JP2001063276A - Writing implement - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the necessity of using a moving cap and simplify a structure by disposing air together with ink in an ink tank. SOLUTION: Air 6 is stored together with ink 4 in a shaft cylinder 1 working as an ink tank. An elastic valve 5 composed of an ethylene propylene terpolymer is disposed between an opening 1a of the shaft cylinder 1 and an inner step section 3a of a front shaft. The elastic valve 5 is provided with a slit shape hole 5a formed on its central section. The slit-shaped hole 5a is closed in the state of not applying pressure and the ink or the air is not passed through therein, while when the press force is applied, it is opened to feed the ink 4 into a nib 2 and also communicated with the opening of the front shaft 3 to introduce the air into the shaft cylinder 1. Thus the interior of the shaft cylinder 1 forming a closed space in the state of closing the elastic valve 5 can be equilibrated with atmospheric pressure. The use of a moving cap, therefore, is not required and the structure of a writing implement is simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an ink tank for storing ink in a free state as a rear portion of a shaft body, and an elastic member disposed between the ink tank and a pen tip protruding forward of the shaft body. When a specific pressure is not applied to the elastic member, the ink communication is cut off. When a specific pressure is applied, the elastic member is opened to communicate the ink, and the ink in the ink tank is supplied to the pen tip. The present invention relates to a writing implement having a slit-like hole capable of controlling the writing.

[0002]

2. Description of the Related Art Conventionally, a moving stopper that moves following an ink interface is arranged so that the volume in an ink tank is the same as the volume of ink to be accommodated, and a silicone rubber is provided between the ink tank and the pen tip. Writing implements in which a valve member formed of an elastic material such as the above is arranged are known.

[0003]

In the above-mentioned writing implement, unless the movable stopper moves quickly with the change in the ink volume, the inside of the ink tank is depressurized and the smooth supply of ink to the pen tip is hindered. However, solid materials such as synthetic resin and rubber molded products will come into contact with the inner wall of the ink tank, causing frictional resistance, such as when writing at high speed or discharging large amounts of ink. Was disadvantageous. In the case where a viscous fluid such as silicone oil is disposed, the viscous fluid adheres to the inner wall of the ink tank and remains in that portion. There is also a concern that it may no longer serve its role, or its viscosity may change due to a change in temperature or the like, and it may not function as a stopper. In any case, strict control of dimensions and quality had to be performed. In particular, when a writing instrument having pen tips at both ends of the shaft is used, it is difficult to use a common ink for both pen tips with the above-described moving stopper, and separate inks are used. Even if used, the strict management described above is increased and the cost is high.

[0004]

That is, according to the present invention, an ink tank for storing ink in a free state is formed as a rear portion of a shaft body, and an elastic member is provided between the shaft and a pen tip protruding forward. When a specific pressure is not applied to this elastic member, the ink communication is cut off, and when a specific pressure is applied, the elastic member is opened to communicate the ink, and the ink pen in the ink tank is opened. A writing instrument having a slit-shaped hole capable of controlling supply to the above, wherein air is arranged together with ink in the ink tank.

[0005]

With the presence of air together with ink in the ink tank, air is taken into the ink tank through the slit-shaped hole of the elastic member interposed between the ink tank and the pen tip, thereby increasing the pressure in the ink tank. Can be kept in equilibrium with atmospheric pressure. Therefore, there is no need to use a moving stopper that requires strict management, and a simple structure can be obtained, so that an inexpensive writing instrument can be obtained.

[0006]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
FIG. 1 shows a bottomed cylindrical barrel 1 and this barrel 1
And a front shaft 3 protruding the tip of a pen 2 made of a convergent body such as polyester fiber into the opening of the front end 3. It is an example of a raw ink type writing implement stored in a state. Shaft barrel 1
Is formed of a transparent synthetic resin having low moisture permeability such as polypropylene so that the remaining amount of ink is visible. An elastic valve 5 made of ethylene propylene terpolymer is disposed between the opening 1a of the barrel 1 and the inner step 3a of the front shaft. It is pinched and fixed.

The elastic valve 5 has a slit-shaped hole 5a at the center.
This slit-shaped hole 5a is closed when no pressure is applied, and neither ink nor air passes. Here, the pen point 2 is disposed so as to be slidable in the front-rear direction inside the front shaft 3, and the rear end 2a has a small diameter portion. When it comes into contact, it moves rearward, and the rear end 2 a comes into contact with the elastic valve 5. When it moves further backward, the slit-shaped hole 5 of the elastic valve 5
The slit-shaped hole 5a is opened by applying a pressing force to the vicinity of a and deforming it. When the slit-shaped hole 5a is opened, the ink 4 inside the barrel 1 is supplied to the pen tip 2 and air is supplied into the barrel 1 in communication with the opening of the front shaft 3. That is, by supplying the air corresponding to the volume of the ink discharged to the pen tip 2, the inside of the shaft cylinder, which is a closed space when the elastic valve is closed, is kept in equilibrium with the atmospheric pressure. Air 6 is originally stored together with the ink 4 in the barrel 1 serving as an ink tank, and acts as a buffer against pressure changes in the ink tank. A part of the wall surface of the ink tank is made of an elastic material. By using a certain elastic valve 5, even when the internal pressure is increased, it can be elastically deformed and exert a buffering action.

FIG. 2 shows a modification. That is, this is an example of a so-called twin pen in which different types of pens are attached to both ends of the shaft. Unlike the above-described example, the barrel 1 is open at both ends, and the front shafts 3, 3 'are provided at the respective ends.
Are fitted by uneven fitting. A synthetic resin pipe-shaped nib 2 'having a center hole serving as an ink passage, fixed to a tip holder 7 for preventing falling off, is disposed on the front shaft 3' side, which is located above the drawing. The pen tip 2 ′ is also arranged so as to be able to move back and forth together with the fixed chip holder 7, and is similar to the above-described example such as moving backward during writing to open the slit-shaped hole 5 a of the elastic valve 5. is there.

A silicone rubber partition 8 is press-fitted into the center of the barrel 1 to divide the interior of the barrel 1 into two parts in a liquid-tight manner. In each of the divided ink tank portions, inks 4 having different ink colors are arranged, and air 6 is stored in each of the divided ink tank portions.

When assembling the writing instrument, the elastic valve 5 is press-fitted and temporarily fixed with the pen point 2 inserted from the rear part of one of the front shafts 3, and the partition tube 8 and the front barrel are not press-fitted. After fitting with No. 3, ink is filled from the opening of the barrel 1. After filling a certain amount of ink, the partition body 8 is press-fitted and fixed to an appropriate position, and is filled with another kind of ink. Attach a pen tip 2 'and an elastic valve 5 set on a front shaft 3' prepared in advance.

FIG. 3 shows another example. The point that the pen point 2 and the elastic valve 5 are mounted in the front shaft 3 is the same as in the above-described example. The rear end of the barrel 1 is open, but in this embodiment, it stores one type of ink, and the opening is provided with an elastic wall 9 having a slit-like hole 9a. The elastic wall 9 is preferably made of a synthetic rubber having low moisture permeability such as ethylene propylene diene terpolymer in consideration of the problem of ink transmission. When the ink 4 is consumed, the volume of the ink in the barrel 1 decreases due to the consumption of the ink 4 and the pressure in the ink tank becomes negative. When high pressure is applied, it can be deformed by the pressure and absorb the force, and the difference in pressure can affect the ejection of ink from the pen tip and the repulsion of ink. In this case, the slit-shaped hole 9a is opened so that the internal and external pressures can be kept constant.

FIG. 4 shows a modification. This is an example in which the example shown in FIG. 3 is applied to a twin pen. In the illustrated example, both the nibs made of a fiber converging body are attached, but the nib illustrated on the lower side has a shape having corners, and the nib illustrated on the upper side has a dome-shaped round core. is there. here,
When writing with one pen tip, the pen tip 4 is
Is pressed to open the slit-shaped hole 5a to supply ink and take air into the ink tank, but when there is a sudden change in pressure, the elastic valve 5 'on the pen tip side not used for writing is used. Since the slit-shaped holes 5a 'can be opened, the structure can be strong against pressure changes.

[0013]

As described above, the writing implement of the present invention suppresses ink leakage in the ink tank without requiring strict size and quality control, and also supports high-speed writing which requires a large amount of ink ejection. Writing implements that can be used can be obtained at low cost.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an example.

FIG. 2 is a longitudinal sectional view showing a modification.

FIG. 3 is a longitudinal sectional view showing another example.

FIG. 4 is a longitudinal sectional view showing a modification.

[Explanation of symbols]

 Reference Signs List 1 shaft cylinder 1a opening 2 pen tip 2a rear end 3 front shaft 3a inner step 4 ink 5 elastic valve 5a slit-shaped hole 6 air 7 chip holder 8 partition 9 elastic wall 9a slit-shaped hole

Claims (4)

[Claims] 1. An ink tank containing ink in a free state is formed as a rear portion of a shaft body, and an elastic member is disposed between the ink tank and a pen tip protruding forward of the shaft body. When no pressure is applied, the ink communication is cut off, and when a specific pressure is applied, it is opened to allow ink to communicate, and a slit-like shape that can control the supply of ink in the ink tank to the pen tip A writing implement having holes formed therein, wherein air is arranged together with ink in the ink tank. 2. An elastic member is disposed as a wall member on a part of a shaft constituting the ink tank, and the elastic member serving as the wall member is temporarily opened when the pressure in the ink tank is reduced. The writing implement according to claim 1, wherein a slit-shaped hole through which air can communicate with the ink tank is formed. 3. The elastic member has a Shore hardness A of 30 to 30.
60 and a cylindrical measuring object having a diameter of half the maximum width of the slit-shaped hole when the slit-shaped hole is closed, sandwiching the slit-shaped hole from both sides of the ink tank side and the pen tip side. 3/4 of the shortest distance of ink passing distance
, The resistance value per unit area of the cylindrical measurement object is 0.5 to 4.
The writing instrument according to claim 1, wherein the writing implement is set to 5 kg / cm ² . 4. A pen tip is attached to both ends of the shaft body, each pen tip has a different shape or writing line size, and inks are commonly supplied from the same ink tank in the barrel. The ink supply to each pen tip is controlled by an elastic member with a slit-shaped hole. When one pen tip is used for writing, the elastic member attached to the other pen tip is used. The writing implement according to any one of claims 1 to 3, wherein the slit-shaped holes are temporarily opened as the pressure in the ink tank is reduced, so that air can be communicated with the ink tank.