JP2000263986A - Ball point pen - Google Patents

Abstract

PROBLEM TO BE SOLVED: To assist the outflow of an ink by utilizing the pressurizing action of writing pressure for a nock type ball point pen using the ink for correcting erroneous writings or the ink to be erased by a rubber eraser. SOLUTION: A ball point pen refill 21 is provided with a ball point pen tip 23 on its end and an ink storage tube 22 on its rear, and a spring 20 is inserted into the tip, and the end of the spring is so provided as to press the back of a tip ball by the end of the spring and bring the tip ball into contact with the inner edge of a ball wrapping section on the end of the tip. The ink storage tube is a pumping type pressurizing mechanism, in the constitution of which the ink and a follower preventing the evaporation of ink and following the ink when the ink is consumed on the rear end of the ink are provided, and a valve chamber to be expanded and contracted on the rear of the follower and valve elements closing the front and rear ends are provided, and the valve chamber is expanded and contracted to pressurize and evacuate the interior of the valve chamber, and the valve mechanisms in the front and at the rear are opened alternately to push in air into the rear end of the follower for pressurizing. The ink flow properties to the tips side is assisted by the above arrangement.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention is configured so that the tip of a writing tip can be protruded and retracted from the tip end of a front shaft by a knocking operation, and that the outflow of ink is supported by pressurizing means using writing pressure. The present invention relates to a ballpoint pen capable of correcting a typographical error or the like by concealing it with white ink or a ballpoint pen capable of erasing a character 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. On the other hand, a ballpoint pen using an ink which is formed by adding a cross-linking substance to an ink solvent, turning into a sol by the rotation of a tip ball during writing, gelling in a drawn line state, and not penetrating into paper, so that it can be erased with an eraser is known. This ballpoint pen also has a problem that it tends to settle because the pigment particles are coarse.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a ballpoint pen for correcting errors such as erroneous writing or a ballpoint pen which can be erased with an eraser without the need to stir and to press the side of the container. It is in.

[0004]

The present invention has the following arrangement to achieve the above object. In the ballpoint pen according to the first aspect of the present invention, a stopper is provided in the inner bore of the tip end of the tip shaft, the stopper being pivoted in conjunction with the relative longitudinal movement of the ballpoint refill, and the stopper is provided when the refill retreats. In a ball-point pen which is pressed against the tip of a ball-point pen and the plug turns so that the tip can protrude from the tip end of the front shaft when the refill advances, the ball-point refill is attached to the tip. The tip of the ballpoint pen and the ink storage tube at the back are provided, and a spring is inserted inside the tip.The tip of the spring presses the back of the tip ball so that the tip ball comes into close contact with the inner edge of the ball holding part at the tip of the tip. The ink storage tube is provided with a follower at the rear end of the ink that prevents evaporation of the ink and follows the ink as the ink is consumed. A valve body that has a contractible valve chamber and seals the front and rear ends thereof is provided, and the valve chamber is pressurized and depressurized by expanding and contracting the valve chamber. A pumping type pressurizing mechanism for pressing air by pushing air into the end is provided to assist fluidity of the ink to the chip side.

[0005] The ballpoint pen according to the second aspect of the present invention is the ballpoint pen according to the first aspect, wherein the ink comprises:
It is a white pigment ink containing at least a white pigment such as titanium oxide and polymer hollow fine particles and a gelling agent, and formulated so as to prevent sedimentation of the pigment and to minimize the loss of fluidity.

A ballpoint pen according to a third aspect of the present invention is the ballpoint pen according to the first aspect, wherein the ink comprises:
It is characterized by adding a cross-linking substance to the solvent, turning it into a sol by the rotation of the tip ball during writing, gelling in a drawn line state, and erasing it with an eraser because it does not penetrate paper.

A ballpoint pen according to a fourth aspect of the present invention is the ballpoint pen according to the first aspect, wherein the guide cylinder 8 fixed in the front shaft 5 is constantly urged rearward by a spring 20 to move forward and backward. A seal cylinder 11 movably mounted on the shaft is provided,
At the tip of the seal cylinder 11, a stopper part 18 rotatable about 90 ° by a hinge part 17 and an elastic piece 13 are provided on the substantially middle side surface together with an elastic piece 13, and a protruding part 15 is provided inside the tip of the seal cylinder 11. When the tip portion is fitted, the tip portion of the tip 23 is appropriately pressed against the plug portion 18, and when the ball-point pen refill 21 moves forward together with the seal tube 11 by knocking operation, the hinge portion 17 moves the guide tube 8 The stopper 18 is rotatable in a state of being removed from the inner hole of the
3 pushes up the plug portion 18 to protrude from the distal end port 6 of the tip shaft 5, and the elastic piece 13 is expanded.
Until is positioned behind the plug 18, the seal cylinder is configured to be stationary with respect to the front shaft 5.

[0008]

1 to 8 show a knock-type ballpoint pen according to an embodiment of the present invention. First, as shown in FIG. 1, the shaft cylinder 1 is made of resin, has a slit 43 on the rear side surface, has a step portion 2 in front of the inner hole portion, and has a male screw portion 3 at the tip of the outer peripheral portion.
However, an inclined step 4 is formed at the tip.
A tip shaft 5 described later is attached to the male screw portion 3 by a female screw portion 7. Incidentally, the attachment means may be crimping. A base portion 49 is provided on the rear end side surface of the barrel 1, and a rear end portion of the clip 44 is fixed to the base portion 49, and a ball portion 45 having a locking step 45 a is provided at a tip end of the clip 44.
Is fixed. In addition, a cam cylinder 46 having a common cam groove (not shown) having a plurality of circumferential grooves and ribs on its inner surface and having a cam at its tip is inserted into the rear inner hole of the shaft cylinder 1. Locking projections 4 formed on the side surfaces of the cam cylinder 46.
6a is fitted in the slit 43 so that the shaft cylinder 1 and the cam cylinder 46 can only move back and forth.

In the cam cylinder 46, a knock rod 47 having a cam portion 47a which engages with the cam groove and a rotary cam member 4 are provided.
8 is fitted in the cam cylinder so as to be free to move in the axial direction.
The rotary cam member 48 engages with the distal end cam portion of the cam groove while being rotated by the index angle of the cam groove each time it is moved back and forth, and is positioned at the advance / retreat position. The knock mechanism composed of the cam cylinder 46, the knock bar 47 and the rotary cam member 48 has the same configuration as a well-known Kern type knock mechanism. A knock cover 50 is fixed to the outer periphery of the rear portion of the knock bar 47, and a slit 4 is formed at the front end of the knock cover 50.
3 and a projection 50a is formed at the front end of the base 49 so as to be in a contact state.

In the ballpoint pen according to the embodiment, when the knock cover 50 is advanced in the state shown in FIG. 1, the front end thereof abuts on the rear end of the cam cylinder 46 to advance the cam cylinder 46 in conjunction therewith.
a is locked to the locking step 45a of the ball portion. At that time, as described later, the state is as shown in FIG. 3 or FIG. When the clip 44 is inserted into a breast pocket or the like, the locking step 45a and the locking projection 46a are unlocked, and the state shown in FIG. 1 is obtained again. That is, even if the tip of the ball-point pen 23 is inserted into a pocket with the tip 23 protruding from the front end port 6 of the tip shaft 5, the tip 23 is prevented from immersing and soiling the clothes.

On the other hand, a tip shaft 5 attached to the tip of the barrel 1
Has a guide tube 8 fixed in its inner hole. The guide cylinder 8 has a tapered surface 10 at the tip. Also, the sealing cylinder 11
The elastic piece 13 is provided with a notch 14 on the side surface of the tubular part 12 behind the flange 19, and is provided with an elastic piece 13 which can be expanded and contracted. Formed,
One side end of the cylindrical portion 16 on the front side is substantially 90
A rotatable stopper 18 is provided. In addition, stopper part 18
A rubber bush 18a is fixed to the center of the head. The seal cylinder 11 is fitted in an inner hole of the guide cylinder 8 in a state where a spring 20 is urged between the rear end 9 of the guide cylinder 8 and the flange 19, and is capable of moving back and forth.

FIG. 8 shows an embodiment of a ballpoint pen refill mounted on a ballpoint pen according to the present invention.
The ballpoint pen refill 21 has a collar 22a formed outside the ink container 22. The ink container is filled with a white pigment ink 29, and the rear end of the ink has a grease-like shape that follows the ink as the ink is consumed. Follower 30 is filled. In addition, the follower is not compatible with the ink and has a property of preventing the ink from drying.
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. The follower may be a follower such as silicon rubber. The white pigment ink 29 contains at least a white pigment such as titanium oxide and polymer hollow fine particles and a gelling agent, and is blended so that sedimentation of the pigment is prevented and fluidity is minimized. Ink.
In addition, since the ink has a shear thinning property, the viscosity can be reduced by the rotation of the tip ball, so that a coating having a high concealing property can be performed. On the other hand, the white pigment ink 9 is an ink that can be erased with an eraser by adding a cross-linking substance to the ink solvent, turning into a sol by the rotation of the tip ball accompanying writing, gelling in a drawn line state, and not penetrating the paper.

Further, as shown in FIG.
A front shaft portion 24a is formed in front of b, and a rear shaft portion 24c is formed in the rear, and a shaft portion 23b of the tip 23 holding the tip ball 26 is fixed to a tip fitting hole 24d at the tip of the front shaft portion 24a. . In addition, if necessary, a convex locking portion is formed on the outer peripheral portion of the shaft portion 23a of the chip 23 so that the chip fitting hole 24d is formed.
It is locked in a biting manner.

The tip 23 is in a state where the tip ball 26 is substantially in contact with a seat having a channel into which ink can flow.
The tip ball 26 is swaged so as to be rotatably held. Further, a spring 27 is inserted into the inner hole of the chip 23, the rear end of the shaft 23a of the chip is appropriately caulked, and the rear end of the spring 27 is provided so as not to be pulled out.

A linear rod 27a is formed in front of the spring 27, and the tip of the rod 27a abuts against the back of the tip ball 26 in a pressing manner. The tip ball 26 is brought into close contact with the inner edge of the ball holding portion (formed by caulking or the like) of the chip 23 by the pressing. In addition, it is extremely important that the tip ball 26 is in close contact with the inner surface of the ball holding portion, even if the ink has a high viscosity, for drying the writing tip and preventing direct current of the ink. That is, in order to increase the amount of ink discharged, the ballpoint pen for correcting and writing the erroneous writing as in the present application is set to have a larger retreat size of the tip ball than the ballpoint pen for writing. In addition, grinding of the inner surface to improve the surface roughness of the inner surface of the chip holding the tip ball 26 and close contact accuracy by caulking, and secondary plastic working to improve the caulking accuracy are considered. Also, if necessary, a surface treatment or the like may be considered on the surface in close contact with the tip ball.

A valve chamber 25, which is appropriately eccentric with the axis of the chip 23, is provided behind the chip fitting hole 24d. A tapered or spherical shape is provided at the rear of the valve chamber 25 so as to communicate with the guide hole 25b. Is formed. A groove 25c through which ink can flow is formed on one side of the inner wall of the valve chamber 25. Further, a spherical valve element 28 is loosely fitted in the valve chamber 25, and the valve element 28 is
Abuts on the tip of the tip 23b of the tip so that the ink flowing from the guide hole 25b through the groove 25c and the like flows into the tip inner hole. 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. or,
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 that is in contact with the rear end of the shaft portion of the chip.

A rear shaft portion 24c extends behind the flange portion 24b of the joint 24. On the outer periphery of the rear shaft portion 24c, a cylindrical ink storage tube 22 is press-fitted and fixed with its tip abutting on the rear end of the flange portion 24b, and the inner diameter portion of the ink storage tube 22 is conducted to the guide hole 25b of the joint 24. I have. The ink storage tube 22 is made of, for example, a transparent PP resin molded product. In the above-described ball-point pen refill according to the first embodiment, the joint and the ink storage tube are formed as separate members, but both may be formed as an integral resin molded product.

As shown in the figure, a pumping type pressurizing mechanism is provided at the rear end of the ink storage tube 22. First, the pressurizing mechanism portion includes a bush 32, a joining cylinder 33, a receiving member 38, two springs and two valve bodies, a return spring 41, and the like. The bush 32 is opposed to the rear end of the follower 30. It is fixed in the ink storage tube 22.

The joining cylinder 33 includes a front cylinder 34 and a rear cylinder 36.
The space between them is provided integrally or connected with a stretchable bendable portion 35 such as a bellows. A valve chamber 34b is provided at the front axis of the front cylinder portion 34, and a tapered or spherical valve body receiving seat 34a is formed at the rear end of the valve chamber.
4c is provided. The front end of the front tube 34 contacts the rear end of the bush 32, and the flange 34 d provided at the rear end of the front tube 34 contacts the rear end of the ink tube 22. Is done. At this time, a ball-shaped first valve body 37 is loosely fitted into the valve chamber 34b, and a first spring 40a is further provided between the valve body and the rear end of the bush 32 so that the valve body is It is urged to be in close contact with the receiving seat 34a.

The receiving member 38 has a tapered or spherical valve body receiving seat 38a formed at the rear end of the inner circumference and a through hole 38b provided further rearward, and is pressed against the outer circumference of the rear cylinder portion 36. . At this time, the ball-shaped second valve body 39 is loosely fitted in a state of contact with the valve body receiving seat 38a, and further, the valve body and the stepped portion formed at the rear end of the through hole 34c of the front cylindrical portion. Second in between
Is provided, and the valve element is mounted on the valve element receiving seat 38.
a, and a return spring 41 is provided between the rear end of the flange portion 34d of the front cylindrical portion and the flange portion 38c formed at the front end of the receiving member 38,
The receiving member 38 is urged rearward with respect to the front cylinder portion 34. The valve chamber 35a sealed between the two valve bodies is extendable and contractible.

As described above, the ballpoint pen refill 21 has the stepped portion 2 in the inner hole of the shaft cylinder 1 and the flange 2 provided in the ink containing tube.
The knock mechanism is attached to the slit 43 by fitting the locking projection 46a of the cam cylinder 46 from the rear end of the shaft cylinder 1 with the return spring 42 interposed therebetween.
The tip of the ball-point pen refill 21 is fitted in the inner hole of the seal cylinder 11, and the tip 23 bites into contact with the rear end surface of the rubber bush 18 a of the plug 18 by appropriately pressing the spring 20.

[0022]

Next, the operation of the embodiment will be described below. First,
When the rear end of the knock cover 50 is knocked from the state shown in FIG. 3 and the knock mechanism is moved forward, the seal cylinder 11 moves forward in conjunction with the ballpoint refill 21 from the state shown in FIG. The hinge portion 17 is disengaged from the inner hole of the guide cylinder 8, and the stopper 18 rotates while being guided by the tapered surface 10, and the tip of the tip 23 is released from the stopper 18. At this time, when the stopper 18 starts rotating, the front end of the flange 24b of the ballpoint pen refill 21 abuts on the inner step 15a of the seal cylinder 11, and the advance of the seal cylinder 11 is prevented with the stopper 18 fully rotated. (With full compression of the spring or with a stopper), the flange portion 24b rides over the protrusion 15 of the elastic piece 13 and expands the forward end of the elastic piece 13.

When the knock mechanism is further advanced, the rotating cam member 48 is positioned at the advanced position, and the tip 23 is
Protruding from the front end port 6 of FIG. At that time, the knock portion is in the state shown in FIG. Also, the plug 18 is fitted in the window 5a drilled forward of the front shaft. Although the window 5a is provided to avoid interference between the tip and the plug, it is not always necessary to provide the window 5a because of design convenience.

In the state shown in FIG. 5, a coating operation such as writing or correcting a typographical error is performed. Since the rear end of the receiving member 38 of the ball-point pen refill 21 is prevented from retreating by the rotary cam member 48, when writing pressure is applied to the tip of the tip 23, the bendable portion 35 contracts with the retraction of the ball-point refill 21 due to the writing pressure. The inside of the valve chamber 35a is pressurized, and the first valve body 37 is opened to push air into the rear end of the follower 30 so that the rear end of the follower is pressurized, and the fluidity of the ink to the chip side is increased. To help. This has the effect of preventing the ink from separating from the peripheral surface of the tip ball due to knock impact, poor ink fluidity, and the like, thereby preventing continuous outflow of the ink. Further, the spring member 20 for urging the seal cylinder 11 rearward, and the receiving member 38 of the pressurizing mechanism unit for urging the spring force in the operating range of the return spring 42 for urging the ballpoint refill 21 rearward. The spring force of the return spring 41 is set appropriately strong. The receiving member 38 of the ballpoint pen refill 21 is fixed to the rotating cam member 48 and the return spring 4
It is possible to set so that the spring force of the return springs 41 and 42 is not affected by the method in which the rear end of the rotary cam member 48 contacts the front end of the rotary cam member 48.

When the writing pressure is released, the bendable portion 35 is restored by the return spring 21, the pressure in the valve chamber 35a is reduced, the second valve body 39 is opened, and air flows into the valve chamber 35a from the through hole 38b. Inflow. That is, the second spring 40b is set with a weak spring force. The strength of the first spring 40a is set within a range in which a necessary pressurization can be obtained. Therefore, the spring force of the return spring 41 needs to be set within a range where the receiving member 38 can be reliably restored to the front cylinder portion 34 and the strength is set in consideration of an appropriate writing pressure.

When the rear end of the knock cover 50 is knocked again, the ball-point pen refill 2 is interlocked with the knock mechanism.
At this time, the elastic piece 13 of the seal cylinder 11 expands at the flange portion 24b and the outer peripheral portion of the projection 15 comes into contact with the step portion 4, so that the seal cylinder 11 comes to a stationary state, and the tip 23 is plugged. The protruding portion 15 is positioned behind the portion 18 and the front shaft portion 24a
The contact state between the outer peripheral portion of the projection 15 and the step portion 4 is released, and the state returns to the state of FIG.

Next, the operation of the ballpoint pen refill will be described. FIG. 8 shows a state in which the tip 23 faces upward, and at this time, the valve body 28 is
Since the guide hole 25b is sealed at the position 5a, even if the ink is written upward and the ink on the back surface of the tip ball 26 of the chip runs out, the ink is caught by the head and does not flow backward. Therefore, when the tip 23 is turned downward, the ink can immediately flow out. By the way, in the structure without the ball valve, when the upward writing is repeated, the ink acts in the backward flow direction, so that air is entrapped in the chip, and it is difficult for the ink to immediately flow out in the downward writing. However, there is a problem that the flow path of the ink that is difficult to flow is obstructed and the ink is cut off. Therefore,
In some cases, it is better not to provide the valve body 28 for design reasons.

In this ball-point pen, the tip ball 26 is brought into close contact with the inner edge of the chip holding portion by the pressing of the rod shaft 27a of the spring 27, so that direct current of ink is prevented. In addition, since the tip ball 26 retreats due to the writing pressure, a gap is generated so that ink can flow out. With the help of the pressurizing action, the ink flows out by the rotation of the tip ball 26 by writing, and correction of typographical errors and the like can be erased with an eraser. A ballpoint pen using ink can be provided.

[0029]

As described above, the present invention comprises at least a white pigment such as titanium oxide and polymer hollow fine particles and a gelling agent, and is blended so that sedimentation of the pigment is prevented and fluidity is not impaired. By using the prepared white pigment ink, there is no problem that the white pigment and the solvent are separated as in the prior art, and therefore, it is not necessary to agitate the ink.
Further, by using the above-described ball-point pen structure, the side surface of the container is not pressed during writing. In addition, it is possible to provide a ball-point pen which can be erased with an eraser because it is formed into a sol by the rotation of the tip ball accompanying writing and gelated in a drawn line state and does not permeate into paper.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing the entirety of a ballpoint pen according to an embodiment of the present invention, showing a state in which a chip is housed in a shaft and the tip of the chip is sealed with a plug.

FIG. 2 is an enlarged sectional view of a main part in a state where a tip end portion of a chip is sealed.

FIG. 3 is a sectional view of a main part showing a state of a knocking part corresponding to FIG. 2;

FIG. 4 is a cross-sectional view of a main part showing a state in which the stopper is knocked and the plug part is being expanded.

FIG. 5 is a cross-sectional view of a main part showing a state in which the plug portion is knocked out and the writing tip protrudes from the tip end of the tip shaft.

FIG. 6 is a sectional view of a main part showing a state of a knocking part corresponding to FIG. 5;

FIG. 7 is a perspective view showing a seal cylinder.

FIG. 8 is a longitudinal sectional view showing the entire ballpoint pen refill mounted on the ballpoint pen of the present invention, and shows a state in which a chip is directed upward.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 shaft cylinder 2 step part 3 male screw part 4 step part 5 leading shaft 5a window 6 tip end port 7 female screw part 8 guide cylinder 9 rear end part 10 taper surface 11 seal cylinder 12 cylinder part 13 elastic piece 13a 14 Notch 15 Protrusion 15a Inner step 16 Tube 16a Rotation stop groove 17 Hinge 18 Plug 18a Rubber bush 19 Flange 20 Spring 21 Ballpoint pen refill 22 Ink storage tube 22a Flange 23 Tip 23a Shaft 24 Joint 24a Front shaft portion 24b Flange portion 24c Rear shaft portion 24d Chip fitting hole 25 Valve chamber 25a Valve body receiving seat 25b Guide hole 25c Groove 26 Tip ball 27 Spring 27a Rod shaft 28 Valve body 29 Ink 30 Follower 31 Follower rod 32 Bush 33 Joining cylinder 34 Front shaft portion 34a Valve body receiving seat 34b Valve chamber 34c Through hole 34d Part 35 bendable part 36 rear cylinder part 37 first valve body 38 receiving member 38a valve body receiving seat 38b through hole 38c flange 39 second valve body 40a first spring 40b second spring 41 return spring 42 return Spring 43 Slit 44 Clip 45 Ball part 45a Locking step 46 Cam cylinder 46a Locking projection 47 Knock rod 47a Cam part 48 Rotating cam member 48a Cam part 49 Base 50 Knock cover 50a Projection

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) B43L 19/00 B43K 7/02 B C09D 11/18 24/00 A

Claims (4)

[Claims] A stopper is provided in an inner hole at the tip of the tip of the tip of the ball-point pen so as to rotate in conjunction with the relative longitudinal movement of the ball-point refill, and the stopper is pressed against the tip of the ball-point pen when the refill retreats. In a ballpoint pen configured such that the stopper rotates and the tip of the tip can protrude from the tip end of the front shaft when the refill advances, the ballpoint refill has a tip of the ballpoint pen at the tip and ink at the rear. A spring is inserted into the tip, the tip of the spring presses the back of the tip ball, and the tip ball is provided so as to be in close contact with the inner edge of the ball holding portion at the tip end, and contains ink. The tube is provided with an ink and a follower at the rear end of the ink which prevents evaporation of the ink and follows the ink as the ink is consumed. A valve body that seals the rear end is provided, and the valve chamber is pressurized and depressurized by expanding and contracting the valve chamber, the front and rear valve mechanisms are alternately opened, and air is pushed into the rear end of the follower and pressurized. A ball-point pen having a pumping type pressurizing mechanism disposed therein to assist the flow of ink toward the chip. 2. A white pigment ink containing at least a white pigment such as titanium oxide and polymer hollow fine particles and a gelling agent, and formulated so as to prevent sedimentation of the pigment and to minimize the loss of fluidity. The ballpoint pen according to claim 1, wherein 3. The ink is characterized in that a cross-linking substance is added to the solvent and the ink is turned into a sol by the rotation of the tip ball accompanying writing, gelled in a drawn line state, and can be erased with an eraser because it does not penetrate into paper. Item 2. The ballpoint pen according to item 1. 4. A guide cylinder 8 fixed in the front shaft 5 is provided with a seal cylinder 11 which is always urged rearward by a spring 20 and is axially fixed so as to be movable forward and backward. A projection 15 is provided inside the tip of the stopper 18 together with the elastic piece 13 on a substantially intermediate side surface at about 90 ° rotatable at 17, and the tip of the ballpoint pen refill 21 is fitted into the seal cylinder 11, The tip of the tip 23 is appropriately pressed against the stopper 18, and when the ball-point pen refill 21 advances together with the seal cylinder 11 by the knocking operation, the hinge 17 is disengaged from the inner hole of the guide cylinder 8. The plug portion 18 becomes rotatable, the tip 23 pushes up the plug portion 18 to protrude from the distal end port 6 of the front shaft 5, and the elastic piece 13 is expanded, so that the tip 23 is located behind the plug portion 18 when retracted. Until the seal cylinder is the leading axis Ballpoint pen according to claim 1, characterized in that it is configured to be stationary with respect to the.