JPH0710610B2 - Ribbon cassette - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a ribbon cassette used in a printing machine.

2. Description of the Related Art Conventionally, as shown in FIG. 5, a ribbon drive shaft 52 and a lever 54 that rotatably holds a ribbon winding shaft 53 are provided on one side of a cassette case 51, and the other side of the cassette case 51 is provided. The ribbon supply reel 55 and the ratchet wheel 56 are connected to each other so as to rotate integrally, and the pawl 58 urged by the spring 57 is elastically engaged with the ratchet wheel 56 and pulled out from the ribbon supply reel 55. The ribbon 59 is wound around the ribbon winding shaft 53, and the lever 54 is urged by the spring 60 so that the ribbon 59 on the ribbon winding shaft 53 is wound.
Is pressed against the needle-like protrusions 61 on the outer periphery of the ribbon drive shaft 52, and the ribbon drive shaft 52 is rotated clockwise to wind the ribbon 59 of the ribbon supply reel 55 around the ribbon take-up shaft 53, and
There is a ribbon cassette in which the engagement between the ratchet wheel 56 and the pawl 58 prevents the ribbon supply reel 55 from rotating due to inertia and applies tension to the ribbon 59.

However, the spring 60 causes the ribbon winding shaft 53 to move toward the ribbon drive shaft.
Although it is pressed against 52, the amount of bending changes greatly due to the change in the ribbon winding diameter of ribbon take-up shaft 53.
The power transmission force of 52 is unstable. Also, the ribbon drive shaft 52
The ribbon take-up shaft 53 and the ribbon supply shaft that come into contact with the plate are rotatably attached to one plate, the plate is movably provided in the cassette case 51, and the plate is biased toward the ribbon drive shaft 52 side by a spring. Although such a thing is also considered, this also changes the amount of bending of the spring due to a change in the ribbon winding diameter of the ribbon winding shaft 53,
The power transmission force of the ribbon drive shaft 52 becomes unstable and the number of parts increases.

Means for solving the problem A ribbon drive shaft having a large number of needle-like projections formed along the outer periphery and a roller are rotatably provided on both sides of a flat cassette case, and a long ribbon is wound. And a ribbon take-up shaft for taking up the ribbon drawn from the ribbon supply shaft, the ribbon supply shaft and the ribbon having a length from the ribbon drive shaft to the roller. A groove for rotatably and movably holding a shaft portion of the winding shaft is formed in the cassette case, and a leg for pressing the ribbon supply shaft to the roller side and the ribbon winding shaft are arranged on the ribbon drive shaft side. A twisting strip having a pressing leg is provided, and a holding part for holding the base of the leg of the twisting strip is provided in the cassette case at an intermediate position between the roller and the ribbon drive shaft.

Therefore, one leg of the twisting spring presses the ribbon on the ribbon winding shaft against the ribbon drive shaft, and the other leg presses the ribbon on the ribbon supply shaft against the roller. Transmits the rotational force to the ribbon take-up shaft, and as the ribbon take-up diameter of the ribbon take-up shaft increases and the ribbon take-up diameter of the ribbon supply shaft decreases, the ribbon take-up shaft and the ribbon supply shaft are guided by the groove. And guide it to the roller side. This time,
Since the change in the force of the twisting bar is negligible, the power transmission force of the ribbon drive shaft is stable. Furthermore, the ribbon take-up shaft is pressed against the ribbon drive shaft by one twisting spring to urge the ribbon supply shaft toward the roller side, and the ribbon supply shaft and the ribbon take-up shaft are directly attached to the cassette case to reduce the number of parts. To reduce.

Embodiment An embodiment of the present invention will be described with reference to FIGS. 1 to 4. 1 is a cassette case, this cassette case 1
Is a bottom case 2 with a one-sided opening, and this bottom case 2
The upper case 3 closes the opening surface of the. An arcuate groove 4 is formed on the bottom surface of the bottom case 2 and the inner surface of the upper case 3, a roller 5 is rotatably held near one end of the groove 4, and a large number of rollers 5 are provided on the outer periphery near the other end of the groove 4. The ribbon drive shaft 7 having the needle-like protrusions 6 is rotatably held. Then, a ribbon supply shaft 9 that holds the ribbon 8 in a wound state, and a ribbon 8 that is pulled out from the ribbon supply shaft 9.
A shaft portion with a ribbon winding shaft 10 for winding the tape is fitted in the groove 4 rotatably and movably.

Further, the center of the radius of the groove 4 is located at the ribbon drive shaft 7.
An intermediate portion between the roller 5 and the roller 5, and a boss 11 as a holding portion is formed at this position. The boss 11 holds a base portion 15 of a torsion spring 14 having two legs 12 and 13 biased toward each other in the leg opening direction. Between the legs 12 and 13 along the inner surface of the upper case 3 and the ribbon 8, a hard slippery sheet 16 is interposed.

Further, as shown in FIG. 4, an annular groove 17a is formed in the upper portion of the roller 5, and an elastic wire 17 is tightened in the annular groove 17a. The wire 17 has a hook 18 and long elastic legs 19.

In such a structure, the ribbon take-up shaft 10 is biased by the leg 12 so that the ribbon 8 wound around the outer circumference thereof is pressed against the needle-like projection 6 of the ribbon drive shaft 7, and the ribbon supply shaft 9 is moved by the leg 13. The ribbon 8 which is urged and wound around the outer periphery of the roller 5 is
Is pressed against.

When the ribbon drive shaft 7 is rotated clockwise in this state, this rotational force is transmitted from the needle-like projections 6 to the ribbon 8, and the ribbon winding shaft 10 winds the ribbon 8 on the ribbon supply shaft 9. At this time, the ribbon supply shaft 9 rotates counterclockwise by the pulling output of the ribbon 8 as shown by the arrow in FIG. 4, and the roller 5 rotates clockwise with the wire 17. As a result, the elastic leg 19 of the wire 17 comes into contact with the inner surface of the bottom case 2, and when the roller 5 still rotates, the hook 18 is displaced clockwise as shown by the phantom line, but the elastic leg 19 is curved. The distance from the hook 18 is increased and the tightening force on the roller 5 is weakened. During this time, the roller 5 rotates while slipping on the wire 17. If the ribbon feeding operation is interrupted, the wire 17
Tightens the roller 5 with the hook 18 and the elastic leg 19 and rotates the roller 5 counterclockwise by the restoring force of the elastic leg 19 from the curved state to the linear state. The ribbon supply shaft 9 in which the ribbon 8 is pressed against the roller 5 slightly rotates in the clockwise direction and imparts tension to the ribbon 8.

In addition, as the ribbon winding diameter of the ribbon winding shaft 10 increases and the ribbon winding diameter of the ribbon supply shaft 9 decreases, the ribbon winding shaft 10 and the ribbon supply shaft 9 extend along the groove 4 toward the roller 5 side. Is displaced to. Therefore, ribbon winding shaft 10 and ribbon supply shaft 9
The change in the distance between and is small, and the change in the strength of the twisting bar 14 is negligibly small. Therefore, the power transmission force by the needle-like projections 6 is stable and does not slip on the ribbon 8 or tear the ribbon 8. Further, the ribbon take-up shaft 10 and the ribbon supply shaft 9 can be biased by one twisting ridge 14, and the ribbon take-up shaft 10 and the ribbon supply shaft 9 can be directly attached to the cassette case 1. Therefore, the number of parts can be reduced, and the structure and the assembling work can be simplified.

EFFECTS OF THE INVENTION Since the present invention is configured as described above, as the ribbon winding diameter of the ribbon winding shaft increases and the ribbon winding diameter of the ribbon supply shaft decreases, the ribbon winding shaft and the ribbon supply shaft are separated from each other. Since it is guided by the groove and displaced to the roller side, it is possible to make the amount of flexure of the torsion bar and the change in force so small that it can be ignored, and thus the power transmission force of the ribbon drive shaft can be stabilized. Moreover, the ribbon take-up shaft is pressed against the ribbon drive shaft by one torsional spring to urge the ribbon supply shaft toward the roller side, and the ribbon supply shaft and the ribbon take-up shaft are directly attached to the cassette case, The number of points can be reduced, and the structure and the assembling work can be simplified.

[Brief description of drawings]

1 to 4 show an embodiment of the present invention. FIG. 1 is a plan view of the inside of a cassette case showing the initial state of the ribbon winding operation, and FIG. 2 is the latter state of the ribbon winding operation. Is a plan view of the inside of the cassette case, FIG. 3 is a vertical sectional side view of the cassette case, FIG. 4 is a partially enlarged plan view, and FIG. 5 is a plan view showing a conventional example. 1 ... Cassette case, 4 ... Groove, 5 ... Roller, 6 ...
... Needle-like projections, 7 ... Ribbon drive shaft, 8 ... Ribbon, 9 ...
… Ribbon supply shaft, 10 …… Ribbon winding shaft, 11 …… Boss (holding part), 12,13… Legs, 14 …… Twisting bar, 15 …… Base part

Claims (1)

[Claims] 1. A ribbon drive shaft having a large number of needle-like protrusions formed along its outer periphery and a roller are rotatably provided on both sides of a flat cassette case to hold a long ribbon in a wound state. A ribbon supply shaft and a ribbon winding shaft for winding the ribbon drawn from the ribbon supply shaft are provided, and the ribbon supply shaft and the ribbon winding shaft have a length from the ribbon drive shaft to the roller. A groove for rotatably and movably holding the shaft part of the and is formed in the cassette case, and a leg for pressing the ribbon supply shaft toward the roller side and a leg for pressing the ribbon winding shaft toward the ribbon drive shaft side. A ribbon provided with a twisting strip having a and a holding part for holding the base of the leg of the twisting strip is provided in the cassette case by arranging the holding part at an intermediate portion between the roller and the ribbon drive shaft. Cassette.