JPH0641216B2 - Ribbon switching device for printing machine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a ribbon switching device for a printing machine.

2. Description of the Related Art Conventionally, a support for holding a cassette case accommodating a ribbon is provided rotatably up and down, and a wire is fastened to both sides of a ribbon guide that slidably holds the ribbon facing the printing unit. Secure both ends of the wire to both sides of the support,
One in which a support is rotated around a fulcrum using a motor or electromagnet as a drive source, and ribbon movement is linked to the vertical movement of this support to switch ribbons, thereby performing multicolor printing. Exist.

Problems to be Solved by the Invention However, when the support is frequently moved up and down at high speed, the ribbon guide suspended by the wire vibrates, and the operation is not stable until the vibration is stopped. On the other hand, there are 4 ribbons for multicolor printing.
Some of them are color-coded into more than one color zone. When printing multiple colors, print with one selected zone, or multiple zones are overlapped on the same print line to perform printing operations, so the ribbon is placed at the correct position. It is necessary to move at high speed, and the switching frequency is extremely high. Further, there is a demand to make the print width of each zone as narrow as possible, and the margin for the print width of each zone is extremely small. Therefore, if the shift amount of the ribbon is slightly incorrect, color mixture will occur above and below the printed characters.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a ribbon switching device for a printing machine that can prevent vibration of the ribbon guide and reliably prevent color mixing.

Means for Solving the Problems According to the present invention, a support 8 for holding a cassette case 16 is movably provided in a direction orthogonal to a feeding direction of a ribbon 17 and fixed at an arbitrary position, and a carrier 21 is provided with a ribbon guide 1.
8 is movably provided in the same direction as the moving direction of the support body 8, and a spindle 11 for holding the ribbon guide 18 slidably along the moving direction of the carrier 21 is provided on both sides of the support body 8. Further, a flat surface 11a parallel to the surface along the moving direction of the support 8 is formed on the outer periphery of the support shaft 11.

Accordingly, the support 8 is moved in the direction orthogonal to the feeding direction of the ribbon 17 together with the cassette case 16 and the ribbon guide 18 to switch the ribbon 17. At this time, the support shaft 11 receives an impact in the direction along the moving direction of the support body 8, but the support shaft 11 has a strong strength in the direction along the moving direction of the support body 8 due to the formation of the flat surface 11a, and this support shaft 11 The ribbon guide 18 fitted in is stable without vibration.

Embodiment An embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 2, a pulse motor 3, which is a forward / reverse rotatable motor for driving a drive gear 2, is held on one of the side plates 1 facing each other. In addition, these side plates 1 have drive gears 2
A drive shaft 6 to which a driven gear 4 meshing with and a pair of left and right gears 5 are fixed is rotatably held, and a carrier shaft 7 is installed.

Then, a support 8 is provided as shown in FIGS. 1 and 2. Two guide shafts 9 and two racks 10 are vertically fixed on both sides of the support 8, and a horizontal support shaft 11 is laterally provided on the front portion. The support shaft 11 is a drawing material having a D-shaped cross section having a horizontally long flat surface 11a along the movement direction of the support 8 on the outer circumference. The front rack 10 is meshed with the gear 5, and the rear rack 10 is meshed with an idler gear 12 meshed with the gear 5. The idler gear 12 is rotatably supported on the side plate 1. Further, guide members 13 and 14 for slidably holding either the guide shaft 9 or the rack 10 are fixed to the side plate 1. Springs 15 are stretched on both sides of the support 8 and both ends of the drive shaft 6. A ribbon guide 18 for holding a ribbon 17 drawn from a cassette case 16 that is detachably mounted on the support 8 is provided, and the ribbon guide 18 is slidably fitted to the spindle 11. A U-shaped groove 18a is formed. The cassette case 16 is provided with a winding shaft 19 connected to a ribbon drive shaft (not shown).

Further, a printing movable body 22 including a dot printer head 20 which is a printing unit and a carrier 21 which is equipped with the printing head 20 and is slidably held by the carrier shaft 7 is provided. The ribbon guide 18 is also held by the carrier 21 so as to be vertically movable. The dot printer head 20 is formed with a protrusion 23 slidably held by the drive shaft 6. Further, serrated pieces 24 having a plurality of vertically arranged teeth are integrally formed on both sides of the ribbon guide 18, and locking claws 25 that elastically engage with these serrated pieces 24 are provided. Attached to the carrier 21, these serrated pieces 24
A detent mechanism 26 is formed by the locking claw 25 and the locking claw 25.

In such a structure, the carrier 21 is moved to drive the dot printer head 20 to perform printing. Also,
When the pulse motor 3 is rotated, the support body 8 moves together with the cassette case 16 in a straight line direction orthogonal to the feeding direction of the ribbon 17, and this operation also interlocks with the ribbon guide 18 held by the support shaft 11 so that the ribbon 17 moves up and down. Shift to.

In this way, the support 8, the ribbon guide 18, and the cassette case 16 move in the linear direction orthogonal to the feeding direction of the ribbon 17, so that the ribbon at the tip of the dot printer head 20 is controlled by controlling the rotation angle of the pulse motor 3. The shift amount of 17 can be set to an accurate value that matches the movement amount of the rack 10.

Further, the support shaft 11 receives an impact in a direction along the operation direction of the support body 8 during the switching operation, but since the flat surface 11a parallel to the surface along the switching operation direction of the support body 8 is formed on the outer periphery, the impact is generated. Strong against force. The ribbon guide 1 held by the support shaft 11 whose strength is effectively increased in this way
8 does not vibrate in the vertical direction during the switching operation of the support 8. Moreover, since the support 8 is urged by the spring 15 together with the rack 10, even if there is some backlash between the gear 5 and the idler gear 12 and the rack 10, when the support 8 is frequently moved up and down. Very little vibration and stable quickly. Therefore, high-speed printing can be performed. In addition, the flat surface 11a of the support shaft 11
The outer peripheral surface of the ribbon guide 1 contacts the bottom of the groove 18a.
Position 8.

In this way, the shift amount of the ribbon 17 is accurate and the vibration of the ribbon guide 18 in the ribbon switching direction is prevented, so that color mixing can be prevented during multicolor printing.

EFFECTS OF THE INVENTION As described above, according to the present invention, the ribbon guide is fitted to the support shaft erected on the support that performs the switching operation, and the support shaft is formed with the flat surface parallel to the surface along the switching operation direction of the support. By doing so, it is possible to effectively increase the strength of the support shaft, which prevents vibrations of the support shaft and the ribbon guide during the switching operation of the support, and thus prevents color mixing during multicolor printing. Has the effect of being able to.

[Brief description of drawings]

The drawings show one embodiment of the present invention. FIG. 1 is a perspective view with a part cut away, and FIG. 2 is a perspective view showing a state where a ribbon guide is attached to a support body by cutting out a part and reducing the size. 3 is a perspective view showing a fitting state of a support shaft and a ribbon guide by enlarging a part thereof, and FIG. 4 is a side view of a part thereof. 8 ... Support, 11 ... Spindle, 11a ... Flat surface, 16
...... Cassette case, 17 ...... Ribbon, 18 ...... Ribbon guide, 20 ...... Dot printer head (printing section), 2
1 ... Carrier

Claims (1)

[Claims] 1. A carrier provided with a printing section is provided so as to be reciprocally movable, and a support body holding a cassette case accommodating a ribbon pulled out to the front surface of the printing section is orthogonal to the feeding direction of the ribbon. A ribbon guide that is movable in any direction and fixed in any position and that holds the ribbon slidably facing the printing unit is provided in the carrier movably in the same direction as the moving direction of the support, and the support is provided. A support shaft for slidably holding the ribbon guide along the moving direction of the carrier is provided on both sides of the body, and a horizontally long flat surface parallel to the surface of the supporting body is provided on the outer circumference of the support shaft. A ribbon switching device for a printing machine characterized by being formed.