JPS6235895A - Ink type pen - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an ink pen having a nib, a tank for liquid ink, and means for conveying ink from the tank to the nib.

[Prior Art] Such ink pens are particularly known as fountain pens, but are also known as so-called rollerball or fiber tip pens.

In these ink pens, ink is transported from the reservoir to the nib by one of two principles: capillary action. As the tank empties gradually in this way, a partial vacuum gradually develops within the tank, and this
Prevents ink from reaching the nib any further. To avoid this, the partial vacuum must be overcome by an external supply of air.

This is done by providing a small orifice in the bottom of the tank in the writing position, through which a small air bubble can overcome the partial vacuum, enter the tank and rise through the ink. There is.

However, there still remains the following disadvantage.

On the one hand, the entire device is extremely sensitive to temperature and pressure. In particular, if the volume of air in the tank increases as a result of an increase in temperature or a decrease in external pressure, as a result of excessive pressure, ink may escape through an expensive capillary ink reservoir or the like. It is pushed towards the tip of the pen, which is no longer there. Furthermore, ink may flow out through small orifices where air bubbles are supposed to enter.

These difficult to overcome problems can be avoided by using so-called ink pads, ie porous, for example fibrous materials soaked with ink. However, the disadvantage of this ink pad is that it cannot be completely emptied. Ink flow also decreases, especially if after some writing the amount of ink and therefore the degree to which the porous pad is wetted decreases. In other words, the writing performance is impaired. Therefore, a disadvantage of ink pads associated with conventional tanks is that the tanks must be refilled or replaced more frequently. Furthermore, ink pens with tanks provide higher writing speeds. This is because, due to the high writing speed, the ink flows only slowly from the moist areas of the ink pad to the partially dry areas, and as the number of empty areas of the ink pad increases, capillary attraction This is because, in a pen with an ink pad, the ink flow becomes poor at high writing speeds because the pen prevents the ink flow from increasing.

[Problems to be Solved by the Invention] As a result, although the tank has many advantages, it also has disadvantages as mentioned in the introduction. Thus, such ink pens are very sensitive to temperature and must be provided with compensation space, e.g. in the form of a capillary ink reservoir. Furthermore, the internal pressure within the tank depends on the filling level. This is because changes in the filling amount and changes in the hydrostatic pressure at the orifice where air enters,
This is because it changes the inflow of air bubbles.

SUMMARY OF THE INVENTION The object of the invention is to provide an ink pen of the type mentioned in the preamble which has the advantages of a tank and at the same time the ink flow is independent of temperature changes, pressure fluctuations and filling level. Our goal is to provide the following.

In the solution of this invention, the tank is closed off by a porous wall, at least on the side facing away from the nib.

Such porous walls are known in principle as so-called wet membranes in medicine, electrochemistry, biology and similar fields. The value of this invention lies in the recognition that the disadvantages of known ink pens with reservoirs can be overcome in a surprising way by means of porous walls. Substantially the advantages of an ink pad are obtained without the disadvantage that ink flow is dependent on the fill level of the ink pad.

[Operations and effects of the invention] The porous wall functions as follows. Ink soaks into the walls. In order to ensure that this is always the case, the porous wall must be connected to a suitable capillary, for example the area at the bottom of the tank in the writing position, where some ink is usually always present, through the porous wall as well. It is appropriate to connect it to However, in order for the upper part to remain constantly moist, it is advantageous if the side walls are also made of porous material.

During writing, when ink is lost and a partial vacuum is gradually created, small air bubbles flow through the pores of the ink-filled porous wall until a pressure balance is achieved or the pressure difference is so small that no more air bubbles flow. flows. Of course, the pressure difference beyond which the bubbles flow does not depend on the filling level.

This is because, unlike conventional ink pens with a tank, the pressure at the orifice where the bubble enters does not depend on the hydrostatic pressure of the ink in the tank.

On the other hand, if excessive pressure develops in the tank, for example as a result of an increase in temperature or a decrease in pressure in the surroundings, air bubbles can conversely escape from the tank into the surroundings through the porous walls, resulting in internal Excessive pressure of will be reduced. At the same time, unlike traditional ink pens with a tank, the ink is not forced out of the tank.

The tank of the invention, which is at least partially made of a porous wall,
Therefore, the ink flow is uniform and independent of the fill level as a result of the valve function for air bubbles that is independent of the knee fill level, which has the following advantages:

Since it is insensitive to one temperature, its ink retention ability is extremely high.

- Requires less space than conventional ordinary tanks.

Compared to a single ink pad, the ink supply is fast enough even at high writing speeds exceeding 9 m7 minutes.

The perforated-walled tank of the invention can be used with all ink pens, rollerball pens, fiber dip pens, and even fountain pens.

In conventional tanks, the air bubbles must first flow through the ink, whereas here the pressure compensation by the porous walls directs the air bubbles directly into the space above the ink; The properties of the pressure balance that lead to the smaller pressure step are determined by the shape of the micropores and their diameter. In this connection, a bubble point or bubble generation pressure is defined. It is the pressure required to overcome the capillary pressure in the pores to form a gas bubble.

This relationship is expressed formally as follows.

F・σ case Pv= Pv=Bubble generation pressure or bubble point σ=Surface tension of liquid θ=Wetting angle of liquid in membrane material d=Average diameter of pores F=Shape factor The tank is porous all around it It is convenient if it is surrounded by material. This is because the top area in the writing position always remains completely wet with ink. To prevent the tank from drying out, the tank is suitably covered at its bottom and side walls with an impermeable material. At the same time, the side walls and the part facing the nib, excluding the means for conveying ink to the nib, are covered with an impermeable material. This impermeable material may be, for example, a shrinkable plastic.

Porous wall materials may also be made of plastic.

However, it can also be made of other materials such as glass or sintered metal or ceramic.

Porous wall materials have pores with an average diameter of 1 to 100 μm1.
Preferably, 10 to 50 μm is advantageous.

It is advantageous if the porous wall material has an average pore diameter of approximately 25 μm.

As mentioned above, the porous walls are soaked with ink. This can be achieved by choosing the wall material appropriately. In particularly preferred embodiments, the porous wall material is made water absorbent;
In other words, the wall material has been specially treated so that it absorbs water particularly well, and therefore attracts water and becomes completely immersed in water or ink in a particularly effective manner.

However, in another preferred embodiment, the porous wall material is treated to be water repellent, ie to repel water or ink. In this case, the porous wall material repels the ink liquid that can no longer penetrate into the wall material, but on the other hand also forms a film of ink on the inner surface of the water-repellent wall, and here the space in the tank The area is closed off from the outside air.

When the tank becomes partially empty as a result of writing, a certain amount of vacuum is created in the space, which prevents the ink from flowing out. However, if this vacuum exceeds a certain value, the ink film located on the water-repellent porous wall material may rupture, resulting in at least partial pressure compensation. This liquid film then closes again. Its mode of action is therefore similar to that of air bubbles flowing through pores filled with ink liquid in a water-absorbing or made-water-absorbing porous wall.

However, a wall material is selected that completely repels ink. In other words, it is possible that the ink film on the inner surface of the tank does not wet the water-repellent wall at all. In such a case, it is quite possible for ink to leak out with a normal fountain pen, but here, the flow orifice is completely closed and the nib guides the ink from the tank to the nib, so that even if the ink is inside the tank, Even if there is no vacuum state in
No ink will flow out.

If the walls of the porous wall were too wide, there could be a risk that too much ink would evaporate through the corresponding orifice, so that the ink would dry up too quickly. These walls are therefore usually not very wide, or the porous walls are at least partially closed off by an impermeable layer.

However, in yet another preferred embodiment, if at least a part of the wall of the tank is formed of a water-absorbing porous wall material, the outer surface of which is covered with a water-repellent porous wall material,
This additional coating may itself be a porous wall.

[Embodiments] The present invention will be described below by means of preferred embodiments based on the attached drawings. FIG. 1 is a schematic side view showing the principle of a conventional ink pen.

FIG. 2 is a drawing similar to FIG. 1. The principle of the ink type pen of this invention is shown.

Figure 3 shows the mode of action of the porous walls. FIG. 4 is a drawing similar to FIG. 2, showing the principle of another embodiment of the ink pen of the present invention.

FIG. 1 illustrates a conventional ink pen, for example a fountain pen, with a tank l filled with ink 2. FIG. Air bubble part 3
is located above ink 2.

During writing, when ink 2 is withdrawn through capillary tube 5 in the direction of arrow 4, a partial vacuum is gradually created in the tank.

In order to balance the pressure, there is a small orifice 6 at the base of the bottom of the tank in the writing position, through which an air bubble 7 rises in the tank 2 with a considerable partial pressure.

And in this way the partial vacuum in the air volume 3 is reduced.

When there is an increase in temperature or a decrease in external pressure, the ink in the space 3 expands, so that the ink is forced downward or outward through the capillary tube 5 and possibly also the orifice 6.

As a result, the ink flowing through the capillary tube 5 drips, and it is therefore necessary to provide a relatively expensive capillary type ink reservoir 8, such as the nib of a fountain pen, for example.

FIG. 2 shows a first embodiment of the ink pen of the invention. The upper end wall 9 of the tank 1, which is located here on top (in the writing position), is made of porous material.

Sidewall 10 is also made of a similar porous material. In this embodiment, the lower end face is made of an impermeable wall material, but it could also be a porous material. At the same time, the lower end face 2 and the side walls 10 are covered with a coating 12 made of impermeable material, so that the ink does not evaporate here.

The writing ink is extracted downward in the direction of arrow 4. The ink is conveyed from the tank to the outside through a suitable capillary, for example a nib 13 made of a porous material similar to the wall material.

The pressure balance between the external pressure and the air pressure in the air-filled space 3 occurs through the ink-filled porous walls, as shown diagrammatically in FIG.

When the internal pressure inside the tank at the bottom in FIG. 3 is lower than the external pressure at the top in FIG. FIG. 3 at the same time shows the different stages from a to g in the flow-through of the bubble 7. A very precise pressure balance occurs in this way, even when the differential pressure is small, and in particular regardless of the level of ink filling in the tank. At the same time, a pressure equilibrium in the air chamber 3 above the ink liquid 2 in the tank 1 is directly obtained. If excessive internal pressure occurs, the bubbles 7 will flow out in a similar manner from the inside to the outside, ie from the bottom upwards in FIG.

FIG. 4 shows another embodiment including a pen nib with a pole 15 and a lead 13.

The micropores are of course present throughout the entire wall, although they are only visible in one part of the walls 9,101 and 11.

High writing speeds can be achieved if the cross-section of the nib is calculated so that the flow path resistance is low enough to supply enough ink even for a wide nib or wide tip (PENTIP). is obtained.

In the case of a double black nib (BBNIB), at a writing speed of 9 m/min, the ink supply amount is approximately 30 m/100 m.
0111g, and the writing pressure is 80g.

Ideally, the cross-section, length and average diameter of the pores of the nib are individually matched to the nib.

The following results were obtained when the roller ball type was used and the total amount of ink sold was 2 g. A value of 25 μm was chosen for the average diameter of the pores. On a sheet of paper traditionally used in the writing instrument industry for test applications, the ink pen of the present invention has been tested in an air-conditioned room at a writing pressure of 80g and a writing speed of 4.50/min. , achieved an allowable writing length of 100 m. This value ranges from the current customary writing length of about 800 to 1. It sufficiently exceeds room. For a 0.8 mm ball with a nickel-silver nib, the ink consumption m was approximately 50 to 60 gg/l O0-. I was also able to write until 95% of the ink reservoir was empty. Further, the amount of free ink (F'REEINK) was 1.7 g, while the amount of pores was 0.3 g.

At writing speeds of 9IIlZ minutes or higher, there was only a slight decrease in ink consumption. For the initial 2.00 On, the ink was less than 10g9/100m.

As already mentioned, the porous wall material may be treated to be particularly absorbent so that the ink penetrates the pores of the wall material more effectively. However, on the other hand, the porous wall material may be treated to be water repellent so that ink does not penetrate into the wall material. Depending on the particular application, intermediate values of the degree of water-absorbing or water-repellent treatment are also possible.

The porous wall can also consist of several layers that are partly water-absorbing and partly water-repellent.

Another advantage of a water-repellent porous wall is that it can store more ink than a pad-type ink reservoir. Until now, tanks that had pad-type ink reservoirs had a water-repellent porous membrane,
For a typical otherwise identical tank involving a padded ink reservoir, the ink fill level is 1.1
Since it has the property of being able to increase the weight from 1.6 g to 1.6 g, the pad-type ink reservoir can be eliminated.

As with pad-type ink reservoirs, there is at the same time the advantage that the amount of ink supplied is substantially independent of the filling level.

[Brief explanation of drawings]

FIG. 1 is a schematic side view showing the principle of a conventional ink pen. FIG. 2 is a drawing similar to FIG. 1 and illustrates the principle of the ink pen of the present invention. Figure 3 shows the mode of action of the porous walls. FIG. 4 is a drawing similar to FIG. 2, showing the principle of another embodiment of the ink pen of the present invention. l...Tank, 2...Ink, 3...Space, 4...Arrow, 5...Capillary, 6...
Orifice, 7...Bubble, 8...Ink reservoir, 9
...Tank upper end, 10...Tank side wall, 11
... Tank lower end wall, 12 ... Covering, 13 ... Pen tip,
14...Stomata, 15...Ball.

Claims (13)

[Claims] (1) a nib, a tank for liquid ink, and means for conveying ink from the tank to the nib, the tank (1) being at least on the side (9) facing away from the nib (15);
An ink pen characterized by being closed by a porous wall. (2) The ink pen according to claim 1, wherein the tank (1) also has a porous wall material on the side wall (10). (3) The ink-type pen according to claim 1, wherein the tank (1) also has a porous wall material on the side (11) facing the pen tip (15). (4) An ink pen according to claim 3, characterized in that at least some of the side walls (10) are covered with an impermeable material (12). (5) the impermeable material (12) of the side wall (10) is impermeable in the part (11) facing the nib (15), except for the means (13) for conveying ink to the nib (15); 4. Ink pen according to claim 3, characterized in that it is covered with a transparent material (12). (6) An ink pen according to any one of claims 4 and 5, characterized in that the impermeable material (12) is shrinkable. (7) The ink pen according to any one of claims 1 to 6, wherein the porous wall material is made of plastic. (8) Claims 1 to 6, characterized in that the porous wall material is made of glass or ceramic.
The ink-type pen described in any one of paragraphs. (9) Ink formula according to any one of claims 1 to 8, characterized in that the porous wall material has an average pore diameter of 1 to 100 μm, preferably about 10 to 50 μm. pen. (10) The ink pen according to any one of claims 1 to 9, wherein the porous wall material has an average pore diameter of about 25 μm. (11) The ink pen according to any one of claims 1 to 10, wherein the porous wall material is water absorbent. (12) The ink pen according to any one of claims 1 to 10, wherein the porous wall material is water repellent. (13) At least a portion of the tank wall ((9), (10), (11)) is formed of a water-absorbing porous wall material whose outer surface is covered with a water-repellent porous wall. An ink-type pen according to any one of claims 1 to 10, characterized in that: