JPH10138687A - Dual type writing instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dual type writing instrument of a low cost with a simple structure equipped with a plurality of ballpoint pen writing elements so that tips of the elements smoothly project or retract by charging water base ballpoint pen ink having shear-viscosity thinning properties or low viscosity oil base ink in an ink container of a large size and non-deformation. SOLUTION: In the dual type writing instrument comprising a plurality of ballpoint pen writing elements mounted in a barrel so that their writing tips are selectively alternately projectable from or retractable into an end port of the barrel, ink containers of the elements 1a, 1b are substantially non- deformed and inserted into the barrel without oscillation. A long flexibly bendable front shaft 3 is provided between a front end of the container and an end of the elements. A step 30 is provided at a rear peripheral wall of the end port of the barrel. A coiled spring is engaged with an outer periphery of the front shaft. Its rear end is locked to a front end of the container in a contact state. A linear locking part 42a is formed forward of the spring, and its end is locked to the step 30 of the barrel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved writing instrument having a plurality of ballpoint pen writing bodies filled with an aqueous ballpoint pen ink having low viscosity or a low viscosity oily ink.

[0002]

2. Description of the Related Art In general, there has been known a double-type writing instrument equipped with a plurality of writing objects such as a mechanical pencil and a ball-point pen, the writing tip of which can selectively appear and disappear from an axis by rotation or knocking.

Conventionally known oil-based ballpoint pens have high resistance to the rotation of the ball when the ink flows out of the pen tip because the ink used for it has a high viscosity of several thousand mPa · S or more. Therefore, there is a drawback that writing is bad.
In addition, there is a problem in that the amount of ink flowing out from the tip during writing is small, there is a dent phenomenon, the writing line is uneven, the writing density is low, and a high writing pressure is required.

Recently, as an improvement of the oil-based ballpoint pen,
A ballpoint pen for water-based ink called a medium viscosity using an ink having an intermediate viscosity region between water and oil (several mPa · S to several thousand mPa · S) has been developed. This is a ballpoint pen using a relatively low-viscosity water-based ink having a characteristic of lowering the viscosity by the rotation of the tip ball and smoothly flowing out the ink, that is, a so-called shear thinning property. Further, as an improvement of the oil-based ball-point pen, a ball-point pen using a low-viscosity oil-based ink having excellent drying resistance can be considered.

The ballpoint pens using the medium-viscosity water-based ink and the low-viscosity oil-based ink are all low-viscosity, so that when the tip side faces downward, a gap between the tip ball and the tip holding portion occurs. There is a phenomenon in which the ink tends to flow backward due to a direct current problem in which the ink bleeds, upward writing, or an impact. If the ink causes backflow or direct current, there is a risk of soiling clothes and the like.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a mechanism capable of maintaining a dry end of a writing tip, allowing a seal cap to be removed and leaving the seal cap, and preventing direct current or backflow of ink. It has a medium-viscosity water-based, low-viscosity oil-based ballpoint pen writing body, and has a large number of ballpoint pen writing bodies that have a large ink container and are non-deformable. Further, it can be provided at a low cost with a simple structure.

[0007]

SUMMARY OF THE INVENTION The present invention has a tip for holding a tip ball and an ink container at the back, and the viscosity of the tip ball is reduced by the rotation of the tip ball during writing and flows out into the ink container. A grease-like translucent non-drying material which is filled with an aqueous ballpoint pen ink having a so-called shear thinning property or a low-viscosity oil-based ink and moves at the rear end of the ink in accordance with the consumption of the ink accompanying writing. A plurality of ball-point writing bodies filled with a ball-point pen are mounted in the barrel, and each writing tip can selectively appear and disappear alternately from the tip end of the barrel. The ink container is substantially non-deformable, and is inserted into the shaft without swinging, and a long front shaft that can be flexibly bent is provided between the front end of the ink container and the writing tip, Rear circumference of the tip end of the barrel A step portion is provided, a coil spring is inserted into the outer peripheral portion of the front shaft portion, and a rear end portion thereof is engaged with a front end of the ink storage portion in a contact state, and a linear engagement is provided in front of the coil spring. A stop portion is formed, and the tip of the stop portion is locked to the step of the barrel. Even in the case of a ballpoint pen writing body having a large and non-deformed ink storage portion, the tip of the writing tip is the tip of the barrel. It can be moved in and out smoothly from the end opening, and is simple and inexpensive.

As an example of the writing body retracting mechanism, an operating body fixed to the shaft cylinder so as to be rotatable only and a cam slope provided on the inner periphery of the operating body are provided at substantially the rear end of the ink storage of the ballpoint pen writing body. In addition to engaging the sliding projections provided integrally, the ballpoint pen writing body is provided so as to be movable only in the axial direction with respect to the barrel, and each ballpoint pen writing body is rotated by rotating the operating body with respect to the barrel. Can be moved back and forth. Further, as two examples, a plurality of ballpoint pen writing bodies are selectively knocked so that the respective writing tip portions can be alternately protruded and retracted from a shaft tip opening.

Further, the ballpoint pen writing body has a spring provided so that the tip ball always presses and comes in close contact with the inner edge of the ball holding portion at the tip end of the tip, and is released when writing. . Further, a valve chamber, in which a ball valve is loosely fitted, is provided facing the rear end of the chip. A ball valve is closely attached to the rear of the valve chamber to prevent a backflow of ink. A guide hole communicating with the inside of the ball is provided to prevent drying of the ink on the back surface of the tip ball, thereby preventing the first brush from being blurred, and preventing direct current and reverse flow of the ink.

[0010]

1 to 6 show a first embodiment of the present invention. In FIG. 1, two ballpoint pen writing bodies 1a and 1b are provided. The ballpoint pen writing bodies 1a and 1b have the same configuration, for example, different ink colors and writing line widths. Further, the double-type writing instrument of the present invention,
A ballpoint pen writing material filled with a medium-viscosity aqueous or low-viscosity oil-based ballpoint pen ink having a so-called shear thinning viscosity is used in combination as needed.

First, the writing pen 1a will be described. The tip 11 is caulked so that the tip ball 12 is rotatably held with the tip ball 12 substantially in contact with a seat having a channel into which ink can flow.
A spring 14 is inserted into the inner hole of the chip 11,
The rear end of the tip is appropriately caulked so that the rear end of the spring 14 cannot be pulled out. In addition, it is extremely important that the tip ball 12 is in close contact with the inner surface of the tip holding portion in order to dry the writing tip and to prevent direct current of ink. Therefore, the surface roughness of the tip holding the tip ball and the caulking In order to improve the close contact accuracy, grinding of the inner surface and secondary plastic working to increase the crimping accuracy are considered. In addition, a surface treatment or the like is taken into consideration for the surface in close contact with the tip ball. Further, the tip of the spring 14 becomes a straight rod shaft portion 15, and the tip of the rod portion 15 comes into contact with the back surface of the tip ball 12 in a pressed state.
The tip ball 12 is brought into close contact with the inner edge of the ball holding portion (formed by caulking or the like) of the chip 11 by the pressing.

The cylindrical body 2 is formed by a long front shaft portion 3 for pressing the tip 11 to the tip and an ink container 4, and the front shaft portion 3 is formed of a resin molded product that can be flexibly bent.
Further, a valve chamber 7 in which a ball valve 16 is loosely fitted is provided in a front end inner hole of the front shaft portion 3 so as to face the rear end of the chip 11,
When the tip 11 is downward, the guide hole 9 is opened and the ink 18 is conducted to the tip side. On the contrary, when the tip 11 is upward, the ball valve 16 closes the guide hole 9 to prevent the ink from flowing back. .

The cross section of the ink container 4 is substantially D
It has a shape (FIG. 6), and has a substantially circular shape in a state where the two flat portions are in contact with each other. In the case of three ink containers, the cross section of the ink storage tube is formed in a substantially fan shape obtained by dividing a circle into 120 degrees. The ink container 4 is filled with the above-mentioned medium-viscosity water-based or low-viscosity oil-based ink, and the rear end of the ink is in the form of a grease that can follow the ink surface and move following the consumption of the ink. Is filled with a follower 18 made of a translucent non-drying material. In the follower 18, a resin follower rod 19 having a specific gravity substantially equal to that of the follower is immersed.

An axially integral guide rib 5a is formed on the rear outer peripheral portion of the ink storage portion 4, and a slide protrusion 6a which is appropriately swelled on the outer surface is formed at the rear end of the guide rib 5a. The sliding projection 6a has a cam slope on its rear end side that comes into sliding contact with a cam slope of an operation body described later. Further, in the embodiment, the sliding protrusion 6a and the guide rib 5a are provided integrally with the ink container 4, but it is also possible to fasten to the ink container as a separate member. Thus, the ballpoint pen writing body 1a is configured. In addition, ballpoint pen writing body 1b
Is similarly configured.

The double-type writing instrument shown in FIG. 1 has two types of ballpoint pen writing bodies, a barrel 30 for accommodating the ballpoint pen writing bodies,
It comprises a tubular operating body 34 fixed to the rear of the barrel 30 so as to be rotatable only. The operating body 34 is detached from the barrel 30 as necessary, and the writing body is replaced. It is also possible to make the shaft cylinder 30 separable into a front shaft portion and a rear shaft portion so that the ballpoint pen writing body can be replaced.

By the way, two bulges 33 are formed on the outer periphery of the barrel 30 slightly to the rear, and a locking portion composed of a convex 33b and a concave 33a is formed on the front of the bulge 33. I have. As shown in FIGS. 1 and 2, a tubular portion 31 is extended behind the bulging portion 33, and a circumferential projection 32 a is formed on the peripheral surface of the tubular portion 31. The contact rib 32b is formed in the front part. A guide groove 33c is formed in the inner peripheral portion of the shaft cylinder 30. In addition, a step portion 30b is provided on a rear peripheral wall of the distal end opening of the shaft cylinder 30.

As described above, return coil springs 42, 42 are provided on the outer peripheral portion of the front shaft portion 3 of each ballpoint pen writing body.
43 is inserted and its rear end is abuttedly engaged with the front end of the ink storage unit.
a and 1b are inserted and the respective guide grooves 33c are inserted.
The guide ribs 5a, 5b formed on the rear outer peripheral portions of the ballpoint pen writing bodies 1a, 1b are fitted into the guide pen. The linear locking portions 42a, 43 are provided in front of the coil springs 42, 43.
a is formed, and its tip is the stepped portion 30 of the barrel 30.
b, the ballpoint pen writing bodies 1a, 1b are constantly urged rearward by coil springs 42, 43 provided between the front end of the ink container 4 and the stepped portion 30b.
In order to prevent the coil spring from rotating around the front shaft portion 3, the inner periphery of the rear end of the coil spring is set to have a size set to bite the outer periphery of the front shaft portion, or a locking portion or the like is provided on the outer periphery of the front shaft portion. The inner diameter of the coil spring is provided slightly larger than the outer circumference of the front shaft portion so that the coil spring does not deform and the expansion and contraction is smooth.

As shown in FIG. 3, the operating body 34 is a cylindrical body having a closed rear end, and a clip 38 connected to a rear outer peripheral side of the cylindrical body by a base 38a extends forward. or,
The convex portion 41a and the concave portion 41 are provided on the rear surface of the ball portion 41 of the clip 38.
b is formed, and an operating body 3 to be described later is formed.
The convex portion 41 a of the ball portion 41 is disengaged from the concave portion 33 a of the bulging portion 33 due to the circumferential movement of the clip accompanying the rotation of 4.
A circumferential concave groove 39 is formed on the inner periphery of the front end of the operation body 34, and a cam slope 35 is formed on the inner periphery on the rear side thereof, and a notch 36 is formed on the front end thereof.
Are formed. A semicircular groove 40 is formed at the front of the concave groove 39 as shown in FIG.

As described above, the operating body 34 is fitted into the cylindrical portion 31 of the shaft cylinder, and the projection 32a is engaged with the concave groove 39 by elastic deformation, so that the operating body 34 is rotatable with respect to the shaft cylinder 30 and is prevented from falling off.
In addition, the contact rib 32b of the cylindrical portion 31 is located in the groove 40, and the operating body 34 rotates in a range of approximately 180 degrees with respect to the shaft cylinder 30. At this time, the sliding projections 6a and 6b are in sliding contact with the cam slope 35, and the ballpoint pen writing bodies 1a and 1b alternately move back and forth by the rotation of the operating body 34 with respect to the barrel 30.
When the respective writing tips protrude from the tip end of the barrel, the sliding projections 6a and 6b engage with the notch 36 at the front end of the cam slope 35. Further, when the writing pen of the ball-point pen appears and disappears, the ink storage section 4 is not deformed as described above, but the front shaft section 3 is bent and can be operated smoothly.

FIGS. 7 to 11 show a second embodiment of the present invention. In addition, ballpoint pen cursives 50a and 50b
Has substantially the same configuration as the above-mentioned ballpoint pen writing materials 1a and 1b, but differs in ink color, drawing line width, and the like. Further, it is a medium-viscosity aqueous ink having a shear thinning viscosity, and a low-viscosity oil-based ink.

The difference between the ball-point pen writing bodies 50a and 50b and the above-mentioned ball-point pen writing bodies 1a and 1b is as follows.
1 is that the tail plug 53 having the ventilation groove 53a at the rear end is fixed. Further, the guide ribs 5a, 5b and the sliding protrusions 6a,
Instead of 6b, locking protrusions 54a and 54b bulging out on the outer peripheral portion of the ink containing portion 51 and stopper pieces 55a and 55b bulging in a plate shape behind the locking protrusions 54a and 54b are formed. Further, in the embodiment, the stopper piece 55a and the locking protrusion 54a are provided integrally with the ink containing tube 4, but it is also possible to fix the stopper piece to the ink containing tube as a separate member. As described above, the ballpoint pen writing body 50a is configured. The ballpoint pen writing body 50b is similarly configured.

Next, a slit 6 is formed on the rear shaft side surface of the shaft cylinder 60.
The cylindrical base 63 at the rear end of the clip 62 is fixed to the outer peripheral portion of the rear end of the shaft cylinder 60 under the condition that it can be detached. An engagement between the locking portions 60a and 63a such as a concave groove and a ridge and a rotation stopping engagement (not shown) such as a vertical groove and a rib are provided between them. The clip 62 is attached so as to face the slit 61 of the barrel 60. A ball portion 64 is formed at the tip of the clip 62, and the ball portion 64 is provided with a hook-shaped locking step 65 and a side wall 66. A substantially mountain-shaped projection 67 is formed behind the ball. In addition, clip 6
2 is a locking projection 54 of the ballpoint pen writing body 50a, 50b.
a, 54b can be elastically displaced in the lateral direction by a distance that can disengage the engagement between the locking step 65. Also, the shaft cylinder 60
A step portion 60c is provided on the rear peripheral wall of the front end opening 60b in the same manner as in the first embodiment.
A coil spring 5 having locking portions 56a, 57a forwardly between the front end of the front shaft portion 52 and the step portion 60c.
6,57 are energized.

[0023]

First, the first embodiment will be described.
When the operating body 34 is rotated to one side with respect to 0, the sliding protrusions 6a and 6b of the ballpoint pen writing body slide along the spiral groove 42 with the rotation of the operating body 34, and either one of the ballpoint pen writing bodies is rotated. Is advanced, and the other is retracted, so that the writing tip on the advancing side can protrude from the tip end of the barrel 30.
Further, even if the ink storage portion of the writing pen of the ballpoint pen is not deformed, the writing tip portion flexibly shifts, so that the writing tip portion smoothly comes out of the tip opening without disturbing the operation.

When the ballpoint pen writing body 1a is in a protruding state, as shown in FIG. 1, the ball portion of the clip and the bulging portion of the peripheral surface of the barrel are engaged with each other, and the clip is moved to the breast pocket. And so on. Next, when the operating body 34 is rotated to the other side, the ball-point pen writing body 1a is retracted, and its writing tip is immersed in the barrel 30, and the ball-point pen writing body 1a is rotated.
b moves forward. At that time, the writing tip is brought into a portable state in which it is accommodated in the barrel 30, and the clip for that state is at a position where the engagement with the bulging portion is released, so that the clip can be easily inserted into a breast pocket or the like. . When the cap 30 is further rotated, the ball-point pen writing body 1a further retreats, the ball-point pen writing body 1b further advances, and its writing tip projects from the tip opening of the barrel 30. In this state, the clip and the bulge of the peripheral surface of the shaft cylinder are engaged with each other so that the clip cannot be inserted into a breast pocket or the like.

The writing pen 1a for a ball-point pen has a tip 11
When the ball valve 16 faces upward, the ball valve 16 is positioned on the ball receiving seat 8 of the valve chamber 7 and seals the guide hole 9.
Even if the ink is written upward and the ink on the back surface of the tip ball 12 of the chip runs out, the ink is caught by the head and does not flow backward. Therefore, when the chip 11 is turned downward, the ink can immediately flow out, and the writing is prevented from being rubbed.
(By the way, in the structure without a ball valve, the ink acts in the backward direction when writing upwards, so that air is trapped in the chip and the ink does not follow immediately when writing downwards, causing scuffing.)

In a writing state in which the tip 11 is directed downward, the ball valve 16 abuts on one of the rear ends of the tip 11 in a biased state, and the other side has a flow path through which ink can flow into the tip 11. Then, the ink 17 that has entered the valve chamber 7 from the inside of the ink storage section 4 through the guide hole 9 is guided to the back of the tip ball 12. In this state, the tip ball 12 is brought into close contact with the inner edge of the chip holding portion by the pressing of the rod shaft portion 15, so that the direct current of the ink is prevented. In addition, the tip ball 12 slightly retreats due to the writing pressure, so that a gap is created and ink can flow out. By writing, the rotation of the tip ball 12 allows the ink to flow smoothly, and there is no dent and writing with high handwriting density is possible. Becomes On the back surface of the tip ball 12, there is a channel (a seat for the tip ball having a plurality of ink inflow grooves penetrating toward the inner hole of the chip), and the rod shaft portion 15 passes through the center hole of the channel. The ink in the chip is guided to the back of the tip ball 12 through the ink inflow groove and the gap between the center hole and the rod shaft portion 15.

First, FIGS. 9 and 10 show a state in which the writing tip portions of the ballpoint pen writing bodies 50a and 50b are housed in the shaft cylinder 60. FIG. FIGS. 7 and 8 show a state in which one rear end is knocked from this state. As shown in the drawing, the locking projection 54a of the ballpoint pen writing body 50a is locked to the locking step 65 of the ball portion 64 of the clip, and the ballpoint pen writing body 50a is locked.
The writing tip of “a” protrudes from the tip end port 60 b of the barrel 60. (In this state, when the side surface of the ball portion 64 is pressed and the clip is laterally deformed, the locked state is released and the writing tip is housed in the barrel.) Next, the other ballpoint pen writing body 50b
When the rear end is knocked, the locking projection 54b appropriately pushes up the projection 67 to raise the ball portion 64 of the clip 62, thereby releasing the locking between the locking projection 54a and the locking step 65, and The ballpoint pen cursive 50a is retracted. Further, when the ballpoint pen writing body 50b is advanced, the locking projection 54b is
5, the writing tip of the ballpoint pen writing body 50b projects from the tip end port 60b of the barrel 60.

When the writing tip of any of the writing pens of a ballpoint pen is inserted into a breast pocket or the like with the writing tip protruding,
Since the ball portion 64 of the clip 62 is pushed up with the cloth, the locking is released and the writing tip is stored in the shaft cylinder 60, thereby avoiding an accident that the clothes are stained with ink. In addition, when the writing implement is inserted into the breast pocket, the front ends of the stopper pieces 55a and 55b abut against the edges of the pocket or the like. Therefore, even if an external force is accidentally applied to the rear end, the stopper is not knocked and the clothes are stained with ink. Can be avoided.

[0029]

The composition and operation of the double-type writing instrument of the present invention are as described above. The dry end of the writing tip is maintained, the seal cap can be removed and the writing tip can be left, and direct current and reverse flow of ink can be prevented. Medium viscosity aqueous with a mechanism to enable
Constructs a low-viscosity oil-based ballpoint pen writing body, with multiple large, non-deformed ballpoint pen writing bodies mounted, the writing tip can smoothly appear and disappear by rotating or knocking means, consisting of simple parts It can be provided at low cost. Further, according to the embodiment, in the case of the rotary type, the clip cannot be inserted into the breast pocket or the like while the writing tip protrudes, so that the protruding state of the writing tip can be easily recognized and the stains of clothes and the like can be prevented. Become. In the case of the knock type, if the clip is inserted into a breast pocket or the like with the writing tip protruding, the writing tip is automatically immersed in the barrel, so that it is possible to prevent clothes and the like from being stained.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing the entirety of a double-type writing instrument according to a first embodiment of the present invention, which is partially not shown in section. 2
It has a kind of ballpoint pen cursive.

FIG. 2 is an external view of a main part showing a rear part of a shaft cylinder part.

FIG. 3 is a cross-sectional view of the operation body.

FIG. 4 is a sectional view taken along the line AA in FIG. 1;

FIG. 5 is a longitudinal sectional view of a writing pen of a ballpoint pen used in the present invention.

FIG. 6 is a sectional view taken along line BB in FIG. 5;

FIG. 7 is an overall front view of a cross section of a main part of a double-type writing instrument according to a second embodiment of the present invention, showing a state in which a writing tip of one ballpoint pen writing body projects from a tip end of a front shaft.

FIG. 8 is a longitudinal sectional view corresponding to FIG.

FIG. 9 is a partially non-sectional longitudinal sectional view of the double-type writing instrument according to the second embodiment, showing a state in which a writing tip of a ballpoint pen writing body is stored.

FIG. 10 is a longitudinal sectional view of a principal part corresponding to FIG. 9 on the front side of a partly non-cross section.

FIG. 11 is a longitudinal sectional view showing the entire ballpoint pen writing body mounted on the double-type writing instrument according to the second embodiment.

[Explanation of symbols]

 1a Ball-point pen writing body 1b Ball-point writing body 2 Cylindrical body 3 Front shaft part 4 Ink storage part 5a Guide rib 5b Guide rib 6a Sliding protrusion 6b Sliding protrusion 7 Valve chamber 8 Ball receiving seat 9 Guide hole 10 Inner hole 11 Chip 12 Tip ball 13 Shaft portion 14 Spring 15 Bar shaft portion 16 Ball valve 17 Ink 18 Follower 19 Follower bar 30 Shaft tube 30b Step portion 31 Tube portion 32a Projection portion 32b Contact rib 33 Swelling portion 33a Recess 33b Convex portion 33c Guide groove 34 Operating body 35 Cam slope 36 Notch 37 Rear end 38 Clip 38a Base 39 Concave groove 40 Groove 40a Contact part 40b Contact part 41 Ball part 41a Convex part 41b Concave part 42 Coil spring 42a Lock part 43 Coil spring 43a Lock part 50a Ball-point pen cursive 50b Ball-point pen cursive 51 in Housing part 52 Front shaft part 53 Tail plug 53a Vent groove 54a Locking protrusion 54b Locking protrusion 55a Stopper piece 55b Stopper piece 56 Coil spring 56a Locking part 57 Coil spring 57a Locking part 60 Shaft barrel 60a Locking part 60b Tip opening 60c Step 61 Slit 62 Clip 63 Base 63a Locking portion 64 Ball 65 Locking step 66 Side wall 67 Projection

Claims (5)

[Claims] 1. A chip holding a tip ball and an ink storage section at the rear, and has a so-called shear thinning property in which viscosity is reduced and flows out by rotation of the tip ball during writing into the ink storage section. A plurality of ball-point pens filled with an aqueous ball-point pen ink or a low-viscosity oil-based ink and filled with a follower made of a grease-like translucent non-drying substance that moves at the rear end of the ink in accordance with the consumption of the ink during writing. In a double-type writing instrument in which the writing body is mounted in the barrel and the respective writing tips can be alternately protruded and retracted from the tip end of the barrel, the ink storage portion of the ballpoint pen writing body is substantially non-deformed. And a long front shaft portion that can be flexibly bent is provided between the front end of the ink storage portion and the writing tip portion, and is fitted behind the tip end of the shaft cylinder. A step is provided on the surrounding wall, A coil spring is fitted around the outer peripheral portion of the front shaft portion, and a rear end portion thereof is abuttedly locked to a front end of the ink storage portion, and a linear locking portion is formed in front of the coil spring. A compound writing instrument, the tip of which is locked to the step of the barrel. 2. An operation body fixed to the shaft cylinder so as to be rotatable only, and a slide integrally provided on a cam slope provided on an inner periphery of the operation body at substantially a rear end of ink storage of a ballpoint pen writing body. Along with the projections, the ball-point pen writing body is provided so as to be movable only in the axial direction with respect to the barrel, and each ball-point writing body can be moved back and forth by rotating the operating body with respect to the barrel. The double-type writing instrument according to claim 1. 3. The double writing implement according to claim 1, wherein the writing pen has a so-called knock type, wherein a plurality of ball-point pen writing bodies are selectively shifted along the axis so that each writing tip can be alternately protruded and retracted from a shaft tip opening. . 4. The ballpoint pen writing body has a spring provided such that the tip ball always presses and contacts the inner edge of the ball holding portion at the tip of the tip, and the contact state is released during writing. The compound writing implement according to any one of claims 1 to 3, comprising: 5. The ballpoint pen writing body is provided with a valve chamber in which a ball valve is loosely fitted, facing the rear end of the chip, and the ball valve is in close contact with the rear of the valve chamber to prevent a backflow of ink. 5. The dual writing implement according to claim 4, further comprising a guide hole extending from the ball receiving seat to the ink storage section.