GB2254311A

GB2254311A - Ink ribbon cassette

Info

Publication number: GB2254311A
Application number: GB9204552A
Authority: GB
Inventors: Yoichi Ando
Original assignee: Mitsubishi Pencil Co Ltd
Current assignee: Mitsubishi Pencil Co Ltd
Priority date: 1991-03-08
Filing date: 1992-03-03
Publication date: 1992-10-07
Anticipated expiration: 2012-03-03
Also published as: JPH04109165U; CA2062459A1; GB2254311B; GB9204552D0; DE4207344A1

Description

2 25 43 11 -I- INK RIBBON CASSETTE The present invention relates to an ink

ribbon cassette for a printer or the like.

A known ink ribbon cassette comprises an endless ink ribbon and a driving roller (or gear) and a driven roller (or gear) for advancing the ink ribbon. By rotating the driving roller by hand, the ink ribbon can be stretched so as not to be slack, and a knob for rotating the driving roller is provided for this purpose on the outside of the cassette case. However, this knob protrudes and, because no other part protrudes except for the knob, the overall height of the cassette case is almost doubled merely by the presence of this knob alone. This is disadvantageous because the packing box must be large and hence the cost is also increased. Moreover, if dropped or subjected to some other shock, the protruding knob or cassette case is likely to be damaged.

According to the present invention, there is provided an ink ribbon cassette comprising a cassette case and a knob detachably mountable on the cassette case for tightening an ink ribbon contained therel.n.

The invention will now be described by way of a non-limiting embodiment with reference to the accompanying drawings, in which:- Fig. 1 is a plan of an ink ribbon cassette in accordance with the present invention and whose cassette case is partly in section; and Fig. 2 is a sectional view of the cassette of Fig. 1 taken along the line A-A.

The ink ribbon cassette of the present invention requires a smaller packing box than the prior art cassette. This not only reduces costs but also increases shock resistance, e.g. if dropped or the like. Even so, it is still possible to tighten the ink ribbon when it has slackened.

When the ink ribbon cassette is housed in a packing box with the rotating knob detached, the packing box can be miniaturized. Furthermore, when the ink ribbon cassette is carried about, even if it should be dropped, it is unlikely to be damaged on account of the fact that the rotating knob cannot be broken off from the cassette case. When the ink ribbon 1 has slackened, needless to say, the rotating knob 2 is attached to the ink ribbon cassette case and by rotating it the ink ribbon can be tightened.

Since the rotating knob 2 is made to be freely attachable and detachable, except when the slackened ink ribbon 1 is being tightened, it can be left detached for most of the time, and therefore the present invention, by leaving the rotating knob 2 detached even when the ink ribbon cassette is housed in the packing box, enables the packing box to be miniaturized. Also, if the rotating knob is left detached when the ink ribbon cassette is carried about, damage can be avoided if the cassette is dropped by mistake.

The path of the endless ink ribbon 1 is provided within the cassette case 3 and at the middle of the path there is provided a ribbon compartment 4 for housing the ink ribbon 1 in a folded state. On one side of the ribbon compartment 4 are provided a driving roller 5 and a driven roller 6. The ink ribbon 1 is designed to be fed into the ribbon compartment 4 while being held between the driving roller 5 and driven roller 6. A mandrel 7 of the driving roller 5 has a bottom hole 8 for receiving a driving shaft, of the printer, so that the driving roller 5 may be rotated by the printer. The driven roller 6 is biased by a spring 9 towards the driving roller 5, and ink ribbon 1 is gripped between the rollers 5, 6. In the top of the mandrel 7 of the driving roller 5 there is provided a hole 11 into which a shaft 10 of the rotating knob 2 can be removably inserted. The shaft 10 and the hole 11 are provided with a convex portion 12 and a concave portion 13, respectively, which can engage with and disengage from each other by elastic deformation. When the slackened ink ribbon 1 is to be tightened, the rotating knob 2 is fitted in the mandrel 7 of the driving roller 5; at other times it is left detached. Accordingly, when the ink ribbon cassette is housed in a packing box, the rotating knob is left detached, so that the packing box can be minaturized by as much as the protruding height of the rotating knob 2. The shaft 10 of the rotating knob 2 and the hole 11 of the mandrel 7 of the driving roller 5 are formed into shapes which prevent rotation so that the rotating knob 2 and the driving roller 5 can move the ink ribbon 1 by rotating as an integral unit when the rotating knob 2 is mounted in the driving roller 5 and then rotated by hand.

Claims

1. An ink ribbon cassette comprising a cassette case and a knob detachably mountable on the cassette case for tightening an ink ribbon contained therein.

2. An ink ribbon cassette according to claim 1, wherein the cassette case includes a rotatable roller for moving the ink ribbon, the roller having an aperture and the knob having a shaft which is removably insertable into the aperture.

3. An ink ribbon cassette according to claim 1 or 2, further comprising elastically deformable means for resisting detachment of the knob from the cassette case.

4. An ink ribbon cassette according to claims 2 and 3, wherein the elastically deformable means comprises an annular convex projection around the shaft of the knob or the aperture of the roller, and an annular concave groove around the aperture of the roller or the shaft of the knob, respectively.

5. An ink roller cassette substantially as herein described with reference to, or with reference to and as illustrated in, the accompanying drawings.

6. An ink ribbon cassette according to any one of claims 1 to 5, when packaged with the knob detached.

7. An ink roller cassette according to claim 6, wherein the thickness of the packaging is less than the overall thickness of the cassette case and knob, when assembled.