JPS6342588B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cassette-type ink ribbon for a printing device.

A type in which an endless ink ribbon is stretched across two cassette cases is disclosed in, for example, Japanese Utility Model Application No. 53-107210. In this known device, a storage chamber is formed in one of the cassette cases to store the ink ribbon in a meandering manner, and the ink ribbon is fed into this storage chamber by a drive roller while being pulled out from this storage chamber. Therefore, even when the ink ribbon is set in the printing device, it still exists in the storage chamber. This is because an extremely long ink ribbon is required in view of the ink life of the ink ribbon.

However, this has the disadvantage that the storage chamber increases the size of the entire cassette.

In the present invention, the length of the endless ink ribbon is determined in accordance with the set interval between the two cassette cases, thereby reducing the size of the cassette case. The purpose of this invention is to prevent the ink ribbon from becoming excessively tense or loosening even if it is attached with high precision.

Examples of the cassette-type ink ribbon according to the present invention will be described below.

The cassette type ink ribbon of this example has the first
As shown in the figure and FIG. 2, it is equipped with two cassette cases 1, 1,
is composed of a lower case 2 and an upper case 3 made of plastic such as ABS. The lower case 2 has four coupling holes 4, and the upper case 3 has protrusions (not shown) formed protruding at positions corresponding to the holes, and are press-fitted into the holes 4. It is fixed to the lower case 2. An ink roller 5 and a transfer roller 6 in contact with the ink roller are provided inside the left cassette case 1.

The ink roller 5 is made of nitrile butadiene rubber (NBR), and is forcibly impregnated with ink. As the material of the ink roller 5, various other sponge-like porous rubbers, felt, etc. may be used. Inside the right cassette case 1,
A tension applying member 7 is provided. This tension applying member 7 has a cove-shaped cavity 8 with an open right end.
and a semi-cylindrical part 9 formed at the rear of this hollow part 8.
and collar portions 10, 10 projecting from both sides of this semi-cylindrical cavity portion 9. A coil spring 12 is arranged between the semi-cylindrical portion 9 and the wall surface 11 of the lower case. In this embodiment, the left and right cassette cases 1, 1 have completely symmetrical structures in common, and the lower case 2 has a guide groove 13 on the bottom surface for supporting the tension applying member 7 so as to be slidable left and right. is formed to have a depth approximately equal to the wall thickness of the collar portion 10. Furthermore, a bearing 15 rotatably receives the shaft 14 of the ink roller in the lower case 2.
and a long groove-shaped bearing 17 that receives the shaft 16 of the transfer roller 6. The bearing 17 has a width approximately corresponding to the diameter of the shaft 16, so that the transfer roller 5 is rotatable and also movable left and right. The inner surface shape of the upper case 3 is exactly the same as the bottom surface shape of the lower case 2. Furthermore, narrow slit-shaped openings 18 are formed in the upper and lower positions of the opposing surfaces of the left and right cassette cases 1, 1, respectively, and in the center, both cassette cases 1, 1
Connecting pawls 19, 19 are formed that can combine and separate the two. Both cassette cases 1 and 1 have connecting claws 1
9 and 19, they are assembled into a connected body and sold in this state. The endless ink ribbon 20 is folded over a considerable length in a meandering manner and packed inside the cavity 8 of the guide body 7, and is further divided into both sides from the tip of the guide body 7. It passes through each opening 18 and is wrapped around the outer peripheral surface of the transfer roller 6. In the state shown in FIG. 1, the tension applying member 7 is pushed to the right by the coil spring 12, so that the ink ribbon is pushed between the tip of the tension applying member 7 and the inner surface of the lower case 2. The ink ribbon 2 is clamped by the force of the coil spring 12, and a slight external impact will cause the ink ribbon 2 to
0 does not come out naturally from the cavity 8, and there is no problem such as the ink ribbon 20 becoming tangled within the cassette cases 1,1. Further, a fulcrum portion 21 is integrally formed protruding from approximately the center of both outer surfaces of the lower case 2, and a plate-shaped spring portion 22 is formed around the fulcrum portion 21 on the outside of the lower case 2 as shown in FIG. It is integrally formed to hang down along the wall surface.

The lower end of the plate-shaped spring portion 22 protrudes below the lower surface of the lower case 2, and a locking pawl 23 is provided at this lower end.

When this cassette-type ink ribbon is set in a printing device such as a serial printer, it is carried out as follows. First, in FIG. 1, hold the left and right cassette cases 1, 1 in your hands and shift them up and down relative to each other. Then, the coupling claws 19, 19 are disengaged, and the two cassette cases 1, 1 become separable.

Then, when both cassette cases 1, 1 are opened left and right, the ink ribbon packed in the cavity 8 is moved to the tension applying member 7 by the coil spring 12.
The ink ribbon 20 is pulled out against the frictional force between the tip end and the inner surface of the lower case 2, and finally the ink ribbon 20
completely disappears from the cavity 8, and the tension applying member 7 is guided by the guide groove 13 against the coil spring 12 and moves slightly to the right inside the case, as shown in FIG. The distance between the two cassette cases 1, 1 at this time is set in advance to the installation length of the cassette cases 1, 1 of the printing device. The printing device is provided with a mounting plate 24 shown in FIG. 4 as an example, and when the cassette cases 1, 1 are pushed down toward this mounting plate 24, the locking pawl 23 locks on the end face of the mounting plate 24, Each cassette case 1, 1 is held on a mounting plate 24 by the spring force of a plate-shaped spring portion 22.

In the installed state shown in the first figure, one of the two strips of ink ribbon 20 pulled out from the openings 18 of both cassette cases 1, 1 and exposed is inserted into a printing head and a platen (both not shown). At this time, an appropriate tension is applied to the ink ribbon 20 via the tension applying member 7 which receives the spring force of the coil spring 12, and the transfer roller 6 is brought into elastic contact with the ink roller 5 due to the tension. When printing is performed with the scanning of the printing head, the ink ribbon 2
0 is fed through a suitable ink ribbon feed mechanism in conjunction with the scanning of the print head, particularly in conjunction with the movement of the print head carriage return, and the transfer roller 6 and ink roller 5 also rotate. The ink impregnated in the ink roller 5 adheres to the outer peripheral surface of the transfer roller 6 in the form of a thin film. Therefore, when the ink ribbon 20 rotates as described above, the surface of the transfer roller 6 is attached to the ink ribbon 20. The ink adhering to the printer is replenished.

When removing the cassette case 1 from the installed state shown in FIG. 4, by holding the upper ends of both plate-shaped spring parts 22, 22 with your hands and moving them inward, the lower ends of these plate-shaped spring parts 22, 22 will become the fulcrum. The cassette case 1 can be easily removed by simply lifting the cassette case 1 upward.

The above-described cassette-type ink ribbon according to the present invention is configured to apply tension to the ink ribbon by a tension-applying member that is slidably disposed in one of the two cassette cases and is resiliently sprung by a spring. Therefore, even if there is an error in the set interval between the two cassette cases, an appropriate tension is always applied to the ink ribbon as long as the error is within the range in which the tension applying member can freely slide. In other words, the set interval may have relatively rough accuracy. In addition, since ink is replenished to the ink ribbon using an ink roller and a transfer roller, sufficient ink life can be ensured even when the length of the ink ribbon is shortened to the minimum necessary. Therefore, the conventional ribbon storage chamber is not required, and the entire cassette can be constructed compactly.

[Brief explanation of drawings]

The drawings relate to a cassette-type ink ribbon according to the present invention, and FIG. 1 is a cross-sectional view in a connected state, and FIG.
The figure is a vertical cross-sectional view of the same as above, Figure 3 is a cross-sectional view of the printer set in the printing device, and Figure 4 is the same as Figure 3-
FIG. 1... Cassette case, 5... Ink roller,
6...Transfer roller, 7...Tension applying member, 12...
...Spring, 13...Guide groove, 20...Ink ribbon.

Claims (1)

[Scope of Claims] 1. An endless ink ribbon is stretched across two separate cassette cases that are installed opposite to each other with an interval between them, and one of the two cassette cases has an endless ink ribbon. , a transfer roller in contact with the ink ribbon and an ink roller in contact with the transfer roller are rotatably supported, and the other of the two cassette cases is provided with a roller that abuts the ink ribbon from the inside and guides the ink ribbon. A guide body is slidably supported in parallel with the opposing directions of the two cassette cases, and between the rear part of the guide body and the wall surface of the case where it faces, the guide body is supported as shown in FIG. A cassette-type ink ribbon for a printing device, characterized in that a spring is provided for applying tension to the ink ribbon by springing both cassette cases in a direction away from each other.