JPH09104194A - Writing utensil using low viscosity ink - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a writing utensil having an ink reserving part, in which enough amount of ink can be reserved. SOLUTION: This writing utensil is provided with a top axial tube, an ink inductive core extending along its center axis line within the top axial tube, a pen body provided integrally with the ink inductive core on the tip side of the ink inductive core, a pen core 14 having a bellows-like ink reserving part 14b, which is formed radially outside the ink inductive core and separate from the ink inductive core, and an ink cartridge 22, in which low viscosity ink is housed. In addition, the ink reserving part 14b is equipped with an axially extending gas-liquid exchange groove 14, a plurality of annular reserving grooves 14d, the groove width of each of which becomes gradually larger towards the axial front, and a first flank groove 14e extending axially adjacent to the gas- liquid exchange groove 14c. Further, the gas-liquid exchange groove 14c and the first flank groove 14e are separated from each other through an axially extending partition plate 14g. Furthermore, one end of each annular reserving groove 14d is so constituted as to communicate with the gas-liquid exchange groove 14c and the other end of each annular reserving groove 14d with the first flank groove 14e.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a writing instrument such as a direct liquid fountain pen using a low-viscosity ink, a marker pen, a felt-tip pen, and a water-based ballpoint pen.

[0002]

2. Description of the Related Art Conventionally, as a writing instrument using a low-viscosity ink, there is a writing instrument provided with a pen core having a bellows-shaped ink reservoir. FIG. 6A is a perspective view of the pen core seen from above, FIG. 6B is a perspective view seen from below, and FIG. 6C.
FIG. The pen core 4 includes a center cylinder 4a into which an ink guide core (not shown) is inserted, and a bellows-shaped ink band reservoir 4b provided on the outside in the radial direction of the center cylinder 4a. Gas-liquid exchange groove 4 extending in the axial direction
c, a plurality of annular band-retaining grooves 4d whose groove width increases toward the front in the axial direction, and an abdominal groove 4e for air bleeding that extends in the axial direction at a position substantially radially opposite to the gas-liquid exchange groove 4c. Consists of. The band reservoir groove 4d is divided into left and right when viewed from the gas-liquid exchange groove 4c and communicates with the abdominal groove 4e to form a substantially annular groove as a whole.

In a writing instrument equipped with such a pen core 4, when the internal pressure of the ink storage cylinder drops due to the consumption of ink by writing, air is stored through the gas-liquid exchange groove 4c in accordance with the consumption amount of the ink. The ink is supplied to the cylinder so that writing can be continued, and when the internal pressure of the ink storage cylinder rises due to temperature rise and atmospheric pressure change and more ink than necessary is supplied, excess ink is generated. Pen core 4
When the internal pressure in the ink storage cylinder is temporarily stored in the annular storage groove 4d, the surplus ink temporarily stored is returned to the ink storage cylinder, so that the ink is blown out or the pen body is damaged. The pre-accumulation phenomenon is reduced.

[0004]

When the excess ink is stored, the ink band reservoir is divided into the gas-liquid exchange groove 4c and is stored in the annular band reservoir groove, and the rear groove width is narrow. Ink is sequentially stored from the annular banding groove. However, when molding or assembling the pen core 4, variations occur in the groove width of the annular band retention groove 4d, or warpage occurs in the fin-shaped wall 4f partitioning the adjacent annular band retention grooves 4d. The width of the band reservoir groove that is divided into the left and right sides when viewed from the gas-liquid exchange groove 4c,
The groove shape etc. may not be the same. Therefore, the ink is less likely to be evenly stored on the left and right in the zoning groove and is gradually stored from the rear, and the ink is stored only on one of the left and right sides.
There was a problem that it could not be effectively stored in the storage groove in front of it, and it could not be used effectively.

Therefore, there is a problem that the ink is insufficiently stored and the tip of the pen body or the ink is ejected when the internal pressure of the ink storage cylinder rises. The present invention has been made in view of the above problems, and an object of the present invention is to provide a writing instrument using a low-viscosity ink capable of sufficiently storing ink in an ink band portion.

[0006]

In order to achieve the above object, a writing instrument using the low-viscosity ink of the present invention comprises a shaft cylinder,
An ink guide core extending on the central axis in the barrel, a pen body provided on the tip side of the ink guide core so as to contact the ink guide core integrally or separately, and an ink. A pen core having a bellows-shaped ink band reservoir formed separately from the ink guide core on the outer side in the radial direction of the guide core; and an ink storage cylinder for storing low-viscosity ink,
The ink band reservoir portion includes a gas-liquid exchange groove extending in the axial direction, a plurality of annular band reservoir grooves whose groove width increases toward the front in the axial direction, and an antinode extending in the axial direction adjacent to the gas-liquid exchange groove. The gas-liquid exchange groove and the abdominal groove are separated by a partition plate that extends in the axial direction.One end of each annular band reservoir groove communicates with the gas-liquid exchange groove, and the other end is an abdominal groove. It is characterized in that it is configured to communicate with the groove.

When the excess ink is stored, it is stored from the gas-liquid exchange groove into the annular band-reservoir groove. However, since one side of the gas-liquid exchange groove is isolated via the partition plate, the ink is different from the conventional one. The ink is not divided into right and left, and the ink is accumulated in one direction from the gas-liquid exchange groove to the annular band accumulation groove, and is further sequentially accumulated from the rear band accumulation groove having a strong capillary force. In this way, since the ink storage direction is set to one direction, it is possible to eliminate the leftover storage of the band-holding groove due to the left-right unbalance and to effectively use the band-holding groove near 100%.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a vertical cross-sectional view showing a form example of a writing instrument using a low-viscosity ink according to the present invention. In the figure, 10 is a front barrel, which is detachably screwed to the rear barrel 12 to form a barrel. However, the rear barrel 12 and the front barrel 10
It may not be removable and may be press-fitted and fixed.

A pen core 14 is provided in the front barrel 10. 2 is a perspective view of the pen core 14 seen from the upper rear side thereof, FIG. 3 is a perspective view of the pen core 14 seen from the lower rear side thereof, FIG. 4 is a cross-sectional view taken along the arrow A in FIG. 2, and FIG. FIG. 5 shows a cross-sectional view of FIG. The pen core 14 includes a center cylinder 14a into which the ink guide core 20 extending on the center axis is inserted, and a bellows-shaped ink band reservoir 14b formed on the outer periphery of the center cylinder 14a. The ink guide core 20 and the ink band reservoir 14b are radially separated from each other by the central cylinder 14a.

The ink band reservoir 14b has a gas-liquid exchange groove 14c having a narrow axial width and a larger width than the gas-liquid exchange groove 14c, and the width of the ink-liquid reservoir portion 14b is gradually increased toward the front in the axial direction. Ring-shaped storage groove 14d and gas-liquid exchange groove 14c
Abdominal groove 14e for air bleeding that extends axially adjacent to
And the gas-liquid exchange groove 14c in front of the first abdominal groove 14e.
A second abdominal groove 14f extending in the axial direction is formed at a position on the opposite side substantially in the radial direction. Gas-liquid exchange groove 14c
The first abdominal groove 14e and the first abdominal groove 14e are isolated from each other by a partition plate 14g extending in the axial direction. One end of each annular band reservoir groove 14d communicates with the gas-liquid exchange groove 14c and the other end of the first abdominal groove 14e. It is configured to communicate. In addition, an air hole 14h that can communicate with the outside air is formed on the front outer periphery of the pen core 14.
A pen body 18 integrally formed with the ink guide core 20 is held on the inner circumference of the tip of the pen core 14 and projects forward. In this embodiment, the pen body 18 is the ink guide core 20.
However, the pen body 18 and the ink guide core 20 may be separately formed so as to be in contact with each other.

Further, the tip of an ink cartridge 22 which is an ink storage cylinder is inserted and connected to the boss portion 10a which projects rearward from the front barrel 10. The ink cartridge 22 may be detachably connected to the front barrel 10 for replacement, but may be an ink storage cylinder fixedly connected to the front barrel 10 by press fitting. .

The ink cartridge 22 contains low-viscosity ink, and a plurality of ribs 22a extending in the axial direction are formed on the inner peripheral surface of the ink cartridge 22 to prevent the ink from moving in the cartridge 22 due to surface tension. Is being prevented. A connection hole 10e penetrating the inside of the boss portion 10a makes the inside of the ink cartridge 22 communicate with the rear ends of the ink guide core 20 and the gas-liquid exchange groove 14c. On the front surface of the base of the boss portion 10a, there are formed a first step portion 10f with which the rear end edge of the pen core 14 abuts, and a second step portion 10g which is on the central axis side of the first step portion 10f and is drawn rearward. ing. That is, the pen core 14 is fixed in the front barrel 10 by being stopped from moving backward by the first step portion 10f, and a gap 24 is provided between the second step portion 10g and the rear end of the pen core 14.

Reference numeral 30 is a cap, and the cap 30
Includes a top body 31, a cylindrical body 32, a covering body 33 arranged in the cylindrical body 32, a spring 34 for urging the covering body 33 toward the pen body 18, and a clip 35.
Is completely attached to the front barrel 10, the covering body 33 is biased, and the inside of the end of the covering body 33 comes into close contact with the front end of the pen core 14, thereby blocking the pen body 18 and the air hole 14h from the outside air,
Ink is prevented from evaporating from the pen body 18 and the air holes 14h.

In the writing instrument configured as described above,
The ink in the ink cartridge 22 is the ink guide core 20.
Is supplied to the pen body 18 via the. Further, the air hole 14h through the gas-liquid exchange groove 14c prevents the pressure inside the ink cartridge 22 from being reduced due to ink consumption and prevents the pressure inside the ink cartridge 22 from rising due to a change in atmospheric pressure and a temperature rise. Further, when the pressure in the ink cartridge 22 rises, the excess ink is stored from the gas-liquid exchange groove 14c to the annular band-holding groove 14d.

At this time, since one side of the gas-liquid exchange groove 14c is isolated via the partition plate 14g, the ink is not divided into the left and right as in the conventional case, and the ink is separated into the gas-liquid exchange groove 1.
It is stored in the annular band reservoir groove 14d in one direction from 4c and is sequentially stored from the rear band reservoir groove 14d having a narrow groove width. In this way, because the ink storage direction is one direction,
It eliminates the residual bandage caused by the imbalance between the left and right sides of the bandage groove as seen from the gas-liquid exchange groove as in the conventional case, and the bandage groove is made 100
% Can be used effectively. Even if an error occurs in the groove width or the groove shape of the band-holding groove during molding or assembly, the tendency that the groove width becomes wider as it goes forward is maintained, so that the backward width of the groove having a strong capillary force is narrowed. Obizo groove 14
It is possible to store the water sequentially from d. Since the ink is stored from the rear side, it is sufficient to provide the partition wall 14g only on the rear side as in this example, but it is also possible to further extend the partition wall 14g and the first abdominal groove 14e to the front side. Is. In this way, in this embodiment, since the ink can be sufficiently stored, it is possible to prevent the tip of the pen body and the ink from being blown out when the internal pressure of the ink storage cylinder rises.

[0016]

As described above, according to the present invention,
Set the ink storage direction from the gas-liquid exchange groove to the ring-shaped banding groove to 1
Since only the direction is set, the remaining unreserved area of the band-reservoir groove due to the imbalance of the annular band-reservoir grooves located on the left and right sides of the conventional gas-liquid exchange groove is eliminated, and the band-reservoir groove is 100%.
It can be used effectively in the near future.

[Brief description of the drawings]

FIG. 1 is a vertical cross-sectional view showing a form example of a writing instrument using a low-viscosity ink according to the present invention.

FIG. 2 is a perspective view of the pen core of FIG. 1 as seen from above a rear portion thereof.

FIG. 3 is a perspective view of the pen core of FIG. 1 as viewed from below a rear portion thereof.

4 is a cross-sectional view taken along the arrow A in FIG.

5 is a cross-sectional view taken along the arrow B in FIG.

FIG. 6A is a perspective view of a pen core used in a conventional writing instrument as seen from above, and FIG. 6B is a perspective view as seen from below.
(C) is a plan view.

[Explanation of symbols]

 10 Front barrel 12 Rear barrel 14 Pen core 14b Ink band reservoir 14c Gas-liquid exchange groove 14d Band reservoir 14e First abdominal groove (abdominal groove) 14g Partition plate 18 Pen body 20 Ink guide core 22 Ink cartridge

Claims (1)

[Claims] 1. A shaft cylinder, an ink guide core extending on a central axis in the shaft cylinder, and a tip end side of the ink guide core integrally with the ink guide core or separately from the ink guide core. A pen core provided, a pen core having a bellows-shaped ink band reservoir formed separately from the ink guide core on the outer side in the radial direction of the ink guide core, and an ink storage cylinder for storing low-viscosity ink, The ink band reservoir comprises a gas-liquid exchange groove extending in the axial direction, a plurality of annular band reservoir grooves whose groove width increases toward the front in the axial direction, and an axial direction adjacent to the gas-liquid exchange groove. The gas-liquid exchange groove and the abdominal groove are separated by a partition plate extending in the axial direction, and one end of each annular band reservoir groove communicates with the gas-liquid exchange groove. Writing instrument using low-viscosity ink, characterized in that the end is configured to communicate with the abdominal groove