JP2002036778A - Ballpoint pen - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent leakage of a follower and an ink in an ink housing tube to the outside on impact. SOLUTION: In an ink housing tube 4, an ink 41 and a follower 42 in a greased state are housed. The ink housing tube 4 is housed in a barrel 2. A tail plug 5 is inserted in a rear end opening of the barrel 2. A bottomed barrel part 51 insertable into the rear end opening of the barrel 2 is provided at the plug 5. The bottomed barrel part 5 has its front end opened and its rear end closed. A contacting part 8 which abuts against the rear end of the ink housing tube 4 in a shaft direction, and in a peripheral contact is provided at the front end of the bottomed barrel part 51.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a ballpoint pen. More specifically, the present invention relates to a ball-point pen in which ink and a grease-like follower are accommodated in an ink accommodating tube accommodated in a barrel, and a tail plug is fitted to a rear end of the barrel. In the present invention, “front” indicates the pen tip side, and “rear” indicates the tail plug side.

[0002]

2. Description of the Related Art Conventionally, in a ballpoint pen of this kind, a rear end face of an ink container is supported by a plurality of radial vertical ribs provided on an inner surface of a tail plug (for example, Utility Model Registration No. 2590457). Alternatively, a configuration is known in which the rear end opening of the ink storage tube is closed by a cylindrical portion having an air flow hole in the bottom wall (for example, Japanese Patent Application Laid-Open No. H11-20370).

[0003] The above-mentioned conventional ball-point pen is,
The follower and the ink in the ink storage tube may move backward, and the follower and the ink may leak from the rear end opening of the ink storage tube. At that time, the utility model registration No. 25904
In the case of the No. 57 type, since the rear end face of the ink storage tube and the vertical rib abut in a substantially point-like manner, the gap between the adjacent vertical ribs is large, so that even if the air passage is sufficient, It is not enough to prevent leakage of body and ink. for that reason,
The follower and the ink move from the rear end opening of the ink storage tube to the space between the inner surface of the barrel and the outer surface of the ink storage tube through the vertical ribs, and finally from the air hole at the front of the barrel. May leak to the outside. Further, Japanese Unexamined Patent Application Publication No. 11-2037
In the case of the No. 0 type, the follower and the ink may be scattered outside from the air flow hole of the tail plug due to impact or the like.

The present invention solves the above-mentioned conventional problems. Even if the follower and the ink inside the ink container move backward due to an impact or the like, the follower and the ink leak or scatter outside. An object of the present invention is to provide a ball-point pen that is not likely to be damaged.

[0005]

Means for Solving the Problems [1] According to the present invention, an ink 41 is provided inside an ink container 4 having a pen tip 3 at a front end.
And a grease-like follower 42 which advances with consumption of the ink 41 is accommodated, the ink accommodating tube 4 is accommodated inside the barrel 2, and the pen tip 3 is projected from the front end of the barrel 2. A ball-point pen 1 having a tail plug 5 fitted into a rear end opening of the barrel 2, the tail plug 5 being insertable into a rear end opening of the barrel 2, having a front end opened and a rear A bottomed tubular portion 51 whose end is closed is provided, and a contact portion 8 is provided at the front end of the bottomed tubular portion 51 so as to axially abut against the rear end of the ink storage tube 4 and to come into circumferential contact therewith. (Claim 1) is a requirement.
(See FIGS. 1 to 4)

(Operation) When an impact or the like is applied to the ballpoint pen 1 of the present invention, it is assumed that the follower 42 and the ink 41 in the ink container 4 move rearward and leak from the rear end opening of the ink container 4. Also, since the contact portion 8 at the front end of the bottomed tubular portion 51 is in circumferential contact with the rear end between the ink containers (that is, non-point contact), the follower 4 leaked from the ink storage tube 4
2 and the ink 41 are accommodated in a bottomed tubular part 51 whose rear end is closed. Thereby, the follower 42 and the ink 41
Does not leak through the gap between the inner surface of the barrel 2 and the outer surface of the ink storage tube 4 to the outside through the air hole at the front part of the barrel 2, and does not leak or scatter outside from the rear end of the barrel 2. .

[2] In the ballpoint pen 1 according to the first aspect, a radial notch is provided at a front end of the bottomed tubular portion 51, and the notch serves as a non-contact portion 7 with the rear end of the ink storage tube 4. It is preferable that the front end of the bottomed cylindrical portion 51 excluding the notch be a contact portion 8 with the rear end of the ink storage tube 4 (Claim 2). (See FIGS. 1 to 3)

(Action) The notch (that is, the non-contact portion 7)
As a result, the rear end of the ink storage tube 4 and the bottomed tubular portion 51 of the tail plug 5
Between the ink storage tube 4 and the front end of the ink storage tube 4 can be ventilated. Thereby, the space behind the follower 42 inside the ink storage tube 4 can be always maintained at the atmospheric pressure, and the follower 42 can be appropriately moved forward with the consumption of ink during writing.

[3] In the ballpoint pen 1 according to claim 1, a radial notch is provided at a rear end of the ink storage tube 4, and the notch is formed in a non-contact portion 7 with the front end of the bottomed tubular portion 51. Preferably, the rear end of the ink storage tube 4 excluding the notch is a contact portion 8 with the front end of the bottomed tubular portion 51 (Claim 3). (See Fig. 4)

(Action) The notch (that is, the non-contact portion 7)
As a result, the rear end of the ink storage tube 4 and the bottomed tubular portion 51 of the tail plug 5
Between the ink storage tube 4 and the front end of the ink storage tube 4 can be ventilated. Thereby, the space behind the follower 42 inside the ink storage tube 4 can be always maintained at the atmospheric pressure, and the follower 42 can be appropriately moved forward with the consumption of ink during writing.

[4] In the ball-point pen 1 according to claim 2 or 3, the circumferential length of the contact portion 8 is set to be larger than the circumferential length of the non-contact portion 7 (claim 4).
Is preferred. Thereby, it is possible to further prevent the follower 42 and the ink 41 from leaking from the non-contact portion 7 (notch) to the outside of the ink storage tube 4 and the tail plug 5. If the total length of the contact portion 8 in the circumferential direction is smaller than the total length of the non-contact portion 7 in the circumferential direction, the outer surface of the ink storage tube 4 and the inner surface of the shaft cylinder 2 pass through the non-contact portion 7 (notch). And the follower 42 and the ink 41 may leak between them.

Here, the total length of the contact portion 8 in the circumferential direction means the sum of the circumferential lengths of the respective contact portions 8 when the contact portions 8 are formed at a plurality of positions. When the non-contact portions 7 are formed at a plurality of locations, the total length in the circumferential direction of 7 means the sum of the circumferential lengths of the respective non-contact portions 7.

[0013]

Embodiments of the present invention will be described with reference to the drawings.

(First Embodiment) FIGS. 1 and 2 show a ballpoint pen 1 according to a first embodiment of the present invention. The ballpoint pen 1 has a pen tip holder 6 in which the pen tip 3 is press-fitted and held at the front end, an ink accommodating pipe 4 in which the pen tip holder 6 is press-fitted and fixed in the front end opening, and the ink accommodating pipe 4 accommodated therein. Shaft barrel 2
And a tail plug 5 fitted into the rear end opening of the barrel 2.

The ink container 4 is a cylindrical body obtained by extrusion molding of a synthetic resin, and contains therein an ink (for example, a water-based gel ink provided with a shear thinning property or an oil-based ink having a medium viscosity). A grease-like follower 42 which moves forward with the consumption of the ink 41 at the rear end of the ink 41
And are filled.

The pen point 3 is a ball-point pen tip made of a metal body that rotatably holds a ball at the front end. The nib 3 has several types of ball seats. For example, a ball seat is formed by pressing and inwardly deforming a side wall of a metal body inward. Examples include a type formed by cutting the inner wall of the main body, and a type in which the ball receiving seat is formed of another member such as a synthetic resin.

The pen tip holder 6 is obtained by injection molding of a synthetic resin. The pen tip holder 6 is a cylindrical body having a hole penetrating in the axial direction (that is, a pen tip mounting hole and an ink circulation hole behind the pen tip mounting hole). The pen tip holder 6 includes a front portion, a flange portion 61 formed behind the front portion,
And a rear portion formed behind the flange portion 61. The pen tip 3 is secured to the front end of the pen tip holder 6 at the front end thereof, and projects out of the front end hole 21 of the barrel 2 together with the pen tip 3. The rear part of the pen tip holder 6 is press-fitted and fixed to the front end opening of the ink storage tube 4. The flange 61 of the pen tip holder 6 is in contact with the front end surface of the ink container 4 and has an outer diameter substantially equal to the outer diameter of the ink container 4.

A plurality of vertical ribs 62 are formed integrally on the front outer surface of the pen tip holder 6 and press-contact with the inner surface of the front end hole 21 of the barrel 2 so that the pen tip holder 6 is pressed. A ventilation path (that is, an air hole that communicates with the outside) is formed between the outer surface of the front end and the inner surface of the front end hole 21 of the barrel 2.

The shaft cylinder 2 is a cylindrical body obtained by injection molding of a synthetic resin, having a tapered front end portion, and having a hole penetrating in the axial direction therein. A plurality of vertical ribs 22 having an inclined surface are integrally formed on the inner surface of the front end portion of the barrel 2, and the flange portion 61 of the pen tip holder 6 is pressed against the inclined surface of the vertical rib 22. Thereby, a ventilation path is formed between the inner surface of the barrel 2 and the flange 61. In addition, an annular gap is formed between the outer surface of the ink storage tube 4 and the inner surface of the barrel 2, and serves as an air passage communicating with the rear end opening of the ink storage tube 4.

The air passage is not limited to the above embodiment. For example, a groove may be provided on the outer surface of the flange 61 or a groove may be provided on the outer surface of the ink container 4. . Further, the air hole is not limited to the above-described embodiment. For example, a groove may be provided on the inner surface of the front end hole 21 of the barrel 2, or a hole may be provided through the side wall of the barrel 2. You may.

The tail plug 5 is obtained by injection molding of a synthetic resin. The tail plug 5 has a cylindrical inner cylindrical portion 51 which is a bottomed cylindrical portion having an open front end and a closed rear end. A bottomed outer cylindrical portion 52 which is provided inside and has a front end opened and a rear end closed is concentrically and integrally connected.

The front end of the inner tubular portion 51 of the tail plug 5 is in line or surface contact with the rear end of the ink storage tube 4 in a circumferential manner.
The outer diameter of the front end surface of the inner tube portion 51 is set to be larger than the inner diameter of the rear end surface of the ink container tube 4, and the size of the inner tube portion 51 is set substantially equal to the rear end surface of the ink container tube 4. The inner diameter of the front end face is set smaller than the outer diameter of the rear end face of the ink storage tube 4). Two square notches (that is, non-contact portions 7) are provided at the front end surface of the inner cylindrical portion 51 at opposing positions. Then, the front end surface of the inner cylindrical portion 51 excluding the notch can be a contact portion 8 with the rear end surface of the ink storage tube 4. The circumferential length of the contact portion 8 on the front end face of the inner cylindrical portion 51 (that is, the sum of the circumferential lengths of the two arc-shaped contact portions 8) is calculated as the circumferential length of the non-contact portion 7. (That is, the sum of the circumferential lengths of the two notches).

The bottom wall 53 of the outer cylinder 52 of the tail plug 5
Is annular, and connects the outer tube portion 52 and the inner tube portion 51. Further, the bottom wall 53 of the outer cylinder portion 52 is
Close to the rear end face in the axial direction, so that
Even if the follower 42 and the ink 41 overflow from the inside of the inner cylinder portion 51 (that is, the bottomed cylinder portion), the leakage of the follower 42 and the ink 41 from the rear end of the barrel 2 is avoided. be able to. The inner surface of the outer cylindrical portion 52 of the tail plug 5
The outer surface of the rear end portion of the barrel 2 is fitted (for example, screw fitting, press fitting, or over-riding fitting).

Further, since the front end of the inner cylinder 51 projects forward from the front end of the outer cylinder 52, when the tail plug 5 is fitted into the rear end opening of the shaft cylinder 2, The cylindrical portion 51 (that is, the bottomed cylindrical portion) can be smoothly inserted into the shaft cylinder 2, and assemblability is improved.

(Second Embodiment) FIG. 3 shows a second embodiment (a modification of the first embodiment). In this embodiment, as in the first embodiment, a notch is provided in the front end surface of the bottomed tubular portion 51 of the tail plug 5 so that a line contact or a surface contact is made circumferentially with the rear end surface of the ink storage tube 4. A non-contact portion 7 that forms a ventilation path is provided between the contact portion 8 and the rear end surface of the ink storage tube 4. The difference from the first embodiment is that the bottomed cylindrical portion 5 of the tail plug 5
The outer surface of the rear portion 63 of the first cylinder is fitted to the inner surface of the rear end opening of the barrel 2 (for example, screw fitting, press fitting, or crossover fitting).
However, there is no portion corresponding to the outer cylindrical portion 52 of the first embodiment. The other configuration is the same as that of the first embodiment, and the description is omitted.

(Third Embodiment) FIG. 4 shows a third embodiment (a modification of the first embodiment). The present embodiment is different from the first embodiment in that the front end surface of the inner cylindrical portion 51 (that is, the bottomed cylindrical portion) of the tail plug 5 is not provided with a notch, and two rear ends of the ink storage tube 4 are provided. Is formed at opposing positions. The notch provides a non-contact portion 7 that forms a ventilation path between the front end surface of the inner cylinder portion 51 and the front end surface of the inner cylinder portion 51 at the rear end surface of the ink storage tube 4 other than the notch. A contact portion 8 that makes line contact or surface contact is provided.
The other configuration is the same as that of the first embodiment, and the description is omitted.

[0027]

According to the first aspect of the present invention, even when an impact or the like is applied, the follower and the ink in the ink storage tube move rearward and leak from the rear end opening of the ink storage tube, and the follower and the ink remain in the ink storage tube. There is no danger of leakage or scattering outside the barrel.

According to the second aspect of the present invention, the space behind the follower inside the ink storage tube can always be maintained at the atmospheric pressure, and during writing, the follower can be appropriately moved forward with the consumption of ink. it can.

According to the third aspect, the space behind the follower inside the ink storage tube can always be maintained at the atmospheric pressure, so that the follower can be properly moved forward with the consumption of ink during writing. it can.

According to the fourth aspect, it is possible to further prevent the follower and the ink from leaking from the non-contact portion (notch).

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a first embodiment of the ballpoint pen of the present invention.

2A is a plan view of the tail plug of FIG. 1, and FIG. 2B is a front view of the tail plug of FIG.

FIG. 3 is a longitudinal sectional view of a ballpoint pen according to a second embodiment of the present invention.

FIG. 4 is a longitudinal sectional view of a third embodiment of the ballpoint pen of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ball-point pen 2 Shaft cylinder 21 Front end hole 22 Vertical rib 3 Pen tip 4 Ink storage tube 41 Ink 42 Follower 5 Tail plug 51 Inner cylinder part (bottomed cylinder part) 52 Outer cylinder part 53 Bottom wall 6 Pen tip holder 61 Flange part 62 vertical rib 7 non-contact part (notch) 8 contact part

Claims (4)

[Claims] 1. An ink container having a pen tip at a front end thereof accommodates an ink and a grease-like follower advancing with consumption of the ink, and accommodates the ink container in a shaft cylinder. A ball-point pen having a pen tip protruding from a front end of the barrel, and a tail plug fitted into a rear end opening of the barrel, wherein the tail plug can be inserted into a rear end opening of the barrel. There is provided a bottomed cylindrical portion having a front end opened and a rear end closed,
A ball-point pen, wherein a contact portion is provided at a front end of the bottomed cylindrical portion, the contact portion being in axial contact with the rear end of the ink storage tube and in circumferential contact therewith. 2. A front end of the bottomed cylindrical portion excluding the notch, wherein a notch in a radial direction is provided at a front end of the bottomed cylindrical portion, and the notch is a non-contact portion with a rear end of the ink storage tube. 2. The ball-point pen according to claim 1, wherein a contact portion with a rear end of the ink storage tube is provided. 3. A notch in a radial direction is provided at a rear end of said ink storage tube, said notch being a non-contact portion with a front end of a bottomed cylindrical portion, and a rear end of said ink storage tube excluding said notch. To
The ballpoint pen according to claim 1, wherein the ballpoint pen is a contact portion with the front end of the bottomed cylindrical portion. 4. The ballpoint pen according to claim 2, wherein the total length of the contact portion in the circumferential direction is set to be larger than the total length of the non-contact portion in the circumferential direction.