JPH1076789A - Duplex writing instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure a wide space for fitting writing bodies of the thickness of a holder of satisfactory portability and handling properties, provide the state of not inserting a clip into a breast pocket or the like in the state of protruding writing tips and prevent an accident of soiling clothes by not protruding the writing tips carelessly in the state of storing the writing tips. SOLUTION: In a duplex writing instrument in which two kinds of ball point pen writing bodies 1a and 1b are fitted and respective writing tips are fitted selectively to appear and disappear alternately out of the end of a front shaft, the front shaft 49 and a rear shaft 30, an operation body 40 fixed on the rear end of a rotating shaft 33 protruding on the rear end of the rear shaft and a pair of slide blocks 43a and 43b set on the outer periphery of the rotating shaft are provided, and respective ball point pen writing bodies are provided on the front of respective slide blocks. A spring 41 is set between the operation body and the rear end of the rear shaft to move forward properly the operation body and the rotating shaft, and respective slide blocks are moved forward and backward alternately linking with the rotation of the rotating shaft following the rotation of the operation body to make the writing ends of respective writing bodies appear and disappear from and into the front shaft end opening.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double-type writing instrument equipped with a ballpoint pen writing material filled with an aqueous (medium viscosity), low-viscosity oil-based ballpoint pen ink having a shear thinning property.

[0002]

2. Description of the Related Art In general, there has been known a double-type writing instrument having a plurality of writing objects such as a ball-point pen mounted thereon so that a writing tip can be selectively protruded and retracted from an axis. In addition, as a retracting mechanism of the writing tip portion of the double-type writing instrument, a knocking type, a slider type that alternately slides a slider protruding from the side of the shaft cylinder of the writing instrument, and a cam cylinder having an inclined surface are rotated. Various types such as a cam type are known. The conventional retracting mechanism has a built-in return spring for returning the writing body to the inside of the barrel, so the structure is complicated and the number of parts is large,
There is a problem of high cost. Further, the space for incorporating the mechanism is large, and the degree of freedom of the refill shape is small.

On the other hand, when a medium-viscosity water-based and low-viscosity oil-based ballpoint pen is mounted on a double-sized writing instrument having a normal thickness due to a large ink container tube, the tip of the writing body protrudes without freedom between the writing bodies. The part is not smoothly centered on the tip hole of the barrel, and the operation is hindered, so that the writing tip cannot appear or disappear.
Therefore, there is a disadvantage that the shaft cylinder becomes extremely thick to enable the operation, and the portability and the usability are deteriorated.

[0004] Aqueous ballpoint pens have a low viscosity of several mPa · S or less, and therefore have the advantage of being able to be written with a light writing pressure, and are characterized by good writing taste. However, there is a drawback that a DC phenomenon in which the ink flows slowly from the pen tip, and a reverse flow phenomenon in which the air flows in from the tip of the ballpoint pen and the ink flows out, are likely to occur. A method of preventing these phenomena by using a fiber convergence material called batting is used. Also, if left in a cap-off state, there is a problem that the vapor pressure of the solvent is high and the solvent is leaked, so that the tip is dried and the ink does not flow out, making it impossible to write.

On the other hand, conventionally known oil-based ballpoint pens have a high viscosity of several thousands mPa · S or more of ink, so that the resistance to the rotation of the ball when the ink flows out of the pen tip is high. There is a drawback that writing is bad because of large size. 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. As an improvement of the oil-based ballpoint pen, recently, an intermediate viscosity region (a few mPa · S to a few thousand mP) between the above-mentioned water and oiliness
Ballpoint pens for aqueous inks called medium viscosity using the inks of a · S) have 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. However, since this ink has a drawback that the ink easily dries, a cap for sealing the writing tip is usually required.
In addition, the amount of outflow of ink is increased, and it is necessary to increase the diameter of the ink storage tube and increase the amount of ink to be filled in order to extend the writing life.

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. However, the amount of the ink flowing out is increased, and the ink storage tube is required to extend the writing life. It is necessary to increase the diameter of the ink and increase the filling amount of the ink. Also, due to the low viscosity of the ink, if the tip side faces downward and there is a gap between the tip ball and the tip holding portion, the ink will bleed (DC) or the amount of ink flowing out during writing will increase. There are drawbacks.

[0007] Since both the above-mentioned medium-viscosity aqueous ink and low-viscosity oil-based ink have low viscosities, there is a phenomenon that the ink easily flows backward or direct current. If the ink causes backflow or direct current, there is a risk of soiling clothes and the like. In addition, there is a drawback that handwriting is apt to occur due to drop or knock impact. Another problem is that when it is mounted on a writing instrument and inserted into a breast pocket or the like with its writing tip protruding, the clothes are soiled. In addition, a medium-viscosity aqueous ball-point pen is usually filled with a grease-like translucent non-drying substance called a follower at the rear end of an ink storage tube. What is necessary is just to consider the reduction of evaporation from the gap. For example, if a solvent having a considerably low vapor pressure, such as an oil-based ballpoint pen, is mainly used, evaporation of the ink need not be considered. However, in the case of water-based ink, since water is the main solvent, evaporation of water cannot be prevented only by selecting a low vapor pressure solvent.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art, that is, to mount a plurality of writing bodies in a barrel and write the respective writing bodies from the tip of the barrel. An object of the present invention is to provide a double-type writing instrument that allows the tip to selectively appear and disappear, and is excellent in manufacturing cost, portability, and usability. In addition, there is no backflow of ink and no DC phenomenon, the drying resistance of the pen tip is maintained, the cap can be removed and the pen can be left alone. Also, the backflow of ink due to drop impact, upward writing and the direct current of ink can be prevented. A medium-viscosity water-based, low-viscosity oil-based ballpoint pen writing body having a mechanism
Mounted in a seed barrel, the writing tip of each writing body can be selectively protruded and retracted from the tip of the barrel, and if the writing tip is protruding, it will not be worn in the breast pocket etc. It is possible to provide a convenient double-type writing instrument without any.

[0009]

According to the present invention, there is provided a writing instrument comprising:
In a dual-type writing instrument equipped with two kinds of ballpoint pen writing materials, each writing tip of which can be selectively protruded and retracted alternately from the tip opening of the front shaft, a front shaft, a rear shaft, and a rear shaft. An operating body fixed to a rear end of the rotary shaft protruding from a rear end of the rear shaft, the operating body being rotatably disposed within a range of about 180 degrees with respect to the rear shaft, and a pair of sliding members on an outer periphery of the rotary shaft. A moving piece is arranged, and a ball-point pen cursive is provided in front of each sliding piece, respectively.
In addition, a spring is provided between the operating body and the rear end of the rear shaft so that the operating body and the rotating shaft can be appropriately advanced, and the rotating shaft is urged rearward in a state where the rotating shaft is stopped at the rear end of the rear shaft. At this time, the rotation shaft and the rear shaft engage with each other to prevent rotation of the rotation shaft with respect to the rear shaft, and the rotation shaft can rotate when the operating body is rotated with the operation body appropriately advanced with respect to the rear shaft. In conjunction with the rotation of the rotating shaft accompanying the rotation of the operating body, each sliding piece moves back and forth alternately so that the writing tip of each writing body can be protruded and retracted from the front shaft tip opening. Is done.

The ballpoint pen writing body has a tip for holding the tip ball and an ink storage tube at the rear, and the viscosity of the tip ball is reduced by the rotation of the tip ball during writing into the ink storage tube. A water-based ballpoint pen ink or a low-viscosity oil-based ink having a shear-thinning property is filled, and the rear end of the ink is filled with a follower made of a grease-like translucent non-drying substance that moves following the consumption of the ink accompanying writing. Wherein the ink storage portion of the ink storage tube has a relatively large cross-sectional area and is non-deformable,
The portion connecting the tip and the ink storage portion can be easily shifted in the lateral direction with respect to the axial direction.

Further, the ballpoint pen writing body has a spring provided so 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. . Further, the ballpoint pen writing body is provided with a valve chamber in which a ball valve is loosely fitted in contact with 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. A guide hole is provided from the seat to the ink storage tube.

A clip provided from one side of the operating body toward the front of the rear shaft, and a bulging portion provided at a predetermined position on the rear shaft peripheral surface in contact with the ball portion of the clip, Is rotated so that only when the writing tip protrudes from the tip of the front shaft, the clip between the ball portion of the clip and the bulging portion is engaged so that the clip cannot be inserted into a breast pocket or the like. Features.

[0013]

1 to 7 show an embodiment of the present invention. In FIG. 1, two ballpoint pen cursives 1a,
1b is provided. The double-type writing implement intended by the present invention uses a ball-point pen writing material filled with an aqueous or low-viscosity oil-based ball-point pen ink having a so-called shear thinning property.

The double-type writing instrument shown in FIG. 1 comprises a front shaft 49 and a rear shaft 30 for accommodating a portion of a writing tool mechanism located at a front portion, and an operating body 40 disposed at a rear end of the rear shaft. Also, the front shaft 49
A female screw 49a is formed on the inner periphery of the rear part. A male screw 32 is formed at a front portion of the rear shaft 30, and is screwed with the female screw 49a of the front shaft 49, and is removed as necessary to replace a writing body. A rib 30a for preventing rotation is formed on the inner periphery of the rear end of the inner hole of the rear shaft 30 for restricting a rotation range of a rotating shaft 33, which will be described later, and a rear end step portion 30b is formed.
And four guide ribs 31 formed in the axial direction at intervals of 90 degrees on the front inner peripheral portion of the rear shaft 30. Further, bulging portions 39 are formed at two locations facing the outer periphery of the rear shaft 30 slightly rearward, and a convex portion 39a and a concave portion 39b are provided on the front side of each bulging portion.

The rotary shaft 33 has a small diameter portion 3 in front of the large diameter portion 36.
The spiral cam groove 35 is formed on the peripheral surface of the small diameter portion 34. Further, a circumferential groove 36a cut out at the rear end side of the large diameter portion peripheral surface located behind the cam groove 35, and a narrow vertical groove 36 cut out at the front end at the center position of the groove 36a.
e is formed. As will be described later, a rib is formed on the inner periphery of the rear end of the rear shaft 30 so that the rib
It is configured to slide in the rotation direction within a range of 0 degrees, and the rib is fitted into the vertical groove 36e to prevent rotation. A locking portion 38 having a shaft portion 37 at the rear of the large diameter portion 36, a shaft portion 38a having a reduced diameter at the rear thereof, and a flange portion 38b at a rear end of the shaft portion is provided. Further, a detent groove 38d is provided at a required position of the shaft portion 38a.

The operating body 40 is formed of a cylindrical portion 40a which is provided on the rear end portion 40b of the rear shaft 30, and a clip 40c extending forward from one side surface of the outer peripheral portion of the cylindrical portion 40a. A ball portion 40d is provided inside the clip 40c, and a rib (not shown) provided on the peripheral surface of the shaft portion 38a of the rotary shaft 33 is provided in a hole of the rear end portion 40b of the cylindrical portion 40a. As will be described later, the flange portion 38b of the rotating shaft 33 protrudes from the rear end of the rear end portion 40b, and the rotating shaft 33 and the operating body 40 are fixed. A crown 42 is fixed to the rear end of the operation body 40.

Insertion holes 45a and 45b are provided in front of the sliding pieces 43a and 43b, and the respective insertion holes are provided with locking portions of inward projections for fixing rear ends of ballpoint pen writing bodies 1a and 1b to be described later. 46a and 46b are provided. On the rear inner surface side, projections 44a, 44 for each sliding piece to move back and forth by the pressing of the cam groove 35 due to the rotation of the rotating shaft 33.
b is formed. Grooves 48a and 48b are provided on the outer circumference of the sliding pieces 43a and 43b so as to stop and engage with the guide ribs 31 of the rear shaft 30. Therefore,
Grooves 48a, 48 provided on the side surfaces of the sliding pieces 43a, 43b
The sliding pieces 43a and 43b are smoothly moved back and forth by b engaging the guide ribs 31 respectively. The cross section of the sliding pieces 43a, 43b is substantially D-shaped. Therefore, there is an advantage that a complicated structure for mounting a guide cylinder having two opposing guide grooves, which is often shown in the conventional example, is not required. The sliding pieces 43a and 43b are in contact with each other on their flat sides, but in order to make the sliding between them smoother, a guide projection 47b is provided on the sliding piece 43b, and a guide projection 47b is provided on the sliding piece 43a. Guide groove 4 to be inserted
7a is provided.

The rotating shaft 33 is connected to the sliding piece 43.
The ribs 30a formed on the inner periphery of the rear end of the rear shaft 30 are inserted into the inner hole of the rear shaft 30 while the projections 44a, 44b of the shafts 43a, 43b are engaged with the cam grooves 35. 36e
And the rear end of the large diameter portion 36 is a rear end step portion 30b of the rear shaft.
And the operating body 40 is fixed to the rear end shaft portion of the rotating shaft 33. At this time, a spring 41 is biased between the inner step of the operating body 40 and the rear end of the rear shaft 30.
Note that, as described above, the rib 30a extends approximately 180 degrees in the groove 36a.
The rib 30a slides in the rotation direction within the range of
And the rotation shaft 33 is prevented from rotating with respect to the rear shaft 30.

The rotating shaft 33 is rotated by rotating the operating body 40 with respect to the rear shaft 30 while maintaining the state where the operating body 40 is advanced, so that one sliding piece moves forward and the other sliding piece moves backward. (State in FIG. 1) The rear ends of the ballpoint pen writing bodies 1a, 1b are fixed to the insertion holes 45a, 45b of the sliding pieces 43a, 43b, and the front shaft 49 is fixed in front of the rear shaft 30.

Next, the ballpoint pen writing body 1a mounted on the compound writing instrument of the present invention will be described. Note that the ballpoint pen writing bodies 1a and 1b have the same configuration, and have different ink colors, for example. The ink applied to the ballpoint pen writing material is a water-based, low-viscosity oil-based ink having a so-called shear thinning property.

As shown in FIG. 6, 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, and the rear end of the shaft 13 of the chip 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 is a linear rod 15, and the tip of the rod 15 is the ball 12.
Abuts on the rear end of the device 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 joint 2 has a shaft 1
A front shaft 3 for pressing the third shaft 3 and a rear shaft 5 to be pressed against the front end of the ink storage tube 17 are formed. The space between the front shaft 3 and the rear shaft 5 is flexible, for example, a bellows 4 or the like. Is formed of a resin molded product connected to. A valve chamber 7 in which a ball valve 16 is loosely fitted is provided behind the inner hole of the front shaft portion 3, and a tapered or spherical ball receiving seat 8 is provided behind the valve chamber 7.
And a guide hole 9 provided eccentrically to the axis as appropriate.
The inner holes of the bellows 4 and the rear shaft portion 5 communicate with the inner holes of the ink storage tube 17. A groove is provided on one side of the inner wall of the valve chamber 7 so that ink flows in the axial direction. (Not shown)
The loosely fitted ball valve 16 in the valve chamber 7 is
In a state where 1 is turned downward, an ink flow path is formed in contact with a state biased to the rear end of the shaft portion 13 of the chip, and the ink in the ink storage tube passes through the guide hole 9 and passes through the groove, the ink flow path, etc. Through the chip inner hole. On the other hand, in the upward state, the ball valve 16 comes into contact with the ball receiving seat 8 to obtain a function of preventing the ink from flowing backward.

The ink container tube 17 is filled with the ink 18 of the above-mentioned ball-point pen, and the rear end of the ink 18 is a grease-like half which can move following the ink surface by contact with the ink surface as the ink is consumed. A follower 19 made of a transparent non-drying substance is filled. Further, a resin follower rod 20 having a specific gravity substantially equal to that of the follower 19 is immersed in the follower 19 as necessary in order to prevent deformation due to dropping, knock impact or the like. A tail plug 21 is fixed to the rear end of the ink storage tube 17.
a, locking portion 46 of an insertion hole provided at the front portion of 43b
The locking grooves 23 are detachably fixed to a and 46b. The tail plug 21 is provided with a ventilation groove 22 for communicating the inside of the ink storage tube 17 with the outside air. The ink storage tube 17 is made of, for example, a transparent PP resin molded product. Further, the ink container 17 is selected from a material having excellent clear drain properties. Further, the ink storage tube may be formed integrally with the joint 2.

Further, the ink storage portion of the ink storage tube 17 is a non-deformed one having a relatively large cross-sectional area. In the embodiment, the ink storage portion has a substantially D-shaped cross-sectional shape which is fitted into the rear shaft 30 without waste. Have. The portion connecting the tip 11 and the ink storage portion can be easily shifted in the lateral direction with respect to the axial direction. It is also possible to connect a flexible tube between the joint for crimping the rear end of the chip 11 and the ink containing tube.

[0026]

When the operating body 40 is rotated in one direction while maintaining the state where the operating body 40 is advanced with respect to the rear shaft 30, the sliding pieces 43a, 43b are rotated.
The projections 44a and 44b slide along the cam groove 35 with the rotation of the rotating shaft 33, so that one of the sliding pieces moves forward,
The other side is retracted, and the writing tip of the cursive body on the forward side is
9 can be protruded from the front end port 9. At this time, the contact portion 36b of the large diameter portion 36 contacts the rib 30a to prevent the rotation. 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 operation is not hindered and the writing tip portion smoothly comes out of the tip end of the front shaft 49.

When the ballpoint pen writing body 1a is in a protruding state, as shown in FIG.
The convex portion 40e of 0d is engaged with the concave portion 39b of the bulging portion 39 of the rear shaft, so that the clip 40c cannot be inserted into the breast pocket or the like.

Next, when the rotating shaft 33 is rotated in the opposite direction, the sliding piece 43a is retracted so that the writing tip of the ballpoint pen writing body 1a is immersed in the front shaft 49 and the sliding piece 43b is rotated.
Moves forward. At this time, the writing tip is in a portable state accommodated in the front shaft 49, and the clip for that state is shown in FIG.
And can be easily inserted into a breast pocket or the like. Also, at this time, when the advance of the operating body 40 is released, the rib 30a of the rear shaft is fitted into the vertical groove 36e of the rotary shaft, and the writing body is fixed so as not to move back and forth. In addition, as shown in FIG. 5, the rib 30a can be easily guided to the vertical groove 36e by providing a radius or an appropriate large inclination at the entrance 36f of the vertical groove.

When the operating body is moved forward and the rotating shaft 33 is further rotated, the sliding piece 43a is further retracted, and the sliding piece 43b is further advanced, and the writing tip of the ballpoint pen writing body 1b is moved to the front shaft 49. Protruding from the tip of the mouth. In this state, the clip is in the position C shown in FIG. 3 and the convex portion 40e of the ball portion 40d of the clip is engaged with the concave portion 39b of the bulging portion 39 of the rear shaft so that the clip 40c cannot be inserted into a breast pocket or the like. create. The groove 36 of the large diameter portion 36 of the rotating shaft shown in FIG.
The abutting portion 36c abuts the rear shaft rib 30a, and the other rotation is restricted.

In a state where the tip 11 is turned upward, the ball valve 16 is positioned in the ball receiving seat 8 of the valve chamber 7 and seals the guide hole 9 in the ballpoint pen writing body 1a. Even if the ink immediately below the tip ball 12 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 reverse flow direction by writing upward, so air is trapped in the chip,
Ink does not immediately follow with downward writing, causing rubbing)

In the writing state in which the chip 11 is directed downward, the ball valve 16 abuts on one of the rear ends of the chip 11 in a biased state, and the other side has a flow path through which ink can flow into the chip 11. Then, the ink 18 that has entered the valve chamber 7 from the ink storage tube 17 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 receiving seat for the tip ball having a plurality of ink inflow grooves penetrating toward the inner hole of the chip), and a 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.

[0033]

The construction and operation of the dual writing instrument according to the present invention are as described above. By simplifying the structure, it is advantageous in terms of assemblability and cost, and it is almost closely packed in the barrel of the writing instrument. A convenient double-type writing instrument loaded with a large ballpoint pen writing material can be provided with a shaft thickness that satisfies portability and usability. In addition, it is equipped with a ballpoint pen writing material using water-based, low-viscosity oil-based ink with so-called shear thinning, no writing, no dark drawing, no writing scratches, and no need for a cap It is possible to appear and disappear, and it is possible to prevent accidents that stain the inside of the shaft cylinder, hands, clothes, and the like due to the direct current of ink, upward writing, knocking, and reverse flow of ink with respect to a drop impact. In addition, only when the operating body is rotated and the writing tip protrudes from the tip of the front shaft, the protrusion of the ball portion of the clip is engaged with the recess of the bulging portion of the rear shaft, and the clip is inserted into a breast pocket or the like. Because it makes no state, it does not insert it into the breast pocket etc. with the writing tip protruding, so
Accidents that stain clothes are prevented. Further, in the state where the writing tip is stored, the writing tip does not rotate unless the operating body is pressed and advanced with respect to the rear shaft, so that there is no problem that the writing tip protrudes carelessly.

[Brief description of the drawings]

FIG. 1 is a vertical cross-sectional view showing the entirety of a double-type writing instrument according to an embodiment of the present invention, which is partially not shown. In addition, two kinds of ballpoint pen cursives are mounted.

FIG. 2 is a cross-sectional view taken along the line CC in FIG. 1, but shows a state in which a writing body is not fixed to the sliding piece 43a.

FIG. 3 is a sectional view taken along line BB in FIG. 1; or,
The position of the clip accompanying rotation of the operating body is shown.

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

FIG. 5 is a perspective view showing a rear end portion of the rotating shaft.

FIG. 6 is a longitudinal sectional view of the ballpoint pen writing body 1a.

FIG. 7 is a cross-sectional view of the ink storage tube.

[Explanation of symbols]

 1a Ballpoint pen writing body 1b Ballpoint pen writing body 2 Joint 3 Front shaft part 4 Bendable part 5 Rear shaft part 6 Flange part 7 Valve room 8 Ball receiving seat 9 Guide hole 10 Inner hole part 11 Chip 12 Tip ball 13 Shaft part 14 Spring 15 Rod shaft part 16 Ball valve 17 Ink storage tube 18 Ink 19 Follower 20 Follower rod 21 Tail plug 22 Vent groove 23 Locking groove 30 Rear shaft 30a Rib 30b Rear end step 31 Rib for guide 32 Male screw 33 Rotating shaft 34 Small diameter Part 35 Cam groove 36 Large diameter part 36a Groove 36b Contact part 36c Contact part 36d Wall part 36e Vertical groove 36f Inlet 37 Shaft part 38 Lock part 38a Shaft part 38b Flange part 38c Split groove 38d Rotation stop groove 39 Swelling part 39a convex portion 39b concave portion 40 operating body 40a cylindrical portion 40b rear end portion 40c clip 40d ball portion 40e convex portion 40 Recess 41 Spring 42 Crown 43a Sliding piece 43b Sliding piece 44a Projection 44b Projection 45a Insertion hole 45b Insertion hole 46a Locking portion 46b Locking portion 47a Guide groove 47b Guide protrusion 48a Groove 48b Groove 49 Front shaft 49a Female screw 50 Point End

Claims (6)

[Claims] Claims: 1. A double-type writing instrument equipped with two types of ballpoint pen writing bodies, wherein each writing tip can be alternately protruded and retracted from a tip opening of a front axis. An operating body fixed to a rear end of the rotating shaft, which is rotatably disposed in the inner hole of the rear shaft in a range of approximately 180 degrees with respect to the rear shaft, and protrudes from a rear end of the rear shaft; A pair of sliding pieces are arranged on the outer circumference, a ballpoint pen writing body is provided in front of each sliding piece, and a spring is provided between the operating body and the rear end of the rear shaft, and the operating body and The rotating shaft can be moved forward as appropriate, and the rotating shaft is urged backward in a state where the rotating shaft is stopped at the rear end of the rear shaft. At this time, the rotating shaft and the rear shaft are engaged with each other to rotate the rotating shaft with respect to the rear shaft. The rotation shaft is rotatable when the operation body is rotated while maintaining the state in which the operation body is appropriately advanced with respect to the rear shaft, and the rotation of the operation body is prevented. In conjunction with the rotation of the rotating shaft associated with, each sliding piece is alternately moved back and forth so that the writing tip of each writing body can be protruded and retracted from the tip end of the front shaft. Writing instrument. 2. A rotating shaft having a cam groove formed on a shaft peripheral surface,
Each sliding piece formed on the inner side where the projection engaging with the cam groove is opposed to each other, and a circumferential direction cut out at the rear end side of the large diameter portion peripheral surface located behind the cam groove of the rotating shaft. A groove, a narrow vertical groove which is cut open at the front end at a center position of the groove, and a rib formed on the inner periphery of the rear end of the rear shaft.
2. The dual writing implement according to claim 1, wherein the writing implement slides in the rotation direction within a range of 0 degrees, and the rib is fitted into the vertical groove to prevent rotation. 3. A ball-point pen writing body has a tip for holding the tip ball and an ink storage tube at the rear, and the viscosity of the tip ball is reduced by rotation of the tip ball during writing into the ink storage tube. A water-based ballpoint pen ink or a low-viscosity oil-based ink having a shear-thinning property is filled, and the rear end of the ink is filled with a follower made of a grease-like translucent non-drying substance that moves following the consumption of the ink accompanying writing. Wherein the ink storage portion of the ink storage tube has a relatively large cross-sectional area and is not deformed, and a portion connecting the tip and the ink storage portion is formed in a lateral direction with respect to the axial direction. 3. The double writing implement according to claim 1, wherein the double writing implement is easily movable. 4. The ballpoint pen writing body comprises a spring provided so 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 double writing implement according to claim 3. 5. A ball-point writing body is provided with a valve chamber in which a ball valve is loosely fitted in contact with a rear end of a chip, wherein 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, wherein a guide hole is provided from the ball seat to the ink storage tube. 6. A clip provided from one side of the operating body toward the front of the rear shaft, and a bulging portion is provided at a predetermined position on a peripheral surface of the rear shaft in contact with a ball portion of the clip. Is rotated so that only when the writing tip protrudes from the tip of the front shaft, the clip between the ball portion of the clip and the bulging portion is engaged so that the clip cannot be inserted into a breast pocket or the like. The double-type writing instrument according to claim 3, 4 or 5, wherein