JPH09188092A - Dual writing instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a dual writing instrument convenient for carrying with an eraser feeding mechanism to satisfy the versatility in design. SOLUTION: When a rear barrel 49 is rotated with respect to an intermediate barrel 30, either writing unit is selected by the cam oblique surface 35 upon rotation of a cylindrical cam 34, and the writing end protrudes from the end port of the head barrel 51. Even if the ink containers of ballpoint pen writing units 1a, 1b are non-deformed type, the head site of writing is flexibly displaced, and hence the operation is not disturbed, and a tip 11 smoothly protrudes from or retract to the end port of the head barrel 51. When the selected unit is the mechanical pencil unit, the rear end of the rear barrel is knocked to feed the lead. When an eraser is used, the head crown 44 of the rear end is picked up, and the inner cylinder 43 is rotated. Then, an eraser holder 46 is guided to the spiral groove 38 of the cylindrical cam and the slit 43a of the cylinder 43, retracted, and the eraser 55 is fed from the rear end.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mechanical pencil writing body, an ordinary oil-based ballpoint pen writing body, or a ballpoint pen writing body filled with an oil-based ballpoint pen ink of shear thinning viscosity and low viscosity. The present invention relates to a compound writing instrument that is installed.

[0002]

2. Description of the Related Art In general, there is known a double-type writing instrument having a plurality of writing objects such as a mechanical pencil and a ball-point pen mounted thereon so that a writing tip can be selectively protruded and retracted from an axis. In addition, as the mechanism of the writing tip of the double-type writing instrument,
Various types are known, such as a knock type, a slider type that alternately slides a slider that protrudes from a side surface of a writing barrel, and a cam type that rotates a cam cylinder having an inclined surface. In addition, the present applicant has published a Japanese Utility Model Application No. 60-12088.
As disclosed in Japanese Patent Application Laid-Open No. 9, there is a conventional dual writing implement in which a crown protruding from the rear end of a rear shaft is rotated to make an eraser appear and disappear. The conventional example has problems that metal parts are used in many parts, the structure is complicated, the number of parts is large, and the cost is high. In addition, since the rear shaft is longer than the front shaft, there is a problem in flexibility in design, and when the cursive body is retracted, one hand grasps the shaft tip and the other hand grasps the shaft rear end for rotation operation. There is a drawback in that it is not convenient to use. Also, since the crown is short, it is difficult to feed out the eraser.

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, in the conventionally known oil-based ballpoint pens, since the ink used has a high viscosity of several thousand mPa · S or more, the resistance when the ball rotates when the ink flows out from the pen tip. Has a drawback that the writing quality is bad because it is large. In addition, there is a problem that the amount of ink flowing out from the tip during writing is small, there is a battering phenomenon, there is uneven writing line, the handwriting 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 mPa ·
A ballpoint pen for water-based ink, called medium viscosity, using the ink of 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. However, since this ink has a defect that the ink is easily dried, a cap for sealing the writing tip is usually required. Further, the outflow amount of ink increases, and in order to extend the writing life, it is necessary to increase the diameter of the ink containing tube to increase the ink filling amount.

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. In addition, since a medium-viscosity water-based ballpoint pen is usually filled with a grease-like translucent non-drying substance called a follower at the rear end of the ink containing tube, the problem of ink evaporation prevention is a problem of the pen tip, that is, the ball and holder. It may be considered to reduce evaporation from the gap. For example, if a solvent with a fairly low vapor pressure such as an oil-based ballpoint pen is mainly used, ink evaporation does not need to 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.

Further, by utilizing the difference in the solubility of the rubber component in the ink solvent, it is a gel in the ink containing tube, becomes a sol by the rotation of the tip ball accompanying writing, gels in the drawn state, and does not soak into the paper. Erasable ink is known.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art, that is, by mounting a plurality of writing bodies in a barrel, and writing each writing body from the tip of the barrel. To provide a compound writing instrument that has a tip part that can be selectively retracted and has an eraser feeding mechanism and is excellent in portability and usability, and when the eraser appears and disappears by rotating the crown part lightly. It means that the crown is stopped and the eraser is held. In addition, ink backflow and direct current phenomenon do not occur, the drying resistance of the pen tip is maintained, the cap can be removed and left, and drop impact, backflow of ink due to upward writing and direct current of ink are prevented. A medium-viscosity water-based, low-viscosity, oil-based ballpoint pen writing system having a mechanism
A plurality of cursive bodies having at least one ballpoint pen cursive body are mounted in a barrel so that the curl tip of each cursive body can be selectively retracted from the barrel tip, and an eraser is used. (EN) It is possible to provide a convenient double-sided writing instrument that combines an erasable ballpoint pen writing body and an eraser feeding mechanism.

[0010]

DISCLOSURE OF THE INVENTION The present invention is a compound writing instrument comprising a writing instrument mechanism having a plurality of writing instruments and an eraser feeding mechanism, and a center shaft provided between a front shaft and a rear shaft, A return spring, one end of which is locked to the center shaft to urge the writing body to the rear, a sliding piece attached to the rear portion of the writing body and urged to the rear by the return spring, and a sliding piece A cylindrical cam having a cam slant surface on the front surface for pressing any one of the rear ends of the cursive body to selectively advance the cursive body, and including an engaging portion which is engaged with the center shaft and is rotatable. A spiral groove is formed on the inner circumference of the rear cylindrical portion of the cylindrical cam, and a split groove is further provided on a required side surface of the cylindrical portion.
A rear shaft is attached to the outer periphery of the rear cylinder of the cylindrical cam, and a slit is provided on the rear side surface of the rear shaft. The rear cam is rotatably fitted to the cylindrical cam, and the rear end of the rear shaft is attached to the rear end. The eraser includes a crown portion located therein, an inner cylinder in which a slit is formed in the front axial direction of the crown portion, and a projection provided in the inner cylinder and engaged with the spiral groove of the cylindrical cam, and the eraser. And an eraser holder capable of sliding along the slit of the inner cylinder in the axial direction.

A non-deformable ball-point pen writing body in which the ink containing portion of the ink containing tube has a relatively large cross-sectional area,
The part that connects the joint for fixing the tip and the ink storage part can be easily displaced laterally with respect to the axial direction.
A plurality of cursive bodies including at least one of the ballpoint pen cursive bodies are mounted so that the tip portions of the cursive bodies can be selectively retracted from the tip of the shaft.

A ball-point pen writing material is characterized in that it is made into a sol by the rotation of a tip ball during writing by adding a cross-linking substance to an ink solvent, gels in a drawing line state, and does not soak into paper, so that it can be erased with an eraser. Also, the ballpoint pen cursive
A water-based ballpoint pen ink having a so-called shear thinning viscosity, which has a tip for holding the tip ball and an ink containing tube at the rear side, and whose viscosity is reduced and discharged by the rotation of the tip ball accompanying writing in the ink containing tube or A low-viscosity oil-based ink is filled, and a trailer made of a grease-like semi-transparent non-dry material is filled at the trailing end of the ink so as to follow the consumption of the ink due to writing.

Further, in the writing body of the ball-point pen, the tip ball has a spring which is always pressed against the inner edge of the ball holding portion at the tip of the tip so as to come into close contact with the inner edge of the ball-holding portion. It consists of Furthermore, a valve chamber, in which a ball valve is loosely fitted, is provided in contact with the rear end of the chip, and a ball valve is closely attached to the rear part of the valve chamber to prevent backflow of ink, and an ink storage from the ball receiving seat. A guide hole communicating with the pipe is provided.

[0014]

1 to 5 show an embodiment of the present invention. In FIG. 1, two ballpoint pen cursive bodies 1
a and 1b are provided. Incidentally, as will be described later, the embodiment of the present invention shown in FIG. 1 has a ballpoint pen writing body filled with a ballpoint pen ink that can be erased with an eraser. The compound writing instrument of the embodiment has a writing instrument function in the front part and an eraser feeding mechanism in the rear part. The dual writing instrument intended by the present invention is a ballpoint pen writing body filled with an aqueous or low-viscosity oil-based ballpoint pen ink having a so-called shear thinning property, a ballpoint pen writing body filled with a ballpoint pen ink that can be erased with an eraser, and a mechanical pencil writing body. Ordinary oil-based ballpoint pen writing materials are used in combination as necessary.

The compound writing instrument of FIG. 1 comprises a front shaft 51 and a center shaft 30 for accommodating a writing instrument mechanism portion located at the front portion, and a rear shaft 49 for accommodating an eraser feeding mechanism at the rear portion. A female screw 52 is formed on the inner circumference of the rear portion of the front shaft 51. Further, the rear shaft 49 has an opening at the rear end through which the eraser is fed. Further, a male screw 32 is formed on the small diameter portion of the front end of the center shaft 30, and a female screw 52 of the front shaft 51 is formed.
It is screwed in and removed as necessary to replace the cursive body, and if a mechanical pencil cursive body is mounted, refill the lead. Further, a stopper provided on the outer periphery of a cylindrical cam, which will be described later, is brought into contact with the rear end of the center shaft 30 to form a circumferential notch stopper for restricting the rotational position, and a rib for enabling the knocking operation of the cylindrical cam. A notch for fitting is formed.
A window portion 33 is formed in the rear side surface of the center rod 30 (not shown), and four guide ribs 31 are formed in the inner periphery of the center rod 30 at intervals of 90 degrees in the axial direction. Are formed.

A return spring 5 for biasing the ballpoint pen writing bodies 1a and 1b rearward is provided on the front portion of the center shaft 30.
The front ends of 4a and 54b are locked. Then, the sliding shafts 39a, 39b are fitted to the receiving shafts 41a, 41 toward the front.
b is fixed by penetrating the inner holes of the return springs 54a, 54b, the rear ends of the ball-point pen writing bodies 1a, 1b are attached to the front ends of the receiving shafts 41a, 41b, and the rear ends of the return springs 54a, 54b are slidable pieces. 39a, 39
They are locked in front of b and are urged rearward. Further, the sliding pieces 39a, 39b have a cam surface which is advanced by the pressing of the cam slant surface 35 accompanying the rotation of a cylindrical cam described later and projections 40a, 40b at the rear ends thereof.

Further, the grooves 50a and 50b provided on the side surfaces of the sliding pieces 39a and 39b mesh with the guide ribs 31 provided inside the center shaft 30, respectively, whereby the sliding pieces 39a and 39b are smoothly moved. Move back and forth. The cross-sectional shape of the sliding pieces 39a, 39b 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.

Next, the cylindrical cam 34 is provided with a ring-shaped engagement projection 37 on its outer periphery, which engages with the center shaft 30 and is rotatable. Since the center shaft 30 has a pair of thick-walled portions 33a facing the rear portion and the window 33 is bored therein, when the front end of the cylindrical cam 34 is press-fit into the center shaft 30, the ring-shaped engagement projection 37 is inserted. At this time, the thick-walled portion 33a is pushed and fitted into the opening window portion 33 so that the cylindrical cam 34 is rotatably retained. Further, when the cylindrical cam 34 needs to be appropriately advanced (knocking operation of the mechanical pencil, etc.), the window 33 is formed in a length that does not hinder the operation of the engagement projection 37.

Further, a spiral groove 38 is formed on the inner circumference of the rear cylinder of the cylindrical cam 34, and an axial dividing groove 38a is provided at a required position on the outer circumference of the rear cylinder. The rear cylinder is elastically appropriately compressed by lateral pressure. Diameter. Further, a rear shaft 49 is provided on the rear outer periphery of the cylindrical cam 34.
Grooves and ribs are formed between the inner circumference and the inner circumference to prevent them from rotating. Also, an axial slit 49b is provided on one side surface behind the rear shaft 49 (not shown) so that the diameter is appropriately reduced by lateral pressure. Further, the inner cylinder 43, which will be described later, rotates by being locked to the step portion 42 provided in the cylindrical cam 34, but is prevented from coming off in the axial direction.

Further, the inner cylinder 43 is rotatably fitted to the cylindrical cam 34, has a crown portion 44 at the rear end, and has a long slit facing the axial side in front of the crown portion 44 in the axial direction. 43a is formed. In addition, a locking projection 45 is provided at the tip of the inner cylinder 43 for preventing the slip-out from engaging with the stepped portion 42 that extends inward of the cylindrical cam 34. Further, when the inner cylinder 43 is assembled, the crown portion 44 is exposed from the rear end of the rear shaft 49 and serves as a rotation operation portion when the eraser is fed out. The eraser holder 46 is provided in the inner cylinder 43 and has a protrusion 48 that engages with the spiral groove 38 of the cylindrical cam 34. The eraser holder 55 holds the eraser 55 and the slit 43a of the inner cylinder 43.
The elastic piece 47 is slidable in the axial direction.

In the above embodiment, the case of two writing bodies has been described, but basically three writing bodies are possible.

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. In addition, 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, or a cross-linking substance is added to an ink solvent, and the tip ball is rotated during writing to form a sol, which is in a drawn state. It is an ink that can be erased with an eraser because it gels and does not soak into the paper.

As shown in FIG. 4, the tip 11 is crimped so that the tip ball 12 is rotatably held in a state where the tip ball 12 is 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 becomes an upright rod shaft portion 15, and the tip of the rod shaft portion 15 has a tip 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 its pressing.

The joint 2 has a shaft 1 of the tip 11 at the tip.
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 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 that can move following 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 needed in order to prevent deformation due to dropping or knocking impact. The ink containing tube 17 is, for example, a transparent PP resin molded product. Also, select the ink storage tube with a material with excellent clear drainage. Further, the ink containing tube 17 may be formed integrally with the joint 2.

Further, the ink containing portion of the ink containing tube 17 is a non-deformable one having a relatively large cross-sectional area, and in the embodiment, it has a substantially D-shaped cross-sectional shape to be inserted into the center shaft 30 without waste. doing. 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.

Further, FIG. 5 shows a mechanical pencil cursive body 60.
And a normal oil-based ballpoint pen writing body 61 is mounted. Basically, it is the same as that shown in FIG.

[0029]

When the rear shaft 49 is rotated with respect to the center shaft 30, one of the writing bodies can be selected by the cam slope 35 accompanying the rotation of the cylindrical cam, and the writing tip can be projected from the tip opening of the tip shaft 51. Becomes Further, even if the ink storage portion of the ball-point pen writing body is not deformed, the writing tip portion is flexibly displaced, so that the operation is not hindered and the writing tip portion smoothly appears and disappears from the tip opening of the tip shaft 51. When the selected cursive body is a mechanical pencil cursive body, the rear end of the rear shaft 49 is knocked to extend the lead. When the eraser is used, the eraser holder 46 is guided by the spiral groove 38 of the cylindrical cam and the slit 43a of the inner cylinder 43 when the inner crown 43 is rotated by pinching the crown portion 44 at the rear end, and the eraser is retracted. 5
5 is delivered from the rear end. Further, when the eraser is used, the rear outer peripheral portion of the rear shaft 49 is narrowed so that the lateral pressure is hung by the fingers, so that the rear groove 49b and the split groove 38a provided in the rear cylindrical portion of the cylindrical cam are used to remove the rear There is no problem that the eraser 55 inadvertently appears and disappears even if the eraser is strongly rubbed, because the shaft and the rear tubular portion are reduced in diameter and the side surface of the inner cylinder 43 is pressed to stop the crown portion 44 from rotating.

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 with upward writing, so that air is trapped in the tip,
The ink does not follow immediately with downward writing and blurring occurs)

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. Also, since the tip ball 12 retreats slightly due to the writing pressure, a gap is created to allow the ink to flow out, and the writing allows the ink to flow out smoothly with the rotation of the tip ball 12, and it is possible to write with a high degree of handwriting density without fluffing. 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 structure and operation of the compound writing instrument of the present invention are as described above, and the flexibility of the design is satisfied, and the convenient compound writing instrument having the eraser feeding mechanism satisfies the portability and usability. It can be provided with the thickness of the shaft. 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, it becomes possible to provide a combination of a ballpoint pen writing body, a mechanical pencil writing body, and the like using ink that can be erased with an eraser according to the specifications.

[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 shown in a non-cross-sectional view. In addition, two kinds of ballpoint pen cursives are mounted.

FIG. 2 is a cross-sectional view of a sliding piece portion located on a center shaft.

FIG. 3 is a cross-sectional view of an ink-accommodating portion of a ball-point pen writing body located on the center axis.

FIG. 4 is a vertical cross-sectional view of a ballpoint pen writing material according to an embodiment.

FIG. 5 is a vertical cross-sectional view showing the entire compound writing instrument of one embodiment of the present invention, which is partially shown in non-cross section. In addition, a mechanical pencil and a ballpoint pen writing material of ordinary oil-based ink are mounted.

[Explanation of symbols]

 1a Ballpoint pen writing body 1b Ballpoint pen writing body 2 Joint 3 Front shaft part 4 Bellows 5 Rear shaft part 6 Collar part 7 Valve chamber 8 Ball receiving seat 9 Guide hole 10 Inner hole part 11 Tip 12 Tip ball 13 Shaft part 14 Spring 15 Bar shaft Part 16 Ball valve 17 Ink storage pipe 18 Ink 19 Follower 20 Follower rod 30 Middle shaft 31 Rib for guide 32 Male screw 33 Window part 33a Thick part 34 Cylindrical cam 35 Cam slope 36 Notch 37 Engagement projection 38 Spiral groove 38a Split groove 39a Sliding piece 39b Sliding piece 40a Protrusion 40b Protrusion 41a Receiving shaft 41b Receiving shaft 42 Step portion 43 Inner cylinder 43a Slit 44 Crown crown 45 Engaging protrusion 46 Eraser holder 47 Elastic piece 48 Protrusion 49 Rear shaft 49a Clip 49b Splitting 50a Groove 50b Groove 51 Leader shaft 52 Female screw 53 Rubber Grip 54a return spring 54b return spring 55 Eraser 60 mechanical pencil cursive 61 normal oily ballpoint cursive 62 tubular core 63a sliding piece 63b sliding piece

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location B43K 24/18 B43L 19/00 C B43L 19/00 B43K 7/02 B

Claims (6)

[Claims] 1. A compound writing instrument comprising a writing instrument mechanism having a plurality of writing instruments and an eraser feeding mechanism, and a center shaft provided between a front shaft and a rear shaft, and one end of which is locked to the center shaft. A return spring for urging the writing body backwards respectively, a sliding piece attached to the rear portion of the writing body and urged backwards by the return springs, and either rear end of the sliding piece is pressed. A cylindrical cam having a cam inclined surface for selectively advancing the cursive body on the front surface and provided with an engaging portion that is rotatable by engaging with the center shaft, and a cylindrical inner surface of a rear cylindrical portion of the cylindrical cam. A spiral groove is formed, and a split groove is further provided on the required side surface of the cylinder portion, a rear shaft is attached to the outer periphery of the rear cylinder portion of the cylindrical cam, and a slit is provided on the rear side surface of the rear shaft. It is rotatably fitted to the cylindrical cam, and
A crown portion located at the rear end of the rear shaft, an inner cylinder having a slit formed in the front axial direction of the crown portion, and provided in the inner cylinder to engage with a spiral groove of the cylindrical cam. A multiple writing instrument comprising a protrusion and an eraser holder which holds an eraser and is axially slidable along a slit of an inner cylinder. 2. A non-deformable ballpoint pen writing body having a relatively large cross-sectional area in the ink containing portion of the ink containing tube, wherein a portion connecting the joint for fixing the tip and the ink containing portion is in the axial direction. It is configured to be easily translatable in the lateral direction, and is equipped with a plurality of cursive bodies including at least one ballpoint pen cursive body so that the tip of each cursive body can be selectively retracted from the tip of the shaft. The compound writing instrument according to claim 1, wherein 3. A ball-point pen writing material is converted into a sol by adding a cross-linking substance to an ink solvent and rotating the tip ball accompanying writing.
The double-sided writing instrument according to claim 2, characterized in that it can be erased by an eraser because it gels in a drawn state and does not soak into paper. 4. A so-called ball-point pen writing body has a tip for holding a tip ball and an ink containing tube at the rear side, and the viscosity of the tip pen is lowered by the rotation of the tip ball accompanying the writing in the ink containing tube so that the ink is discharged. A water-based ball-point pen ink having a shear thinning property or a low-viscosity oil-based ink is filled, and a follower composed of a grease-like semitransparent non-dry substance that moves following the consumption of the ink accompanying writing is filled at the rear end of the ink. The multiple writing instrument according to claim 2, wherein 5. A ball-point pen writing body, wherein a tip ball has a spring provided so as to constantly press and closely contact an inner edge of a ball holding portion at the tip of the tip, and the contact state is released during writing. The compound writing instrument according to claim 3 or 4, wherein 6. A ball-point pen writing body, wherein a ball chamber, in which a ball valve is loosely fitted, is provided in contact with the rear end of the tip, and the ball valve is closely attached to the rear part of the valve chamber to prevent backflow of ink. 6. The double-sided writing instrument according to claim 5, wherein a guide hole is provided from the seat and the ball receiving seat to the ink containing tube.