JPS6342575B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention uses a print wheel cassette,
The present invention relates to a printer in which a wheel drive unit for character selection moves relative to a print wheel cassette and is attached to and detached from the print wheel.

Printing with serial printers uses a petal-shaped printing wheel with type attached to the tips of many spokes arranged radially around a boss, and is driven by a drive unit with a selection motor to print the desired characters. I selected them one by one and brought them to the printing position,
Printing is done by using a printing hammer from the back of the type, but in recent years, due to improvements in operability and the need to avoid dirtying the operator's hands when changing wheels, a printing wheel cassette, in which the printing wheel is housed in a cassette, has been developed.
came to be used.

If it becomes necessary to replace the print wheel cassette, disconnect the print wheel cassette from the drive unit, remove the print wheel cassette from the carriage, insert another cassette into the carriage, and adjust the rotation position with the drive unit. Match and combine. Further, from the standpoint of reliability and durability, it is common knowledge that the print wheel is placed as close to the platen as possible.

The general structure of a conventional cartridge in this type of printer is as shown in FIGS. 1 and 2.
The carriage 1 is mounted on a carriage drive device 35, such as a linear motor, so that it can move within a certain range in the front and back direction, and furthermore, a bracket 5 of a wheel drive unit is mounted on it so that it can move in the back and forth direction within a certain range. Printing wheel cassette 3
When replacing the printing wheel cassette 30, the wheel drive unit 5 is moved backward relative to the carriage 1 to release the connection with the wheel, and then the carriage 1 is moved rearward relative to the carriage drive 35, and the printing wheel cassette 30 is moved to the platen. After separating from 29,
Take out the print wheel cassette 30 vertically upward.
The print wheel cassette to be replaced is installed and connected by operating in the reverse order and direction as described above.

As mentioned above, in the conventional device, the front and back movement of the wheel drive unit is a double slide type, which tends to cause mechanical play, and also raises the center of gravity of the wheel drive unit, causing a line of action between the carriage drive and the carriage. The distance between the centers of gravity increases, and swinging motion due to inertia is likely to occur, which not only causes a decline in print quality, but also complicates the mechanism and increases costs. In addition, the amount of movement of the carriage 1 in the longitudinal direction is small, and the direction of insertion and removal of the printing wheel cassette 30 is vertical, so it is difficult to operate, and it is easy to get caught on the ribbon and get your hands dirty. It was hot too.

SUMMARY OF THE INVENTION In view of the operability of this type of printer, an object of the present invention is to provide a printer whose printing wheel cassette can be easily removed and inserted.

In order to achieve the above object, the present invention provides a printer using a replaceable printing wheel cassette, which includes: a wheel drive unit for character selection; a printing hammer for printing characters; and a platen facing the printing hammer. The wheel drive unit is placed in the first position near the platen for printing.
a carriage movably carrying the print wheel cassette between the first position and a second position for exchanging the print wheel cassette, which is further away from the platen than the first position; a cassette holder having a space in which the print wheel cassette can move when the wheel drive unit moves from a first position proximate to the platen to a second position for changing the print wheel; a mechanism for tilting the upper part away from the platen; and a mechanism provided on the cassette holder, the upper part being inclined so that the upper part is closer to the wheel drive unit side than the lower part, and the surface of the printing wheel cassette facing the wheel drive unit side. When the wheel drive unit moves from the first position to the second position, the upper part of the printing wheel cassette is tilted away from the platen by the tilting mechanism. Afterwards, the surface of the print wheel cassette on the side of the wheel drive unit comes into contact with the inclined surface, resulting in a stable state.

Hereinafter, the present invention will be explained in detail based on drawings showing embodiments. As shown in FIGS. 3 and 4, the front end of a bracket 5 of a wheel drive unit is placed on a carriage frame 1 attached to a carriage drive device (not shown), such as a linear motor, and slides when moving back and forth. A plastic piece 2 serving as a surface and a guide pin 3 are provided. The guide pin 3 has a step in the middle of the shaft, and the thin part engages with the guide hole 6 of the wheel drive unit, and the step surface maintains a very small clearance with the side surface of the bracket 5 to secure the carriage. It is fixed to the frame 1 with a set screw 4 to take up the lateral play of the drive unit 5. Carriage frame 1
There are vertically long guide grooves 19 on both sides of the rear upper part of the
A spring stopper 19 having a shape is provided, and a frame as a cassette holder for mounting the printing wheel cassette 30 is formed in the front part. The top surface of the print wheel cassette 3
Vertical positioning surface 2 that supports the left and right protrusions 31 of 0
4'. A print wheel cassette reset spring 26 is installed in a groove 25' provided in the front and rear positioning surface 25, and a force acts to press the print wheel cassette against the inclined surface 22 continuing above the front and rear positioning surface 23. There is.

The wheel drive unit is pulled in the direction shown by the arrow P in FIG. 4 when the wheels are connected by a spring 10 stretched between the pin 8 on the bracket 5 and the pin 9 on the carriage frame 1. A counterclockwise rotational moment acts around the guide pin 3, and the bracket 5 resists the reaction force during printing.
The underside of the front end of is pressed against the plastic piece 2. However, after the wheel drive unit 5 is moved backward and the line of action of the spring 10 is moved from the guide pin 3 to the right side of the figure, the direction of the moment that rotates the wheel drive unit 5 is reversed, and the wheel drive unit 5 The front end rotates in a direction away from the plastic piece 2, and the rear end abuts against a stopper 34 fixed to the carriage frame 1 to stably hold the position.

The wheel drive unit has a first position closer to the platen for printing, as shown by the solid line in FIG. It is movably carried on a carriage to and from a second position for changing the cassette 30.

Wheel drive unit selection motor 1
A wheel catch 12 for connecting the shaft to a wheel 32 in a cassette 30 is fixed near the front end of one shaft by a set screw 13. As shown in detail in FIG. 5, the wheel catch 12 includes:
When coupled to the wheel 32, a stopper 12a having an axial positioning end; a wheel catch piece 12b that fits into a holding hole 32b provided in the wheel 32 and hooks on the opposite edge of the hole to hold the wheel 32; An output transmission piece 12c that fits into the engagement hole 32c of the wheel 32 and transmits the rotation of the selection motor 11 to the wheel 32 is provided.

The front end of the U-shaped bracket 5 of the wheel drive unit has a protrusion 20 extending upward, and a printing hammer 21 is fixed near the upper end of the protrusion 20.
The printing hammer 21 operates according to the printing command and prints the characters on the wheel 32 from the back side, and the card guide 2
7 and the platen 29
Then, printing is performed using the ribbon 28 which is fixed by a fixing device (not shown).

The bosses 14 provided on the left and right sides near the front upper edge of the bracket 5 guide the pins 15 as abutting means, and when the wheel drive unit 5 is moved backward by a wheel drive unit moving means (not shown), the bosses 14 as shown in the figure When the pin 15 has moved by a distance a, its rear surface contacts the E-ring 17 that is engaged with the pin 15, and thereafter pushes the E-ring 17 and moves the pin 15 backward while resisting the force of the compression spring 16.
The rear part of the pin 15 fits into a guide groove 19a provided vertically in the spring stop 19, so that the pin 15 can move freely up and down, and the washer 18 attached to the pin 15 contacts the front surface of the spring stop 19. The spring 16 is supported by the pin 15, and the pin 15 can also be moved in the front-back direction. When the wheels are connected, the front end of the pin 15 contacts the upper part of the wheel cassette 30 by the spring 16 and pushes it forward, and resists the force of the reset spring 26 to move the print wheel cassette housing consisting of the front and rear positioning surfaces 23 and 25. stabilize in position. Note that the distance a mentioned above is between the printing wheel cassette 30 and the wheel catch 12.
The distance is set longer than the retreat distance required for the vehicle to leave.

This device is configured as described above, so
When removing the printing wheel cassette 30, move the wheel drive unit 5 rearward using a wheel drive unit moving means (not shown), and it will be fixed to the guide hole 6 provided in the bracket 5 of the wheel drive unit and the carriage frame 1. Due to the engagement of the guide pin 3 and the action of the spring 10, the wheel drive unit moves horizontally backwards while its front end slides on the upper surface of the plastic piece 2, and the printing wheel cassette 30 and wheel catch 12 are separated. do. After that, when the amount of movement of the wheel drive unit 5 reaches a, the bracket 5
The rear surface of the boss 14 provided at
5 is pushed down backward against the force of the spring 16, the tip of the pin 15 tends to separate from the print wheel cassette 30, and the print wheel cassette 3
0 is pushed by the reset spring 26 and tilts around the connection point between the front-rear positioning surface 23 and the inclined surface 22 continuing above it, comes into contact with the inclined surface 22, and reaches the position 30' shown by the chain line in FIG. It becomes a stable state.

When the wheel drive unit moves from the first position close to the platen to the second position to replace the print wheel, the tilting mechanism causes the upper part of the print wheel cassette 30 to fall away from the platen. Thereafter, the surface of the print wheel cassette 30 facing the wheel drive unit comes into contact with the inclined surface 22. Incidentally, as shown in FIG. 4, the inclined surface 22 is inclined so that its upper part is closer to the wheel drive unit than its lower part.

On the other hand, when the working paper of the spring 10 passes the position of the guide pin 3, the guide pin 3 fits into the groove 7 at the front end of the guide hole 6, and the wheel drive unit 5 rotates clockwise around the guide pin 3. The rear lower end of the bracket 5 comes into contact with the stopper 34 and becomes stable in an inclined position as shown by the chain line 5' in FIG. As a result, the printing hammer 21 is displaced to 21', the pin 15 is displaced to 15', and they are separated from the platen 29.

As described above, according to the present invention, when replacing the printing wheel cassette, the distance between the printing hammer and the platen and ribbon can be greatly increased, so that a remarkable effect is achieved in that the printing wheel cassette can be attached and removed very easily. can get.

Moreover, when replacing the printing wheel cassette, the printing wheel cassette does not have to be manually tipped over by the operator; the printing wheel cassette is automatically tipped down by the folding mechanism, and comes into contact with the inclined surface and becomes stable. Therefore, operability is greatly improved.

Further, since the print wheel cassette is stabilized by tilting the upper part away from the platen, it is possible to take the print wheel in and out in an oblique direction, and the insertion and removal operations can be performed extremely smoothly.

[Brief explanation of the drawing]

FIG. 1 is a side view showing an example of a conventional carriage device, FIG. 2 is a rear view, FIG. 3 is a plan view showing an embodiment of the present invention, FIG. 4 is a side view thereof, and FIG. FIG. 3 is a perspective view showing the engagement relationship between the wheel catch and the printing wheel. DESCRIPTION OF SYMBOLS 1... Carriage frame, 3... Guide pin, 5... Wheel drive unit, 6... Guide hole, 10... Spring (for tilting the wheel drive unit), 15... Pin, 16... Spring,
26... Print wheel cassette reset spring, 29... Platen, 30... Print wheel cassette, 32... Print wheel.

Claims (1)

[Claims] 1 In a printer that uses a replaceable printing wheel cassette, there is a wheel drive unit for character selection, a printing hammer for printing characters, a platen facing the printing hammer, and a platen for printing the wheel drive unit. a carriage for carrying a print wheel cassette movably between a first position proximate the platen and a second position for changing the print wheel cassette remote from the first position; a cassette holder that is removable and has a space in which a print wheel cassette can move; and a cassette holder that is removable and has a space in which a print wheel cassette can move; a mechanism for tilting the upper part of the print wheel cassette in a direction away from the platen; and a mechanism provided on the cassette holder, the upper part being inclined so that the upper part is closer to the wheel drive unit than the lower part, An inclined surface is provided in contact with a surface on the drive unit side, and when the wheel drive unit moves from the first position to the second position, the upper part of the printing wheel cassette is separated from the platen by the tilting mechanism. 1. A printer using a printing wheel cassette, characterized in that the printing wheel cassette falls in a direction, and then the surface of the printing wheel cassette on the side of the wheel drive unit comes into contact with the inclined surface to be in a stable state.