JP2010260218A - Multi-core type thermochromic writing utensil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multi-core type thermochromic writing utensil which quickly performs heat discoloration of the handwriting of thermochromic ink by friction and, in opening/closing an opening part, facilitates operation of a lid part. <P>SOLUTION: A plurality of writing bodies 3 are housed in a barrel 2 so as to be movable forward and backward. From window holes 22 of the barrel 2, the operation part 41 of operating bodies 4 is protruded, the pen point 31 is alternatively made to move in and out from the front end hole 21 of the barrel 2. In the rear end of the barrel 2, an opening part 23 for opening the window holes 22 rearward is installed in a freely opened and closed manner. Also, in the rear end part of the barrel 2, a lid part 5 is installed making the opening part 23 freely openable and closable. A thermochromic ink is stored inside the writing bodies 3. On the exterior of the lid body 5, there is provided a rubbing part 7 that is made of an elastic material and that can perform heat discoloration of the handwriting by frictional heat generated when the handwriting of the thermochromic ink is rubbed with the rubbing part 7. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to a multi-core thermochromic writing instrument.

Document 1 contains thermochromic ink inside the writing core, a pen tip capable of discharging the thermochromic ink at the front end of the writing core, and the front end of the friction core, A tip capable of thermally discoloring the handwriting of the thermochromic ink by rubbing the handwriting of the thermochromic ink is provided, and the pen tip of the writing core and the tip of the friction core are alternatively provided as shafts. There is described a thermochromic writing instrument provided with a retracting mechanism that allows it to protrude from the front end hole of the cylinder.

Further, in Document 1, an elastic body that urges the writing core body backward and an elastic body that urges the friction core body backward are accommodated in a shaft tube, and the writing core An operating body is connected to the rear end of the body, an operating body is connected to the rear end of the friction core, and a plurality of window holes extending in the front-rear direction are provided in a radial direction in the side wall of the shaft cylinder, By projecting each of the operating bodies radially outward from the window hole and sliding one operating body forward along the window hole, the pen tip of the writing core corresponding to the one operating body Alternatively, the tip of the friction core is protruded to the outside from the front end hole of the shaft cylinder, and the pen tip of the writing core or the tip of the friction core that has been previously protruded is immersed in the shaft cylinder. A thermochromic writing instrument with a haunting mechanism is described.

JP 2008-247025 A

In the tip of the friction core of the conventional thermochromic writing instrument, when the handwriting by the thermochromic ink is large, it is difficult to quickly thermally discolor the handwriting by the thermochromic ink by friction. Moreover, since the said conventional thermochromic writing instrument has few parts which operate a cover part when opening and closing an opening part, operation of a cover part is not easy.

The present invention solves the above-mentioned conventional problems, and can quickly discolor a large handwriting by a thermochromic ink by friction, and when opening and closing the opening, the operation of the lid can be performed. An object of the present invention is to provide an easy multi-core thermochromic writing instrument. In the present invention, “front” refers to the pen tip side, and “rear” refers to the opposite side.

[1] In the first invention of the present application, a plurality of writing bodies 3 are accommodated in the shaft cylinder 2 so as to be movable in the front-rear direction, thermochromic ink is accommodated in each of the writing bodies 3, and each A pen tip 31 capable of discharging the thermochromic ink is provided at the front end of each of the writing bodies 3, and the operation bodies 4 are attached to the rear ends of the respective writing bodies 3. A plurality of window holes 22 extending in the axial direction are provided in the side wall of the shaft cylinder 2 in the radial direction, and the operation portions of the respective operation bodies 4 are radially outward from the respective window holes 22. 41 is protruded, and one operation portion 41 is slid forward along the window hole 22 so that the pen tip 31 of the writing body 3 to which the one operation body 4 is attached protrudes from the front end hole 21 of the shaft cylinder. In addition, the pen point 31 of the other cursive body that had been in the protruding state was immersed in the shaft tube 2 and the front Openable and closable openings 23 for opening the respective window holes 22 rearward are provided at the rear end of the shaft cylinder 2, and the writing body 3 and the operation body 4 are connected to each other through the openings 23 in the shaft cylinder 2. A multi-core thermochromic writing instrument that is configured to be removable from the shaft cylinder 2 and to be inserted into the shaft cylinder 2 and is provided with a lid 5 at the rear end of the shaft cylinder 2 that allows the opening 23 to be opened and closed. It is a requirement that the outer surface of the lid portion 5 is provided with a friction portion 7 made of an elastic material capable of rubbing the handwriting of the thermochromic ink and heat-discoloring the handwriting with frictional heat generated at that time.

The multi-core thermochromic writing instrument 1 of the first invention is made of an elastic material capable of rubbing the handwriting of the thermochromic ink on the outer surface of the lid 5 and heat-discoloring the handwriting with frictional heat generated at that time. By providing the friction part 7 as described above, the friction part 7 can be formed large, and a large handwriting by the thermochromic ink can be rapidly discolored by friction. Furthermore, the multi-core thermochromic writing instrument 1 of the first invention is provided with the friction part 7 made of an elastic material on the outer surface of the lid part 5, so that the friction part 7 is operated when the opening part 23 is opened and closed. At that time, when the lid 5 is opened and closed, the friction portion 7 and the finger can be prevented from slipping, the finger is not painful, and it is easy to apply force to the lid 5. Becomes easy.

[2] In the second invention of the present application, in the multi-core thermochromic writing instrument 1 of the first invention, the attachment portion 54 is formed on the rear surface of the lid portion 5 and the attachment portion 71 is formed on the friction portion 7. In addition, it is a requirement that the attaching portion 54 of the lid portion 5 and the attached portion 71 of the friction portion 7 are engaged.

The multi-core thermochromic writing instrument 1 according to the second aspect of the present invention is configured such that the attaching portion 54 of the lid portion 5 and the attached portion 71 of the friction portion 7 are engaged with each other, thereby Strong attachment is possible, and it is possible to prevent the friction portion 7 from being detached from the lid portion 5 during friction.

[3] The third invention of the present application is that, in the multi-core thermochromic writing instrument 1 of the first invention, the lid portion 5 and the friction portion 7 are integrally formed of an elastic material.

The multi-core thermochromic writing instrument 1 according to the third aspect of the present invention can be provided at a low cost by reducing the number of parts by integrally forming the lid portion 5 and the friction portion 7, and the friction portion 7 can be provided at the time of friction. Does not come off the lid 5.

Friction part The elastic material constituting the friction part of the present invention is preferably a synthetic resin (rubber or elastomer) having elasticity, such as silicone resin, SBS resin (styrene-butadiene-styrene copolymer), SEBS resin. (Styrene-ethylene-butadiene-styrene copolymer), fluorine resin, chloroprene resin, nitrile resin, polyester resin, ethylene propylene diene rubber (EPDM) and the like. The synthetic resin having elasticity constituting the friction body 4 is a low-abrasion elastic material in which wear debris (erasure debris) hardly occurs at the time of friction as compared with a high-abrasion elastic material (for example, an eraser). Preferably it consists of.

-Thermochromic ink In the present invention, the thermochromic ink is preferably a reversible thermochromic ink. The reversible thermochromic ink is a heat decoloring type that decolors by heating from a colored state, a color memory retaining type that reversibly stores and retains a colored state or a decolored state in a specific temperature range, or from a decolored state Various types such as a heating coloring type that develops color by heating and returns to a decolored state by cooling from the colored state can be used alone or in combination.

The coloring material contained in the reversible thermochromic ink includes conventionally known (a) electron donating color-forming organic compounds, (b) electron-accepting compounds, and (c) color reactions of both. A reversible thermochromic pigment in which a reversible thermochromic composition containing at least the essential three components of a reaction medium for determining the occurrence temperature of the polymer is encapsulated in a microcapsule is preferably used.

In the present invention, as shown in FIG. 5, the shape of the curve plotting the change in the color density due to the temperature change is contrary to the case where the temperature is raised from the lower temperature side than the color change temperature range, from the higher temperature side than the color change temperature range. The color changes by following a different path depending on the descending state, and the color development state in the low temperature range below the complete color development temperature (t ₁ ) or the color erase state in the high temperature range above the complete color erase temperature (t ₄ ) It is preferable to apply a color memory retention type thermochromic ink that can be stored and retained in a specific temperature range [temperature range between t _{2 and} t ₃ (substantially two-phase retention temperature range)]. In FIG. 5, ΔH indicates a temperature width (ie, hysteresis width) indicating the degree of hysteresis. When the value of ΔH is small, only one of the two states before and after the color change can exist. When the value of ΔH is large, it is easy to maintain each state before and after the color change.

In the present invention, the color change temperature due to frictional heat of the friction part of the thermochromic ink is set to 25 ° C. to 95 ° C. (preferably 36 ° C. to 95 ° C.). That is, in the present invention, the high temperature side discoloration point [complete decoloring temperature (t ₄ )] is set in a range of 25 ° C. to 95 ° C. (preferably 36 ° C. to 90 ° C.), and the low temperature side discoloration point [ It is effective to set the complete color development temperature (t ₁ )] in the range of −30 ° C. to + 20 ° C. (preferably −30 ° C. to + 10 ° C.). Accordingly, it is possible to effectively maintain the color exhibited in the normal state (daily life temperature range), and it is possible to easily change the handwriting by the reversible thermochromic ink with the frictional heat generated by the friction body 4.

The multi-core type thermochromic writing instrument of the present invention can quickly discolor a large handwriting by thermochromic ink by friction, and the lid can be easily operated when opening and closing the opening.

It is a longitudinal cross-sectional view of the closed state of the opening part of the 1st Embodiment of this invention. It is the side view of the opening state of the opening part of FIG. 1, and the longitudinal cross-sectional view of a cover part. It is a longitudinal cross-sectional view of the closed state of the opening part of the 2nd Embodiment of this invention. It is the side view of the opening state of the opening part of FIG. 3, and the longitudinal cross-sectional view of a cover part. It is explanatory drawing which shows the color change behavior of a thermochromic ink.

<First Embodiment>
A first embodiment of the present invention is shown in FIGS.
In the multi-core thermochromic writing instrument 1 of the present embodiment, a plurality of (specifically, two) writing bodies 3 are accommodated in a shaft cylinder 2 so as to be movable in the front-rear direction. Each of the writing bodies 3 is urged rearward by an elastic body 6 (specifically, a compression coil spring).

(Shaft tube)
The shaft cylinder 2 includes a front shaft 2a formed of a tapered cylindrical body and a cylindrical rear shaft 2b attached to the rear end portion of the front shaft 2a by screwing or press-fitting. At the front end of the front shaft 2a, a front end hole 21 through which the pen tip 31 of the writing body 3 can protrude is provided in the axial direction. The front shaft 2a and the rear shaft 2b are obtained by injection molding of a synthetic resin (for example, polycarbonate).

A plurality of (specifically, two) elongated window holes 22 extending in the front-rear direction are provided in the radial direction in the rear side wall of the rear shaft 2b. The two window holes 22 are formed at symmetrical positions with respect to the axis. In addition, an opening 23 that penetrates in the axial direction and opens outward in the radial direction is formed at the rear end of the rear shaft 2b. The opening 23 communicates with the window hole 22 at the rear end of the rear shaft 2b (that is, the rear end of the shaft cylinder 2), whereby the rear end of the window hole 22 is notched rearward and opened rearward. The writing body 3 with the operating body 4 attached thereto can be inserted into the shaft tube 2 and taken out from the shaft tube 2 through the opening 23.

Further, a locking wall portion (not shown) made of a rib extending in the front-rear direction is formed on the inner surface of the side wall between the window holes 22 of the rear shaft 2b, and a pen tip 31 is formed on the locking wall portion. The rear end of the operation body 4 of the writing body 3 when protruding is locked. Further, a clip 25 is provided on the outer surface of the side wall between the window holes 22 of the rear shaft 2b.

(Cover)
At the rear end portion of the rear shaft 2b, a lid portion 5 that freely opens and closes the opening portion 23 is rotatably provided. One end of the lid 5 is pivotally connected to the base of the clip 25 by a hinge 51. The lid 5 is rotatable in a substantially front-rear direction. A contact wall 52 is formed on the front surface of the lid 5. The rear end of each operation body 4 connected to the rear end of the writing body 3 in the pen tip immersion state is in contact with the contact wall portion 52. In the present invention, the abutting wall portion 52 may be formed integrally with the shaft cylinder 2 (rear shaft 2b) in addition to the configuration formed on the front surface of the lid portion 5.

On the front surface of the other end portion of the lid portion 5, an engaging portion 53 including a concave portion or a hole portion is provided. At the rear end of the rear shaft 2b, an engaged portion 24 including a protrusion that can engage with the engaging portion 53 is provided. An inward projection is formed on the inner surface of the engaging portion 53, while an outward projection that can get over and engage with the inward projection is formed on the outer surface of the engaged portion 24.

(Friction part)
An attachment portion 54 (specifically, a convex portion protruding rearward) is formed on the rear surface of the lid portion 5. The mounting portion 54 is engaged with a mounted portion 71 (specifically, a concave portion) of the friction portion 7 (specifically, the convex portion is press-fitted into the concave portion). Thereby, the friction part 7 is fixed to the rear surface of the lid part 5. In addition, the structure which the said attaching part 54 is a recessed part and the said to-be-attached part is a convex part besides this may be sufficient. The friction part 7 is made of an elastic material. The friction part 7 includes a convex curved surface whose outer diameter decreases toward the rear. In addition, the said friction part 7 can also be made detachable with respect to the rear surface of the cover part 5 so that replacement | exchange is possible.

(Cursive)
Each of the writing bodies 3 is a ball-point pen refill, and includes a ball-point pen tip (that is, a pen tip 31) in which a ball is rotatably held at the front end, and an ink container that includes the ball-point pen tip at the front end and has an open rear end. A tube 32; The ink storage tube 32 is filled with a thermochromic ink made of an aqueous gel and a follower made of a high-viscosity fluid that is disposed at the rear end of the ink and moves forward as the ink is consumed.

The ballpoint pen tip employs a configuration in which a ball held rotatably at the front end is urged forward by a projectile or the like, and the ball is brought into close contact with the inner surface of the front end edge. In addition, the ballpoint pen tip may be directly attached to the front end opening of the ink containing tube 32 by press fitting or the like, but in this embodiment, it is fixed to the front end opening of the ink containing tube 32 via the pen tip holder.

(Operation body)
The operation body 4 is attached to the rear end of each of the writing bodies 3 (that is, the rear end opening of the ink containing tube 32). Each of the operation bodies 4 includes an operation portion 41 formed at the rear end portion and projecting outside from the window hole 22 of the shaft cylinder 2, a rear side projection portion 43 provided on the opposite side of the operation portion 41, A front projecting portion 42 provided in front of the rear projecting portion 43 on the opposite side of the operation portion 41; a fitting portion 44 formed at the front end portion and fitted into the rear end opening of the ink containing tube 32; and the fitting portion 44 and a flange 45 formed behind 44. In addition, the rear end of the projectile 6 is locked to the front surface of the flange portion 45. Further, a retaining projection 46 is formed on both side surfaces of the operating body 4. The retaining projection 46 can be engaged with the inner surfaces of both side walls of the window hole 22.

Each operation body 4 is formed of a molded body of a synthetic resin (for example, polyacetal resin, ABS resin, etc.). Each of the operation bodies 4 is colored in substantially the same color as the color of the ink stored in the connected writing body 3 (that is, in the ink storage tube 32). Specifically, each of the operation bodies 4 is formed of a synthetic resin molded body colored in substantially the same color as the ink color of the connected writing body 3.

When the pen point 31 of the writing body 3 is in an immersive state, the rear end portion of the operating body 4 attached to the writing body 3 is brought into contact with a contact wall portion 52 formed on the front surface of the lid portion 5. On the other hand, when the pen tip 31 of the writing body 3 is in a protruding state, the rear end portion of the operation body 4 attached to the writing body 3 is locked to a locking wall portion formed on the inner wall of the shaft tube 2. .

The front protruding portion 42 of the operating body 4 connected to the rear end of the writing body 3 in the pen tip immersing state is in a pen tip protruding state when the operating portion 41 of the operating body 4 is slid forward. The pendant protruding state of the other cursive body 3 is released by contacting the rear projecting portion 43 of the operating body 4 connected to the rear end of the other cursive body 3.

The multi-core thermochromic writing instrument 1 of the present embodiment is made of an elastic material capable of rubbing the handwriting of the thermochromic ink on the outer surface of the lid portion 5 and thermally changing the handwriting with frictional heat generated at that time. By providing the friction part 7, the friction part 7 can be formed large, and a large handwriting by the thermochromic ink can be rapidly discolored by friction. Furthermore, the multi-core thermochromic writing instrument 1 of the first invention is provided with the friction part 7 made of an elastic material on the outer surface of the lid part 5, so that the friction part 7 is operated when the opening part 23 is opened and closed. At that time, when the lid 5 is opened and closed, the friction portion 7 and the finger can be prevented from slipping, the finger is not painful, and it is easy to apply force to the lid 5. Becomes easy.

The multi-core thermochromic writing instrument 1 according to the present embodiment engages the attachment portion 54 of the lid portion 5 and the attached portion 71 of the friction portion 7, thereby firmly connecting the friction portion 7 and the lid portion 5. Mounting is possible, and it is possible to prevent the friction portion 7 from being detached from the lid portion 5 at the time of friction.

<Second Embodiment>
A second embodiment of the present invention is shown in FIGS.
In the multi-core thermochromic writing instrument 1 of the present embodiment, a plurality of (specifically, two) writing bodies 3 are accommodated in a shaft cylinder 2 so as to be movable in the front-rear direction. Each of the writing bodies 3 is urged rearward by an elastic body 6 (specifically, a compression coil spring).

(Shaft tube)
The shaft cylinder 2 includes a front shaft 2a formed of a tapered cylindrical body and a cylindrical rear shaft 2b attached to the rear end portion of the front shaft 2a by screwing or press-fitting. At the front end of the front shaft 2a, a front end hole 21 through which the pen tip 31 of the writing body 3 can protrude is provided in the axial direction. The front shaft 2a and the rear shaft 2b are obtained by injection molding of a synthetic resin (for example, polycarbonate).

A plurality of (specifically, two) elongated window holes 22 extending in the front-rear direction are provided in the radial direction in the rear side wall of the rear shaft 2b. The two window holes 22 are formed at symmetrical positions with respect to the axis. In addition, an opening 23 that penetrates in the axial direction and opens outward in the radial direction is formed at the rear end of the rear shaft 2b. The opening 23 communicates with the window hole 22 at the rear end of the rear shaft 2b (that is, the rear end of the shaft cylinder 2), whereby the rear end of the window hole 22 is notched rearward and opened rearward. The writing body 3 with the operating body 4 attached thereto can be inserted into the shaft tube 2 and taken out from the shaft tube 2 through the opening 23.

Further, a locking wall portion (not shown) made of a rib extending in the front-rear direction is formed on the inner surface of the side wall between the window holes 22 of the rear shaft 2b, and a pen tip 31 is formed on the locking wall portion. The rear end of the operation body 4 of the writing body 3 when protruding is locked. Further, a clip 25 is provided on the outer surface of the side wall between the window holes 22 of the rear shaft 2b.

(Cover)
At the rear end portion of the rear shaft 2b, a lid portion 5 that freely opens and closes the opening portion 23 is rotatably provided. One end of the lid 5 is pivotally connected to the base of the clip 25 by a hinge 51. The lid 5 is rotatable in a substantially front-rear direction. A contact wall 52 is formed on the front surface of the lid 5. The rear end of each operation body 4 connected to the rear end of the writing body 3 in the pen tip immersion state is in contact with the contact wall portion 52. In the present invention, the abutting wall portion 52 may be formed integrally with the shaft cylinder 2 (rear shaft 2b) in addition to the configuration formed on the front surface of the lid portion 5.

On the front surface of the other end portion of the lid portion 5, an engaging portion 53 including a concave portion or a hole portion is provided. At the rear end of the rear shaft 2b, an engaged portion 24 including a protrusion that can engage with the engaging portion 53 is provided. An inward projection is formed on the inner surface of the engaging portion 53, while an outward projection that can get over and engage with the inward projection is formed on the outer surface of the engaged portion 24. The lid 5 is made of an elastic material.

(Friction part)
A friction part 7 is integrally formed on the rear surface of the lid part 5. That is, the lid part 5 and the friction part 7 are made of the same elastic material. The friction part 7 includes a convex curved surface whose outer diameter decreases toward the rear. In addition, the said cover part 5 can also be made detachable with respect to the hinge part 51 of the axial cylinder 2 so that replacement | exchange is possible.

(Cursive)
Each of the writing bodies 3 is a ball-point pen refill, and includes a ball-point pen tip (that is, a pen tip 31) in which a ball is rotatably held at the front end, and an ink container that includes the ball-point pen tip at the front end and has an open rear end. A tube 32; The ink storage tube 32 is filled with a thermochromic ink made of an aqueous gel and a follower made of a high-viscosity fluid that is disposed at the rear end of the ink and moves forward as the ink is consumed.

The ballpoint pen tip employs a configuration in which a ball held rotatably at the front end is urged forward by a projectile or the like, and the ball is brought into close contact with the inner surface of the front end edge. In addition, the ballpoint pen tip may be directly attached to the front end opening of the ink containing tube 32 by press fitting or the like, but in this embodiment, it is fixed to the front end opening of the ink containing tube 32 via the pen tip holder.

(Operation body)
The operation body 4 is attached to the rear end of each of the writing bodies 3 (that is, the rear end opening of the ink containing tube 32). Each of the operation bodies 4 includes an operation portion 41 formed at the rear end portion and projecting outside from the window hole 22 of the shaft cylinder 2, a rear side projection portion 43 provided on the opposite side of the operation portion 41, A front projecting portion 42 provided in front of the rear projecting portion 43 on the opposite side of the operation portion 41; a fitting portion 44 formed at the front end portion and fitted into the rear end opening of the ink containing tube 32; and the fitting portion 44 and a flange 45 formed behind 44. In addition, the rear end of the projectile 6 is locked to the front surface of the flange portion 45. Further, a retaining projection 46 is formed on both side surfaces of the operating body 4. The retaining projection 46 can be engaged with the inner surfaces of both side walls of the window hole 22.

Each operation body 4 is formed of a molded body of a synthetic resin (for example, polyacetal resin, ABS resin, etc.). Each of the operation bodies 4 is colored in substantially the same color as the color of the ink stored in the connected writing body 3 (that is, in the ink storage tube 32). Specifically, each of the operation bodies 4 is formed of a synthetic resin molded body colored in substantially the same color as the ink color of the connected writing body 3.

When the pen point 31 of the writing body 3 is in an immersive state, the stopper 47 of the rear end portion of the operating body 4 attached to the writing body 3 is brought into contact with the abutting wall portion 52 formed on the front surface of the lid portion 5. Abutted. On the other hand, when the pen tip 31 of the writing body 3 is in a protruding state, the rear end portion of the operation body 4 attached to the writing body 3 is locked to a locking wall portion formed on the inner wall of the shaft tube 2. .

The front protruding portion 42 of the operating body 4 connected to the rear end of the writing body 3 in the pen tip immersing state is in a pen tip protruding state when the operating portion 41 of the operating body 4 is slid forward. The pendant protruding state of the other cursive body 3 is released by contacting the rear projecting portion 43 of the operating body 4 connected to the rear end of the other cursive body 3.

The multi-core thermochromic writing instrument 1 of the present embodiment is made of an elastic material capable of rubbing the handwriting of the thermochromic ink on the outer surface of the lid portion 5 and thermally changing the handwriting with frictional heat generated at that time. By providing the friction part 7, the friction part 7 can be formed large, and a large handwriting by the thermochromic ink can be rapidly discolored by friction. Furthermore, the multi-core thermochromic writing instrument 1 of the first invention is provided with the friction part 7 made of an elastic material on the outer surface of the lid part 5, so that the friction part 7 is operated when the opening part 23 is opened and closed. At that time, when the lid 5 is opened and closed, the friction portion 7 and the finger can be prevented from slipping, the finger is not painful, and it is easy to apply force to the lid 5. Becomes easy.

The multi-core thermochromic writing instrument 1 of the present embodiment can be provided at a low cost by reducing the number of parts by integrally forming the lid portion 5 and the friction portion 7, and the friction portion 7 can be provided at the time of friction. It does not come off from the lid 5.

DESCRIPTION OF SYMBOLS 1 Multi-core type thermochromic writing instrument 2 Shaft cylinder 2a Front shaft 2b Rear shaft 21 Front end hole 22 Window hole 23 Opening part 24 Engagement part 25 Clip 3 Writing body 31 Pen tip 32 Ink storage pipe 4 Operation body 41 Operation part 42 Front projecting portion 43 Rear projecting portion 44 Fitting portion 45 Eave portion 46 Retaining protrusion 5 Lid portion 51 Hinge portion 52 Abutting wall portion 53 Engaging portion 54 Attaching portion 6 Ejector 7 Friction portion 71 Attached portion

Claims (3)

A plurality of writing bodies are accommodated in a shaft cylinder so as to be movable in the front-rear direction, thermochromic ink is accommodated in each of the writing bodies, and the thermochromic ink can be discharged to the front end of each writing body. A pen tip is provided, an operating body is attached to a rear end of each writing body, each operating body is urged rearward by a resilient body, and a plurality of window holes extending in the axial direction are provided on a side wall of the shaft cylinder. By piercing in the radial direction, projecting the operation part of each operation body radially outward from each window hole, and sliding one operation part forward along the window hole, the one The pen tip of the cursive body to which the operating body is attached is projected from the front end hole of the shaft cylinder, and the pen tip of another cursive body that has been in the projecting state is immersed in the shaft cylinder, and the rear end of the shaft cylinder Are provided with openable and closable openings for opening the respective window holes rearwardly, and through the openings. A multi-core structure in which the writing body and the operation body are connected to each other so that they can be removed from the shaft tube and inserted into the shaft tube, and a lid is provided at the rear end of the shaft tube so that the opening can be opened and closed. The thermochromic writing instrument is provided with a friction part made of an elastic material capable of rubbing the handwriting of the thermochromic ink on the outer surface of the lid part and thermally changing the handwriting by frictional heat generated at that time. A multi-core thermochromic writing instrument characterized by that. The multi-core thermochromic according to claim 1, wherein an attachment portion is formed on a rear surface of the lid portion, an attachment portion is formed on the friction portion, and the attachment portion of the lid portion and the attachment portion of the friction portion are engaged. Sex writing instrument. The multi-core thermochromic writing instrument according to claim 1, wherein the lid and the friction portion are integrally formed of an elastic material.

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