JP2002293081A - Capless writing utensil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a capless writing utensil, in which a pen point part within a barrel can be tightly closed by a simple constitution and the tightly closed state of the pen point part is made sure before its use. SOLUTION: In the capless writing utensil 1 having a writing body arranged in the barrel 2 and the pen point part 6 of the writing body 5 projected through the tip part 3 of the barrel, an inner cap 20 made of a silicone rubber is provided at the tip part 3 of the barrel 2. The surface including at least the inside surface facing towards the inside of the barrel 2 or the outside surface facing towards the outside of the barrel 2 of the inner cap 20 is covered with an ink screening layer 40 made of a rubber material or elastic resin material having the non-permeability to an ink solvent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a capless writing instrument, and more particularly to a capless writing instrument having a drying prevention mechanism.

[0002]

2. Description of the Related Art Conventionally, in a writing implement such as a water-based or oil-based marking pen, a water-based ball-point pen, and a fountain pen, a tip opening is sealed to prevent the ink at the tip of a writing portion from drying out and making writing impossible. Is generally used. In addition, in the case of a writing instrument having a cap as described above, when frequently used, it is necessary to attach and detach the cap each time it is used, which is troublesome, so that a separate cap is unnecessary, so-called Many capless writing instruments have been proposed.

However, in the case of a capless writing instrument, it is necessary to construct a sealing mechanism for sealing the tip opening inside a narrow writing instrument instead of a separate cap, and according to the conventional method, the sealing mechanism becomes complicated. In addition, as the number of component parts increases, the assembling work becomes complicated, and the production cost increases.

Therefore, as a method for sealing the tip of the writing portion, as disclosed in Japanese Utility Model Laid-Open Publication No. 49-32731 (hereinafter referred to as Conventional Example 1), the tip portion inside the shaft cylinder of the writing instrument has a center. A method in which a valve plate having a notch cut outward from the plate is incorporated, and the tip of the writing portion is projected from the notched portion, is disclosed in Japanese Utility Model Laid-Open No. 49-107421 (hereinafter referred to as Conventional Example 2). As described above, packing is provided at the base end and the tip end inside the barrel of the writing instrument to seal the inside of the barrel, and the tip of the writing part protrudes from the abutting part of the packing that the tip abuts against. The method described above and Japanese Utility Model Laid-Open No. 63-23084 (hereinafter, referred to as
This is referred to as Conventional Example 3. ), An elastic self-closing body having an opening in the front of the cap body is provided so that the pen tip at the tip of the barrel is projected.

[0005]

However, according to the systems of the prior arts 1, 2 and 3, since the seal portion from which the pen tip protrudes is already formed with an opening, it is sealed before use. There was a problem with sex. Further, according to the method as in the conventional example 1, the gap remains open after the pen tip is put in and out depending on the material of the front end, and the ink solvent is exerted from the gap in the cut part to dry up the pen tip. There was a problem that it would. Therefore, there are rubber materials and resin materials having excellent resilience, such as silicone rubber, which are hard to form a gap even when the pen tip is put in and taken out. Even when the gap between the caps is completely eliminated, there is a problem that the ink solvent permeates through the inner cap itself and volatilizes, and the pen tip dries up.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and it is possible to seal the pen tip inside the barrel with a simple structure and to ensure that the pen tip is sealed before use. It is an object of the present invention to provide a capless writing instrument which has been described.

[0007]

SUMMARY OF THE INVENTION The present invention relates to a capless writing instrument, in which a writing body is arranged in a shaft cylinder, and a pen point of the writing body can be freely protruded from a tip opening of the shaft cylinder. In the capless writing instrument, an inner cap formed of a rubber material or an elastic resin material is provided at a distal end opening of the barrel, and the inner cap faces at least an inner surface facing the inside of the barrel or an outer side of the barrel. The surface including the outer side surface is covered with an ink shielding layer formed of a rubber material or an elastic resin material having impermeability to an ink solvent.

Further, in a capless writing instrument in which a writing body is arranged in a barrel and a pen tip of the writing body can freely protrude from a tip opening of the barrel, a rubber tip is provided in the tip opening of the barrel. An inner cap formed of a material or an elastic resin material, wherein the inner cap has at least a rubber material or an elastic resin material that is impermeable to an ink solvent at an inside of a tip side opposed to a tip end opening of the barrel. May be arranged such that the ink shielding layer formed by the above is disposed and the ink shielding layer is sandwiched between rubber materials or elastic resin materials.

Further, it is preferable that the inner cap is formed of a sponge-like elastic body. The inner cap is preferably made of silicone rubber. Further, the ink shielding layer comprises at least one selected from chloroprolene rubber, nitrile butadiene rubber, butyl rubber, ethylene propylene rubber, urethane rubber, fluorine rubber, chlorosulfonated polyethylene rubber, epichlorohydrin rubber, and polysulfide rubber. Is preferably performed.

According to the present invention, the following effects can be obtained. That is, in a capless writing instrument, a surface that includes an inner cap formed of a rubber material or an elastic resin material at a distal end opening of a barrel and includes at least an inner surface facing the inside of the barrel or an outer surface facing the outside of the barrel. Is covered with an ink shielding layer formed of a rubber material or an elastic resin material that is impermeable to the ink solvent, so that the inside of the barrel can be sealed without volatilizing the ink solvent. Drying up of the tip can be prevented.

An ink shielding layer formed of a rubber material or an elastic resin material having a non-permeability to an ink solvent is disposed at least inside the distal end of the inner cap facing the distal end opening of the shaft cylinder. Since the ink shielding layer is sandwiched between rubber or elastic resin material, the inside of the barrel can be sealed without volatilization of the ink solvent from the front end side. Can be prevented.

In addition, since the inner cap is formed of a sponge-like elastic body, the portion of the inner cap where the pen tip protrudes when the pen tip is taken in and out can be easily deformed and restored. Can be even higher. In addition, by using silicone rubber for the material of the inner cap, it is possible to improve the deformation and the resilience and realize the inner cap with high durability. Further, the ink shielding layer is composed of at least one selected from chloroprolene rubber, nitrile butadiene rubber, butyl rubber, ethylene propylene rubber, urethane rubber, fluorine rubber, chlorosulfonated polyethylene rubber, epichlorohydrin rubber, and polysulfide rubber. By doing so, the evaporation of the ink solvent in the barrel can be prevented, and the inside of the barrel can be securely sealed before and after use of the capless writing instrument, and the inner cap can be closed with the pen tip at the start of use. Can easily be performed.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings. 1 to 3 show an example of an embodiment of the present invention. In the drawings, portions denoted by the same reference numerals as those in the drawings represent the same components. FIG. 1 is a cross-sectional view showing the overall configuration of a capless writing instrument according to an embodiment of the present invention, FIG. 2 is a cross-sectional view showing a state when the capless writing instrument is used, and FIG. -A section arrow view,
FIG. 4B is a sectional view taken along line BB of FIG.

A capless writing instrument 1 according to the present embodiment.
As shown in FIG. 1, a writing body 5 is disposed in a barrel 2, and a pen point portion 6 of the writing body 5 can be freely protruded from an opening 4 formed in a tip 3 of the barrel 2. It is composed. The writing body 5 is urged rearward by a coil spring 7 arranged along the inner periphery of the front side in the barrel 2, and is held rearward by a stopper 10 provided in the rear part of the barrel 2. I have. A push portion 14 for projecting the pen tip portion 6 is provided at the rear end portion 11 of the writing body 5 so as to protrude from the rear end portion 12 of the barrel.

At the rear portion of the writing body 5, a stopper locking portion 15 is formed in a wide wedge shape which is directed rearward along the axial direction.
And it is formed so as to protrude in the axial direction. At the rear end of the stopper locking portion 15, the locking portion 1 is substantially perpendicular to the axial direction.
5a is formed, and the stopper 10 is provided with the locking portion 1
Notch 10a is formed opposite to 5a. The writing body 5 is configured such that the pen tip 6 projects from the opening 4 at the front end when the writing end 5 is directed toward the front end with the rear end portion 11 facing forward and overcoming the spring force of the coil spring 7 toward the front end side.

FIGS. 1 and 3 show a front end 3 of the shaft cylinder 2.
(A) and (b), an inner cap 20 having a convex portion 21 formed in a dome shape in the distal direction.
Is provided.

The inner cap 20 is formed of silicone rubber. As shown in FIG. 3 (b), a distal end side sealing portion 27 having a triangular cross section is provided on the outer peripheral end of the base 22 of the dome-shaped convex portion 21. Along the outer circumference, the projection is continuously provided in the distal direction along the circumference. In addition, the base 2
A rear seal portion 29 having a small-diameter rectangular cross-section inside the front seal portion 27 is continuously provided on the rear end surface 28 over the entire circumference in the rear direction. .

The dome-shaped projection 21 has a base 22
A slit portion 25 is formed in a streak shape along the outer shape in a substantially linear manner in plan view from a portion 22a to a portion 22b facing the center in the axial direction through the substantially central portion 23 of the convex portion. .

An ink shielding layer 40 is baked on the convex and concave surfaces of the dome-shaped projection 21 so as to sandwich the silicone rubber forming the dome-shaped projection 21. The ink shielding layer 40 is formed of a rubber material or an elastic resin material having an impermeability to an ink solvent. Specifically, chloroprolene rubber, nitrile butadiene rubber, butyl rubber, ethylene propylene rubber, urethane rubber, fluorine Rubber, chlorosulfonated polyethylene rubber,
It is composed of at least one selected from epichlorohydrin rubber and polysulfide rubber.

As shown in FIG. 1, the inner cap mounting portion 3a is formed stepped inside the distal end portion 3 of the shaft cylinder 2, and a seal groove 3b into which the distal end side seal portion 27 is fitted is formed. Have been. An inner cap holder 30 for attaching the inner cap 20 to the inside of the distal end portion 3 is provided behind the inner cap 20.
Is arranged.

The inner cap holder 30 is formed in a ring shape, and its outer peripheral surface in the circumferential direction is
Of the inner cap 2
The inside of the barrel 2 is hermetically sealed by the inner cap 20 by attaching 0 to the inside of the distal end portion 3.

Next, the operation of the capless writing instrument according to this embodiment will be described. First, when the capless writing instrument 1 is not used, as shown in FIG. 1, the pen tip 6 is housed inside the barrel 2 together with the writing body 5. The slit portion 25 formed in the inner cap 20 provided at the distal end portion 3 of the barrel 2 is closed by the elasticity of silicone rubber.

Next, when the capless writing instrument 1 is used, as shown in FIG. 2, the shaft cylinder 2 is gripped, and the pushing portion 14 formed at the rear end of the writing body 5 is pressed by the spring force of the coil spring 7. And push it toward the tip. As shown in FIGS. 1 and 2, the writing body 5 enters the inside of the barrel 2, and a stopper locking portion 15
Moves toward the tip. Then, it passes through the stopper 10 and moves to a position opposing the notch 10 a at the end of the stopper 10 and the locking portion 15 a of the stopper locking portion 15. At this time, the pushing portion 14 is disposed at the end of the rear end portion 12 of the barrel. On the other hand, the pen tip portion 6 pushes the slit portion 25 of the inner cap 20 open to open the slit portion 25 of the tip end portion 3 of the barrel 2.
It is in a more protruding state.

In this state, when the pressing portion 14 is released, the writing body 5 is pushed back by the spring force of the coil spring 7, but the locking portion 15a is stopped by the notch 10a. It does not protrude from behind. Therefore, the pen tip 6 is held in a state where it protrudes from the opening 4.

When the pen tip 6 is accommodated, the stopper 1
0, the notch 10a and the locking portion 15
a can be easily removed, the writing body 5 can be moved backward by the spring force of the coil spring 7, and the pen tip 6 can be housed inside the barrel 2.

The inner cap 20 has a pen tip 6
Is retracted into the barrel 2, the slit portion 25 pushed and opened by the pen tip 6 attempts to return to the original state by the elastic force, and is restored to the minimum gap state. Therefore,
Even when the capless writing instrument 1 is not used, volatilization of the coating agent from the mating portion of the slit portion 25 can be minimized.

With the above configuration, according to the capless writing instrument 1 according to the present embodiment, the distal end 3
Is provided with an inner cap 20 made of silicone rubber, so that the inside of the barrel 2 in which the pen tip portion 6 is accommodated can be easily sealed. Further, the inner cap 20 has an inner surface facing the inside of the barrel 2 and an outer surface facing the outer side of the barrel 2 covered with an ink shielding layer 40 that is impermeable to an ink solvent. The evaporation of the ink solvent in 2 can be prevented, and the inside of the barrel can be reliably sealed before and after the start of use of the capless writing instrument 1.

Further, according to the present embodiment, since the inner cap 20 is made of silicone rubber,
The slit portion 25 is brought into close contact with the elastic force of the silicone rubber so that the sealed state of the distal end portion 3 of the shaft cylinder 2 is kept good, and the durability of the inner cap 20 can be increased. Further, since the front end side seal portion 27 and the rear side seal portion 29 are formed on the inner cap 20, the shaft cylinder 2
The inside sealing state can be ensured. Further, since the distal end side seal portion 27 and the rear side seal portion 29 are formed in the inner cap 20, a sealed state inside the shaft cylinder 2 can be ensured.

Further, according to the present embodiment, the distal end side of the inner cap 20 is formed in a dome shape so as to project toward the distal end opening, so that the rigidity of the outer peripheral portion on the distal end side can be increased, and the slit 25 can be securely adhered. Can be.

In this embodiment, since the ink shielding layer 40 is formed of a rubber material or an elastic resin material having an impermeability to the ink solvent, the inner cap 20 can be removed when the pen tip portion 6 is taken in and out. Even if it is deformed, it can be deformed following the deformation, so that the tight state of the broken portion 20a can be maintained, and the sealed state inside the inner cap 20 can be ensured.

In this embodiment, the inner cap 20
However, the present invention is not limited to the shape of the inner cap 20. For example, the slit 25 may be formed in the shielding layer 40.
It may be formed so as to cover from either side of the convex outside or inside. According to this configuration, when the capless writing instrument 1 has never been used, since the shielding layer 40 of the slit portion 25 of the inner cap 20 does not penetrate, the air-tight state inside the barrel 2 by the ink shielding layer 40 is reduced. It is kept completely and volatilization of the coating agent can be minimized until the capless writing instrument 1 is used.

In this embodiment, the inner cap 2
Although silicone rubber is adopted as the material of No. 0, the present invention is not limited to this. For example, the inner cap may be formed of a sponge-like elastic body. According to this configuration, the part where the pen tip of the inner cap protrudes can be more easily deformed and restored when the pen tip is taken in and out, so that the tightness of the broken part of the inner cap can be increased and the sealing performance can be further improved. Even if a liquid leak occurs, it does not directly drip because of the water absorption.

In this embodiment, the inner cap 2
Although the shape of the tip side of 0 is a dome shape, the present invention
The shape of the inner cap 20 is not limited. For example, the inner cap 20 may have a flat front end, a concave shape, a conical shape, or a polygonal pyramid shape.

In this embodiment, the surface of the inner cap is covered with the ink shielding layer 40. However, as another embodiment of the present invention, the structure of the inner cap is changed so that the front end facing the front end opening of the barrel is provided. A configuration in which an ink shielding layer is disposed inside the side and sandwiched by a rubber material or an elastic resin material may be employed. Also according to this method, similarly to the effect of the present embodiment, the evaporation of the ink solvent in the barrel can be prevented, and the inside of the barrel before and after use of the capless writing instrument can be reliably sealed. .

Further, the capless writing instrument of the present invention is not limited to the illustrated example described above, and it goes without saying that various changes can be made without departing from the spirit of the present invention.

[0036]

As described above, according to the capless writing instrument according to the first to fourth aspects of the present invention, the pen tip portion inside the barrel can be sealed with a simple structure, and before use, The sealed state of the pen tip can be ensured, and a capless writing instrument excellent in long-term storage can be realized. In other words, by providing an inner cap made of rubber or elastic resin material at the tip opening of the barrel, the pen tip inside the barrel can be sealed, and the pen tip can be protruded with a simple configuration when used. it can. Furthermore, an ink shield formed of a rubber material or an elastic resin material impermeable to an ink solvent on a surface including at least an inner surface facing the inside of the barrel or an outer surface facing the outside of the barrel on the surface of the inner cap. By coating with the layer, the ink can be sealed without volatilization of the ink solvent from the inside of the barrel, so that there is an excellent effect that the inside of the barrel can be securely sealed before the start of use and after the start of use. .

Further, a rubber material or an elastic resin material which is impermeable to the ink solvent is disposed at least inside the distal end of the inner cap facing the distal end opening of the shaft cylinder,
By sandwiching this between rubber material or elastic resin material, the ink can be sealed without volatilization of the ink solvent from inside the barrel, so that the inside of the barrel before and after use is securely sealed. It has an excellent effect that it can be performed.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an overall configuration of a capless writing instrument according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a state when the capless writing instrument is used.

3A is a sectional view taken along the line AA of FIG. 1, and FIG. 3B is a sectional view taken along the line BB of FIG. 3A.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Capless writing implement 2 Shaft barrel 3 Tip part 3a Inner cap attaching part 3b Seal groove 4 Opening 5 Writing body 6 Pen tip part 20 Inner cap 20a Breaking part 21 Dome-shaped convex part 25 Slit part 27 Tip side seal part 29 Rear side Seal part 30 Inner cap holder 40 Ink shielding layer

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Takahiro Nagata 1091 Tateishi, Fujioka City, Gunma Prefecture F-term in Gunma R & D Center, Mitsubishi Pencil Co., Ltd. (reference) 2C353 HA01 HA09 HC04 HC06 HJ11 HJ14 HJ16

Claims (5)

[Claims] 1. A capless writing instrument in which a writing body is arranged in a barrel and a pen tip of the writing body can freely protrude from a tip opening of the barrel. An inner cap formed of a material or an elastic resin material, wherein the inner cap has a surface including at least an inner surface facing the inside of the barrel or an outer surface facing the outside of the barrel, which is impermeable to the ink solvent. A capless writing implement covered with an ink shielding layer formed of a rubber material or an elastic resin material having a property. 2. A capless writing instrument in which a writing body is disposed in a barrel, and a pen tip of the writing body can freely protrude from a tip opening of the barrel. An inner cap formed of a material or an elastic resin material, wherein the inner cap has a rubber material or an elastic resin material that is impermeable to an ink solvent at least inside a front end side facing the front end opening of the barrel. A capless writing implement characterized in that the ink shielding layer formed by the above is arranged and the ink shielding layer is sandwiched by a rubber material or an elastic resin material. 3. The inner cap is formed of a sponge-like elastic body.
The capless writing instrument according to item 1. 4. The capless writing instrument according to claim 1, wherein the inner cap is made of silicone rubber. 5. The ink shielding layer is at least one selected from chloroprolene rubber, nitrile butadiene rubber, butyl rubber, ethylene propylene rubber, urethane rubber, fluorine rubber, chlorosulfonated polyethylene rubber, epichlorohydrin rubber, and polysulfide rubber. The capless writing instrument according to any one of claims 1 to 4, wherein the writing instrument is formed as a kind.