JP2789940B2 - Ink ribbon cassette - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink ribbon cassette used for a printer or the like.

[0002]

2. Description of the Related Art In a conventional ink ribbon cassette, an optimum ribbon tension is secured by sandwiching a ribbon cloth between a leaf spring and a projection provided on a cassette case.

[0003]

The conventional ink ribbon cassette is designed to obtain the optimum printing quality by securing the ribbon cloth to the slack of the ribbon cloth, and sandwiching the ribbon cloth between the leaf spring and the projection of the cassette case. Because the leaf spring is worn out, and the ribbon fabric expands and contracts like wakame,
There is a possibility that the optimum tension is changed, which may lead to a fixed price of printing quality or a breakage of a wire in the case of a dot serial printer.

[0004]

According to the present invention, there is provided an ink ribbon cassette comprising: an endless ink ribbon; a feed roller for feeding the ink ribbon having passed through a printing range to a stocker in a case; An eccentric bush, which is provided on a runway in the case of the ink ribbon and is eccentrically rotatable and substantially half of the outer periphery is formed in a gear shape; and the ink ribbon sandwiched between the eccentric bush is pressed against the eccentric bush. Includes a leaf spring fixed to the case, and a fixing claw provided on the case and engaged with a gear-shaped portion of the eccentric bush.

[0005]

An embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a front view showing an internal structure of the ink ribbon according to an embodiment of the present invention, excluding a cover. When the ink ribbon 1 is sandwiched between the feed roller 12 and the pressure roller 9 and the rollers 12 and 9 rotate, the ink ribbon 1 is entrained and travels along the guides of various parts of the case 2. The feed roller 12 is fixed at a fixed position by a roller holder 13, and the pressure roller 9 is incorporated in a holder 10 for guiding rotation, and the holder 10 is pressed against the feed roller 12 by a pressure spring 11 so that the ribbon winding force is increased. Is obtained. The ribbon 1 wound in this way is folded into the stocker and pushed. 1, the ribbon 1 is drawn out again from the left side in FIG. The sheet is sandwiched to obtain a certain tension and comes back into the printing range.

The means for applying a constant tension to the ink ribbon 1 comprises a rotatable and eccentric eccentric bush 4 and a leaf spring 5 whose end face is fixed to the case and is in contact with the eccentric bush 4 in a bent state. The eccentric bush 4 is formed in a gear shape with a half of the circumference, and is fixedly engaged with the fixing claw 3 provided on the case. By rotating the eccentric bush 4 by engaging the tip of a flat-blade screwdriver or the edge of a coin with the slit 14 for rotation provided on the eccentric bush 4, the contact point of the eccentric bush 4 with the leaf spring 5 changes, and 5 has a structure in which the tension of the ink ribbon 1 changes by the change in deflection.

[0008]

As described above, the present invention is most suitable for an ink ribbon cassette used in a printing apparatus or the like due to the deterioration of the ribbon cloth (extending in a wrinkle shape) due to long-time use and the wear of a leaf spring that generates ribbon tension. When the tension of the ink ribbon cannot be obtained, the eccentric bush is rotated by a flathead screwdriver or a coin to change the displacement amount of the leaf spring, thereby obtaining the optimum tension of the ink ribbon.

[Brief description of the drawings]

FIG. 1 is a front view showing the configuration of an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ink ribbon 2 Case 3 Fixed claw 4 Ecsen bush 5 Leaf spring 6 Gate 7 Mobius guide 8 Gate 9 Pressure roller 10 Holder 11 Pressure spring 12 Feed roller 13 Roller holder 14 Rotation slit

──────────────────────────────────────────────────の Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B41J 32/00-32/02 B41J 33/52 B41J 17/02-17/12 B41J 17/22-17 / 26 B41J 17/32

Claims (1)

(57) [Claims] 1. An endless ink ribbon, a feed roller for feeding the ink ribbon that has passed through a print range to a stocker in a case, and a feed path in the case of the ink ribbon from the stocker to the print range. An eccentric bush, which is eccentric and rotatable and substantially half of the outer periphery is formed in a gear shape, a leaf spring having one end fixed to the case by pressing the ink ribbon sandwiched between the eccentric bush and the eccentric bush; An ink ribbon cassette comprising: a fixing claw provided on a case to engage with a gear-shaped portion of the eccentric bush.