JPS5936470Y2 - Ink ribbon drive device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ink ribbon drive device applied to an impact printer.

The printing mechanism section of the impact printer includes a type carrier 2 and a printing machine 1.

During this time, the printing paper 3 and the ink ribbon 4 are interposed, and the printing paper 3 and the ink ribbon 4 are pressed against the type conveyor 2 by the printing machine 1 to print.

The ink ribbon 4 is fed by directly driving a drive shaft 5 to which the ink ribbon 4 is attached by a motor 6.

The ink ribbon 4 is attached to the drive shaft 5 by inserting the protrusion 7 of the drive cap 7 into a keyway 91 provided at the axial end of the bobbin 9 to which the end of the ink ribbon 4 is attached.
1 and press it with spring 8.

This protrusion 71 allows the ink ribbon 4 to be rotated and fed by the motor 6.

When the ink ribbon 4 is wound in one direction, a return bar 41 mounted near the end of the ink ribbon 4 operates a reversal switch 11 via a reversal plate 10, and the ink ribbon 4 begins to be wound in the opposite direction.

The ink ribbon 4 is operated in synchronization with the print command even when it is stopped in order to prevent the print paper 3 from getting dirty while printing is not being performed.

Therefore, the ink ribbon 4 is repeatedly started and stopped.

When this number of times increases, a crack occurs in the keyway 91 of the bobbin 9 of the ink ribbon 4, and this crack gradually spreads and finally reaches the point where it gets over the protrusion 71 of the drive cap I.

As a result, the rotation of the drive shaft 5 is no longer transmitted to the bobbin 9, and the ink ribbon 4 is no longer fed.

Therefore, the ink ribbon 4 is printed at the same location,
It had the disadvantage of tearing and causing misspellings.

The purpose of the present invention is to eliminate the above-mentioned drawbacks of the prior art, and to be able to drive the ink ribbon even if the keyway of the bobbin is broken.
In this way, it is possible to use an ink ribbon with a lifespan of 1 due to a decrease in the density of the ink ribbon.

The present invention focuses on the fact that even if the keyway of the bobbin breaks, unless it spreads, it will not get over the protrusion of the drive cap, and is characterized by providing a bobbin holder that can press the bobbin from spreading.

FIG. 3 shows an embodiment of the device of the present invention.

The bottomed ring-shaped bobbin holder 20 is attached to the inside of the drive cap 7 on the shaft 5, and can be rotated around the shaft 5.

The relief groove 21 is for receiving the return bar 41, and the inner diameter of the bobbin holder 20 is slightly larger than the outer diameter of the bobbin 9.

The end of the bobbin 9 will be attached to the inside of the bobbin holder 20.

Therefore, by repeatedly starting and stopping as described above,
Even if the keyway 91 of the bobbin 9 is cracked, the bobbin presser 1
1, the ink ribbon 4 does not go over the protrusion 71 of the drive cap 7, and the ink ribbon 4 can be used within its lifespan of 1 due to the decrease in density.

The bobbin presser 20 is made of metal (iron, aluminum alloy, etc.) or relatively rigid plastic (phenol, polyacetal, etc.).

According to the present invention, inoperability due to cracking of the keyway of the bobbin can be prevented, and tearing of the ink ribbon or omission of characters due to inoperability can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a side view schematically showing the printing mechanism of an impact printer, FIG. 2 is a partial perspective view of a conventional ribbon drive device, FIG. 3 is a partial cross-sectional view of the ink ribbon drive device of the present invention, and FIG. The figure is a perspective view showing a bobbin presser. In the figure, 4 is an ink ribbon, 5 is a dry shaft, 6 is a motor, 7 is a drive cap, γ1 is a projection, 9
is a bobbin, 91 is a keyway, and 20 is a bobbin holder.

Claims (1)

[Scope of utility model registration request] A drive cap is attached to the other end of the drive shaft, one end of which is connected to a drive source such as an electric motor, and has at least one drive force transmission protrusion on its outer periphery, and an end of the ink ribbon is attached to the drive cap, the axial end of which is attached to the other end of the drive shaft. an ink ribbon drive device comprising: a hollow bobbin having a keyway extending in the axial direction; the rotation of the drive shaft is transmitted to the bobbin through the protrusion and the keyway to feed the ink ribbon; An ink ribbon drive device characterized in that a ring-shaped bobbin holder is provided on the outer periphery of the drive cap so as to cover the key groove of the bobbin.