JP4540828B2 - Double writing instrument - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to an improvement of a compound writing instrument in which writing tip portions of a plurality of ballpoint pen writing bodies are selectively protruded from a shaft tip.
[0002]
[Prior art]
Conventionally, the front shaft and the tip of the guide cylinder are fixed, and a plurality of writing bodies with a sliding piece fixed to the rear end in a plurality of guide grooves provided in the guide cylinder are returned between the guide cylinder and the sliding piece. A cylindrical cam that has a cam slope that is biased by a spring (compression spring) and that can be moved back and forth in the axial direction. Then, by bringing each sliding piece into contact with the cam slope, the sliding piece can be moved back and forth alternately by rotation of the cylindrical cam, and the tip of each writing body can be selectively projected and retracted from the tip end of the front shaft. A dual writing instrument (A) is known.
[0003]
In addition, as a dual-type writing instrument (B) equipped with a ballpoint pen writing body of two colors, a guide cylinder is a die-cast molded product, and a pair of long guide grooves that are open on both side surfaces on the opposite side from the front to the rear end. The shaft portion is formed as a leg portion that is divided into two so as to be elastically displaceable in a direction substantially perpendicular to the guide groove, and the front end communicates with each guide groove in the front, and the front end is an open shaft. And a circumferential groove is formed on the side surface of the rear end. The cylindrical cam has a cam slope on the front surface, and has a semicircular collar part at the rear, and the collar part is fitted into the circumferential groove at the rear end of the guide cylinder by elastically deforming the guide cylinder. The cylindrical cam is fitted to the guide cylinder so as to be rotatable only, and is prevented from coming off. Further, the sliding piece has a protrusion on the outer surface, a cam inclined surface having substantially the same gradient as the cam inclined surface of the cylindrical cam is provided on the rear end surface of the protrusion, and a shaft portion having a screw portion is provided behind the protrusion. In addition, a tension spring is laid between the shaft portion of each sliding piece and the end portion at the rear end of the guide cylinder, and the sliding piece is always urged rearward. Further, a ballpoint pen writing body is detachably attached to the front of the sliding piece via a joining tube or the like. The dual-type writing instrument having this configuration has insufficient rigidity when the guide tube is made of a resin molded product, and has problems in fastening strength and operability.
[0004]
In addition, conventionally known oil-based ballpoint pen inks have high viscosity, and there are problems such as mottling, uneven writing lines, thin density, and high writing pressure during writing. In addition, it is a relatively low-viscosity ink as an improvement over conventional oil-based ballpoint pens, but it is filled with water-based ink with so-called shear thinning, in which the viscosity decreases with the rotation of the tip ball and the ink flows out smoothly. Ballpoint pens are known. When such a ballpoint pen is written upward, if the ink on the back of the tip ball runs out, the ink head is added directly, and there is a risk of causing a significant back flow and soiling hands and clothes. Further, since the viscosity of the ink is low and the amount of outflow is large, when the tip side is faced downward, if the gap between the tip ball and the tip holding portion is generated, the ink bleeds (direct current) occurs. That is, if the tip end of the tip is in contact with the clothing, there is a problem that ink is sucked out and the clothing is soiled.
Further, there is a problem that the writing wrinkle occurs because the ink on the back surface of the tip ball tends to flow backward after upward writing or after impact such as knocking or dropping. (The tip of the water-based ballpoint pen is set to have a larger vertical play between the tip ball and the tip holding portion than the tip of the oil-based ballpoint pen.) For this reason, it usually follows the ink consumption during writing at the trailing edge of the ink. However, a grease-like follower is provided that suppresses the backflow of ink against the ink's own weight and impact. Further, means for pressing the back surface of the tip ball with a spring so that the tip ball is in close contact with the ball holding portion of the tip, or means for providing a valve chamber in which a ball valve is loosely fitted at the rear end of the tip are used.
[0005]
On the other hand, a low-viscosity oil-based ink ball pen is considered as an improvement of the conventional high-viscosity oil-based ink ball-point pen. When low viscosity oil-based ink is used, there is no problem of drying of the tip end portion of the chip. Further, since the vertical play between the tip ball and the chip holding portion can be reduced with respect to the water-based ballpoint pen, it is advantageous as compared with the water-based ink having shear viscosity and low viscosity with respect to the direct current of the ink.
[0006]
By the way, in the case of the ballpoint pen refill mounted on the above-mentioned double writing instrument, when the tip ball diameter is 0.5 mm or less (for 0.3 mm and 0.4 mm thin characters), the amount of ink flowing out is small and the ink flow in the chip is small. The narrow path is advantageous for preventing direct current and backflow of ink. Further, the shorter the length of the ink storage tube (ink filling length), the smaller the inner diameter of the ink storage tube, the more advantageous for preventing direct current and backflow of the ink.
Based on the above, using a low-viscosity oil-based ink, the ink containing tube has an outer diameter of 3 to 3.5 mm and a tip ball diameter of 0.5 mm or less, preventing direct current and backflow of special ink. Even when a mechanism is not provided, it is possible to provide a ball pen refill for a double writing instrument that has a satisfactory use satisfaction including the writing life.
Also, if the tip ball diameter is 0.5 mm or more, the ink containing tube is lengthened, or the ink containing tube is made of a thin metal tube to expand the inner hole and the ink filling amount is increased, the ink is further reduced in viscosity. In this case, the ink direct current and the backflow prevention mechanism described above are incorporated in the water-based ink having a low viscosity shear thinning depending on the degree.
[0007]
[Problems to be solved by the invention]
The dual-type writing instrument to which the present invention is directed is not a high-grade product having many parts made of metal and having a complicated structure, but most of the parts are resin-molded products and are inexpensive and simplified in structure. The writing instrument has a drawback that the shaft diameter becomes thick. In addition, a ball-point pen writing body using a low-viscosity ink, especially a water-based ink having shear thinning viscosity, has a large ink flow rate, and therefore tends to increase the ink filling amount and increase the diameter of the ink containing tube.
Moreover, although it is an inexpensive compound writing instrument, there is a tendency that a thin one is preferred because of its design and luxury.
Therefore, an object of the present invention is to make it possible to make the shaft diameter as thin as possible and to solve the structural defects caused by making it thin.
[0008]
[Means for Solving the Problems]
The present invention has the following configuration in order to achieve the above-described problems.
The compound writing instrument according to the invention of claim 1 is arranged with a guide cylinder having a plurality of guide grooves in the shaft cylinder, and a ballpoint pen writing body is joined to the front end of the sliding piece provided in each guide groove, A tension spring is fixed to the rear end of the sliding piece so that the ballpoint pen is always drawn backward, and a cylindrical cam with a cam slope on the front contacts the cam slope on each sliding piece. In this state, it is fixed to the outer periphery of the guide tube so as to be rotatable only, and the operating body is engaged with the outer periphery of the rear end of the guide tube so as to be integrated in the rotational direction at the rear of the cylindrical cam. The rear end of the tension spring is locked to the operating body so that only the rotation is possible, and the cylindrical cam is integrally engaged with the shaft cylinder in the rotation direction within the shaft cylinder. When the operating body is rotated with respect to the cylindrical cam, Rolling, and wherein the writing tip of the ballpoint pen cursive is configured to be selectively retractable from the barrel tip opening.
[0009]
The dual writing instrument according to the invention described in claim 2 is the dual writing instrument according to claim 1, wherein the shaft cylinder is provided with the front shaft detachably fixed in front of the rear shaft, The rear end portion is provided in a state protruding from the rear end of the rear shaft, and a cylindrical portion integrally having a clip in the forward direction is fixed to the outer periphery of the rear end portion of the operating body.
[0010]
A compound writing instrument according to a third aspect of the present invention is the compound writing instrument according to the first aspect, wherein the ball-point pen writing body is a tip of a ball-point pen formed of a resin molded product that is transparent or the same color as the ink color. The tip is provided so that the tip ball is always pressed against the inner edge of the ball holding portion at the tip of the tip, and the tip is released when writing. The ink containing tube has a water-based ballpoint pen ink having a so-called shear thinning viscosity or a low-viscosity oil-based ink that flows out with a reduced viscosity due to rotation of the tip ball accompanying writing. Further, the ink is filled with a follower made of a grease-like or gel-like non-drying material that moves following the ink consumption accompanying writing.
[0011]
According to a fourth aspect of the present invention, there is provided the dual writing instrument according to the first aspect, wherein the ballpoint pen writing body is a tip of a ballpoint pen formed of a resin molded product that is transparent or of the same color as the ink color. The ink storage tube is fixed to the rear end of the joint, the front shaft is transparent, the grip portion is covered with a substantially opaque grip, at least the front of the grip can be seen through, and the writing front end is the front end of the front shaft. The joint is visible from the outside when protruding from the outside.
[0012]
【Example】
First, FIG. 1 is a longitudinal sectional view showing the whole of a dual writing instrument according to an embodiment of the present invention.
The compound writing instrument shown in the figure shows a state in which two kinds of ball-point pen writing bodies 8 using water-based ink having shear thinning viscosity are mounted. However, the present invention is not limited to the above, and low-viscosity oil-based ballpoint pen inks and ordinary oil-based ballpoint pens It is possible to mount a ballpoint pen using ink or an eraser-type ballpoint pen ink.
[0013]
As shown in the figure, the shaft cylinder is composed of a rear shaft 1 and a front shaft 2, and the rear of the front shaft 2 is detachably fixed to the front of the rear shaft 1 by a joint 4 by means such as screwing.
Further, the rear shaft 1 is made of resin, and as shown in FIGS. 2 and 3, circumferential concave grooves 1b and 1c are formed in the vicinity of the rear end of the inner hole, and in the axial direction on one side of the rear portion of the inner hole. A guide groove 1a extending in the direction is formed. Further, a screw portion that is screwed with the front shaft is formed in the vicinity of the front end of the inner hole. Further, the front shaft 2 is a transparent resin molded product so that the ink color of the ballpoint pen writing body can be understood, and a grip of substantially opaque rubber or thermoplastic elastomer is provided on the grip portion so that at least the front of the grip can be seen through. Thus, when the writing tip portion protrudes from the tip end of the tip shaft, the joint portion can be provided so as to be visible from the outside. At that time, the rear shaft is also made transparent to improve display properties.
[0014]
4 to 9 show the guide tube 3.
As shown in the figure, the guide tube 3 has a guide groove 3d having a similar guide groove 3d on the side surface opposite to the axially long guide groove 3c and the partition wall 3b that are open on the side surface from the front end to the substantially rear end of the shaft portion 3a. Is provided. In addition, a slightly large-diameter shaft portion 3e provided at the front end of the guide tube 3 has a groove portion of the same shape that penetrates the guide grooves 3c and 3d, and a presser 3j that appropriately protrudes from both sides is formed at the upper end of the groove portion. Further, the shaft portion 3a has a step portion 3h at an appropriate front position from the rear end, and the front portion has a slightly larger diameter, and the recess portion 3i is formed on the circumference behind the step portion 3h. A protrusion 3g is formed. Further, the outer diameter of the protrusion 3g and the outer diameter of the shaft portion 3a in front of the stepped portion 3h are usually set to the same diameter.
A longitudinal groove 3k is formed on the axial surface near the rear end of the shaft portion 3a, and an inner shaft 3f is formed on the rear end portion axis.
[0015]
FIG. 10 shows a sectional view of the cylindrical cam 5.
The cylindrical cam 5 has a cylindrical shape, and has a cam slope 5a that is displaced circumferentially at the front end edge, and a notch 5b is formed at the foremost end of the cam slope 5a. Further, guide ribs 5c are formed on the side surfaces of the cylindrical cam 5 in the axial direction, and a flat rear end portion 5e is formed at the rear end of the cam inclined surface 5a. The rear end portion 5e is connected to the cylindrical shaft portion 5d. Thus, a circumferential protrusion 5f is formed in the rear end inner hole of the shaft 5d.
[0016]
11 and 12 show the sliding piece 6.
As shown in the figure, the sliding piece 6 has a projection 6b formed at the rear end of the projection 6a provided on the outer surface of the central shaft portion, and is substantially the same gradient as the cam slope 5a of the cylindrical cam 5 in front of the projection 6b. The cam slope 6g is formed, and a screw-like portion 6f is formed on the shaft provided at the rear end of the central shaft. The screw-like portion 6f is a part for locking an end portion of a tension spring, which will be described later, and is not limited to a screw but may be a circumferential protrusion or a protrusion. Further, an engaging rib 6d is formed at a required position on the outer peripheral portion of the shaft portion 6c provided at the center shaft front end, and a ventilation groove 6e is formed on one side surface of the shaft portion 6c from the front end to the center shaft portion. ing. The engagement rib 6d is an engagement portion for removably fixing a rear end portion of a ball-point pen writing body, which will be described later, and the ventilation groove 6e is for air replacement between the inside and the outside of the ink containing tube after the ball-point writing body is fixed. It was actively established for the purpose.
[0017]
13 and 14 show the operating body 7.
As shown in the figure, the operating body 7 is an engagement in which circumferential protrusions 7b and 7c are formed on the front outer peripheral portion of the cylindrical shaft portion 7a, and the peripheral protrusion is similarly formed on the rear outer peripheral portion. A portion 7e is formed, and a piece-like protrusion 7d is formed on one side of the substantially outer peripheral portion.
Further, ribs 7h are formed in the required positions of the inner hole portion of the shaft portion 7a in the above-described longitudinal grooves 3k of the guide tube 3 so as to be integrated with each other in the rotational direction. A spring mounting portion 7f for locking the rear end portion of the tension spring is formed. The spring mounting portion 7f is provided with a hook portion 7g for hooking a hook portion provided at the rear end of the tension spring.
[0018]
FIG. 15 shows a ballpoint pen.
The ballpoint pen 8 shown in the figure is filled with a low-viscosity oil-based ink or a water-based ink having shear thinning viscosity.
The structure of the ball-point pen writing body 8 will be described. The tip 8c is crimped so that the tip ball can be rotatably held with the tip ball 8d substantially in contact with a seat having a channel through which ink can flow. .
Further, a spring 8e is inserted into the inner hole portion of the tip 8c, the rear end of the shaft portion of the tip is caulked appropriately, and the rear end of the spring is provided so as not to be extracted.
Further, a linear rod shaft portion is formed at the tip of the spring 8c, and the tip of the rod shaft portion abuts against the rear end of the tip ball 8d in a pressing manner. The tip ball is brought into close contact with the inner edge of the ball holding portion of the chip 8c by the pressing. A circumferential groove is formed on the outer periphery of the rear end shaft portion of the chip. (Not shown)
[0019]
The joint 8b is a PP resin molded product, and the rear shaft portion is fixed to the ink storage tube 18a. Further, a protrusion (not shown) is formed in the inner hole portion of the front shaft portion of the joint 8b, and a circumferential shape provided on the outer periphery of the rear end shaft portion of the chip when the chip is press-fitted into the inner hole portion. The protrusion is engaged with the groove, and the fixing force of the chip is enhanced.
Further, the joint 8b is provided in the same color as transparent or ink. When the joint is transparent, the remaining amount of ink can be correctly grasped. This is more effective when the ink containing tube is made of metal.
[0020]
Further, the ink containing tube 8a is filled with low-viscosity oil-based ink or water-based ink 8g having shear thinning viscosity, and the rear end of the ink comes into contact with the ink surface along with ink consumption and can be moved along with the grease. Or a gel-like follower 8h is disposed. In addition, the ink containing tube 8a can be a molded body made of a thermoplastic resin such as polyethylene, PP resin (polypropylene), polyethylene terephthalate, etc. from the viewpoint of low ink evaporation and productivity. A PP resin molded product or the like is used. Note that the joint 8b is not always necessary if the inner diameter of the ink storage tube is always constant, and the tip 8c can be directly fixed to the ink storage tube.
[0021]
By the way, when a low-viscosity oil-based ink is used for a ballpoint pen writing body, there is no problem of drying of the tip of the tip, but when a water-based ink having shear thinning viscosity is used, a seal resin (hot The initial quality is not deteriorated when it is attached and is not used for a long time. Of course, the sealing resin is removed at the start of writing.
[0022]
Hereinafter, the assembly structure will be described.
First, the sliding pieces 6 and 6 are disposed in the guide grooves 3c and 3d of the guide cylinder 3, and the tension springs 9 and 9 are locked to the screw-like portions provided at the rear ends of the sliding pieces 6 and 6, respectively. In addition, the rear end inner hole portion of the ink containing tube 8a of the ballpoint pen writing bodies 8 and 8 is engaged with the shaft portions 6c and 6c provided at the front end of the sliding piece. Further, the projection 5f of the cylindrical cam 5 is fitted into the recess 3i of the guide cylinder 3 by using elastic deformation, and the cylindrical cam 5 is fixed to the guide cylinder 3 so as to be rotatable only. Further, the operating body 7 is attached to the guide cylinder in a state where the rib 7h is fitted in the longitudinal groove 3k provided on the outer periphery of the rear end portion of the shaft portion 3a of the guide cylinder, and the front end of the operating body 7 is attached to the rear end of the cylindrical cam 5. The hooks 9a and 9a provided at the rear ends of the tension springs 9 and 9 are attached to the hooks 7g and 7g of the spring mounting portions 7f and 7f provided in the inner hole portion of the operation body 7. A cylindrical spring 5 having a cam inclined surface 5a on the front surface is fixed to a cam inclined surface 6g provided on each sliding piece. It will be in the state made to contact. Further, in the assembled state, it is inserted into the inner hole portion from the rear end of the rear shaft 1.
[0023]
Further, the guide rib 5c of the cylindrical cam 5 is fitted into the guide groove 1a of the rear shaft 1, and the cylindrical cam is integrated with the rear shaft in the rotation direction, and the protrusion provided at the front portion of the shaft portion 7a of the operating body 7 is provided. The portions 7b and 7c engage with the concave grooves 1b and 1c of the rear shaft 1 by mutual elastic deformation, and the operating body 7 is fixed to the rear shaft 1 so as to be rotatable only, and the guide tube 3 is integrated with the operating body. Can be rotated.
In addition, the cylindrical portion 10a is engaged with the engaging portion 7e provided at the rear portion of the shaft portion 7a of the operating body in a state where the protruding portion 7d of the operating body is engaged with the concave portion provided at the rear end portion of the clip body 10. Thus, the clip body 10 and the operation body 7 are integrated.
[0024]
As described above, when the clip body 10 is rotated 180 degrees in one direction with respect to the rear shaft 1, the guide cylinder 3 is similarly rotated with respect to the cylindrical cam 5, and the two-color ballpoint pen writing bodies 8, 8 are rotated. The writing tip part alternately appears and disappears from the tip end of the front shaft 2.
It is also possible to restrict the rotation of the clip body within a range of 90 degrees left and right. Further, the means includes a structure in which an engaging portion for restricting the rotation range is provided between the cylindrical cam and the guide tube, a structure for restricting the rotation of the operating body with respect to the rear shaft, and a step portion facing the front end portion of the guide tube. There is a structure in which a rotation restricting portion is provided between the holes in the rear shaft inner hole.
[0025]
By the way, although the above-mentioned embodiment is a two-color compound writing instrument, of course, it can be easily set to three colors.
FIG. 16 shows the state of the guide groove in the cross section of the guide tube 13 in the case of three colors.
FIG. 17 shows the state of the operating body 14 in the case of three colors.
FIG. 18 is a longitudinal sectional view showing the whole of the three-color compound writing instrument, but is shown in a state where one color is deleted from the cross-sectional relationship.
Further, the case of three colors is basically the same as that of two colors, and the description thereof is omitted.
[0026]
[Action]
In the dual writing instrument of the present invention, the rear end of the ballpoint pen writing body is not engaged with the front end of the sliding piece through the inner hole of the return spring as in the conventional dual writing instrument (A), so the inner diameter of the rear shaft is reduced. However, the operability is good.
Incidentally, in the case of the compound writing instrument (A), the return spring deforms into a kinked shape due to buckling when it repeatedly expands and contracts, and when replacing the writing body, it interferes with the shoreline of the spring and destroys the spring, causing malfunction. There is a problem that is likely to cause. Therefore, a necessary margin is provided so that such a problem hardly occurs, and the shaft diameter tends to be further increased.
Further, unlike the compound writing instrument (B), the guide tube is not formed as a leg portion that is divided into two so that the shaft portion can be elastically displaced in a direction substantially perpendicular to the guide groove. There is no lack of rigidity. Further, the structure in which the operating body is provided at the rear end of the guide cylinder is reinforced by the strong engagement between the operating body and the rear shaft even if the fastening portion of the guide cylinder and the cylindrical cam that is delicate is weak.
[0027]
Also, the joint is made of transparent or the same color as the ink color, the tip is transparent and the grip part is covered with a substantially opaque grip, and when the writing tip protrudes from the tip of the tip, the joint is By making it visible from the outside, when each writing tip protrudes from the tip end of the front shaft, the joint is visible from the transparent portion of the front shaft tip, and the ink of the ballpoint pen writing that is currently protruding is clear Is displayed. When the joint is transparent, the remaining amount of ink can be correctly grasped.
[0028]
【The invention's effect】
The configuration and operation of the present invention are as described above, and an inexpensive dual-type writing instrument can be made thinner than before, giving it a design and a high-class feeling, and solving the structural defects caused by making it thinner. It becomes possible.
Also, when protruding from the tip of the front shaft, the color of the ballpoint pen is clearly displayed, and when the joint is transparent, the remaining amount of ink can be grasped correctly.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a dual writing instrument (two colors) according to an embodiment of the present invention.
FIG. 2 is a longitudinal sectional view of a rear shaft.
FIG. 3 is a cross-sectional perspective view of a rear shaft.
FIG. 4 is a longitudinal sectional view of a guide tube (two colors).
FIG. 5 shows a top view of the guide cylinder.
FIG. 6 is a cross-sectional perspective view of a guide tube.
7 shows a view from below of FIG. 4 (guide cylinder).
8 is a cross-sectional view taken along line AA of FIG. 4 (guide cylinder).
9 is a cross-sectional view taken along the line BB of FIG. 4 (guide cylinder).
FIG. 10 is a cross-sectional view of a cylindrical cam.
FIG. 11 is a cross-sectional view of a sliding piece.
FIG. 12 shows a top view of the sliding piece.
FIG. 13 is a cross-sectional view of an operating body.
14 shows a view from above of FIG. 13 (operation body). FIG.
FIG. 15 is a longitudinal sectional view of a ballpoint pen writing body.
FIG. 16 is a cross-sectional view of the guide tube corresponding to FIG. 8 in the case of three colors.
FIG. 17 is a view seen from above the operating body in the case of three colors corresponding to FIG. 14;
FIG. 18 is a longitudinal sectional view of a dual writing instrument (three colors) that is an embodiment of the present invention.
[Explanation of symbols]
1 Rear shaft 1a Guide groove 1b Groove 1c Groove 2 Lead shaft 3 Guide tube 3a Shaft 3b Partition wall 3c Guide groove 3d Guide groove 3e Shaft 3f Inner shaft 3g Projection 3h Step 3i Recess 3j Presser 3k Vertical groove 4 Joint 5 Cylindrical cam 5a Cam slope 5b Notch 5c Guide rib 5d Shaft part 5e Rear end part 5f Projection part 6 Slide piece 6a Projection part 6b Projection part 6c Shaft part 6d Engagement rib 6e Ventilation groove part 6f Screw-like part 6g Cam slope 7 Operation Body 7a Shaft portion 7b Protruding portion 7c Protruding portion 7d Protruding portion 7e Engaging portion 7f Spring mounting portion 7g Hanging portion 7h Rib 8 Ballpoint pen writing body 8a Ink receiving tube 8b Joint 8c Tip 8d Tip ball 8e Spring 8f Sealing resin 8g Ink 8h Follower 9 tension spring 10 clip body 10a tube portion 10b clip 11 clip ornament 12 grip 13 guide tube 13a guide groove 13b guide groove 1 c the guide groove 13d partition wall 14 operating body 14a spring mounting portion 14b rib 14c protruding

Claims (4)

 A guide cylinder having a plurality of guide grooves is arranged in the shaft cylinder, and a ballpoint pen writing body is joined to the front end of the sliding piece provided in each guide groove, and the ballpoint pen writing body is always rearward at the rear end of the sliding piece. The tension spring is fixed so that it can be pulled in, and the cylindrical cam with the cam slope on the front surface can only rotate around the guide cylinder with the cam slope in contact with the cam slope on each sliding piece The operating body is engaged with the outer periphery of the rear end of the guide cylinder so as to be integrated in the rotational direction at the rear of the cylindrical cam, and is fixed so as to be rotatable only with respect to the shaft cylinder. The rear end portion of the tension spring is engaged with the cylindrical cam, and the cylindrical cam is integrally engaged with the shaft cylinder in the rotational direction in the shaft cylinder, and when the operating body is rotated with respect to the shaft cylinder, The guide cylinder rotates and the writing tip of each ballpoint pen Multiplex writing implement, characterized in that it is configured to be selectively retractable from the cylinder tip opening.  A shaft cylinder is provided with a front shaft detachably fixed in front of the rear shaft, and a rear end portion of the operating body projects from a rear end of the rear shaft. The compound writing instrument according to claim 1, wherein a cylindrical portion integrally having a clip in the forward direction is fixed to the outer periphery.  A ballpoint pen is a transparent or ink-colored resin molded product with a ballpoint pen tip and an ink receiving tube fixed to the rear end of the joint. There is a spring that is always pressed and in close contact with the inner edge of the holding part, and is released so that the close state is released at the time of writing, and the ink containing tube is viscous due to the rotation of the tip ball accompanying writing. A grease-like or gel that is filled with water-based ballpoint pen ink or low-viscosity oil-based ink having a so-called shear thinning viscosity and that moves after the ink consumption due to writing. The double writing instrument according to claim 1, which is filled with a follower made of a non-drying material. The ballpoint pen is made of a transparent or ink-colored resin molded product with a ballpoint tip and an ink receiving tube fixed to the rear end of the joint. The front shaft is transparent and the grip is almost opaque. The grip is covered, at least the front of the grip can be seen through, and the joint can be seen from the outside when the writing tip protrudes from the tip opening of the tip shaft. Double writing instrument.

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