JP3065593B2 - Writing implement - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a writing instrument in which a small amount of ink is pulled back from a pen when writing is completed, thereby preventing excess ink from being supplied to the pen. More specifically, the present invention forms a small volume chamber in the middle of a passage for supplying ink from the ink chamber to the pen body,
The present invention relates to a writing implement that performs the above-described ink pull-back action by expansion and contraction of a gas sealed in the small chamber.

[0002]

2. Description of the Related Art Generally, a pen body such as a ball tip and a felt tip in a writing instrument has an ability to draw out and hold ink by its own capillary force. For example,
In the above ball chip, there is a minute gap between the ball and the ball holder holding the ball, and the ink is drawn out and held by the capillary force of the gap. In a felt chip or the like, the ink is drawn out and held by the capillary force of the minute gap between the bound fibers.

For this reason, if these pen bodies and the ink chamber are directly communicated with each other, these pen bodies contain ink up to a saturation state during non-writing, and become a so-called ink-rich state. Is undesirably darkened.

[0004] In order to prevent such a problem, for example, a porous member which is made of solidified fibers and is called a relay core is inserted into an ink passage between the ink chamber and the pen body, and its capillary force and ink flow are increased. The supply of the ink to be supplied to the pen body is controlled by the resistance. A flow control mechanism that opens only during writing may be provided in the middle of the ink passage to control the supply of ink. However, even when the above-described ink supply control is performed, surplus ink may be pushed out to the pen body.

That is, in the above-described ink supply control, ink is naturally supplied to the pen body during writing. In this case, when writing is performed quickly, the amount of ink consumption increases, and when the amount of supplied ink is insufficient, problems such as blurred handwriting occur. Therefore, the supplyable flow rate of ink during writing is set to a supply flow rate that has a sufficient margin for the maximum consumption during writing.

Therefore, when writing is stopped, the ink that has been supplied up to that time may be pushed out to the pen body, and the pen body may contain more ink than necessary. In such a case, the next time you start writing,
There is a problem that handwriting becomes undesirably dark.

In particular, in a ball chip using water-based ink, the ink is held in a minute gap between the ball and the ball holder, so that the amount of ink that can be held is very small. When the ink is supplied, surplus ink may be pushed out around the ball from the gap. When writing is started in such a state, the starting end of the line of the handwriting becomes a comma (,), which causes a problem that the appearance of the handwriting is impaired.

In order to prevent such a problem, for example, the density of the above-mentioned relay core may be increased to increase the capillary force and the flow resistance inside the relay core. The flow resistance of the ink flowing through becomes excessive. For this reason, as described above, when writing is performed quickly, for example, the ink supply is insufficient and the amount of ink contained in the pen body is so small that the ink is in a so-called ink poor state. Sometimes.

[0009]

SUMMARY OF THE INVENTION The present invention has been made based on the above circumstances, and when writing is completed, a small amount of ink supplied to the pen body is pulled back, and the surplus ink is stored in the pen body. It is intended to provide a writing instrument that can prevent the writing instrument from being pushed out.

[0010]

According to a first aspect of the present invention, there is provided a writing implement including an ink chamber for storing ink and a pen provided at a tip end of the writing implement. a chamber enclosing the quantification of gas, and the ink chamber side passage communicating the this chamber and said ink chamber, and a pen side passage communicating the pen body of the chamber and above said ink chamber-side passage Is provided with an ink chamber side resistance means for providing a predetermined flow resistance to the flow of ink by writing, and the pen body side passage has a predetermined flow resistance against the flow of ink by writing. And a flow resistance of the resistance means on the ink chamber side is set to be larger than a flow resistance of the resistance means on the pen body side. .

Therefore, at the time of writing, ink is supplied to the pen body through the resistance means on the ink chamber side, and the flow resistance of the ink by the resistance means causes the ink inside the small chamber on the downstream side to be supplied. The pressure becomes negative, and the gas sealed in the chamber expands slightly. When writing is stopped, the gas supplied to the pen body is pulled back by a small amount due to the contraction of the gas in the small chamber. Therefore, pushing out of surplus ink to the pen body at the time of stopping writing is prevented. Since the amount of ink withdrawn due to the contraction of the gas in the small chamber as described above is very small as described above, even when the pen body is a ball chip, all the ink held inside the pen body is pulled back. It will not interfere with the next writing.

[0012]

[0013]

[0014]

[0015]

According to a second aspect of the present invention, the resistance means on the ink chamber side is a porous relay core inserted into the ink chamber side passage. is there. In such a relay core, the flow resistance of the ink can be easily and surely set to a predetermined value depending on the density, so that the characteristics are more stable and the manufacture is easier.

According to a third aspect of the present invention, the resistance means on the ink chamber side is a flow path having a minute cross section formed in the ink chamber side passage. . Such a passage having a minute cross section can be formed by forming a fine groove, fine unevenness, or the like on a fitting surface of a component constituting the writing instrument, and is easy to manufacture and has stable characteristics.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 to 8 show a first embodiment of the present invention. This embodiment is a disposable writing instrument having a ball tip using water-based ink. In this embodiment, the supply of ink and the action of pulling back ink from the pen body are performed by a gas such as air sealed in a small chamber.

Reference numeral 1 in the drawing denotes a barrel of the writing instrument,
An ink chamber 2 for storing aqueous ink is formed in the barrel 1. In this ink chamber 2, liquid ink is stored and a slide stopper 3 is inserted.
This ink and air are partitioned.

A gap is formed between the outer peripheral surface of the slide stopper 3 and the inner peripheral surface of the ink chamber 2, and the slide stopper 3 maintains a non-contact state with the inner peripheral surface of the ink chamber 2. The sliding resistance is set to be substantially zero. In addition,
A liquid film of ink is interposed between the slide stopper 3 and the inner peripheral surface of the ink chamber 2 to prevent direct contact,
Maintains sealing properties.

The slide plug 3 is formed, for example, in a hollow shape and has a specific gravity smaller than that of the ink, and has a floating property with respect to the ink. Therefore,
The slide stopper 3 does not settle even when the writing instrument is upright, and has a sealing property even when the writing instrument is inverted, so that the ink and the slide stopper 3 do not descend, and the ink in the ink chamber 2 always remains. And the air are surely partitioned.

The slide stopper 3 moves in response to the expansion and contraction of the ink to compensate for the expansion and contraction, and the slide stopper 3 moves forward as the ink is consumed. The tail end of the ink chamber 2 is closed by a tail plug 6, and the air side of the ink chamber 2 communicates with the atmosphere via an atmosphere communication tube 7 formed in the tail plug 6. Therefore, the pressure of the ink in the ink chamber 2 is always maintained at a pressure equal to the atmospheric pressure. A small amount of silicone oil or the like is sealed inside the ink chamber 2 on the air side to ensure a seal, and the silicone oil is prevented from leaking to the outside by the atmosphere communication cylinder 7. .

A pen holder 4 is attached to the distal end side of the barrel 1. A pen body, in this embodiment, an aqueous ball tip 5, is attached to the distal end of the pen holder 4. . A cap 8 is detachably fitted to the tip of the barrel 1. The pen body, for example, the ball chip 5 and the ink chamber 2 are communicated via an ink control mechanism 10 as described below.

FIG. 2 shows the ink control mechanism 10 in an enlarged manner. The ink control mechanism 10 includes a small-sized shut-off chamber 11 as a small chamber for containing gas that serves both to control the supply of ink and to pull back ink from the pen body. In this embodiment, a linear through-hole is formed in the center of the pen body holder 4 along the axial direction, and the center of the through-hole is formed as the above-described blocking chamber 11. The through hole on the upper side of the cutoff chamber 11 communicates with the ink chamber 2 and is configured as an ink chamber side passage 12. The lower through hole of the shutoff chamber 11 communicates with the ball chip 5, and is configured as a pen body side passage 13. And this shutoff room 11
A predetermined amount of gas, air in this embodiment, is sealed therein.

In the ink chamber side passage 12,
An ink chamber side relay core 14 is inserted as a resistance means on the ink chamber side. The ink chamber side relay core 14 is made of, for example, a porous material in which fibers are solidified into a rod shape. The ink is drawn out of the ink chamber 2 by the capillary force of a fine gap between these fibers, and a predetermined amount is supplied to the ink flowing inside. It is configured to provide a flow resistance.

An ink holding passage 18 as ink holding means capable of holding ink is formed between the upper portion of the above-mentioned shut-off chamber 11 and the ink chamber side passage 12. In the present embodiment, the ink holding passage 18 is a portion having the same diameter as that of the above-described shut-off chamber 11 and is continuous.
The free surface 20 of the ink 19 that has flowed into the ink 19 is formed on the lower surface thereof by surface tension, and is held in a liquid column shape.

Since the ink holding passage 18 has a small diameter, the lower end of the ink 19 held in a liquid column shape has a free surface 2.
It is held by the surface tension of 0, and is configured so that a part of the liquid column-shaped ink 19 does not flow into the shut-off chamber 11 instead of the air in the shut-off chamber 11. In order to achieve such a holding action, the inner diameter of the ink holding passage 18 is preferably set to, for example, 3 mm or less. It should be noted that this value is for the case of using water-based ink, and this inner diameter differs depending on the type of ink used. In general, if the inner diameter of the ink holding passage 18 is 6 mm or less, air and ink are used. And ink can be held in a liquid column shape.

A pen body relay core 21 for supplying ink to the ball chip 5 is inserted into the pen body side passage 13 as a pen body resistance means. It is formed of the same material as the ink chamber side relay core 14. In this embodiment, the upper part of the pen body-side relay core 21 projects into the lower part of the above-mentioned shut-off chamber 11 and is formed as a relay body 15, and this relay body 15 constitutes ink relay means. .

The relay body 15 has a tip portion formed into a sharp conical portion 16. A slight gap is formed between the outer peripheral surface of the relay body 15 and the inner peripheral surface of the shutoff chamber 11. A wedge-shaped annular gap is formed between the base outer peripheral surface of the conical portion 16 of the relay body 15 and the inner peripheral surface of the shut-off chamber 11. 17 are formed.

Further, in this embodiment, the density of the ink chamber side relay core 14 is formed higher than the density of the pen body side relay core 21, and therefore, the ink chamber side relay core 14 Is the flow resistance when
The flow resistance is set to be larger than the flow resistance when the ink flows through the pen body-side relay core 21.

Next, the operation of the first embodiment will be described with reference to FIG.
This will be described with reference to FIG. FIG. 3 shows a non-writing state of the writing instrument. A small amount of air of a predetermined amount is sealed in the shut-off chamber 11 to shut off ink in the ink chamber-side passage 12 and ink in the pen body-side passage 13. In this case, although the ink flows from the ink chamber side passage 12 into the ink holding passage 18,
As described above, the free surface 20 of the ink 19 is formed on the lower surface by surface tension, and is held in a liquid column shape. The pen body-side relay core 21 and the portion of the relay body 15 above the pen body-side relay core 21 contain substantially saturated ink, and are in a so-called ink-rich state. Also,
The ink reservoir 17 at the base of the conical portion 16 of the relay body 15
A predetermined amount of liquid ink is stored and held by capillary force.

In such a state, that is, in a state of non-writing, the ink in the ink holding passage 18 is blocked by the cutoff chamber 1.
1 and is held at a predetermined position as described above. In this case, the communication between the ink in the ink chamber side passage 12 and the ink in the pen body side passage 13 is interrupted, and the ink in the ink chamber 2 undesirably loses the pen body, that is, the ball chip. 5 is not supplied. Therefore, the ball chip 5 is prevented from containing surplus ink.

Next, when writing is performed by the writing instrument, the ink in the pen body-side relay core 21 is consumed. In this case, since the liquid ink is stored and held in the ink reservoir 17 around the base of the relay 15 above the pen body-side relay core 21, the ink in the ink reservoir 17 has priority. To be consumed.

That is, when the ink in the saturated porous body, that is, in this case, the ink in the pen body-side relay core 21 and the relay body 15 is consumed, the ink existing in the saturated state on these surfaces is removed from the porous body. When being drawn in from the surface of the porous relay body 15, a certain degree of negative pressure is required. However, the ink stored and held in the ink reservoir 17 is in contact with the outer peripheral surface of the base of the relay body 15, and the base surface of the relay body 15 is immersed in the ink at the contact portion of the ink. , Is in a saturated state. Therefore, when the ink in the relay body 15 is consumed, the ink is sucked from the portion having the least resistance, that is, the ink reservoir 17, so that the ink in the ink reservoir 17 is preferentially consumed.

When the ink in the ink reservoir 17 is consumed in this manner, the volume of the space in the shut-off chamber 11 increases accordingly, and the pressure of the air sealed in the shut-off chamber 11 is reduced. Decrease. As a result, as shown in FIG. 4, the liquid columnar ink 19 held in the ink holding passage 18 descends so as to compensate for the pressure drop. When the free surface 20 of the liquid columnar ink 19 contacts the tip of the conical portion 16 of the relay body 15, the surface of the conical portion 16 is wet with the ink.
A part of the surface tension of the free surface 20 is broken, and a part of the ink is transmitted along the surface of the conical portion 16 to form the ink reservoir 1.
It is transferred to 7.

When the ink accumulates in the ink reservoir 17, the volume of the space in the shut-off chamber 11 decreases accordingly, and the pressure of the air sealed in the space increases.
The liquid column-shaped ink 19 in the ink holding passage 18 is pushed up. Thereby, as shown in FIG. 5, the free surface 20 separates from the conical portion 16 again, and returns to the state as shown in FIG.

When the writing is continued, the ink in the ink reservoir 17 is consumed again, and the above operation is repeated, whereby the ink in the ink chamber 2 is supplied to the ball chip 5. Since the volume inside the shut-off chamber 11 is small and the dimensions of the relay body 15 and the like are also small,
When the free surface 20 of the ink 19 in the portion 8 contacts the tip of the conical portion 16 of the relay body 15, a part of the ink 19 is transferred to the ink reservoir 17 in a very short time.

The above operation is basically an intermittent operation. Therefore, while writing is continued, ink is intermittently supplied to the ball chip 5 by the intermittent operation as described above. However, as mentioned above,
This intermittent ink supply operation is repeated in an extremely short cycle, and the pen body-side relay core 21 has a certain amount of ink storage capacity. No shading occurs.

In this embodiment, the density of the ink chamber side relay core 14 is higher than that of the pen body side relay core 21 and the flow resistance of the ink in the ink chamber side relay core 14 is set higher. Thus, the ink supplied to the ball chip 5 is pulled back.

That is, in the ball chip, ink attached to the surface of the ball is transferred to a writing surface such as a paper surface by the rotation of the ball. As described above, this ink is held by a capillary force in a minute gap between the ball and the ball holder that rotatably holds the ball, but the ink is also held in the ball holding portion in the ball holder. Liquid ink is held. Therefore, even if the supply of ink is controlled as described above, when the writing is completed and the rotation of the ball is suddenly stopped, a small amount of a small amount is formed from the gap between the ball and the ball holder. Ink may be pushed out. In this way, if there is excess ink extruded around the ball, the next time you start writing, the beginning of the line of the handwriting becomes a comma (,) as described above, and the handwriting A problem arises that the appearance is impaired.

In this embodiment, while the ink is consumed by writing, the ink in the ink reservoir 17 is always consumed, so that the pressure in the shut-off chamber 11 is negative. When the writing is completed, the cut-off chamber 11
Due to the negative pressure inside, the ink flows from the ink chamber side passage 12 and the pen body side passage 13 into the shut-off chamber 11. In this case, since the flow resistance of the ink chamber side relay core 14 in the ink chamber side passage 12 is set to be larger than the flow resistance of the pen body side relay core 21,
Before the ink flows into the shut-off chamber 11 from above, the ink flows back into the shut-off chamber 11 from the pen body side passage 13 side.

Since the ink in the ball holder of the ball chip 5 is pulled back by such a backflow of the ink,
As described above, the surplus ink is not pushed around the ball, so that a comma (,)-shaped portion can be reliably prevented from being generated at the start end of the handwriting line. Although the volume in the above-mentioned shut-off chamber 11 is small and the amount of ink pulled back as described above is very small, the amount of ink in the ball holder of the ball chip 5 is also very small. Is sufficient to cause the ink to be pulled back.

In this embodiment, in order to perform the above-described ink control operation, the above-described shut-off chamber 11 is required.
It is necessary to accurately set the amount of air enclosed in the inside. That is, if the amount of the enclosed air is too large, the distance between the free surface 20 of the liquid columnar ink 19 held in the ink holding passage 18 and the tip of the conical portion 16 of the relay body 15 is reduced. become longer. Therefore, even when the ink in the ink reservoir 17 is consumed and the ink 19 in the form of the liquid column descends, the free surface 20 may not contact the tip of the conical portion 16. If writing is continued in such a state, the ink inside the porous relay body 15 will be consumed, the amount of ink contained in the relay body 15 will be reduced, and the ink will be in an ink purer state. Relay 15
Air may be sucked into the interior. Once the air is sucked into the porous relay body 15 as described above, even if the ink is newly absorbed by the relay body 15 as described above, the air is not reliably removed, and the air is not removed together with the ink. Is sent to the ball chip 5, which causes trouble in writing on the ball chip 5.

When the amount of air sealed in the shut-off chamber 11 is small, the free surface 20 of the liquid column-shaped ink 19 becomes conical with only a small amount of ink in the ink reservoir 17 being consumed. It contacts the tip of the part 16. Therefore, the ink cutoff operation cannot be performed, and the ink in the ink chamber 2 is always continuous with the ball chip 5, and excessive ink is supplied to the ball chip 5, causing trouble in writing.

In this embodiment, in order to accurately enclose a predetermined amount of air in the shut-off chamber 11, the following manufacturing method of filling with ink is adopted. Hereinafter, this manufacturing method will be described with reference to FIGS.

First, the writing implement as described above is assembled.
In this case, the ink chamber side relay core 14, the pen body side relay core 21, the relay body 15 and the like are all kept in a dry state containing no ink. In addition, the ball chip 5 described above,
The slide stopper 3 and the tail stopper 6 are left unattached.

Then, the writing implement is held in a substantially vertical posture with the ball chip 5 side facing downward, and ink is injected into the ink chamber 2. The injected ink passes through the ink chamber side relay core 14 due to gravity and capillary force,
As shown in FIG. 6, the ink flows into the ink holding passage 18 and becomes a liquid columnar ink 19 which is held in the ink holding passage 18.

In this case, the pen body-side relay core 21 and the relay body 15 are in a dry state not containing ink, and air can pass through the inside. Therefore, the air in the cutoff chamber 11 passes through the pen body-side relay core 21 and the relay body 15 and is exhausted from the tip of the pen body holder 4. Then, as the air is exhausted, the liquid column-shaped ink 19 in the ink holding passage 18 descends.

Then, as shown in FIG. 7, when the free surface 20 of the liquid columnar ink 19 comes into contact with the tip of the conical portion 16 of the relay body 15, the ink is absorbed into the relay body 15 by capillary force. Is done. Since the size of the relay body 15 is small, this relay body 15
The ink is absorbed. When the ink is absorbed by the relay body 15, air cannot pass through the relay body 15, and the air remaining in the shut-off chamber 11 in this state is sealed in the shut-off chamber 11 as it is. You.

Next, when the ink is absorbed by the whole of the relay body 15 and the pen body side relay core 21 to a saturated state and becomes an ink rich state, as shown in FIG. It accumulates in the accumulating part 17. As a result, the volume of the space of the shut-off chamber 11 is reduced, so that the pressure of the enclosed air rises, pushing up the liquid-column-shaped ink 19, and the free surface 20 of the conical portion 16 of the relay body 15 is formed. Move away from the tip. Thereby, the inflow of the ink is stopped, and the non-writing state as shown in FIG. Next, the above-mentioned unmounted parts are mounted to complete the writing implement.

According to such a method, a precise amount of air required for the shut-off chamber 11 can be reliably sealed by a simple process of holding the writing instrument substantially vertically and injecting the ink into the ink chamber 2. can do.

The relay body 15 and the pen body-side relay core 2
1 has a relatively small diameter and a conical portion 16 at the upper end.
Since the ink is absorbed from the tips of the pen holders, the air inside these is pushed out to the tip side of the pen holder 4 together with the permeation of the ink, and the ink and the air do not mix inside these.

In the above-mentioned method, the above-mentioned shut-off chamber 11 is used.
Although the case where air is sealed in the inside has been described, the gas to be sealed is not limited to air. For example, when a special ink that reacts with oxygen is used,
The inside may be filled with nitrogen or an inert gas. In such a case, the inside of the writing instrument may be replaced with such a gas prior to the above-described steps.

The present invention is not limited to the above embodiment. For example, FIG. 9 shows a writing instrument according to a second embodiment of the present invention.

In the second embodiment, the relay 1
The tip of 5 is formed in a diagonally cut portion 25 cut diagonally. A wedge-shaped ink reservoir 17 is formed between the cut surface of the base of the oblique cut portion 25 and the inner peripheral surface of the cutoff chamber 11. Further, the free surface 20 of the liquid columnar ink 19 that has descended in the ink holding passage 18 comes into contact with the tip of the diagonally cut portion 25.

The structure of the second embodiment is the same as that of the first embodiment except for the above points. In FIG. 9, the same reference numerals are used for parts corresponding to those of the first embodiment. The description is omitted here.

The operation and the manufacturing method of the second embodiment are the same as those of the first embodiment.
According to the second embodiment, the oblique cutting section 2 can be obtained by simply obliquely cutting the rod-shaped member of the porous material constituting the relay body 15.
5 can be formed, so that manufacturing is easier.

FIG. 10 shows a third embodiment of the present invention. This is attached to the upper end of the pen body side relay core 21,
This is provided with a relay body 35 as a separate member. This relay 3
5 is formed of a solid material other than a porous material. The relay body 35 has a conical portion 36 which is formed in a conical shape at the tip end thereof and which is sharply formed. And
The relay body 35 is attached to the upper end of the pen body-side relay core 21 and inserted into the shut-off chamber 11. In addition, a gap is formed between the outer peripheral surface of the relay body 35 and the inner peripheral surface of the shutoff chamber 11, and the gap and the conical portion 3 are formed.
A wedge-shaped gap between the root of the nozzle 6 and the inner peripheral surface of the blocking chamber 11 is formed as an ink reservoir 17.

The relay body 35 is formed of a material having wettability with respect to ink, or has its surface subjected to a coating or surface treatment having wettability with respect to ink. In this embodiment, a thin relay groove 37 is formed on the peripheral surface of the conical portion 36 along the generatrix in order to reliably guide the ink.

The third embodiment has the same configuration as that of the first embodiment except for the above points. In FIG. 10, portions corresponding to those of the first embodiment are denoted by the same reference numerals. The description is omitted.

In this embodiment, the ink holding passage 1
When the free surface 20 of the ink 19 in the form of a liquid column in the contact portion 8 comes into contact with the tip of the conical portion 36 of the relay body 35, the ink is collected by the wettability of the surface and the capillary force of the relay groove 37. Except for transfer to part 17,
The operation is similar to that of the first embodiment.

In this embodiment, since the relay body 35 is not a porous material, even if the ink in the ink reservoir 17 is completely consumed, the free surface 20 of the ink 19 in the form of a liquid column can be used. Even if there is no contact with the body 35, no air is sucked into the relay body 35. Also,
There is no need to process a porous material such as hardened fibers, and the relay body 35 can be easily and accurately processed into a precise shape.

FIG. 11 shows a fourth embodiment of the present invention. This is attached to the upper end of the pen body side relay core 21,
This is provided with a relay member 45 as a separate member. This relay 4
5 is formed of a solid material other than a porous material. This relay body 45 is formed in a diagonally cut portion 46 whose tip end is cut off diagonally, and is formed sharply. The relay body 45 is attached to the upper end of the pen body-side relay core 21 and inserted into the shut-off chamber 11. Further, a gap is formed between the outer peripheral surface of the relay body 45 and the inner peripheral surface of the shut-off chamber 11, and this gap is configured as a relay gap 47 for relaying ink.

A plurality of narrow annular grooves 48 are formed on the outer periphery of the base end portion of the relay body 45 so as to be formed in a bellows shape.
The wedge-shaped gap between the bellows portion and the base of the above-mentioned oblique cutting portion 46 and the inner peripheral surface of the cut-off chamber 11 forms the ink pool portion 1.
7 is formed. And the above-mentioned relay gap 47
Communicates with the ink reservoir 17.

As in the third embodiment, the relay body 45 is formed of a material having wettability with respect to ink, or has a coating or surface having wettability with respect to ink on its surface. Processing has been performed.

The fourth embodiment has the same configuration as that of the first embodiment except for the above-mentioned points. In FIG. 11, parts corresponding to those of the first embodiment are denoted by the same reference numerals. The description is omitted.

In this embodiment, the ink holding passage 1
When the free surface 20 of the ink 19 in the form of a liquid column in the container 8 comes into contact with the tip of the oblique cutting portion 46 of the relay body 45 and the tip of the relay gap 47, the wettability of the surface and the capillary force of the relay gap 47. Accordingly, the same operation as in the third embodiment is performed except that the ink is transferred to the ink reservoir 17.

Further, the present invention is not limited to the above-described embodiment, and the above-mentioned shut-off chamber, ink reservoir, ink holding means, and ink relay means may have another structure. For example, FIG. 12 shows a fifth embodiment of the present invention.

In this embodiment, the bottom of the ink chamber 2 is
Ink holding surface 5 orthogonal to the central axis of the writing instrument
8 are formed. A cup-shaped cut-off chamber member 50 is fitted into the lower portion of the ink chamber 2, and a space surrounded by the lower concave portion and the ink holding surface 58 is formed as a cut-off chamber 51.

An ink chamber-side passage 52 is formed in the outer peripheral surface of the above-mentioned shut-off chamber member 50 in the axial direction. A throttle passage 54 is formed on the lower end surface of the shut-off chamber member 50 as an ink chamber-side resistance means. One end of the throttle passage 54 communicates with the ink chamber-side passage 52,
The other end is in contact with the ink holding surface 58 and opens in the lower part of the shutoff chamber 11.

As shown in FIG. 13, for example, the throttle passage 54 is composed of a large number of lattice-like narrow grooves 54a formed on the lower end surface of the cut-off chamber member 50. 52, and has an ink supply opening 54b that opens into the shut-off chamber 51 in contact with the ink holding surface 58 as described above.

As shown in FIG. 14, the throttle passage 54 is formed by a long arc-shaped narrow groove 54c formed on the lower end surface of the above-mentioned shut-off chamber member 50. An ink supply opening 54 d communicating with the passage 52 and in contact with the ink holding surface 58 and opening into the shut-off chamber 51 as described above may be used.

At the center of the ink holding surface 58, the upper end of the pen body side relay core 21 protrudes, and this protruding portion is formed as a relay body 55. And
A corner formed by the protruding base of the relay body 55 and the ink holding surface 58 is formed as an ink reservoir 57, and the ink is stored and held in the ink reservoir 57 by its surface tension. I have. A predetermined distance is set between the ink reservoir 57 at the base of the relay body 55 and the openings 54b and 54d on the outer periphery of the lower part of the cutoff chamber 51.

The fifth embodiment has the same configuration as that of the first embodiment except for the above-mentioned points. In FIG. 12, portions corresponding to those of the first embodiment are denoted by the same reference numerals. The description is omitted.

The device of this embodiment operates as follows. That is, at the time of non-writing, the above-mentioned ink reservoir 5
7 and the ink in the throttle passage 54
It is separated and blocked by the air enclosed inside.

When the ink in the ink reservoir 57 is consumed by writing, the volume of the space in the shut-off chamber 51 increases by that much, and the pressure of the air sealed in the shut-off chamber 51 decreases. I do. As a result, the ink enters the shut-off chamber 51 from the ink supply openings 54b and 54d via the ink chamber-side passage 52 and the throttle passage 54. However, the penetrated ink is held at the corner between the ink holding surface 58 and the inner peripheral surface of the shut-off chamber 51 in a state of being raised by the surface tension as shown by a two-dot chain line 59.

When the amount of the retained ink increases, the ink advances toward the center ink reservoir 57 and comes into contact with the root of the relay core 55 of the ink reservoir 57. By this contact, a part of the retained ink is transferred to the ink reservoir 57 by surface tension, and the ink is retained in the ink reservoir 57 again. By transferring a part of the ink in this manner, the ink that has entered through the opening of the throttle passage 54 retreats, separates from the ink reservoir 57, and is shut off again.

Further, in this embodiment, since the throttle passage 54 is formed in the ink chamber side passage 52, a large flow resistance is given when ink flows through the inside thereof.
Therefore, as described above, when the writing is stopped, the ink in the pen body side passage 13 and the pen body side relay core 21 is pulled back by the negative pressure of the air in the blocking chamber 51, and the surplus of the ball tip 5 around the ball is returned. Pull back the ink.

When the writing implement of this embodiment is manufactured, the pen body-side relay core 21 and the relay body 55 at the upper end thereof hold the writing implement in a dry state containing no ink substantially in the same manner as described above. Then, the ink is injected into the ink chamber 2.
The ink flows from the throttle passage 54 into the lower part of the shutoff chamber 51, travels on the ink holding surface 58, reaches the base of the relay body 55, and is absorbed by the porous relay body 55. Due to the absorption of the ink, the air is not exhausted through the relay body 55 and the pen body-side relay core 21, and the cut-off chamber 51
A predetermined amount of air is accurately enclosed therein.

The present invention is not limited to the above embodiment. For example, in the above embodiment, the flow resistance of the ink chamber-side resistance means is set to be larger than the flow resistance of the pen body-side resistance means, but the invention is not necessarily limited to this. For example, even if the flow resistance of these resistance means is made equal, or conversely, the flow resistance of the resistance means on the ink chamber side is made smaller than the flow resistance of the resistance means on the pen body side, the contraction of the gas in the cutoff chamber, that is, the small chamber. Accordingly, ink is drawn into the shut-off chamber from both sides, so that a small amount of ink can be drawn back from the pen body.

In each of the above embodiments, a resistance means such as a pen body-side relay core is inserted in the pen body side passage. However, it is not necessary to provide a resistance means in the pen body side passage. In some cases, the pen body-side passage resistance means may be omitted.

[0082] The resistance means of the present invention, in the flow path and the like of the wick and small cross-section of the porous as described above is not limited, fine orifice, machinery specific valve which opens at a small differential pressure mechanism,
Other means may be used.

Further, in the above-described embodiment, the gas filled in the small chamber, ie, the shut-off chamber, has been described as having both the ink supply control action and the ink pull-back action from the pen body. The operation of controlling the supply of ink by the gas is not always necessary, and the operation of controlling the supply of ink may be omitted in some cases.

Further, the present invention is not limited to the ball-tip type writing implement using the water-based ink as described above, but may be a writing implement using other inks or other types of pens, or a disposable writing implement. However, the present invention is not limited to this, and can be applied to an ink refill type writing instrument and a so-called refill type writing instrument in which an assembly of an ink chamber and a pen body can be replaced.

[0085]

As described above, in the writing implement of the present invention, when writing, ink is supplied to the pen body via the resistance means on the ink chamber side. The pressure in the small chamber on the side becomes negative pressure,
The gas enclosed in this chamber expands slightly.
When writing is stopped, the gas supplied to the pen body is pulled back by a small amount due to the contraction of the gas in the small chamber. Therefore, pushing out of surplus ink to the pen body at the time of stopping writing is prevented.

[0086] Therefore, pushing out of surplus ink from the pen body when writing is stopped is reliably prevented, and the effect is great, such as the structure is simple and the reliability is high.

[Brief description of the drawings]

FIG. 1 is an overall longitudinal sectional view of a first embodiment of a writing instrument according to the present invention.

FIG. 2 is a longitudinal sectional view of a part of an ink control mechanism of the writing instrument according to the first embodiment of the present invention.

FIG. 3 is an explanatory view of the operation of the first embodiment of the writing instrument of the present invention.

FIG. 4 is an explanatory view of the operation of the writing instrument according to the first embodiment of the present invention.

FIG. 5 is an explanatory view of the operation of the writing instrument according to the first embodiment of the present invention.

FIG. 6 is an explanatory view of a method for manufacturing a writing instrument of the present invention.

FIG. 7 is an explanatory view of a method for manufacturing a writing instrument of the present invention.

FIG. 8 is an explanatory view of a method for manufacturing a writing instrument of the present invention.

FIG. 9 is a longitudinal sectional view of a part of an ink control mechanism according to a second embodiment of the writing instrument of the present invention.

FIG. 10 is a longitudinal sectional view of a part of an ink control mechanism of a writing instrument according to a third embodiment of the present invention.

FIG. 11 is a longitudinal sectional view of a part of an ink control mechanism of a writing instrument according to a fourth embodiment of the present invention.

FIG. 12 is a longitudinal sectional view of an ink control mechanism of a writing instrument according to a fifth embodiment of the present invention.

FIG. 13 shows an example of a throttle passage according to a fifth embodiment.
A-A view of the

FIG. 14 is a view taken along the line AA of FIG. 12, showing another example of the throttle passage of the fifth embodiment.

[Explanation of symbols]

 2 Ink chamber 5 Ball tip 11, 51, 71 Shutoff chamber 12 Ink chamber side passage 13 Pen body side passage 14 Ink chamber side relay core 21 Pen body side relay core 54a, 54c Restriction passage

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B43K 5/00-8/18

Claims (3)

(57) [Claims] 1. A writing instrument comprising an ink chamber for storing ink and a pen provided at the tip of the writing instrument, wherein a small chamber having a predetermined amount of gas sealed therein, An ink chamber-side passage communicating with the small chamber; and a pen body-side passage communicating the small chamber with the pen body. The ink chamber-side passage has a predetermined flow resistance against the flow of ink by writing. The pen body-side passage is provided with a pen body-side resistance means for providing a predetermined flow resistance to the flow of ink by writing. A writing instrument, wherein the flow resistance of the resistance means on the ink chamber side is set to be larger than the flow resistance of the resistance means on the pen body side. 2. The writing implement according to claim 1, wherein the resistance means on the ink chamber side is a porous relay core inserted into the ink chamber side passage. 3. The writing implement according to claim 1, wherein the resistance means on the ink chamber side is a flow path having a minute cross section formed in the ink chamber side passage.