JP3561514B2 - Capless writing instrument - Google Patents

Description

[0001]
TECHNICAL 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]
[Prior art]
Conventionally, in writing instruments such as water-based or oil-based marking pens, water-based ballpoint pens, and fountain pens, a cap for sealing the tip is used to prevent the ink at the tip of the writing part from drying out and making it impossible to write. What is provided is generally used. Further, 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 so-called separate cap is unnecessary, so-called Many capless writing instruments have been proposed.
[0003]
However, in the case of a capless writing instrument, it is necessary to construct a sealing mechanism for sealing the tip inside a narrow writing instrument instead of a separate cap, and according to the conventional method, the sealing mechanism becomes complicated, and component parts As the number of parts increases, the assembling work becomes complicated, and the production cost increases.
[0004]
Therefore, as a method of sealing the tip of the writing portion, as disclosed in Japanese Utility Model Laid-Open No. 49-32731 (hereinafter referred to as Conventional Example 1), the tip of the writing instrument inside the shaft cylinder extends from the center to the outside. A method in which a valve plate having a cut in the opposite direction is incorporated, and the tip of the writing portion is projected from the cut portion, or as disclosed in Japanese Utility Model Laid-Open No. 49-107421 (hereinafter referred to as Conventional Example 2). In addition, packing is provided at the base end and the tip inside the barrel of the writing implement to seal the inside of the barrel, and the tip of the writing part is projected from the contact part of the packing that the tip abuts against. As disclosed in Japanese Unexamined Utility Model Publication No. Sho 63-23084 (hereinafter referred to as Conventional Example 3), an elastic self-closing body having an opening in front of a cap body is provided, and a tip end of a shaft cylinder is provided. Stick out the pen tip It has been proposed those.
[0005]
Further, as another method, as disclosed in Japanese Patent Application Laid-Open No. 1-2281999 (hereinafter referred to as Conventional Example 4), a pen tip portion of a writing portion is formed at a tip inside a barrel of a writing instrument. A seal means for opening and closing the front end of the seal chamber in which the pen tip is protruded from the front end, and a method in which the front end of the seal chamber is opened when the pen tip protrudes from the front end. As disclosed in Japanese Patent No. 89394 (hereinafter referred to as Conventional Example 5), a sealing member for sealing a pen tip portion is tightly fitted to a tip end portion of a writing tool which is disposed at a tip end portion in a shaft cylinder. Thus, there has been proposed a method in which the tip of the close fitting member is opened and closed with the movement of the front shaft.
[0006]
[Problems to be solved by the invention]
However, according to the schemes of the prior art examples 1, 2, and 3, there is a problem in the hermeticity because an opening is already formed in the seal portion from which the pen tip protrudes.
Further, according to the method as in the conventional example 4, there is a problem that the structure such as the seal chamber and the seal opening / closing mechanism becomes complicated. Similarly, in the method as in the conventional example 5, the seal chamber is configured by another component. Thus, there is a problem that the structure becomes complicated such as providing an opening mechanism.
[0007]
The present invention has been made in view of the above-described conventional problems, and has as its object to provide a capless writing instrument that has a simple configuration and ensures a sealed state at the distal end inside a barrel.
[0008]
[Means for Solving the Problems]
The present invention has the following configurations to achieve the above object.
The capless writing implement according to the first aspect of the present invention is a capless writing implement in which a writing body is disposed in a barrel, and a pen tip portion of the writing body can freely enter and exit from a tip opening of the barrel. An inner cap formed of a rubber material or an elastic resin material is provided at a tip end opening of the barrel, and the inner tip of the inner cap is freely penetrated on a pen tip portion exit side along the axial direction of the barrel. A slit is formed, and has a closing portion for closing a tip opening provided with a convex edge around the slit , and a front projection bulging toward the tip opening direction on an outer peripheral portion of the closing portion. A portion is formed, and in a state where the slit is closed, further mounted in the barrel so that a force inward from the outer periphery of the front protruding portion in a direction substantially perpendicular to the slit surface is applied. Is what you do.
[0009]
A capless writing implement according to a second aspect of the present invention is the capless writing implement according to the first aspect, wherein the capless writing implement has a projection on an inner surface of a shaft cylinder mounting surface that is in contact with the outer periphery of the front projection or the outer periphery of the front projection of the inner cap. A portion is provided, and the outer periphery of the front end portion is pushed inward by the action of the convex portion, so that a force inward is applied in a direction substantially perpendicular to the slit surface.
[0010]
A capless writing instrument according to a third aspect of the present invention is the capless writing instrument according to the first aspect, wherein the slit is formed in one character as the simplest slit shape.
[0011]
A capless writing instrument according to a fourth aspect of the present invention is the capless writing instrument according to the first aspect, wherein the closed portion of the inner cap has a shape protruding in an arch shape (dome shape) toward the distal end opening. It is characterized by the following.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 3 show an example showing an embodiment of the present invention.
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 radial cross-sectional view showing a state in which an inner cap according to the present embodiment is mounted on a shaft cylinder, and FIG. FIG. 4 is an axial cross-sectional view showing a state in which the inner cap is mounted on a shaft cylinder.
[0013]
First, as shown in FIG. 1, a capless writing implement 1 has a writing body 5 arranged in a barrel 2, and a pen tip portion of the writing body 5 through an opening 4 formed in a distal end portion 3 of the barrel 2. 6 is configured to be able to protrude freely.
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. Further, the writing body 5 is provided with a knock portion 11 for projecting the pen tip portion 6 from the rear end portion 12 of the barrel. The tip 6 is locked in a state of protruding from the opening 4. That is, the locking mechanism 10 is provided at the rear portion of the barrel 2 and locks the pen tip 6 in a state of protruding and retracting from the opening 4.
[0014]
It should be noted that the locking mechanism is not limited to the illustrated form, but various types are known, and the configuration is not the gist of the present invention, and thus the description is omitted. The knock portion may be separately provided at the rear end of the cursive writing.
[0015]
As shown in FIG. 1 and FIG. 3, an inner cap 20 having a closed portion 21 formed in an arc shape in the distal direction is provided at the distal end portion 3 in the shaft cylinder 2. Further, a slit 25 having a diameter passing through the base portion 22 and the substantially central portion 23 of the closing portion 21 is formed in the closing portion 21 in a single character shape. The slit 25 has a convex edge 26.
[0016]
The inner cap 20 is formed of a rubber material such as silicone rubber or an elastic resin, and is formed on the outer peripheral end of the base 22 of the arch-shaped (dome-shaped) closed portion 21 at a front protruding portion 27 swelling toward a tip opening direction. The front protruding portion 27 is mounted in a concave portion 24 (inner mounting surface of the front protruding portion) provided in an inner hole of the distal end portion 3 of the shaft cylinder, and the front end of the front protruding portion 27 contacts the front end 28 of the concave portion 24. It is provided so that a suitable force may be applied to the outer periphery of the front protruding portion 27 in a direction perpendicular to the slit surface and inward.
[0017]
Further, as another material of the inner cap 20, a rubber material having excellent non-permeability to the ink solvent, such as EPDM, butyl rubber, and fluoro rubber, may be used. Thereby, the volatilization of the ink solvent from the front end side of the inner cap 20 can be further prevented.
[0018]
In the embodiment of the present invention, a flaky front protruding portion 27 projecting from the base 22 in a direction perpendicular to the slit surface is mounted on the concave portion 24 provided in the inner hole of the distal end portion 3 of the barrel, and its outer periphery is formed. A stress (arrow P in FIG. 3) accompanying deformation is applied to the front end or the rear of the portion at a predetermined position, and the stress acts as a pressure for tightening the slit surface along the closed portion 21. It is not limited to, for example, a front protruding portion is provided in the entire circumference, a protruding portion is formed in a direction perpendicular to the slit surface at the outer peripheral portion, or a protruding portion pressing the outer circumference of the front protruding portion is provided. It is possible to provide the same function by providing it on the inner surface of the distal end of the barrel.
[0019]
Further, in the embodiment of the present invention, the slit is formed in one character as the simplest slit shape. However, the present invention is not limited to this. For example, the slit may be radially cut in three directions from the center of the closed part. Even in the case of a slit having a distorted shape, it is possible to set the above-mentioned front projecting portion or convex portion which acts to substantially tighten the respective slit surfaces.
[0020]
A rear protruding portion 29 is formed at the rear end of the base 22, and a ring-shaped stopper 30 is fixed to the rear end with its front end abutting. At this time, the inner cap 20 is narrowed and fixed between the front end 28 of the recess 24 and the front end of the stopper 30. The rear protruding portion 29 is provided on the entire circumference, the entire outer circumference thereof is brought into close contact with the peripheral surface of the inner hole of the shaft cylinder, and the rear protruding portion 29 is formed as a sealing portion on the rear side of the inner cap 20 or provided on the entire circumference. The stopper 30 is closely fitted to the rear end of the rear protruding portion 29 so as to be tightly fitted in the bore of the shaft cylinder to form a seal portion.
[0021]
Further, in the present embodiment, the shape of the closing portion 21 of the inner cap 20 is an arch shape (dome shape). However, the present invention is not limited to the shape of the closing portion, for example, a flat shape. Alternatively, the shape may be a concave shape or a conical shape or a polygonal pyramid shape.
[0022]
Next, the operation of the capless writing instrument according to the present embodiment will be described.
First, when the capless writing implement 1 is not used, the pen tip 6 is housed inside the barrel 2 together with the writing body 5.
[0023]
When the capless writing instrument 1 is used, the writing barrel 5 is gripped by gripping the barrel 2 and pushing the knocking portion 11 formed at the rear end of the writing body 5 toward the distal end against the spring force of the coil spring 7. Moves forward.
A locking portion 10a provided at the front end of the locking mechanism portion 10 is provided through a window portion formed in the barrel 2, and is provided on the outer peripheral portion of the front end of the knocking portion 11 at the rear of the writing body. The writing body 5 is engaged with the engaging step portion 31 and is engaged in a state where the writing body 5 is advanced.
[0024]
At this time, the pen tip 6 pushes open the slit 25 of the closing portion 21 of the inner cap 20 and projects from the opening 4 of the distal end 3 of the barrel 2.
In this state, when the locking state of the locking mechanism is released, the writing body 5 is again stored in the shaft cylinder by the spring force of the coil spring 7.
[0025]
Also, at this time, when the pen tip portion 6 retreats into the barrel 2 from the slit 25 in the inner cap 20, the slit 25 is formed by the elastic force of the silicone rubber and the force acting from the outside to the inside of the closing portion 21. The gap is in close contact.
Therefore, when the capless writing instrument 1 is not used, the volatilization of the ink from the slit 25 can be minimized.
[0026]
[Action]
According to the present invention, the following effects can be obtained.
That is, in a capless writing instrument in which a writing body is arranged in a barrel and the pen tip of the writing body can freely enter and exit from the tip opening of the barrel, a rubber material is provided at the tip opening of the barrel. Or an inner cap formed of an elastic resin material, wherein the inner cap is formed with a slit through which a pen tip portion can freely enter and exit on the pen tip portion exit side along the axial direction of the barrel cylinder, and the tip end opening is formed. It is provided with a closing portion for closing, and by being mounted in the shaft cylinder in a state where a force is applied to the closing portion to close the slit, a force is always applied in a direction to close the slit, and the pen tip protruding portion is closely attached. Therefore, it is possible to ensure a sealed state near the pen tip in the barrel.
[0027]
Further, the rigidity of the closing portion of the inner cap can be increased by forming the closing portion of the inner cap so as to protrude in an arch shape (dome shape) toward the distal end opening. The slit can be brought into close contact.
In addition, by appropriately providing a convex edge around the slit, rigidity of the slit surface in a direction perpendicular to the slit surface is increased, and adhesion is stabilized.
[0028]
【The invention's effect】
As described above, it is possible to solve the problem of incomplete sealing of the conventional slit-shaped seal portion and the problem that the structure of the seal opening / closing mechanism is complicated and cannot be provided at low cost.
According to the capless writing instrument of the present invention, the inner cap is formed of a rubber material or an elastic resin material, has a slit on the front surface of which a pen tip portion can enter and exit, and has a closing portion for closing the tip opening, A forward protruding portion is formed on the outer peripheral portion of the closing portion and bulges toward the opening direction of the tip, and in a state in which the slit is closed, a force inward from the outer periphery of the forward protruding portion in a direction substantially perpendicular to the slit surface. Is mounted in the barrel so as to apply the pressure, the stress accompanying the deformation of the outer periphery acts as pressure to tighten the slit surface along the closed part, and the tip inside the barrel can be sealed with a simple configuration Therefore, the sealed state of the pen tip can be ensured, and a capless writing instrument excellent in long-term storage can be provided at low cost.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view illustrating an overall configuration of a capless writing instrument as an example of an embodiment of the present invention.
FIG. 2 is a radial cross-sectional view showing a state in which the inner cap according to the embodiment of the present invention is mounted on a shaft cylinder.
FIG. 3 is an axial sectional view showing a state in which the inner cap is mounted on a shaft cylinder.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 capless writing implement 2 barrel 3 tip 4 opening 5 writing body 6 pen tip 7 coil spring 10 locking mechanism 10 a locking section 11 knocking section 12 barrel barrel rear end 20 inner cap 21 closing part 22 base 23 Central part 24 Concave part 25 Slit 26 Convex edge 27 Front protruding part 28 Front end 29 Rear protruding part 30 Stopper 31 Locking step

Claims (4)

In a capless writing implement in which the writing body is arranged in the barrel and the pen tip of the writing body can freely enter and exit from the tip opening of the barrel,
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 is configured such that a pen tip portion can freely enter and exit on a pen tip portion exit side along the axial direction of the barrel cylinder. A slit is formed, and has a closing portion for closing a tip opening provided with a convex edge around the slit , and a front protruding portion bulging toward the tip opening direction on an outer peripheral portion of the closing portion. Is formed, and in a state where the slit is closed, the slit is mounted in the shaft cylinder such that a force inward from the outer periphery of the front protruding portion in a direction substantially perpendicular to the slit surface is applied. Capless writing instrument. A convex portion is provided on the outer surface of the front protruding portion of the inner cap or on the inner surface of the shaft tube mounting which is in contact with the outer perimeter of the front protruding portion. The capless writing instrument according to claim 1, wherein the writing instrument is configured. The capless writing instrument according to claim 1, wherein the slit is formed in one character. The capless writing instrument according to claim 1, wherein the closing portion of the inner cap has a shape protruding in an arch shape toward the distal end opening.

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