JP2017087457A - Writing instrument refill - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a writing instrument refill capable of securing a sufficient storage amount of ink without expanding the outer diameter dimension of an ink storage tube and solving the problem that the writing instrument side easily comes off from the ink storage tube.SOLUTION: An ink storage tube 1 formed cylindrically from a resin material and a joint member 3 that supports a writing tip 2 mounted by being press-fitted into the end inner peripheral surface of the ink storage tube. The outer peripheral surface on contact with the ink storage tube 1 of the joint member 3 that supports the writing tip 2 is equipped with an edge part 6 comprising a tapered inclined plane 6a that expands the outer diameter gradually toward the tip side of the writing tip and a falling surface 6b that reduces the outer diameter by following the inclined plane. An angle of the intersection of the tapered inclined plane 5a of an axial cutting plane of the edge part 6 with the falling surface 6b is set at an acute angle (less than 90 degrees).SELECTED DRAWING: Figure 3

Description

  The present invention relates to a writing instrument refill used for, for example, a ballpoint pen.

A refill for a writing instrument used for a ballpoint pen or the like is generally attached by fitting a ballpoint pen tip as a writing tip into one end portion (front end portion) of an ink storage tube.
In addition, a transparent or translucent resin material, for example, polypropylene, is used for the ink storage tube in order to ensure ease of molding and visibility of the ink amount.

  FIG. 8 is a sectional view showing an example of a conventional ballpoint pen refill. In the example shown in FIG. 8, a ballpoint pen is connected to a front end portion of a cylindrical ink storage tube 1 via a joint member 3. The structure to which the chip 2 is attached is shown. Further, the outer peripheral surface of the ink storage tube 1 is formed in a flush cylindrical shape, and the inner diameter of the front end portion of the ink storage tube 1 into which the joint member 3 is fitted and the ink storage tube 1 constituting the ink storage portion. The inner diameter of the central portion in the axial direction is configured in a straight shape having substantially the same dimensions. Such a ballpoint pen refill using an ink containing tube having a straight outer peripheral surface and an inner peripheral surface is disclosed in Patent Document 1, for example.

  By the way, in the above-described ballpoint pen refill, in particular, the front end portion of the ink containing tube into which the ballpoint pen tip is fitted needs to have a certain thickness in order to secure the attachment strength. Therefore, according to the ballpoint pen refill having the configuration disclosed in Patent Document 1 described above, since the entire thickness of the ink storage tube is provided with a certain thickness, it is not possible to ensure a sufficient amount of ink storage. It will have practical problems.

  Therefore, if an ink storage tube having a reduced thickness can be employed, a sufficient ink storage amount can be ensured without expanding the outer diameter of the ink storage tube. However, the thin ink storage tube cannot secure a sufficient fitting force with respect to the ballpoint pen tip or the joint member attached to the front end of the ink storage tube, causing a problem that the ballpoint pen tip is easily detached from the ink storage tube. .

  By the way, in order to prevent the ball-point pen tip from coming off from the ink containing tube side, an annular groove is formed in the outer peripheral surface of the ball-point pen tip, and an annular shape is formed on the inner peripheral surface of the joint member press-fitted into the ink containing tube. A ballpoint pen refill with a protrusion is proposed. This is disclosed in Patent Document 2, for example.

  However, the function disclosed in Patent Document 2 considers press-fitting between the ballpoint pen tip and the joint member, and has a flexible ink containing tube with a reduced thickness and the ballpoint pen tip or joint member. Even if the configuration disclosed in Patent Document 2 is employed as it is for the function of preventing the separation between the two, it is difficult to exert its effect.

JP 2002-59682 A JP 2002-52885 A

The present invention intends to employ an ink containing tube having a reduced wall thickness in order to secure a necessary and sufficient amount of ink without expanding the outer diameter of the ink containing tube.
In this case, there is no special processing on the thin ink container tube side, and when a writing tip (ball pen tip) or a joint member is interposed, a sufficient fitting action is secured with the joint member. An object of the present invention is to provide a writing instrument refill that can solve the problem that the writing tip side is easily detached from the ink storage tube. .

  The refill for a writing instrument according to the present invention made to solve the above-described problem is attached by being press-fitted into an inner peripheral surface of an ink storage tube formed in a cylindrical shape by a resin material and an end portion of the ink storage tube. A writing tool refill provided with a writing chip or a joint member that supports the writing chip, wherein the writing chip or a joint member that supports the writing chip has an outer peripheral surface that is in contact with the ink containing tube at the tip of the writing chip. An edge portion having a tapered inclined surface that gradually increases the outer diameter toward the portion side, and a falling surface that reduces the outer diameter following the inclined surface, and is provided in the axial direction of the edge portion. A crossing angle between the tapered inclined surface and the falling surface in the cut surface is set to an acute angle (less than 90 degrees).

In this case, it is desirable that the falling surface constituting the edge portion is formed in parallel with the surface perpendicular to the axial direction of the writing tip or joint member.
In addition, preferably, the surface of the writing tip or joint member on which the edge portion is formed is formed of a material having a hardness higher than that of the ink containing tube, and more preferably the writing tip or joint member on which the edge portion is formed. Is formed of a metal material. In this case, high hardness means showing a high numerical value in the same kind of hardness test method. Examples of the hardness test method include the Rockwell test method (conforming to JIS Z2245), the Vickers test method (conforming to JIS Z2244), and the Knoop test method (conforming to JIS Z2251).

According to the writing instrument refill having the above-described configuration, the writing tip or the joint member that supports the writing tip is attached by being press-fitted to the front end portion of the ink storage tube formed in a cylindrical shape from the resin material.
In this case, the outer peripheral surface in contact with the ink containing tube in the writing chip or the joint member that supports the writing chip is provided with an edge portion having a tapered inclined surface and a subsequent falling surface. The edge portion abuts on the inner surface of the flexible ink storage tube by the resin material, and a sufficient fitting action can be obtained with the ink storage tube.

Further, since the above-described falling surface constituting the edge portion is formed toward the tip end side of the writing chip, the falling surface is locked to the inner peripheral surface of the ink containing tube, and the writing chip or The joint member acts to prevent the coupling member from coming out of the ink containing tube.
Thereby, it is possible to provide a refill for a writing instrument that can effectively prevent the writing tip from dropping from the ink storage tube.

It is an external view of the state which employ | adopted the refill for writing instruments which concerns on this invention for the ball-point pen refill. It is a center sectional view of the refill for writing instruments shown in FIG. It is a partial expanded sectional view of the joint member of the refill for writing instruments shown in FIG. It is the perspective view which expanded and showed the single-piece | unit structure of the coupling seat which comprises a coupling member. It is the perspective view which similarly changed the viewpoint and showed the single-piece | unit structure of the joint receiving seat. It is a front view of a joint seat similarly. It is a center sectional view of a joint receptacle similarly. It is the center sectional view showing an example of the conventional refill for writing instruments.

The writing instrument refill according to the present invention will be described on the basis of an embodiment shown in a drawing using a ballpoint pen refill as an example.
As shown in FIGS. 1 and 2, a ball-point pen tip 2 previously formed of a metal material or a resin material is provided at one end (front end) of an ink storage tube 1 formed in a cylindrical shape by a resin material such as polypropylene. Is attached by press-fitting the joint member 3 to which is attached.

As shown in FIG. 2, the ball pen refill according to this embodiment uses a thinner ink container 1 than the conventional ball pen refill shown in FIG. 8. Therefore, according to this embodiment, a sufficient ink storage amount can be ensured without expanding the outer diameter of the ink containing tube 1.
In addition, the preferable thickness of the ink storage tube 1 formed in a cylindrical shape in this embodiment is set to about 0.1 mm to 0.5 mm.

  On the other hand, the above-described joint member 3 has a first joint 3a to which the ballpoint pen tip 2 is attached, as shown in FIG. It is comprised from the joint seat 3b attached by the press fit in the outer side of the diameter reducing part 4 in which the diameter in the second half part of the 1st joint 3a was reduced.

In other words, the joint receiving seat 3b is provided with the shaft hole 5 to which the reduced diameter portion 4 of the first joint 3a is press-fitted, so that the appearance is substantially cylindrical. Hereinafter, the joint receiving seat 3b is referred to as a second joint 3b.
The joint member 3 is composed of two members including a first joint 3a and a second joint 3b. Therefore, the first joint 3a is formed of, for example, a resin material, and the second joint 3b is formed of a metal material. be able to.

  For example, a single body configuration of the second joint 3b formed of a metal material such as brass is shown in FIGS. An edge portion 6 projecting in an annular shape is formed on the outer peripheral surface of the second joint 3b on the insertion side into the ink containing tube 1. The edge portion 6 includes a tapered inclined surface 6a that gradually increases the outer diameter toward the tip end side of the writing tip 2, and a falling surface 6b that reduces the outer diameter following the inclined surface 6a. It is comprised by.

In this case, it is desirable that the crossing angle between the tapered inclined surface 6a and the falling surface 6b in the axial cut surface of the edge portion 6 is set to an acute angle (less than 90 degrees). As an example, the inclination angle with respect to the axis of the tapered inclined surface 6a shown in a sectional view in FIG. 7 is set to 20 degrees, and the falling surface 6b is formed to be parallel to a surface orthogonal to the axial direction. ing.
Therefore, the crossing angle θ between the tapered inclined surface 6a and the falling surface 6b in the edge portion 6 in this embodiment is set to 70 degrees as shown in FIG.

The second joint 3b includes a first cylindrical surface 7, a second cylindrical surface 8, and an annular shape whose outer diameter increases stepwise toward the tip end side of the ballpoint pen tip 2 following the edge portion 6 described above. The collar portion 9 is formed. The circumferential surface of the annular flange 9 is set to be substantially the same as the outer diameter of the ink containing tube 1 and the first joint 3a as shown in FIG.
That is, the first cylindrical surface 7 and the second cylindrical surface 8 that increase the outer diameter in a step shape function as connecting portions of the ink storage tube 1 described above.

When the combined body of the ballpoint pen tip 2 and the joint member 3 is press-fitted into the front end portion of the ink containing tube 1, the inner surface of the front end portion of the ink containing tube 1 is formed with the edge portion 6 formed on the second joint 3b. It is mounted so as to get over.
In this case, since the edge portion 6 is formed with a tapered inclined surface 6a toward the ink containing tube 1, the flexibility of the ink containing tube 1 is utilized to make the ink containing tube 1 relatively easy. The joint member 3 can be attached to the front end.

  Thus, in the state shown in FIG. 3 in which the combined body of the ballpoint pen tip 2 and the joint member 3 is press-fitted into the front end of the ink containing tube 1, the joint member 3 (particularly the second joint 3b) The edge portion 6 formed on the joint member 3 is made of a resin material because it is made of a material harder than the housing tube 1, for example, a metal material such as brass or stainless steel, or a non-ferrous metal material such as aluminum. In contact with the inner surface of the ink storage tube 1. Thereby, the joint member 3 can obtain a sufficient fitting action with the ink containing tube 1.

Moreover, since the above-described falling surface 6b constituting the edge portion 6 is formed toward the tip end side of the ball-point pen tip, the falling surface 6b is effectively related to the inner peripheral surface of the ink containing tube 1. The joint member 3 acts so as to prevent the joint member 3 from coming out of the ink containing tube 1.
Thereby, it is possible to provide a refill for a writing instrument that can reliably prevent the writing tip 2 from dropping from the ink containing tube 1.
Moreover, the form used as the coupling member 3 with which the 1st coupling 3a and the 2nd coupling 3b were united is also employable. In that case, it is preferable to form the ink containing tube 1 and the writing tip 2 with materials having different hardness.

  In the above-described embodiment, the example in which the ballpoint pen tip 2 as a writing tip is attached to the front end portion of the ink containing tube 1 via the joint member 3 is shown. However, the present invention does not involve the joint member. It is also possible to adopt a configuration in which the writing tip is directly attached to the front end portion of the ink containing tube. In this case, a similar effect can be obtained by forming the edge portion 6 on the rear outer peripheral surface of the writing chip.

1 Ink receiving tube 2 Writing tip (ballpoint tip)
3 joint member 3a first joint 3b second joint (joint seat)
4 Reduced-diameter portion 5 Shaft hole 6 Edge portion 6a Tapered inclined surface 6b Falling surface 7 First cylindrical surface 8 Second cylindrical surface 9 Gutter

Claims (4)

A refill for a writing instrument comprising an ink storage tube formed in a cylindrical shape from a resin material, and a writing chip attached by being press-fitted into the inner peripheral surface of the end of the ink storage tube or a joint member that supports the writing chip There,
On the outer peripheral surface of the writing chip or the joint member that supports the writing chip that contacts the ink containing tube, a tapered inclined surface that gradually increases in outer diameter toward the tip end side of the writing chip, and the inclined surface And an edge portion having a falling surface for reducing the outer diameter, and an intersecting angle between the tapered inclined surface and the falling surface in an axial cut surface of the edge portion is an acute angle ( The refill for writing instruments, characterized by being set to less than 90 degrees.   2. The writing instrument refill according to claim 1, wherein a falling surface constituting the edge portion is formed in parallel with a surface perpendicular to the axial direction of the writing tip or joint member.   The refill for a writing instrument according to claim 1 or 2, wherein a surface of the writing tip or joint member on which the edge portion is formed is formed of a material having a hardness higher than that of the ink containing tube.   The writing tool refill according to claim 3, wherein the writing tip or the joint member on which the edge portion is formed is formed of a metal material.

Images