JP2000015983A - Ball-point pen - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the possibility of the entering of compressed air in a ball tip as much as possible by a method wherein when a cap is placed on the front part of a main body, a ventilation hole is closed, and at the same time, a gap which makes a space in the cap on the tip end side from the closed part communicate with the cap opening end, is formed. SOLUTION: On the bottom part of an internal hole of a cap 1, a packing 8 which is an elastic body made of nitrile butadiene rubber is arranged, and under a state wherein the cap 1 is fitted on a main body 3, the tip end of a ball-point pen tip 2 comes into contact with the packing 8, and an ink discharging hole of the ball-point pen tip 2 is closed. The fitting of the cap is performed in such a manner that in an annular indent 4a located at the tip end part of an exterior body 4, a plurality of inward protuberances which 8 are circumferentially arranged on the internal hole of the cap are fitted, by a male- female getting-over fitting. Also, the cap 1 integrally has a clip 1b, and at the tip end part of the clip 1b, a ball part 1c is formed. In addition, a straight face is provided on the outer diameter of the exterior body 4, and a gap is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a body having a ballpoint pen tip as a pen tip at a tip thereof, and a cap for disposing an elastic body in close contact with the tip of the ballpoint pen tip in an inner hole when fitted on the front part of the body. The main body contains an aqueous ink, and an exterior body that accommodates a refill connected to the ballpoint pen tip via a tip holder at a tip of a pipe body that opens a rear end, and a side portion of the exterior body. The present invention also relates to a ball-point pen having a ventilation hole for supplying air into a pipe body with a decrease in consumption of the aqueous ink by writing.

[0002]

2. Description of the Related Art Conventionally, there has been known a writing implement having a ventilation hole for supplying air in a volume corresponding to the consumption of ink so as not to cause a decrease in internal pressure due to a decrease in ink accompanying ink consumption. By locating this vent in the inner space of the cap which is closed when the cap is attached by the annular sealing portion formed on the inner wall of the cap, the ink does not evaporate through the vent when the cap is not used when not in use. Has been made.

In a ball-point pen using water-based ink, the tip of the ball-point pen tip is closely contacted with the tip of the ball-point pen inside the cap in order to prevent the ink from volatilizing from the gap between the ball and the holder of the ball-point pen tip, which is the tip of the pen during non-writing. There is known a device in which an elastic body such as silicon rubber or nitrile rubber is disposed.

[0004]

When the ventilation hole is located in the space inside the cap, the space inside the cap is a closed space in addition to the space inside the main body, and the ink corresponding to the total volume of these spaces is obtained. Can evaporate. If the space inside the cap is made as small as possible, the amount of ink evaporated can be relatively reduced. However, in the case of a ballpoint pen in which an elastic body disposed in a cap having a very small space inside the cap where the pen tip exists is in close contact with the ballpoint pen tip, it is substantially impossible to locate the ventilation hole in the space inside the closed cap. In order to suppress the volatilization of the ink from the air hole, it is possible to further form an annular sealing portion on the inner wall of the cap and form a sealed space inside the cap separately from the sealing of the pen tip, and to form the air hole therein. Had to be located. However, the closed space in the cap formed by the above-mentioned annular sealing portion is compressed to a considerable extent because the annular sealing portion comes into sliding contact with the main body by the cap fitting stroke. The compressed air loses its escape space and becomes a so-called pump phenomenon in which it penetrates into a pen point, which is a pen tip, and there is a possibility that ink writing is not immediately discharged when writing is used.

[0005]

That is, according to the present invention, a body having a ballpoint pen tip at the tip as a pen tip and an elastic body which is in close contact with the tip of the ballpoint pen tip when fitted on the front part of the body are provided in the inner hole. The cap comprises a cap to be disposed, the main body contains water-based ink, and an exterior body containing a refill connected to the ballpoint pen tip via a tip holder at a tip end of a pipe body opening a rear end, and In a ball-point pen having a ventilation hole for supplying air into a pipe body with a reduction in consumption of the water-based ink by writing on a side of the exterior body, a sealing portion is formed in the cap in close contact with a peripheral portion of the ventilation hole of the exterior body. When the cap is fitted to the front part of the main body, the air hole is sealed, and the space inside the cap at the tip side from the sealed part and the cap opening end are communicated. And gist ballpoint pen, characterized in that the formation of the gap.

[0006]

When the cap is fitted, the air existing in the inner hole of the cap is released from the gap formed between the cap and the main body, and only the ballpoint pen tip, which is the pen tip, is brought into contact with the elastic body and closed. When closing the pores, the space inside the cap where the ball-point pen tip is present is closed and the volume of the space is not reduced, so that the possibility of compressed air entering the ball-point pen tip is minimized.

[0007]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
In common with each of the examples, basically, a cap 1 made of polyethylene terephthalate resin having transparency and a main body 3 having a ball-point pen tip 2 at the tip are provided.
Exterior body 4 which is a cylinder made of transparent acrylic styrene resin
, A metal front end 5 screwed into a male screw portion at the tip of the exterior body 4, a tail plug press-fitted to the rear end of the exterior body 4 (not shown), and a stainless steel inside. A refill 7 consisting of an ink cylinder 6 made of a polypropylene resin and having an open rear end, to which the ball-point pen tip 2 is fixed at the front end via a chip holder (not shown). It has the property of having a fluidity that is reduced by rotation of the ball of the chip.
When m, 1700 cp aqueous pigment ink (not shown)
And a high-viscosity fluid (not shown) containing polybutene as a main component, which is located at the interface of the ink and prevents backflow of the ink.

A packing 8, which is an elastic body made of nitrile butadiene rubber, is arranged at the bottom of the inner hole of the cap 1. When the cap 1 and the main body 3 are fitted and pointed, the tip of the ballpoint pen tip 2 is packed. 8 to close the ink ejection hole of the ballpoint pen tip 2. This cap fitting is based on a so-called concave / convex overfitting that is performed by fitting a plurality of inward projections 1a arranged in a circumferential shape of the cap inner hole into an annular concave portion 4a provided at the distal end of the exterior body 4. In addition, the cap 1 has a clip 1b integrally, and a ball portion 1c for locking a sandwiched one is formed at a tip portion of the clip 1b.

One example shown in FIG. 1 to FIG. 3 is that a straight surface 4
This is an example in which a gap 9 is formed by forming b. I- in FIG.
As shown in FIG. 2 which is a cross-sectional view taken along the line I ′,
Has a cross section in which the straight surface 4b and the curved surface 4c having the same curvature as the inner surface of the cap are alternately formed, and the curved surface 4c is made to be in close contact with the inner wall of the cap. An air hole 10 is formed in this curved surface 4c,
It communicates with the open rear end of the ink cylinder 6 of the refill 7 through the inner hole of the exterior body 4 and supplies air corresponding to the volume of ink consumed by writing. As shown in FIG. 3 which is an enlarged view of a portion A in FIG.
The inner wall of the cap is in close contact with the periphery of the ventilation hole 10 to block the ventilation of the ventilation hole 10. At the same time, the ballpoint pen tip 2 is closed by the packing 8. Although not shown, the chip holder made of a synthetic resin is in circumferential contact with the inner wall of the front end 5, and ventilation cannot be performed from this portion.
By closing 0, the space inside the exterior body 4 is shut off from the outside air, and the evaporation of the ink is suppressed. More preferably,
It is preferable that the material of the exterior body is made of a material having low gas permeability, such as polypropylene, or a surface treatment is performed to make gas permeation difficult.

When the cap 1 is mounted on the main body 3, air existing in the inner hole of the cap 1 is pushed out through a gap between the inner wall of the cap and the main body. And between the exterior body 4 and the straight surface 4b, the possibility that the air in the cap inner hole enters the inside of the ballpoint pen tip is extremely small.

FIGS. 4 to 6 show other examples. Cap 1
This is an example of the same inner hole and outer shape of the exterior body 4. That is, as shown in FIG. 5 which is a cross-sectional view taken along the line II-II ′, a gap 9 for allowing air in the inner hole of the cap 1 to escape when the cap is attached is formed by the ventilation groove 11 formed in the exterior body 4. The ventilation groove 11 extends from the vicinity of the annular concave portion 4a of the exterior body 4 to a portion located outside the cap 1 in the cap mounted state, and communicates the space inside the cap with the outside air even in the cap mounted state. The ventilation hole 10 is formed at a position covered with the cap 1 within the area where the ventilation groove 11 is formed, and as shown in FIG. 6 which is an enlarged view of a portion B in FIG. In this state, the cap is sealed by an annular sealing projection 12 formed on the inner wall of the cap. Therefore, the inside of the main body 3 is sealed by closing the ventilation hole 10, the ballpoint pen tip 2 is sealed by the packing 8, and the space inside the cap can be formed to communicate with the outside air by the ventilation groove 11. The evaporation of the ink from the refill 7 can be limited to a space only in the main body 3 while the air in the cap 1 is prevented from entering the ballpoint pen tip 2 as much as possible.

FIGS. 7 to 9 show still another example. This is an example in which the inner hole of the cap 1 and the outer shape of the exterior body 4 are the same, but as shown in FIG. 8 which is a cross-sectional view taken along the line III-III ′, unlike the above example, the curved surface and the straight surface And alternately exist. That is, in the relationship between the cap 1 and the main body 3, the non-circular cross-sectional shape is adopted, so that the cap 1 cannot be rotated with each other when the cap is mounted. Are straight faces facing each other. In this example, the ventilation hole 10 is formed in the straight surface 4b of the exterior body 4, and the corresponding straight inner wall 1d of the cap 1 is in close contact with the peripheral portion of the ventilation hole 10 to close the ventilation hole 10, Further, a ventilation groove 11 reaching the opening end of the cap is formed in the concave curved surface 1e of the cap 1, and when the cap 1 is mounted, air in the space inside the cap is discharged to the outside through the ventilation groove 11, and the inside of the main body 3 is , FIG.
As shown in FIG. 9 which is an enlarged view of the portion C of FIG. 9, the peripheral portion is sealed by the inner wall of the cap, so that evaporation of the ink is suppressed and the pump phenomenon is also prevented. In this example, it is important to form the ventilation holes 10 and the ventilation grooves 1 on different surfaces. If the ventilation groove 11 and the ventilation hole 10 formed in the cap 1 are both formed on a curved surface portion or both are formed on a straight surface, the ventilation groove 11 of the cap 1 and the ventilation hole 10 of the main body 3 coincide, and the ventilation hole is formed. 10 may not be sealed.

[0013]

According to the present invention, with a simple structure, the evaporation of ink in the refill can be suppressed as much as possible, and the occurrence of handwriting blur due to the pump phenomenon can be prevented as much as possible.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an example of a main part.

FIG. 2 is a cross-sectional view taken along the line I-I 'of FIG.

FIG. 3 is an enlarged view of a portion A in FIG. 1;

FIG. 4 is a longitudinal sectional view of a main part showing another example.

FIG. 5 is a cross-sectional view taken along the line II-II ′ of FIG. 4;

FIG. 6 is an enlarged view of a portion B in FIG. 4;

FIG. 7 is a vertical sectional view of a main part showing still another example.

8 is a cross-sectional view taken along the line III-III 'of FIG.

FIG. 9 is an enlarged view of a portion C in FIG. 7;

[Description of Signs] 1 Cap 1a Inward projection 1b Clip 1c Ball portion 2 Ballpoint pen tip 3 Main body 4 Outer body 4a Depression 4b Straight surface 4c Curved surface 5 Tip 6 Ink cylinder 7 Refill 8 Packing 9 Gap 10 Vent hole 11 Vent groove 12 Sealed convex

Claims (3)

[Claims] 1. A body having a ballpoint pen tip as a pen tip at a tip thereof, and a cap for placing an elastic body in close contact with the tip of the ballpoint pen tip in an inner hole when fitted on the front part of the body, wherein the body is , An exterior body containing a water-based ink, and a refill connected to the ball-point pen tip connected to the tip of a pipe body having a rear end opened via a chip holder. In a ball-point pen having a ventilation hole for supplying air to the inside of a pipe with a decrease in consumption of the pipe, a sealing portion is formed in the cap so as to be in close contact with a peripheral portion of the ventilation hole in the exterior body, and the cap is formed in a front portion of the main body. When the cover is fitted, the vent hole is sealed, and a gap is formed between the cap inside space on the distal end side of the sealed portion and the cap opening end. Ballpoint pen. 2. An annular press-contact band is formed on the inner wall of the cap as the sealing portion, and a concave portion not including an opening edge of the ventilation hole forming the gap is formed in the exterior body in which the ventilation hole is formed. The ballpoint pen according to claim 1, wherein: 3. The cap inner hole has a non-circular cross-sectional shape, and the outer casing has a non-circular shape corresponding thereto.
2. The ball-point pen according to claim 1, wherein a recess is formed in the inner wall of the cap, the recess not including the sealing portion, and the rotation is restricted when the cap is fitted.