ascending cam 21 rotates in the printing direction P, the first driven pin 52 moves the second cam 21d.
To reach the shallow bottom portion 21a. The holder member 32 receives the weight of the holder member 32 and the ribbon cassette 31 and the urging force of a spring member (not shown) that urges the holder member 32 toward the reference swing position.
The first driven pin 52 reaching “a” reaches the first cam 21c through the inclined surface 21f. After that, ascending cam 2
1 rotates in the reverse printing direction and returns to the printing start position, and the erasing operation ends.

Next, a print ribbon winding mechanism 60 for winding a predetermined amount of the print ribbon on the take-up spool for each printing operation.
Will be described with reference to FIG. The detailed structure of the print ribbon winding mechanism 60 is described in Japanese Patent Application No. 12949/1991.
The present invention is described in the specification and the drawings attached to the above-mentioned application, and will be briefly described below.

At the lower left end of the holder member 32, a ratchet having a plurality of teeth is rotatably supported by a pin 62, which is rotatably supported by the pin 62 and provided with a feed claw. The member 63 is connected to a second swinging member 64 pivotally attached to the holder member 32 via a connecting pin 65, and the second swinging member 64 is connected to the second swinging member 64 by a tension spring.
Is elastically urged to the front side. The take-up spool 67 is fixed to the pin 62.

On the other hand, the cam 2 for feeding the ribbon having the above-mentioned approximately tomo shape.
At the position 2, the lower end portion of the first swinging member 69 is rotatably supported by the pivot pin 68 fixed to the left main frame 8, and the upper end portion of the first swinging member 69 is set at the second swinging position. Moving member 6
4 is in contact with the vicinity of the base end portion from the front. Further, the ribbon supply cam 22 is positioned in the substantially circular hole 69a formed in the first swinging member 69, and the protrusion 6 of the first swinging member 69 is formed.
The first swinging member 69 is elastically biased in the clockwise direction in FIG. 9 by a winding spring 70 mounted on the pivot pin 68 so that 9b always contacts a part of the ribbon supply cam 22. ..

Therefore, when the motor 16 is rotated in the printing direction P, the first swinging member 69 rotates counterclockwise in FIG. 9 via the protrusion 69b due to the cam shape of the ribbon supply cam 22. , The second swinging member 64 is rotated in the direction of the paper surface of FIG. 3, the third swinging member 63 is rotated toward the front side, and the ratchet is rotated by one tooth by the feed claw, thereby printing. Immediately before, the take-up spool 67 steps the print ribbon by a predetermined amount.

Next, the erasing ribbon winding mechanism 75 for winding a predetermined amount of the erasing ribbon on the winding spool at the time of erasing will be described with reference to FIGS. 2 and 9.

Side wall 32a at the rear end of the holder member 32
An erasing ribbon supply spool 76 is rotatably pivoted on the disk, and an erasing ribbon take-up spool 77 is rotatably pivoted on the right end thereof. The take-up spool 77 is provided with a ratchet 78 having a plurality of teeth, and a feed pawl 79 for rotating the ratchet 78 by one tooth is provided upright from an auxiliary frame (not shown) on the rear side of the ratchet 78. It is set up.

That is, as described in the erasing mechanism 50, when the phase angle of the motor 16 at the start of printing is set to 0 °, as shown in FIG.
~ As shown in FIG. 11, first, the motor 16 is set to a phase angle of 0 °.
When rotated by about 55 ° (hereinafter referred to as a phase angle of −55 °) from the opposite direction (see FIG. 9), the first driven pin 52 moves from a phase angle of −5 ° to a phase angle of −43 °. And the second tilt cam 21h after moving upward along the first tilt cam 21g.
Located on top. At this time, the first driven pin 52 is
This is a position that is elevated by about 2 mm with respect to the position of the cam 21a. 9 to 10, the raising cam 21 is shown by a solid line, the ribbon supply cam 22 is shown by a one-dot chain line, and the first swinging member 69 is shown by a two-dot chain line.

Then, here, the motor 16 is about -55.
When rotated in the printing direction P from 90 ° to + 90 °, the driven pin 52 moves on the second inclined cam 21h and then moves to the second
The cam 21d is reached (see FIG. 10). That is, at this time, the holder member 32 has the erasing ribbon with the printing hammer 27.
Is switched to the erase position opposite to. At this time, as described above, the second driven pin 54 engages with the fourth cam 21j, so that the first driven pin 52 is slightly separated from the second cam 21d, and the end face of the first driven pin 52 is the bottom surface of the groove 21a. Surely abut.

Here, at the position P1 during the movement, the feed claw 79 and the ratchet 78 start to engage with each other, and the position P2 is reached.
At, the ratchet 78 is rotated by one tooth. That is,
At this time, the erasing ribbon is wound by a predetermined amount on the take-up spool 77.
It is wound up and sent step by step. At this time, the first driven pin 52 is about 5.7 m from the position of the first cam 21c.
It is in a raised position.

Then, the motor 16 is moved to this + 90 °.
To the printing direction P and execute the erasing operation, the motor 1
When 6 rotates in the anti-printing direction by −90 °, the first driven pin 52 moves from the second cam 21d to the shallow bottom portion 21b. The first driven pin 52 that has moved to the shallow bottom portion 21b descends to the first cam 21c through the inclined surface 21f as described above. Along with this lowering, the holder member 32 lowers to the printing position. On the other hand, during this movement, the feed claw 79 and the ratchet 78 are disengaged.

After that, the motor 16 drives the print direction P up to 0 °.
However, at this time, the first driven pin 52 only moves along the reference cam 21a via the position P6.

It is also possible to drive the cam body 20 indirectly by the motor 16 via a gear mechanism.

The ascending cam 21 is not limited to the shape of this embodiment, and it is also possible to construct one or a plurality of various cams in combination.

[0049]

As described above, according to the printing apparatus of the present invention, the first cam follower is reliably engaged with the second cam, and the erase ribbon is erased reliably and stably. Can be placed in position.

[Brief description of drawings]

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

FIG. 2 is a view on arrow 2 of FIG.

FIG. 3 is a partial front view of the internal mechanism of the electronic typewriter.

FIG. 4 is a side view of a main frame and an adjustment plate.

FIG. 5 is a left side view of the lifting cam.

FIG. 6 is a top view of a lifting cam.

FIG. 7 is a side view of a main part of the internal mechanism.

FIG. 8 is a side view of a main part of a holder member.

FIG. 9 is a side view of the main parts of the internal mechanism at the print start position.

FIG. 10 is a view corresponding to FIG. 9 when the first driven pin moves to the second cam.

FIG. 11 is a diagram showing a motion curve of a driven pin.

[Explanation of Codes] 1 Electronic typewriter 3 Platen 14 Carriage body 16 DC motor 18 Printing cam 20 Cam body 21 Ascending cam 21c First cam 21d Second cam 21g First tilting cam 21h Second tilting cam 21j Fourth cam 27 Printing Hammer 30 Dizzy Wheel 31 Ribbon Cassette 32 Holder Member

Claims (1)

[Claims] 1. A carriage body driven to reciprocate in the left-right direction along a platen is provided with a type wheel and a printing hammer, and a holder member for mounting a printing ribbon and an erasing ribbon is provided on the carriage body. The end side is mounted so as to be positionally switchable by rotation between an erasing position in which a predetermined height is lifted up and a printing position in which it is not lifted up, and the holder member is provided with a first cam follower and a second cam follower. , The first cam follower slides on its peripheral surface to hold the holder member at the print position, and the first cam follower slides on its peripheral surface to erase the holder member. A cam body including a second cam held at a position and a third cam that guides the first cam follower from the first cam to the second cam by rotating the motor at least in the forward rotation direction. Driven by A cam body is provided on the carriage body, and engages with the second cam follower when the first cam follower moves from the third cam to the second cam due to at least rotation of the motor in the normal rotation direction, A printing apparatus, wherein a fourth cam for temporarily separating the 1-cam follower from the peripheral surface of the second cam is provided on the cam body.