JP2002254883A - Ball point pen - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ball-point pen which uses inks of such kinds that easily break off during initial writing, easily dry, simply separate into a pigment and a solvent, include various kinds of fillers and easily clog and can be readily erased by rubbing especially a handwriting on a paper space with the help of an eraser without any problems. SOLUTION: This ball-point pen is of such a construction that a ball pen refill with a tip ball to the back face of which a spring pressure is applied so that the tip ball comes into contact closely with the inner edge of a ball embracing part stop the tip, is mounted inside a pen barrel and the point of the tip is positioned so that it protrudes from the tip of the pen barrel. In this ball-point pen, an ink storage tube is filled with the ink which can be erased by an eraser containing water, pigment particles, a resin and a gelling agent, Further, a follower which prevents the ink from vaporizing and follows up with the ink in accordance with its consumption is installed at the rear end of the ink. Besides, the rear end of the follower is structured in such a way that the fluidity of the ink to the tip side is supported by means of a pressurizing means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink which is easy to dry and is easy to run out of ink, an ink which easily separates a pigment and a solvent and is easily clogged, and an ink which is easily clogged with various fillers, and is particularly suitable for writing on paper. The present invention relates to an improvement of a ballpoint pen using an ink which can easily erase a handwriting by rubbing with an eraser.

[0002]

2. Description of the Related Art Conventionally, there has been known a liquid applicator using a white pigment in order to correct a mistake or the like. In addition, since a white pigment and a solvent are easily separated from each other, this type of liquid applicator has a flexible container in which ink, balls, and the like are sealed, and it is necessary to shake and agitate the liquid applicator before use. Further, the ink is ejected by pressing the side surface of the container. However, when the remaining amount of the ink becomes small, even if the side wall of the container is strongly pushed, the ink is not ejected. Further, in the case of the ballpoint pen type, there is a problem that the ink is solidified by drying and the leading end of the coating is easily clogged, and it takes time and effort to return to the normal state.

[0003] In addition, inks which have high viscosity and do not easily flow out, inks which are easily solidified such as glue, inks which have a low viscosity but are mixed with metal powder or various fine film pieces, and which can be easily erased by rubbing with an eraser. Ballpoint pens using such inks have the same problems as the above-mentioned applicators.

[0004] By the way, various inks for ball-point pens have been proposed in which handwriting written on paper can be erased by rubbing with an eraser. Many of them have a weakness that they adhere to paper and are easily peeled off by rubbing with a finger, or they cannot be erased with an eraser. Among them, Japanese Patent Application Laid-Open No. 10-19536
No. 6 discloses a ball-point pen filled with water, pigment particles, a resin having a glass transition temperature or a film-forming temperature of 0 ° C. or lower, and an erasable ink containing an eraser containing a gelling agent. Japanese Patent Application Laid-Open No. 12-136339 discloses water, colored resin granules, a resin having a glass transition temperature or a minimum film-forming temperature of more than 0 ° C. and less than 40 ° C., and a shear thinning agent. An aqueous ink composition for an eraser erasable ballpoint pen is disclosed.

In general, a ballpoint pen using low-viscosity ink or ink having shear-thinning has a large amount of outflow of ink (in order to increase the writing density), so that the diameter of an ink storage tube is increased to increase the amount of loaded ink. Have many. Further, since the viscosity of the ink is smaller than that of the oil-based ball-point pen, the flow resistance to the ink container is small. Accordingly, ink leakage (ink flows backward at the rear end of the ink storage tube) is likely to occur due to the ink's own weight, falling or knocking impact. For this reason, the ink usually moves following the ink consumption at the time of writing at the rear end of the ink, but a grease-like follower that suppresses the backflow of the ink due to its own weight or impact, and if necessary, a follower A rod is provided immersed in the follower. However, even when the follower is provided, if the ink on the back surface of the ball of the chip runs out when writing upward, there is a risk that a remarkable backflow occurs because the ink head is added directly and the hands and clothes are stained. Further, since the viscosity of the ink is low and the amount of outflow is large, there is a problem that the ink is bleeding (direct current) when a gap is formed between the tip ball and the tip holding portion when the tip side is directed downward.

[0006]

DISCLOSURE OF THE INVENTION The present invention relates to inks that are easy to dry, inks that are easily clogged with various fillers, and inks that can be easily erased by rubbing handwriting on paper with an eraser. It is an object of the present invention to improve the above-mentioned problem of a ballpoint pen using an ink which has a problem that the ink tends to be broken in the initial writing.

[0007]

The present invention has the following arrangement to achieve the above object. The ballpoint pen according to the first aspect of the present invention includes a tip of the ballpoint pen at the tip and an ink storage tube at the rear, and a spring pressure is applied to the back of the tip ball so that the tip ball comes into close contact with the inner edge of the ball holding portion at the tip of the tip. In a ball-point pen in which a ball-point pen refill provided with is mounted in a barrel and the tip of the tip is positioned so as to protrude from the tip of the barrel, water, pigment particles, resin A ball-point pen which is filled with an erasable ink containing an eraser containing a gelling agent, and provided with a follower at the rear end of the ink to prevent evaporation of the ink and follow the ink as the ink is consumed.

According to a second aspect of the present invention, in the ballpoint pen according to the first aspect, a tail plug is fixed to a rear end of the ink storage tube and at least an axial direction is provided on an outer peripheral portion of the tail plug. An expandable knock cylinder is provided, a vent hole is opened at the rear end of the knock cylinder, and a ventilation path from the vent hole to the rear end of the follower is formed, and the knock cylinder is closed with the vent hole closed. Is contracted to pressurize the rear end of the follower, thereby supporting fluidity of the ink to the chip side.

According to a third aspect of the present invention, there is provided the ballpoint pen according to the first aspect, wherein the knock cylinder which is at least axially expandable and contractable is fitted on the rear end of the ink storage tube or the ink storage tube. The rear end of the knock cylinder is fixedly attached to the rear end of the knock cylinder in a state facing the rear end of the knock cylinder.A vent hole is opened at the rear end of the knock cylinder, and the knock cylinder is contracted with the vent hole closed. It is characterized in that the rear end of the follower is pressurized so that the fluidity of the ink to the chip side is supported.

A ballpoint pen according to a fourth aspect of the present invention is the ballpoint pen according to the first aspect, wherein a plug having a vent hole is fixed to the rear end of the ink storage tube, and the plug is attached to the plug. A seal portion is provided on the outer peripheral portion, and a resilient member is provided between the rear end of the inner hole of the tail plug fixed to the rear end of the barrel and the rear end of the plug, so that the ballpoint pen refill can be mounted on the barrel. The seal portion provided on the outer peripheral portion of the plug is slid in a state in which the seal portion provided on the outer peripheral portion of the plug body is in close contact with the inner peripheral portion of the tail plug by the retraction operation of the ballpoint pen refill by pressing against the tip end portion of the tip. The air is pushed into the rear end hole, and the rear end of the follower is pressurized, so that the fluidity of the ink to the chip side is supported.

According to a fifth aspect of the present invention, there is provided a ball-point pen according to the fourth aspect, wherein the rear end hole of the ink storage tube is communicated with the outside air immediately before the retreat operation of the chip, so that the tip of the ball-point pen can be properly mounted. Immediately after retreating, the rear end hole of the ink storage tube is configured to be shut off from outside air and pressurized.

[0012]

1 and 2 show a ballpoint pen according to a first embodiment of the present invention. First, the ink storage tube 8 of the ballpoint pen refill 2 shown in FIG. 1 is filled with an erasable ink 9 with an eraser, and the rear end of the ink is filled with a grease-like follower 10 that follows the ink as the ink is consumed. I have. The follower is not compatible with the ink and has a function of preventing evaporation of the ink. If necessary, a resin follower rod 11 having a specific gravity substantially equal to that of the follower is immersed in the follower. The follower can be a follower such as silicon rubber.

The ink 9 comprises water, pigment particles, resin,
Erasable ink containing a gelling agent is filled with erasable ink, and a follower is provided at the rear end of the ink as the ink is consumed, so that sedimentation of the pigment is prevented and fluidity is impaired as much as possible. It is an ink that has been blended so as not to be damaged. In addition, since the ink has a shear thinning property, smooth writing can be performed in combination with a decrease in the viscosity as the tip ball rotates.

Further, as shown in FIG.
The front shaft portion 3a is formed in front of the rear, and the rear shaft portion 3c is formed in the rear,
The shaft 6a of the tip 6 holding the tip ball 7 is fixed to the hole at the tip of the front shaft 3a. Further, a rib 3d is formed at a required position on the outer periphery of the front shaft portion 3a.

The tip 6 is caulked so that the tip ball 7 is rotatably held with the tip ball 7 substantially in contact with a seat having a channel into which ink can flow. A spring (not shown) is inserted into the inner hole of the chip 6, the rear end of the shaft 6a of the chip is appropriately caulked, and the rear end of the coil spring cannot be pulled out.

Further, a pusher having a tip portion having a very small diameter winding portion or a linear rod portion is formed integrally with the spring, or a pusher having a tip portion at the front end of the spring is provided at the forward end of the spring. The distal end portion comes into contact with the back surface of the distal end ball 7 in a pressing manner. The tip ball 7 is brought into close contact with the inner edge of the ball holding portion (formed by caulking or the like) of the chip 6 by the pressing. (Not shown) Further, the tip is made of a resin molded article having excellent wear resistance and ink sealing performance, and a spring seat for pressing the back surface of the tip ball is provided as an integral or separate spring seat. It is also possible. (Not shown)

By the way, it is extremely important that the tip ball 7 is in close contact with the inner surface of the ball holding portion for drying the writing tip and preventing direct current of ink. In addition, in order to improve the surface roughness of the inner surface of the chip holding the tip ball 7 and the close contact accuracy by caulking, grinding of the inner surface and secondary plastic working for increasing the caulking accuracy are considered. If necessary, a surface treatment or the like may be considered on the surface in close contact with the tip ball.

The joint 3 is provided with a valve chamber 4 which is appropriately eccentric with respect to the axis of the chip behind the chip 6, and a tapered or spherical valve is provided at the rear of the valve chamber 4 by communicating with a guide hole 4c. A body receiving seat 4b is formed. A groove 4a through which ink can flow is formed on one side of the inner wall of the valve chamber 4.
Further, a spherical valve element 5 is loosely fitted in the valve chamber 4,
The valve body 5 abuts on a state where the valve body 5 is biased to the rear end of the shaft portion 6a of the chip in a state in which the ink is directed downward, so that the ink flowing from the guide hole 4c through the groove portion 4a or the like flows into the chip inner hole portion. Have been. Note that the valve body may be a shaft-like body having a tapered or spherical shape on the side close to the valve body receiving seat. In this case, the valve chamber does not need to be eccentric with respect to the chip axis as described above by forming a groove through which ink flows into the chip on the peripheral surface of the chip in contact with the rear end of the shaft portion of the chip. .

As described above, the flange 3b of the joint 3
A rear shaft portion 3c extends from the rear. On the outer periphery of the rear shaft portion 3c, a cylindrical ink storage tube 8 is press-fitted and fixed by contacting the front end thereof to the rear end of the flange portion 3b, and the inner diameter portion of the ink storage tube 8 is conducted to the guide hole 4c of the joint 3. I have. The ink storage tube 8 is made of, for example, a transparent PP resin molded product. Further, in the ball-point pen of the above-described embodiment, the joint and the ink storage tube are formed as separate members, but both may be formed as an integral resin molded product.

On the other hand, the tail plug 12 has a shaft portion 12a having a front end formed as a wall portion 12e in front of the flange portion 12c, and a shaft portion 1 in the rear side.
2b is formed on the side wall near the front end of the hole 12d opened from the rear end of the shaft portion 12b to the inner surface side of the wall portion 12e.
f is drilled, and a wall 12e is formed from the lateral hole 12f.
A vertical groove 12g communicating with the front end of the vertical groove is provided.

The tail plug 12 has a shaft portion 12a fixed to a rear end hole of the ink storage tube 8, and a front portion of a knock tube 13 whose rear portion is at least axially expandable and contractible around the shaft portion 12b. Is fixed, and the rear end of the knock cylinder 13 has a vent hole 13a.
Is formed, and a ventilation path from the ventilation hole 13a to the rear end of the follower 10 is formed. The rear end of the knock cylinder 13 is pressed in a state where the ventilation hole 13a is closed, and the knock cylinder is contracted to follow the follower. The rear end of 10 is pressurized to help the ink 9 flow toward the tip.

The barrel 1 is a transparent resin molded product, which has a detachable mouth 1a at the front thereof, and an engagement portion comprising a projection and a groove on the outer periphery slightly rearward thereof. A step portion with which an end portion of a cap 14 described later abuts is formed at the rear end. Further, a step portion 1b is formed in the inner hole of the mouth portion 1a.

The ball-point pen refill 2 is inserted from the front end of the barrel 1, the rear end of the flange 3b of the joint 3 abuts on the front end of the barrel 1, and the tip 1a is screwed around the outer periphery of the front end of the barrel. Ribs 3 joined by joints and the like and provided on the outer periphery of the joint 3
d engages with the step 1b of the lip, and the tip of the tip 6 projects from the tip hole of the lip 1a. The rear end of the knock cylinder 13 projects from the rear end of the shaft cylinder 1.

The cap 14 fitted to the front of the barrel 1 is a resin molded product having excellent elasticity. The clip 16 is positioned on the outer peripheral side of the cap 14, and the rear cylindrical portion 16a is connected to the rear end hole of the cap 14. Is crimped. In addition, a ventilation hole passes through the rear end of the cylindrical portion 16a of the clip. Further, a cylindrical inner cap 14a having a small chamber is provided behind the inner hole of the cap 14, and the inner cap 14a is integrally connected to the cap inner hole by a required number of ribs. As described above, an air passage communicating from the cap insertion port to the air hole is formed between the ribs, and is a safe ventilation means in the event that an infant swallows the cap. A seal plug 15 made of a non-liquid-absorbing, non-continuous-cell elastic body is fixed to the tip of the small chamber of the inner cap 16a. When the cap is fitted, the tip 6 and the tip 1a are positioned at the tip. The tips are closely fitted in the small chambers, and the tips of the tips are closely contacted with the sealing plugs 15.

FIG. 3 shows the rear half of a ballpoint pen according to a second embodiment of the present invention. Hereinafter, the first embodiment described above
Only the differences from the above will be described. A seal portion 17a having a circumferential projection is formed on an inner hole wall near the rear end of the shaft cylinder 17 so that the seal portion 17a is in close contact with the outer peripheral portion near the substantially rear end of the ink storage tube 8. ing. In a state facing the rear end of the ink storage tube 8, a knock cylinder 18 is attached to the rear end of the shaft cylinder 17.
Are fixed, and a vent hole 18 a is provided at the rear end of the knockable tube 18 at the rear end thereof. The above-mentioned seal portion can be provided on the outer peripheral portion of the ink storage tube, or can be provided by providing another seal member, for example, an elastic member such as rubber, on the outer peripheral portion of the ink storage tube.

FIG. 4 shows the rear half of a ballpoint pen according to a third embodiment of the present invention. Hereinafter, similarly, only differences from the first embodiment will be described. A tubular portion 20b provided at the front end of the knock tube 20 is closely fitted to the outer periphery of the rear end portion of the ink storage tube 8, the rear portion of the knock tube 20 projects from the rear end of the shaft tube 19, and the knock tube 20 expands and contracts. A ventilation hole 20a is provided at the rear end of the free rear portion.

FIG. 5 shows the rear half of a ballpoint pen according to a fourth embodiment of the present invention. This embodiment has substantially the same configuration as that of the third embodiment, and has no follower rod in the follower 10.

FIGS. 6 to 9 show a ballpoint pen according to a fifth embodiment of the present invention. First, as shown in FIG. 6 and FIG. 7, a white pigment ink 29 is filled in the ink storage tube 28 of the ballpoint pen refill 22, and a grease-like follower 30 that follows the ink as the ink is consumed is provided at the rear end of the ink. Is filled. The follower is not compatible with the ink and has a function of preventing evaporation of the ink.
A follower rod 31 made of resin and having a specific gravity substantially equal to that of the follower is immersed in the follower as needed. (still,
Although FIG. 7 shows a pipe shape, it may be a rod shape. The follower can also be a follower such as silicon rubber.

The ink 29 is filled with water and an erasable ink with an eraser containing pigment particles, a resin and a gelling agent, and a follower is provided at the rear end of the ink to follow the ink as the ink is consumed. The ink is formulated so as to prevent sedimentation of the pigment and to minimize the loss of fluidity. In addition, since the ink has a shear thinning property, smooth writing can be performed in combination with a decrease in the viscosity as the tip ball rotates.

As shown in FIG. 9, the joint 23 has a front shaft portion 23a formed in front of a flange portion 23b and a rear shaft portion 23c formed in the rear, and a tip ball 26c is formed in a hole at the front end of the front shaft portion 23a.
The shaft 26a of the chip 26 holding the chip 26 is fixed.
A rib 23d is formed at a required location on the outer periphery of the front shaft portion 23a.

The tip 26 is caulked so that the tip ball 26c is rotatably held with the tip ball 26c substantially in contact with a seat having a channel into which ink can flow. A spring 2 is provided in the inner hole of the tip 26.
7, the rear end of the shaft portion 26a of the chip is appropriately caulked, and the rear end of the coiled spring 27 cannot be pulled out.

Further, a distal end having an extremely fine diameter winding portion or a linear rod shaft portion 27a is formed integrally with the spring 27 in front of the spring 27, or a pressing body having a distal end at the front end of the spring is provided. The distal end portion is pressed against the back surface of the distal end ball 26c. The tip ball 26c presses the ball holding portion 26b of the chip 26 by the pressing.
(Formed by caulking or the like).
Further, it is also possible to make the chip into a resin molded product having excellent abrasion resistance and ink sealing performance, and to provide a spring seat for pressing the back surface of the tip ball as an integral or separate spring seat. is there. (Not shown)

By the way, it is extremely important that the tip ball 26c is in close contact with the inner surface of the ball holding portion for drying the writing tip and preventing direct current of ink. In addition, tip ball 26c
Grinding of the inner surface to improve the surface roughness of the inner surface of the chip holding the chip and close contact accuracy by caulking, and secondary plastic working to increase the caulking accuracy are considered. If necessary, a surface treatment or the like may be considered on the surface in close contact with the tip ball.

The joint 23 is provided with a valve chamber 24 which is appropriately eccentric with respect to the axis of the chip behind the chip 26, and a tapered or spherical valve is provided at the rear of the valve chamber 24 by communicating with a guide hole 24c. A body receiving seat 24b is formed. Valve room 2
A groove 24a into which ink can flow is formed on one side of the inner wall of the fourth. Further, a spherical valve body 25 is loosely fitted in the valve chamber 24 and abuts on a state where the valve body 25 is biased toward the rear end of the shaft portion 26a of the chip with the chip 26 facing downward.
The ink flowing from the guide hole 24c through the groove 24a and the like flows into the chip inner hole.
Incidentally, the valve body may be a shaft-shaped body having a tapered or spherical surface on the side close to the valve body receiving seat. In this case, it is not necessary to decenter the valve chamber with respect to the chip axis as described above by forming a groove through which ink flows into the chip on the peripheral surface of the chip which is in contact with the rear end of the shaft portion of the chip. .

As described above, the flange 23 of the joint 23
A rear shaft portion 23c extends behind b. Rear shaft 2
A cylindrical ink storage tube 28 is press-fitted and fixed to the outer periphery of the ink storage tube 2c with its tip abutting on the rear end of the flange portion 23b.
The inner diameter portion 8 is electrically connected to the guide hole 24 c of the joint 23.
In addition, as the ink storage tube 28, a transparent PP resin molded product or the like is used as an example. In the ballpoint pen according to the above-described embodiment, the joint and the ink storage tube are formed as separate members, but they may be formed as an integral resin molded product.

A plug 32 is provided at the rear end of the ink container tube 28. The plug 32 is connected to the front of the ink storage tube 28.
A shaft portion 32a fixed to the rear end hole and a shaft portion 32b having an outer periphery substantially equivalent to the outer periphery of the ink storage tube 28 at the rear, and a vent hole 32d penetrating the axis are provided. I have. Further, a circumferential concave portion 32c is formed in the outer peripheral portion of the shaft portion 32b, and the seal member 33 is fitted in the concave portion 32c. The seal member 33 is made of, for example, an elastic body such as rubber, an elastic molding resin, or the like. In addition, other considerations such as interposition of a lubricant are taken into consideration. The seal part is a shaft part 32.
It is also possible to form integrally with the outer peripheral part of b. Still further, it is also possible to form the stopper integrally with the rear end of the ink storage tube.

The shaft cylinder 21 is a transparent resin molded product, integrally having a mouth portion 21a in front thereof, an engaging portion of a cap 36 formed of a projection and a groove on the outer periphery, and a step in an inner hole. Part 2
1b is formed. A cap 3 is provided at the rear end of the engaging portion.
6 is formed with a step portion with which the end portion abuts. Shaft barrel 2
A tail plug 34 is detachably screwed to the rear of the first plug 1, and an engagement portion including a protrusion and a groove is formed on the outer periphery of the tail plug 34 in the same manner as described above.
At the rear end of the barrel 21, a step is formed in which the end of the cap 36 abuts.

Next, the assembling structure of the ball-point pen will be described. The tip 26 is pressed against the joint 23 from the rear end of the barrel 21, the ink container 28 is filled with the ink 29 and the follower 30, and the ink container tube is further filled. The ball-point pen refill 22 with the stopper plugged into the rear end is inserted, and a resilient member 35 is provided between the step 32 e at the rear end of the plug 32 and the rear end of the inner hole of the tail plug 34.
A tail plug 34 is screwed into the rear end of the barrel 21, and the resilient member 35 is pressed and displaced by the forward movement of the tail plug 34 accompanying the screwing, and the front shaft of the joint is connected to the step 21 b of the mouth. The outer periphery of the inclined rib 23d provided at a required portion of the portion 23a is abutted to prevent the chip 26 from rattling. Note that a coil spring, sponge rubber, or the like can be used as the resilient member 35. An abutting step 34a is provided circumferentially substantially in front of the inner hole of the tail plug 34, and an inner peripheral section 34 is provided behind the abutting step 34a.
b is provided.

The cap 36 to be fitted on the front of the barrel 21 is a transparent resin molded article having excellent elasticity, and the clip 38 is positioned on the outer peripheral side face thereof, and the rear cylindrical part 38a is press-fitted to the rear end hole. are doing. Further, a ventilation hole penetrates through the rear end of the cylindrical portion 38a. A cylindrical inner cap 36a having a small chamber is provided behind the inner hole of the cap 36, and the inner cap is integrally connected to the inner hole of the cap by a required number of ribs. As described above, an air passage communicating from the cap insertion port to the air hole is formed between the ribs, and is a safe ventilation means in the event that an infant swallows the cap. Also, the cap 36 has two engagement portions of ridges formed in the inner hole on the insertion side at separate and independent positions. In addition, inner cap 3
A sealing plug 37 made of a non-liquid-absorbing, non-continuous-cell elastic body is fixed to the distal end of the small chamber 6a, and the tip 26 and the tip 21a are substantially closely fitted in the small chamber.
6c is appropriately pressed against the seal plug 37.

The ball-point pen refill 39 in FIG. 10 shows another embodiment of the ball-point pen refill. The difference from the above-mentioned ball-point pen refill 22 is that it does not have a valve element provided inside the joint and a follower rod provided inside the follower. That is, the valve element and the follower rod are not essential components. Details will be described later in operation.

[0041]

Next, the operation will be described below in accordance with the first embodiment. First, the rear end of the knock cylinder 13 is pressed in a state where the ventilation hole 13a of the knock cylinder 13 is closed with a finger, and the rear end of the follower 10 is pressed by contracting the knock cylinder, so that the ink flows toward the chip side. Liquidity is supported. This has the effect of preventing the ink from separating from the peripheral surface of the tip ball due to drop impact and poor ink fluidity, etc. Become. Incidentally, the above-mentioned basic operation is described in the second and third embodiments.
4 is the same.

Next, the operation of the ballpoint pen refill will be described. When writing pressure is not applied to the tip of the tip, the tip ball 7 is brought into close contact with the inner edge of the tip holding portion by the pressing of the spring, so that the backflow of ink is prevented. When the tip 6 is upward, the valve body 5 is in close contact with the valve body receiving seat 4b to seal the guide hole 4c. Therefore, even if the ink is written upward and the ink on the back surface of the tip ball 7 of the tip runs out, the ink is caught by the head and the backflow occurs. Never do. Therefore, when the tip 6 is turned downward, the ink can immediately flow out. By the way, in the structure having no valve element, when the upward writing is repeated, the ink acts in the backward flow direction, so that air is entrapped in the chip, and the ink tends to be hardly immediately discharged in the downward writing. The follower rod 11 is used when the ink storage tube has a large diameter. That is, the grease-like follower 10 has a problem that when the ink container tube has a large diameter, it is easily deformed and broken by the influence of impact or the like. The rigidity can be increased by immersing a resin follower rod having a specific gravity substantially equal to that of the follower in the follower.

The above-described ink backflow prevention structure having a follower rod and a valve element is effective when the ink storage tube has a large diameter and is easily backflowed, or when repeated upward writing or when an impact is applied. However, it is not essential as a component, and a ballpoint pen for correcting a typographical error is not necessarily used because it is rarely used upward.

[0044]

Next, the operation of the fifth embodiment will be described below. First, in the state where the tip of the tip is under the writing pressure or less,
As shown in FIG. 8, the sealing member 33 provided on the plug 32 faces the contact step 34a provided on the tail plug 34 with a slight gap. Next, the ballpoint pen refill 22 is retracted by applying a pressure equal to or higher than the pen pressure to the tip of the tip, and when the seal member 33 is in close contact with the contact step 34a, the rear end hole of the ink storage tube 28 is shut off from the outside air and Further, when the sealing member 33 retreats while sliding on the inner peripheral portion 34b, air is pushed into the rear end hole of the ink storage tube 28, and the rear end of the follower disposed at the rear end of the ink is pressed. Thus, the fluidity of the ink to the chip side is supported. This has the effect of preventing the ink from separating from the peripheral surface of the tip ball due to drop impact and poor ink fluidity, etc. Become.

That is, the rear end hole of the ink storage tube 28 is communicated with the outside air immediately before the tip of the tip is subjected to a load equal to or higher than the writing pressure, and the rear end hole of the ink storage tube immediately after the ink storage tube 28 is slightly retracted. Are shut off from the outside air and the rear end of the follower 30 is pressurized by further retreat.
The means for allowing the rear end hole of the ink storage tube to communicate with the outside air is provided so as to communicate with the air hole 32d behind the shaft cylinder inner hole through a gap between the front end hole of the mouth part 21a and the outer periphery of the chip. It is also possible to form a ventilation groove at the joint between the barrel 21 and the tail plug 34 so that the ventilation groove communicates with the ventilation hole 32d.

Next, the operation of the ballpoint pen refill will be described. In a state where writing pressure is not applied to the tip of the chip, the tip ball 26c is brought into close contact with the inner edge of the ball holding portion of the chip by the pressing of the spring 27, so that the backflow of ink is prevented. When the tip 26 is upward, the valve body 25 is in close contact with the valve body receiving seat 24b and seals the guide hole 24c.
c Even if the ink on the back is exhausted, the ink is caught by the head and does not flow backward. Therefore, when the tip 26 is turned downward, the ink can immediately flow out. By the way, in the structure having no valve element, when the upward writing is repeated, the ink acts in the backward flow direction, so that air is entrapped in the chip, and the ink tends to be hardly immediately discharged in the downward writing. The follower rod 31 is used when the ink storage tube has a large diameter. That is, the grease-like follower 30 has a problem that when the ink container tube has a large diameter, the grease-like follower 30 is easily deformed and damaged by the influence of impact or the like. The rigidity can be increased by immersing a resin follower rod having a specific gravity substantially equal to that of the follower in the follower.

[0047]

The construction and operation of the knock-type writing instrument according to the present invention are as described above. The ink which is easy to dry, the ink which is easily clogged with various fillers, and especially the handwriting written on the paper is rubbed with an eraser. This makes it possible to provide a ballpoint pen knock-type writing instrument using ink or the like that can be easily erased. In addition, a ballpoint pen using ink that is easy to run out of ink in initial writing can be written with the aid of a pressurizing action.

[Brief description of the drawings]

FIG. 1 is an enlarged sectional view of a front half portion of a ballpoint pen according to an embodiment, showing a state in which a cap is fitted to a front end of a barrel. (Examples 1 to 4)

FIG. 2 is an enlarged sectional view of a rear half of the ballpoint pen according to the first embodiment.

FIG. 3 is an enlarged sectional view of a rear half of a ballpoint pen according to a second embodiment.

FIG. 4 is an enlarged sectional view of a rear half of a ballpoint pen according to a third embodiment.

FIG. 5 is an enlarged sectional view of a rear half of a ballpoint pen according to a fourth embodiment.

FIG. 6 is an enlarged sectional view of a front half of a ballpoint pen according to a fifth embodiment, showing a state in which a cap is fitted to a front end of a barrel.

FIG. 7 is an enlarged sectional view of a rear half of a ballpoint pen according to a fifth embodiment.

FIG. 8 is an enlarged cross-sectional view of the rear half of the ball-point pen in a state where the tip of the tip is pressed with a pressure equal to or higher than the pen pressure and the ball-point refill is retracted.

FIG. 9 is a longitudinal sectional view of a ballpoint pen refill.

FIG. 10 is a vertical sectional view of another embodiment of a ballpoint pen refill.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Shaft cylinder 1a Mouth part 1b Step part 2 Ball pen refill 3 Joint 3a Front shaft part 3b Flange part 3c Rear shaft part 3d Rib 4 Valve room 4a Groove part 4b Valve seat seat 4c Guide hole 5 Valve body 6 Chip 6a Shaft 6b End portion 7 Tip ball 8 Ink storage tube 9 Ink 10 Follower 11 Follower rod 12 Tail plug 12a Shaft portion 12b Shaft portion 12c Flange portion 12d Hole 12e Wall portion 12f Side hole 12g Vertical groove 13 Knock cylinder 13a Vent hole 14 Cap Inner DESCRIPTION OF SYMBOLS 15 Seal plug 16 Clip 16a cylinder part 17 Shaft cylinder 17a Seal part 17b Rear end hole 17c Inner step part 18 Knock cylinder 18a Vent hole 18b Engagement part 19 Shaft cylinder 19a Rear end hole 20 Knock cylinder 20a Vent hole 20b cylinder part 21 Shaft tube 21a Tip 21b Step 22 Ballpoint pen refill 23 Joint 23a Shaft portion 23b Flange portion 23c Rear shaft portion 23d Rib 24 Valve chamber 24a Groove portion 24b Valve body receiving seat 24c Guide hole 25 Valve body 26 Chip 26a Shaft portion 26b Ball holding portion 26c Tip ball 27 Spring 27a Rod shaft portion 28 Ink storage tube 29 Ink 30 Follower 31 Follower rod 32 Plug 32a Shaft 32b Shaft 32c Recess 32d Vent 32e Step 33 Sealing member 34 Tail 34a Contact step 34b Inner circumference 35 Resilient member 36 Cap 36a Inner cap 37 Seal Plug 38 Clip 38a Tube 39 Ballpoint pen refill

Claims (5)

[Claims] 1. A ballpoint pen refill having a tip of a ballpoint pen at the tip and an ink storage tube at the rear, and a spring pressure applied to the back of the tipball so that the tipball is in close contact with the inner edge of a ball holding portion at the tip of the tip. Is mounted in the barrel, and the tip of the tip is positioned so that the tip protrudes from the tip of the barrel. The ink container contains water, pigment particles, resin, and a gelling agent. Erasable ink is filled with eraser,
A ballpoint pen provided with a follower at the rear end of the ink for preventing evaporation of the ink and following the ink as the ink is consumed. 2. A tail plug is fixed to the rear end of the ink storage tube, and a knock cylinder is provided at least in the axial direction on the outer periphery of the tail plug, and a vent hole is opened at the rear end of the knock cylinder. At the same time, a ventilation path from the ventilation hole to the rear end of the follower is formed, and the rear end of the follower is pressurized by contracting the knock cylinder in a state where the ventilation hole is closed, so that the ink flows to the chip side. The ballpoint pen according to claim 1, wherein the ballpoint pen is configured to support fluidity. 3. A knock cylinder which is at least axially extendable and retractable is provided on the rear end of the shaft cylinder while being fitted to the rear end of the ink storage tube or facing the rear end of the ink storage tube.
A vent hole is opened at the rear end of the knock cylinder, and the rear end of the follower is pressurized by contracting the knock cylinder with the vent hole closed, thereby supporting the fluidity of the ink to the chip side. The ballpoint pen according to claim 1, wherein the ballpoint pen is configured to: 4. A plug having a vent hole is fixed to the rear end of the ink storage tube, a seal is provided on the outer periphery of the plug, and the plug is fixed to the rear end of the barrel. A resilient member is provided between the rear end of the inner hole of the tail plug and the rear end of the plug, the ball-point refill is urged forward of the barrel, and the ball-point refill is retreated by pressing against the tip end of the ball-point refill. The seal provided on the outer periphery of the plug body slides in close contact with the inner periphery of the tail plug, and air is pushed into the rear end hole of the ink storage tube, and the rear end of the follower is pressurized, causing ink to flow. The ballpoint pen according to claim 1, wherein the ballpoint pen is configured to support the fluidity of the ballpoint pen toward the chip. 5. Immediately before the retraction operation of the chip, the rear end hole of the ink storage tube is communicated with the outside air. Immediately after the chip is appropriately retracted, the rear end hole of the ink storage tube is shut off from the outside air and pressurized. The ballpoint pen according to claim 4, wherein the ballpoint pen is configured to perform the following.