JPH0446932Y2 - - Google Patents

Description

[Detailed description of the invention] [Summary] This is a ribbon cassette for printers, in which a protrusion is provided on the leaf spring for preventing overfeeding of the ribbon, and this protrusion is brought into contact with a fulcrum, so that the leaf spring moves against the inclination of the running wall. The ribbon is configured to have an inclination that matches the current direction, thereby stabilizing the ribbon running.

[Industrial application field]

The present invention relates to ribbon cassettes used in personal computers, word processors, and other OA-related fields, and more specifically, to stabilizing the running of ribbon in ribbon cassettes for printers.

In ribbon cassettes used in printers such as various office automation equipment, the ribbon housed in the ribbon cassette is fed out by a constant feed force, but since the ribbon is fed and stopped repeatedly, measures must be taken to prevent overfeeding of the ribbon. If it is not removed, the ribbon will overfeed due to inertia, etc., resulting in slack in the ribbon, which may cause printing defects or ribbon entanglement accidents.

Therefore, in order to prevent over-feeding of the ribbon, the leaf spring is supported in contact with the fulcrum inside the cassette case.
The ribbon is sandwiched between a running wall provided inside the cassette case and a leaf spring, and the elastic force of the leaf spring presses the ribbon against the running wall, thereby imparting friction to the ribbon. structure is used.

FIG. 4 shows a preferred example of the pressure distribution of the pressure applied to the running wall 5 due to the pressing force of the leaf spring 6 against the ribbon 3.

In FIG. 4, the pressure PA at a position corresponding to the upper part 3A of the ribbon 3 and the lower part 3B of the ribbon 3 are shown.
It is desirable that the pressure PB at the position corresponding to the middle part 3C of the ribbon 3 is much larger than the pressure PC at the position corresponding to the middle part 3C of the ribbon 3, and that the pressure PA and the pressure PB are almost the same.More preferably, the pressure PA is Pressure slightly more than PB, for example 10-15gr
It is experimentally known that a larger degree is better.

If the balance between pressure PA and pressure PB is greatly disrupted, the ribbon 3 will run in a state of one-sided contact and run diagonally, and as a result, the ribbon 3 will float or sink, resulting in poor ribbon feeding. or cause printing defects.

By the way, the structure of the ribbon cassette is a box-shaped box made of resin that is open on one side and has a bottom surface on the other side in order to accommodate the ribbon and incorporate a mechanism for preventing over-feeding of the ribbon using the leaf spring or the like. It consists of a cassette case and a cassette lid attached to the open surface of the cassette case.

Therefore, the cassette case is manufactured by molding resin into the box-like shape having the open surface.

When molding such a box-shaped cassette case, it is unavoidable that each part of the cassette case tends to deform when the molded product contracts, and as a result, the running wall also tends to deform. It will be deformed and tilted.

If the cassette case is used with the running wall slanted, the above-mentioned leaf springs will come into contact with the ribbon unevenly, so the pressure of the leaf springs giving friction to the ribbon will not be evenly distributed across the ribbon.
As a result, the running stability of the ribbon is impaired, such as when the ribbon runs diagonally upward or downward, lifting up or sinking.

For this reason, there is a demand for an inexpensive and quality-stable countermeasure method for stabilizing the running of the ribbon.

[Conventional technology]

In order to stabilize the running of the ribbon when the running wall is deformed and inclined during the molding of the cassette case, conventionally, various methods using jigs and constant temperature baths described below have been used to straighten the running wall. The deformity of was corrected.

FIG. 5 is a plan view of the cassette case showing the vicinity of the ribbon overfeed prevention mechanism, and FIG. 6 is a sectional view showing a conventional correction method.

In FIG. 5, 1 is a cassette case, 3 is a ribbon, 4 is an arrow indicating the ribbon feeding direction, and 5 is a ribbon.
6 indicates a running wall, 6 indicates a leaf spring, and 8 indicates a fulcrum.

The leaf spring 6 is attached to a fulcrum 8 provided on the cassette case 1.
The ribbon 3 is supported in contact with the protrusion 7, and the vicinity of the tip of the leaf spring 6 presses the ribbon 3 toward the running wall 5 in the direction of the arrow 9.

The tip of the leaf spring 6 is a curved portion 6A for stabilizing the spring constant of the leaf spring 6.

Therefore, the ribbon 3 is moved to the arrow 4 by a mechanism (not shown).
When the ribbon 3 is fed in the direction shown in FIG. 3, friction is applied to the ribbon 3 between the running wall 5 and the leaf spring 6, so that overfeeding of the ribbon is prevented.

However, in FIG. 6A, which shows the AA cross section of FIG. 5, if the running wall 5 opens and slopes as a result of molding the cassette case 1, if this is used as is, the leaf spring 6 will be at the fulcrum 8. Since the lower part of the ribbon 3 hits the running wall 5 much more strongly than the upper part of the ribbon 3, the ribbon 3 is erected due to its contact with the arrow 10 as it runs. The ribbon 3 tends to be lifted in the direction of , and the ribbon 3 is bent, scratched, and scratched, resulting in poor ribbon feeding and printing defects.

In order to prevent this, in the prior art shown in FIG. 6, after molding the cassette case 1, before the resin has cooled down (FIG. 6B), the jig 11 having the closing inclined surface 11A is placed near the running wall 5. (Figure 6C),
In the final product, the running wall 5 is corrected so as to stand upright before use (FIG. 6D).

FIG. 7 shows another conventional technique.

In FIG. 7A showing the AA cross section of FIG. 5,
Running wall 5 as a result of molding of cassette case 1
If it is closed and inclined, if it is used as it is, the leaf spring 6 will still be erect based on the state of contact with the fulcrum 8, so the upper part of the ribbon 3 will be closer to the running wall 5 than the lower part of the ribbon 3. As a result, the ribbon 3 tends to sink in the direction of the arrow 12 as it runs, causing the ribbon 3 to bend and become scratched, resulting in poor ribbon feeding and printing. It becomes defective.

In order to prevent this, in the prior art shown in FIG. 7, the cassette case 1 is
After molding, before the resin cools down (Figure 7B),
A jig 13 having an opening inclined surface 13A is inserted into a position adjacent to the running wall 5 (FIG. 7C), and the deformation of the running wall 5 is corrected in the final product before use (FIG. 7D).

In the case where the running wall 5 is tilted open or closed as shown in FIG. 6A or FIG. 7A, in other conventional techniques, after molding, the cassette case 1 is placed in a constant temperature bath and straightened, and the running wall 5 is tilted open or closed. 5. Prevents deformation. In this case, the temperature of the constant temperature bath is set in the range of 80 to 120°C depending on the type of resin used for the cassette case.

FIG. 8 shows still another conventional technique. In FIG. 8, pin locking holes 14 are formed in each wall of the open surface of the cassette case 1, and these pin locking holes 1
A protrusion or pin 15 is formed in advance by molding on the lower surface of the cassette lid 2 at a position corresponding to 4, and after the cassette case 1 is molded, the cassette lid 2 is attached before it cools down and the pin engagement of the cassette case 1 is fixed. By fitting the pin 15 of the cassette lid 2 into the locking hole 14, the deformed running walls and the like of the cassette case 1 are corrected, and the cassette case 1 is cooled in this state.

The various conventional techniques described above all correct the deformation of the running wall 5 in the cassette case 1, and therefore have the drawbacks of being laborious and time-consuming, and increasing costs.

In addition, the jig 11 in FIG. 6 or the jig 1 in FIG.
3, the running wall 5 cannot easily adapt to the extent of its tendency to deform, and therefore it is inevitable that variations in the straightening results will occur, and the stability of the ribbon running cannot be sufficiently stabilized. There is also a drawback that it cannot be done.

[Problem that the invention attempts to solve]

This conventional method has problems in that since the deformation of the running wall is corrected, the correction results vary and the cost is high.

The present invention was created in view of the above, and by tilting the leaf spring for overfeed prevention in accordance with the deformation of the traveling wall, it is possible to reliably equalize the spring pressure in a simple manner. The object of the present invention is to provide a ribbon cassette for printers that stabilizes ribbon running.

[Means for solving problems]

The printer ribbon cassette of the present invention has a protrusion corresponding to the inclination of the running wall formed on the leaf spring at the position where the overfeed prevention leaf spring contacts its fulcrum.

[Function] In the printer ribbon cassette of the present invention, the leaf spring is supported by the fulcrum with the protrusion formed on the leaf spring in contact with the fulcrum.

Therefore, the leaf spring is inclined at the position where it contacts the fulcrum, and accordingly, the leaf spring is also inclined at the position where it is pressed toward the ribbon running wall.

Therefore, since the leaf spring exerts a pressing action on the ribbon in a state substantially parallel to the inclined running wall, the spring pressure acts uniformly as expected, and the ribbon running is stabilized.

According to the present invention, since the protrusion is simply provided on the leaf spring, the work is simple and inexpensive. Moreover,
Since it is easy to quantitatively control the height of this protrusion according to the inclination of the running wall, there is little variation in the results of stabilizing ribbon running according to the present invention.
Print quality also improves.

〔Example〕

FIG. 1 and FIG. 2 are examples of the present invention, and
Figure 2 is a plan view of the cassette case showing the vicinity of the ribbon overfeed prevention mechanism, and Figure 1A is a plan view of the cassette case before the ribbon and internal structure are installed.
- Cross-sectional view shown at a position corresponding to cross-section A, Figure 1B
1 is a perspective view of the leaf spring, FIG. 1C is a sectional view taken along line BB in FIG. 2, and FIG. 1D is a sectional view taken along line AA in FIG. 2.

This embodiment is intended to stabilize the ribbon running when the running wall 5 opens and tilts as shown in FIG. 1A as a result of molding the resin cassette case 1.

In FIG. 1B, the leaf spring 6 has a dowel 2 in the upper part of the leaf spring 6 at a position where it should contact the fulcrum 8.
Use the one with the dowels removed in step 1.

When this leaf spring 6 is attached to the cassette case 1 as shown in FIG. It stands erect with almost no deformation, and therefore, the leaf spring 6 is inclined substantially parallel to the inclination of the running wall 5, as shown in FIGS. 1C and 1D.

Therefore, the leaf spring 6 applies spring pressure evenly to the ribbon 3, and as a result, it is possible to prevent the ribbon from skewing.

In this embodiment, since the dowel 21 is formed as a protrusion on the leaf spring 6, the work is simple and inexpensive. In addition, the doweling work for the leaf spring 6 can be done by performing the doweling work on the leaf spring in accordance with the inclination of the running wall 5 after the cassette case 1 is molded. The amount can be determined easily, so the work is quick, there is little variation in the inclination of the leaf spring 6 in FIG. do not have.

Furthermore, if the above-mentioned ribbon running is unstable, secondary effects such as damage to the print head and re-reading of print data may also be obtained.

FIG. 3 shows a running wall 5 as another embodiment of the present invention.
This is to stabilize the ribbon running when it is closed and tilted.

3A is a cross-sectional view of the cassette case before the ribbon internal structure is installed at a position corresponding to the AA cross section in FIG. 2; FIG. 3B is a perspective view of the leaf spring;
FIG. 3C is a sectional view corresponding to the BB section in FIG. 2, and FIG. 3D is a sectional view corresponding to the AA section in FIG. 2.

In this embodiment, since the running wall 5 is closed and inclined as described above (FIG. 3A), the position where the dowel 22 is formed in the leaf spring 6 is as shown in FIG. 3B. Lower part.

When this leaf spring 6 is attached to the cassette case 1, the leaf spring 6 will open as shown in FIGS. 3C and 3D.
is inclined, this embodiment also achieves equalization of the spring pressure on the ribbon due to the leaf spring, and therefore,
A method for stabilizing ribbon running at low cost and with stable quality is provided.

Although the two embodiments shown in FIGS. 1 to 3 use dowels as protrusions formed on the leaf spring, other means may be used to form the protrusions, such as laser welding.

[Effect of idea]

As described above, according to the present invention, with a simple configuration, by providing a protrusion on the leaf spring, the leaf spring can be installed in an inclined state, thereby equalizing the spring pressure and stabilizing the ribbon running. This is extremely useful in practice, as it can improve printing quality and prevent ribbon feeding accidents.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of an embodiment of the present invention, Fig. 2 is a plan view of the embodiment of Fig. 1, Fig. 3 is an explanatory diagram of another embodiment, and Fig. 4 is a spring of a leaf spring against a running wall. An explanatory diagram showing pressure distribution, FIG. 5 is a plan view of a conventional structure, FIG. 6 is an explanatory diagram of the conventional technique of FIG. 5, FIG. 7 is an explanatory diagram of another conventional technique, and FIG. FIG. 2 is a cross-sectional view of the prior art. In Figures 1 to 3, 3 is a ribbon;
5 is a running wall, 6 is a leaf spring, 8 is a fulcrum of the leaf spring, 2
1 and 22 are protrusions formed on the leaf springs, respectively.

Claims (1)

[Claims for Utility Model Registration] A running wall 5 for receiving contact with the ribbon 3 during running; a leaf spring 6 for preventing overfeeding of the ribbon that presses the ribbon 3 toward the running wall 5; In a printer ribbon cassette comprising a fulcrum 8 that contacts and supports a leaf spring 6, the leaf spring 6 has a protrusion 21 corresponding to the inclination of the running wall 5 at a position where the leaf spring 6 contacts the fulcrum 8. ，
1. A ribbon cassette for a printer, characterized in that it is formed with a ribbon cassette having a diameter of 22.