JPH0924690A - Ballpoint pen reefill - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ballpoint refill capable of stably sealing a nib up to the start of using and simply releasing the sealing state of the nib at the time of starting to use. SOLUTION: A nib sealing member 4 made of soft synthetic resin is press injected fixedly into a cylinder 3 made of hard synthetic resin. The cylinder 3 is mounted at the front outer surface of a refill body 5 at the rear of the exposed part of a ballpoint pen tip 6.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to ballpoint pen refills. More specifically, the present invention relates to a ballpoint pen refill in which the nib is sealed until the user starts using the pen.

[0002]

2. Description of the Related Art In conventional ballpoint pen refills,
As a means for sealing the pen tip to prevent evaporation of ink from the pen tip until the user starts using it, for example, a hot melt type resin mixture is melted and solidified with the pen tip, or a synthetic resin is used. It is known that a liquid obtained by dissolving the above in an organic solvent is attached to a pen tip to be solidified and sealed.

However, in the above-mentioned conventional seal structure, the sticking of the pen tip and the seal substance becomes unstable and is easily peeled off by an impact or the like, or the sticking of the pen tip and the seal substance is conversely strong. At the beginning of use, it is difficult for the user to remove the sealing substance, and it is not possible to immediately start writing. Furthermore, with the above sealing structure, once the sealing material is removed from the pen tip, it is difficult to reattach it. For example, a plurality of ballpoint pen refills with different ink colors and pen types can be placed inside a single barrel.
In the case where the ballpoint pen refill taken out from the shaft cylinder is selectively stored and used while being exchanged, the seal is released once and the storage is inconvenient.

Further, Japanese Utility Model Publication No. 6-71167 discloses that
"A seal cap that is fitted to the writing tip to prevent the tip ball from drying, and the seal cap is a bottomed tubular body that is made of a non-liquid-absorbing, non-continuous bubble elastic body, There is disclosed a seal cap for a ballpoint pen (ballpoint pen refill in the embodiment), characterized in that a hole for communicating the inside and the outside of the cylindrical body is provided in the vicinity of the bottom where the tip ball is pressed. Further, in the embodiment of the above publication,
A configuration is disclosed in which the seal cap is attached (or fitted) to the ball-point pen tip itself which holds a ball at its tip.

However, in the seal cap of the above publication, since the cylindrical body is made of an elastic body such as rubber having a large frictional force, the seal cap cannot be smoothly attached and detached.

Further, the seal cap of the above publication is fitted on the outer surface of a ball-point pen tip, that is, a so-called metal cutting type ball-point pen tip having a relatively large outer diameter (specifically, 2 mm or more) behind the tip tapered surface. I may be able to do it. However, in the case of a so-called pipe type ball-point pen tip, the tip of the ball-point pen tip is small and the outer diameter behind the taper surface is relatively small (specifically 1.5 mm or less), the ball-point pen tip itself is directly sealed. The mounting of the cap or sealing material reduces the mutual contact area at the mounting location. As a result, the seal cap has a weak fitting force with the outer surface of the chip and thus is easily removed, and the sealing substance has a weak fixing force with the outer surface of the chip or the tapered tip surface, and is easily peeled off.

[0007]

SUMMARY OF THE INVENTION The present invention is to solve the above-mentioned problems of the prior art. It is possible to maintain a stable pen tip seal state during the period from the manufacture to the start of use, and it is easy to start the use. An object of the present invention is to provide a ballpoint pen refill having a seal structure capable of releasing the sealed state of the pen tip. In particular, it is intended to provide a ballpoint pen refill having a seal structure most suitable for a pipe type ballpoint pen tip.

[0008]

In a ballpoint pen refill 1 of the present invention, a cylindrical body 3 made of a hard synthetic resin having a pen tip sealing member 4 made of a soft synthetic resin disposed inside is attached to a front portion of a refill body 5. It is characterized in that the pen tip is sealed. (Claim 1)

The cylindrical body 3 is attached to the outer surface of the refill main body 5 behind the exposed portion of the ball-point pen tip 6. The exposed portion is a portion exposed to the outside of the ballpoint pen tip 6 located at the tip of the refill body 5. (Claim 2)

The ball-point pen tip 6 has a straight portion 62 behind the tapered surface 61, and the straight portion 6
The outer diameter of 2 is 1.5 mm or less (preferably 1.0 mm or less). (Claim 3)

Further, a plurality of ribs 31 extending in the axial direction are provided on the inner surface of the tubular body 3 by integral molding, and the outer surface of the pen tip seal member 4 is pressed and held by the front portion of the rib 31.
The outer surface of the refill main body 5 behind the exposed portion of the ball-point pen tip 6 is held in pressure contact with the rear portion of the rib 31. (Claim 4)

The soft synthetic resin forming the pen tip sealing member 4 is, for example, silicone rubber, isoprene rubber, butadiene rubber, styrene-butadiene rubber, chloroprene rubber, acrylonitrile-butadiene rubber, butyl rubber, ethylene-propylene rubber, acrylic rubber. , Ethylene-vinyl acetate rubber, polysulfide rubber, hydrin rubber, urethane rubber, fluorine rubber, and other synthetic rubbers and various elastomers, etc., which have excellent gas barrier properties, and their elastic deformation causes the pen tip to be buried. Let it effectively seal.

Examples of the hard synthetic resin forming the cylindrical body 3 include polypropylene, polyethylene, ABS, polyacetal, polyethylene terephthalate, polycyclohexane terephthalate, polycarbonate and methacrylic resin. In addition to the above, the synthetic resin forming the cylindrical body 3 may be any as long as it is harder than the synthetic resin forming the pen tip seal member 4. Further, it is also possible to adopt a transparent material for the hard synthetic resin and add a coloring agent having substantially the same color as the ink 91 in the refill main body 5 to make the coloring transparent, thereby making it possible to distinguish the ink color and at the same time to provide a beautiful appearance. Improve.

[0014]

The pen tip sealing member 4 is made of a soft synthetic resin so that the pen tip can be surely sealed when the nibs are brought into close contact with each other. Further, since the cylindrical body 3 mounted on the front portion of the refill main body 5 is made of a hard synthetic resin, the cylindrical body 3 and the refill main body 5 can be securely held without coming off easily due to an impact or the like. Until the start of use, the pen tip seal member 4 can maintain a stable pen tip seal. Further, since the cylindrical body 3 is made of a hard synthetic resin, the frictional resistance at the time of mounting is reduced, so that the cylindrical body 3 and the refill main body 5 can be smoothly attached and detached, and particularly at the start of use, the cylindrical body 3 Can be easily removed. Further, the tubular body 3 and the refill main body 5 can be repeatedly attached and detached.

By mounting the cylindrical body 3 on the outer surface of the refill main body 5 behind the exposed portion of the ballpoint pen tip 6 (claim 2), it is not possible to mount the cylindrical body 3 on the ballpoint pen tip 6 itself as in the conventional case. That is, since it is mounted on the outer surface of the refill main body 5 having a relatively large diameter behind the exposed portion of the ballpoint pen tip 6, the cylindrical body 3 and the refill main body 5 can be securely and securely attached to each other without being affected by the size and shape of the ballpoint pen tip. Stable holding is possible.

The ball-point pen tip 6 has a straight portion 62 behind the tapered surface 61, and the outer diameter of the straight portion 62 is 1.5 mm or less (preferably 1.0 mm or less) (claim 3). In combination with the configuration of claim 2, even with a relatively thin ball-point pen tip 6 in which it is particularly difficult to attach the tubular body 3, the tubular body 3 and the refill main body 5 can be reliably attached, and during the period from the manufacture to the start of use. A stable sealed state of the pen tip is maintained, and the sealed state of the pen tip can be easily released at the start of use. That is, in the case of the ball-point pen tip 6 of claim 3, the smaller the outer diameter of the straight portion 62 is, the more the mounting structure of claim 2 becomes.
It works effectively.

Further, by providing a plurality of ribs 31 extending in the axial direction on the inner surface of the cylindrical body 3, the pen tip seal member 4 is provided.
When press-fitting the front part of the rib 31, the contact with the outer surface of the rib 31 can be reduced to reduce the press-fitting force, and the pen tip sealing member 4 can be smoothly placed at a predetermined position on the front part of the rib 31.
Can be arranged. Further, even when the top wall of the tubular body 3 is closed, when the pen tip sealing member 4 is press-fitted, the air inside the tubular body 3 is not compressed, and the pen 3 can be mounted smoothly. Further, when the refill main body 5 is attached to the tubular body 3, since the inside and the outside of the tubular body 3 are communicated with each other through the gap between the ribs 31, the air inside the tubular body 3 is pressurized and the tip of the ballpoint pen tip 6 is pushed. There is no risk of infiltration of air. That is, the rib 31 allows the pen tip seal member 4 and the refill main body 5 to be smoothly mounted in the tubular body 3, as well as the air releasing action when the pen tip seal member 4 is press-fitted and the air when the refill main body 5 is attached. Combines with the escape function.

Further, the rib 31 and the outer surface of the pen tip seal member 4 and the outer surface of the refill body 5 are held in pressure contact with each other, so that it is possible to absorb the dimensional variation at the time of press contact holding portions at the time of manufacture or the dimensional change due to aging, and to be sure. It is possible to maintain a stable pressure contact holding state for a long period of time.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention is shown in FIGS.

A protective cap 2 including a pen tip seal member 4 and a cylindrical body 3 is attached to the front portion of the refill body 5.

The cylinder 3 is a cylinder whose both ends are open, and is obtained by injection molding of polypropylene resin.
Further, on the inner surface of the cylindrical body 3, a fitting portion with the refill main body 5 and a mounting portion with the pen tip seal member 4 are integrally formed. Specifically, a plurality of ribs 31 extending in the axial direction are integrally arranged on the inner surface of the cylindrical body 3. The outer surface of the pen tip seal member 4 is press-fitted and fixed to the front portion of the rib 31, and the front outer surface of the refill body 5 is fitted to the rear portion of the rib 31. A step portion 33 for locking is integrally provided at the front end of the rib 31, and the front surface of the pen tip seal member 4 is in contact with the step portion 33.

The rib 31 extends from the front part of the cylindrical body 3 to the vicinity of the rear end thereof and has a planar top part directly connected to the curved inner surface of the cylindrical body 3. The rib 31 has a tapered surface 3
It is a two-step straight plane with 2 in between,
The diameter of the imaginary inscribed circle that contacts the tops of the ribs 31 is such that the front portion is smaller than the rear portion. That is, the front portion of the rib 31 serves as a mounting portion for the pen tip seal member 4 and is held in pressure contact with the outer surface of the pen tip seal member 4. Further, the rear portion of the rib 31 serves as a fitting portion with the refill main body 5, and is held in pressure contact with the outer surface of the front portion of the refill main body 5 behind the exposed portion of the ballpoint pen tip 6 (that is, the tip tapered surface 61 and the straight portion 62). More specifically, the rear portion of the rib 31 is held in pressure contact with the straight outer surface of the synthetic resin holder 8 that holds the ball-point pen tip 6. Further, specifically, four ribs 31 are provided at equal intervals, and uniformly press and hold the outer surface of the pen tip seal member 4 and the outer surface of the refill body 5 from four directions.

The cylindrical body 3 is made of a transparent synthetic resin material to which a coloring agent having substantially the same color as that of the ink 91 contained in the refill main body 5 is added. Any colorant such as blue, red, or green is added to make the cylinder 3 a colored transparent body that is lightly smoked. This allows the ink 9 to be easily
One color can be identified. Further, in this embodiment, since the cylindrical body 3 is a transparent cylindrical body, it is possible to see through the pen tip seal member 4 disposed inside the side surface of the main body of the cylinder 3 from all directions. It is possible to quickly determine the presence or absence of No. 4 and defective assembly.

The pen tip seal member 4 is formed of a black colored elastic material (for example, ethylene-propylene rubber to which a black colorant is added). The pen tip sealing member 4 is capable of abutting against the cup-shaped portion 41 having a conical inner surface that comes into close contact with the pen tip, the stepped portion 33 inside the tubular body 3, and the press-contact holding with the front portion of the rib 31. Part 42
And are integrally molded. In addition to this, the pen tip seal member 4 may be a plate-like or spherical elastic body.

FIG. 5 shows the whole ball-point pen refill 1 of the first embodiment.

The ballpoint pen refill 1 has a refill main body 5 including a ballpoint pen tip 6, a support cylinder 7, a holder 8 and an ink containing cylinder 9 in order from the tip, and a protective cap 2 (mounted on the front portion of the refill main body 5). Figure 1
Through FIG. 4).

The ball-point pen tip 6 has a structure in which the tip of a metal (specifically, stainless steel) pipe is pressed and deformed inward to form a ball receiving seat, and the ball is rotatably held. There, it is press-fitted and fixed to the tip of the holder 8 made of synthetic resin. The ballpoint pen tip 6 has a tip angle of 40
Taper surface 61 having a degree of 120 to 120 degrees and a straight portion 62 connected to the rear of the tip surface and having an outer diameter of 0.4 mm to 0.8 mm
And A metal support cylinder 7 is fitted on the tip of the holder 8 to support the outer peripheral surface of the ballpoint pen tip 6. The holder 8 is fitted in the tip opening of the ink containing cylinder 9. Ink 91 (for example, an aqueous gel ink having a thixotropic property or an oil ink having a viscosity of 1000 mPa · s to 10000 mPa · s at 20 ° C.) is housed in the ink container 9. The back end of the ink 91 is filled with a grease-like backflow preventive agent 92 that advances as ink is consumed.

6 to 8 show a second embodiment of the present invention.

The cylindrical body 3 is a cylindrical body 3 whose top is closed, and is obtained by injection molding of synthetic resin such as polyethylene. As in the first embodiment, a plurality of planar ribs 31 (specifically, four) extending straight in the axial direction are provided on the inner surface of the cylindrical body 3 at the front portion of the rib 31. ,
The outer peripheral surface of the pen tip sealing member 4 is pressed and held from four directions, and at the rear portion of the rib 31, the outer surface of the refill main body 5 (specifically, the straight outer surface of the synthetic resin holder 8 for holding the ballpoint pen tip 6). ) Is pressed and held from four directions. Further, a step portion 33 and a recess portion 34 are provided at the front end of the rib 31, and the outer peripheral surface of the front surface of the pen tip seal member 4 is abutted and locked to the step portion 33, and the recess portion 34, A front deformed portion of the pen tip seal member 4 due to contact with the pen tip is accommodated.

The pen tip seal member 4 is a plate-like body having a concave inner surface at the central front-back symmetrical position, and is made of an elastic material such as rubber.

The ball-point pen tip 6 is obtained by cutting a metal material such as stainless steel or brass, and has a straight portion 6 having an outer diameter of 2.3 mm behind the tip tapered surface 61.
2 are connected. Other configurations (holder 8,
The configurations of the ink container 9, the ink 91, the backflow preventive agent 92, and the like), and the effects are the same as in the first embodiment.

[0032]

The ball-point pen refill of the present invention comprises a hard synthetic resin cylindrical body having a soft synthetic resin pen tip sealing member disposed inside the refill body, and the pen tip is sealed. By virtue of this (claim 1), it is possible to maintain a stable sealed state of the pen tip during the period from manufacturing to the start of use, and it is possible to easily release the sealed state of the pen tip at the start of use.

Further, the cylindrical body is attached to the outer surface of the refill body behind the exposed portion of the ballpoint pen tip (claim 2), so that the cylindrical body and the refill body are not affected by the size and shape of the ballpoint pen tip. With this, reliable and stable holding can be achieved.

Further, the ball-point pen tip has a straight portion behind the tapered surface of the tip, and the outer diameter of the straight portion is 1.5 mm or less (claim 3). Even with a relatively thin ball-point pen tip that makes it difficult to attach the barrel, the barrel and the refill body are securely attached, and a stable pen tip seal can be maintained during the period from manufacturing to the start of use. At the start, the pen tip can be easily unsealed.

Further, a plurality of ribs extending in the axial direction are integrally formed on the inner surface of the cylinder, the outer surface of the pen tip seal member is pressed and held by the front portion of the rib, and the ballpoint pen tip is exposed by the rear portion of the rib. The outer surface of the refill main body at the rear of the portion is held in pressure contact (claim 4),
The pen tip seal member and the refill body can be smoothly attached, and in particular, when the refill body is attached, there is no possibility that air will enter from the pen tip. Further, the ribs and the outer surface of the pen tip seal member and the outer surface of the refill body are held in pressure contact with each other, so that it is possible to absorb the dimensional variation at the time of press contact holding portions during manufacturing or dimensional change over time, and thus the pen tip seal member and the refill main body Reliable pressure contact with can be maintained for a long time.

[Brief description of drawings]

FIG. 1 is an enlarged vertical sectional view of an essential part showing a first embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view showing the protective cap of FIG.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is a sectional view taken along line BB of FIG. 2;

FIG. 5 is a vertical cross-sectional view showing the entire first embodiment of the present invention.

FIG. 6 is an enlarged vertical sectional view of an essential part showing a second embodiment of the present invention.

7 is a vertical cross-sectional view showing the protection cap of FIG.

FIG. 8 is a sectional view taken along line CC of FIG. 7;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ball-point pen refill 2 Protective cap 3 Cylindrical body 31 Rib 32 Tapered surface 33 Step portion 34 Recessed portion 4 Pen tip sealing member 41 Cup-shaped portion 42 Collar portion 5 Refill body 6 Ball-point pen tip 61 Tip tapered surface 62 Straight portion 7 Support cylinder 8 Holder 9 Ink storage cylinder 91 Ink 92 Backflow prevention agent

Claims (4)

[Claims] 1. A pen tip seal member (4) made of a soft synthetic resin.
A ball-point pen refill characterized in that a cylindrical body (3) made of a hard synthetic resin inside is attached to the front part of the refill body (5) to seal the pen tip. 2. The ball-point pen refill according to claim 1, wherein a cylindrical body (3) is mounted on the outer surface of the refill body (5) behind the exposed portion of the ball-point pen tip (6). 3. The ball-point pen tip (6) has a straight portion (62) behind the tapered surface (61), and the outer diameter of the straight portion (62) is 1.5 mm or less. Item 2. A ball-point pen refill according to item 2. 4. A plurality of ribs (31) extending in the axial direction are provided on the inner surface of the tubular body (3) by integral molding, and the ribs (31) are formed.
The outer surface of the pen tip seal member (4) is held in pressure contact with the front part thereof, and the outer surface of the refill body (5) behind the exposed part of the ballpoint pen tip (6) is held in pressure contact with the rear part of the rib (31). The ball-point pen refill according to claim 3, wherein