JP3224988B2 - Direct liquid writing instrument - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a direct liquid writing instrument in which ink is directly filled in a shaft cylinder having a pen tip disposed at a tip thereof.

[0002]

2. Description of the Related Art For example, a ball-point pen using water-based ink has been put into practical use, in which ink is absorbed in a batting formed by aligning ultrafine fibers into a rod shape, and the batting is accommodated in a shaft cylinder. However, this batting-type writing instrument has a problem in that the amount of ink absorbed is limited and the writable distance is short, and the end point at which writing becomes impossible due to exhaustion of the ink is difficult to understand.

[0003] On the other hand, a direct liquid type writing instrument in which ink is directly filled in a barrel and does not use a batting has advantages that the end point is clear and the writing distance is long because the ink can be directly visually observed. When the air in the barrel becomes hot and expands, such a direct liquid writing instrument discharges ink excessively and drops, so that the excessively discharged ink is temporarily stored to prevent the dropping of ink, and the ink is discharged. In many cases, a pen core having a gas-liquid exchange function for introducing air into the shaft cylinder with the consumption of is disposed, but the pen core has a complicated structure and a problem of increasing the number of parts.

[0004] For this reason, the tail end of the barrel, whose tail end communicates with the outside air, is sealed with a paste-like backflow preventive body, and an aqueous ink called gel ink is filled in front of the backflow preventive body. A raw ink type writing implement in which the space between the pen tip and the backflow prevention body is filled with ink only has been put to practical use. The gel ink has a relatively high viscosity statically, but the viscosity decreases due to the rotation of the ball during writing, and the ink flows out.
Therefore, the backflow prevention body advances with the consumption of the ink, and the backflow prevention body prevents the backflow of the ink.
Since there is only ink and no air in front of the backflow preventer, the ink is not pushed out by the air which has become hot and expanded.

[0005] By the way, when such a direct liquid type writing instrument is placed in an upward position, the ink head is hit by the backflow preventing agent,
The backflow inhibitor flows backward and falls to the tail end opening side. For this reason, a check valve or the like is arranged on the pen tip so that the check valve closes when the writing implement is in the upward position so that the ink head does not fall on the backflow preventing agent.

[0006]

However, since the sealing of the pen tip by the check valve is not always perfect, air enters the shaft cylinder from the pen tip,
The ink head may be hit by the backflow inhibitor. Therefore, the anti-reflux agent falls to the tail end opening side of the barrel, but at this time, the anti-reflux agent adheres to the wall surface of the barrel in the process of descending, losing the sealing effect, and ink is removed from the air of the tail plug. There is a risk of leaking out of the hole, and if it leaks out while it is being worn in a pocket, the clothes will be soiled.

For this reason, a check valve whose valve body is a ball is provided in the air hole of the tail plug, and this check valve opens at the time of writing, so that air flows from the air hole into the shaft cylinder according to ink consumption. The check valve closes when it enters the upright position,
Even if the sealing effect of the backflow preventing agent is lost, it has been proposed to prevent the leakage of ink by this check valve.

However, the check valve provided on the tail plug does not normally come into contact with the ink, and the contact portion between the ball valve element and the valve seat is not sealed by the capillary action of the ink. Not perfect. Therefore, when the sealing effect of the backflow preventing agent is lost and the ink reaches the check valve for the first time, the initial ink slightly leaks even though the valve body of the ball is in contact with the valve seat. Then, the ink leaks from the air hole of the tail plug, and may stain the clothes.

Therefore, according to the present invention, even if the sealing effect of the anti-reflux agent is lost when the writing instrument is in the upward position, ink leaks to the outside from the air hole of the tail plug fitted to the tail end of the barrel. An object of the present invention is to provide a writing instrument of a direct liquid type which does not have a risk of being put out.

[0010]

SUMMARY OF THE INVENTION In order to achieve the above object, according to the present invention, ink is directly filled in a shaft cylinder having a pen tip disposed at a tip and a tail plug fitted at a tail end. In a direct liquid writing instrument in which the tail end side of the ink is sealed with a paste-like backflow prevention body, a check valve having a ball element disposed on the tail plug, and a tail end side of the check valve, Check this check valve when it is not sealed with ink.
An ink reservoir is formed in which ink leaking from the stop valve and transmitted to the inner wall of the tail plug is stored .

That is, a check valve whose valve body is a ball is disposed on the tail plug, and the check valve is disposed on the tail end side of the check valve.
Leakage from check valve when valve is not sealed with ink
Since the ink reservoir that stores the ink transmitted to the inner wall of the tail plug is formed, when the pen tip is in the upward position, the sealing effect of the backflow preventive agent is lost, and the ink slightly flows from the check valve. Even if leaked, the leaked ink enters the ink reservoir of the tail plug and is retained. Therefore, it is possible to prevent the ink from leaking from the air hole of the tail plug.

[0012]

Embodiments of the present invention will be specifically described below with reference to the drawings. In FIG.
Has an inner diameter of 7.0 mmφ, which is injection molded with a transparent synthetic resin.
The inner diameter of the cylindrical body is larger than that of the shaft barrel of the conventional direct liquid writing instrument, and thus a large amount of ink can be filled. A pen tip 2 of a ball-point pen is attached to a front end portion 11 at the tip of the barrel 1.

The pen tip 2 is formed in a shell shape from stainless steel, and a ball 3 made of a cemented carbide partially faces the ball house at the tip of the pen tip 2 from the tip of the pen tip 2. It is held freely rotatable in the out state. A small spring 4 having a spring force of, for example, 40 g is arranged in the pen body chip 2.
Bounces the ball 3 and presses it against the inward tip edge of the pen tip 2, and the ball 3 and the tip edge constitute a valve mechanism. In other words, when writing, the ball retreats due to the writing pressure and the ink flows out, and when not in use, the pen tip 2 is sealed and serves as a check valve.

Inside the tail end side of the shaft cylinder 1, a lightweight cylindrical body 7 with a bottom is disposed. The columnar body 7 has, for example, an outer diameter of 6 mmφ and a length of 15 mm. Around the columnar body 7, a paste-like backflow prevention body 6 made of, for example, a polybutene compound is applied, and the backflow prevention body 6 is attached to the barrel 1.
The gap between the inner peripheral surface and the columnar body 7 is filled. That is, the tail end side of the barrel 1 is sealed by the columnar body 7 on which the paste-like backflow prevention body 6 is applied.

The barrel 1 in front of the column 7 is filled with, for example, a gel ink (not shown) having a viscosity of 30 to 40 cps, and no air exists in the barrel 1 in front of the column 7. . Then, when the ink is consumed by writing, the columnar body 7 on which the paste-like backflow prevention body 6 is applied moves forward accordingly, but since the inner diameter of the barrel 1 is large and the internal volume is large, a large amount of ink is consumed. The ink I can be filled in the barrel 1 and has an advantage that the writing distance is long.

A tail plug 5 is fitted in the tail end opening of the barrel 1. The tail plug 5 has a bottomed cylindrical shape and has a tubular portion 5 on its bottom surface.
1 are integrally connected, and the inside of the tubular portion 51 is an air hole 52. The outer peripheral surface of the tubular portion 51 and the inner peripheral surface of the bottom portion of the tail plug 5 form a bag-like portion, and the bag-like portion is an ink reservoir 53. A valve seat member 8 having a valve seat 81 and a plurality of semicircular projections 82 is fitted into the distal end opening of the tail plug 5, and a valve body 9 made of a ball is inserted into the valve seat member 8. The valve seat member 8 and the valve body 9 are movably arranged.
Constitutes a check valve. Therefore, at the time of writing, the valve element 9
Is held by the semicircular projection 82, the air passes around the valve body 9, and the valve body 9 is seated on the valve seat 81 when the airbag is in the upward posture.

When the writing instrument is in the upward position, as in the case where the pen is mounted in a pocket, the tip opening of the pen tip 2 is sealed by the ball 3 repelled by the spring 4, so that the ink is The head does not fall on the columnar member 7 or the backflow preventive agent 6, and these do not drop.
However, if the seal is incomplete, the ink head is applied to the columnar body 7 and the backflow preventive agent 6 and flows back and descends. The effect may be lost.

When the sealing effect of the backflow preventive agent 6 is lost, the ink reaches the valve body 9 seated on the valve seat 81.
At this point, the seating portion is not sealed with ink, so that a small amount of ink leaks. Then, the ink leaking from the check valve falls along the inner surface of the tail plug 5, but since the ink pool 53 is formed at the bottom of the tail plug 5, the ink is stored in the ink pool 53 and air is collected. Leakage to the outside from the hole 52 can be prevented. Therefore, the clothes are not stained.

[0019]

As described above, the direct liquid type writing instrument of the present invention is provided with a check valve having a ball as a valve body in a tail plug fitted to the tail end of a shaft cylinder directly filled with ink. At the tail end of the check valve, this check valve is sealed with ink.
When it is not, it leaks from the check valve and is transmitted to the inner wall of the tail plug.
Since the ink reservoir is formed when the ink is stored , even if the backflow prevention agent falls down and the sealing effect is lost when the printer is in the upward position, the ink that has leaked a little from the check valve will remain in the ink reservoir. It is possible to provide a direct liquid-type writing instrument in which ink does not accumulate in the portion and does not leak to the outside through the air hole of the tail plug.

[Brief description of the drawings]

FIG. 1 is a sectional view of an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Shaft cylinder 11 Tip part 2 Pen body tip 3 Ball 4 Spring 5 Tail plug 51 Tube 52 Air hole 53 Ink reservoir 6 Backflow prevention body 7 Columnar body 8 Valve seat member 81 Valve seat 82 Semicircular projection 9 Valve body

Claims (1)

(57) [Claims] An ink is directly filled into a shaft cylinder having a pen tip disposed at a tip thereof and a tail plug fitted at a tail end, and the tail end side of the ink is sealed by a paste-like backflow prevention body. In the direct liquid writing instrument, a check valve having a ball as a valve body is disposed in the tail plug, and the check valve is sealed with ink on the tail end side of the check valve.
Leaks from the check valve when it is not
A direct liquid writing implement, wherein an ink reservoir for storing transmitted ink is formed.