JP2022145792A - thermochromic writing instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermochromic writing instrument capable of performing stable and proper friction without wobbling of a friction body during rubbing and easily exchanging a mounted friction body with a spare friction body.

SOLUTION: A thermochromic writing instrument 1 of the present invention includes a crown 2, a barrel 3, a friction body 4, and a spare friction body 4a. A first crown mounting portion 31 of a shaft cylinder 3 is detachably mounted in a shaft cylinder mounting hole 21 of the crown 2 by screwing. A second crown mounting portion 41 of the friction body 4 and the spare friction body 4a is detachably mounted in a friction body mounting hole 22 of the crown 2 by screwing. The spare friction body 4a is housed inside the barrel 3 and inside the crown 2. The friction body 4 can be replaced with the spare friction body 4a.

SELECTED DRAWING: Figure 2

COPYRIGHT: (C)2023,JPO&INPIT

Description

The present invention relates to a thermochromic writing instrument. More particularly, the present invention relates to a thermochromic writing instrument comprising a friction body capable of thermally discoloring the handwriting of the thermochromic ink by rubbing the handwriting of the thermochromic ink and generating frictional heat.

Patent Literature 1 discloses a friction tool that can be used by selecting a friction portion having an outer shape suitable for a desired heat discoloration area. The friction tool comprises a first holder having a first friction portion at one end and an insertion hole at the other end, and a second friction portion at one end and a third friction portion at the other end. and a third holder having an insertion hole at one end thereof, a first insertion portion is provided on the outer surface of the second holder on the side of the second friction portion, and the The first insertion portion is insertable into the insertion hole of the first holder and insertable into the insertion hole of the third holder, and the third friction portion side of the second holder. A second insertion portion is provided on the outer surface of the second holder, and the second insertion portion can be inserted into the insertion hole of the first holder and can be inserted into the insertion hole of the third holder. , the handwriting of thermochromic ink can be thermally discolored by frictional heat by any of the first frictional portion, the second frictional portion and the third frictional portion. According to the friction tool, it is possible to select and use a plurality of friction parts, such as having an outer shape suitable for a desired heat discoloration area.

Further, Patent Document 2 discloses a retractable writing instrument in which a crown is detachably attached to the rear end portion of a barrel by screw fitting. According to the retractable writing instrument, the crown can be removed when moving, and the overall length of the writing instrument can be shortened. In addition, it becomes possible to replace the crown with a desired one.

JP 2009-66892 A JP 2013-188922 A

However, in the technique disclosed in Patent Document 1, a second soft member (that is, a core) made of a low-wear elastic material (eg, SBS resin, SEBS resin) is inserted in the through hole of the second holder. Therefore, in order to assemble the second holder and the second flexible member, a radial clearance is required between the through hole of the second holder and the second flexible member, resulting in friction. , the second soft member may wobble, and stable and appropriate friction may not be possible.

In addition, in the technology disclosed in Patent Document 2, since only one type of friction body is provided in the retractable writing instrument, the friction body cannot be easily replaced when the friction body is worn, damaged, or soiled. . In addition, even if the friction body alone is kept outside the retractable writing instrument as a spare, the friction body engaged with the crown can be removed because the crown and the friction body are firmly attached so as not to wobble during friction. It may be difficult to replace the friction body with a spare friction body.

The present invention has been made in view of the above findings, and is capable of stable and appropriate friction without wobble of the friction body at the time of friction, and of facilitating replacement of the mounted friction body with a spare friction body. To provide a replaceable thermochromic writing instrument. In the present invention, "front" refers to the pen tip side, and "rear" refers to the opposite side.

In a first invention of the present application, a thermochromic ink is contained inside a barrel, and the thermochromic ink can be discharged from a nib at the front end of the barrel, and at the rear end of the barrel, A thermochromic writing instrument comprising a friction body capable of thermally discoloring the handwriting of the thermochromic ink by rubbing the handwriting of the thermochromic ink and generating frictional heat at that time, the barrel; The head crown detachably attached to the rear end of the barrel by screwing, the friction body detachably attached to the rear end of the crown by screwing, the inside of the barrel and the inside of the crown and a preliminary friction body housed in the barrel, wherein the barrel is provided with a rearwardly protruding first crown mounting portion, and the outer surface of the first crown mounting portion has a first male threaded portion. The head crown is provided with a barrel mounting hole that opens forward, the inner surface of the barrel mounting hole has a first female thread that can be screwed into the first male thread, and the head crown has a rearward opening. The friction body mounting hole is provided with a second female screw portion on the inner surface of the friction body mounting hole, and the friction body and the preliminary friction body are provided with a second crown mounting portion projecting forward. The outer surface of the second crown mounting portion has a second external thread portion, the second crown mounting portion can be mounted in the friction body mounting hole by screwing, and the friction body is the It is required to be replaceable with a spare friction body.

The thermochromic writing instrument of the first invention comprises the barrel, a head crown detachably attached to the rear end of the barrel by screwing, and a crown detachably attached to the rear end of the head crown by screwing. The friction body to be mounted and the preliminary friction body to be accommodated inside the barrel and the crown, wherein the barrel is provided with a first head crown mounting portion projecting rearward; 1 has a first male threaded portion on the outer surface of the crown mounting portion, the crown is provided with a barrel mounting hole that opens forward, and the inner surface of the barrel mounting hole is screwed to the first male threaded portion. The head crown is provided with a rearwardly-opening friction body mounting hole, the inner surface of the friction body mounting hole has a second internal thread, and the friction body and the friction body have a second internal thread. The preliminary friction body is provided with a second crown mounting portion projecting forward, and has a second external thread portion on the outer surface of the second crown mounting portion, and the second crown mounting portion is attached to the friction body. Since the friction body can be attached to the body attachment hole by screwing, and the friction body can be replaced with the preliminary friction body, the friction body does not wobble during friction, and stable and appropriate friction can be achieved. The body can be easily replaced with a spare friction body.

In a second invention of the present application, thermochromic ink is contained inside a barrel, and the thermochromic ink can be discharged from a nib at the front end of the barrel, and at the rear end of the barrel, A thermochromic writing instrument comprising a friction body capable of thermally discoloring the handwriting of the thermochromic ink by rubbing the handwriting of the thermochromic ink and generating frictional heat at that time, the barrel; A head crown detachably attached to the rear end of the barrel by screwing, and the friction body, the barrel being provided with a first head crown mounting portion projecting rearward, The outer surface of the head crown mounting portion has a first male threaded portion, the head crown is provided with a barrel mounting hole that opens forward, and the inner surface of the barrel mounting hole is screwed into the first male threaded portion. the head crown has a rear end with a reduced diameter portion projecting radially inward; the friction body has a friction portion and a preliminary friction portion at both ends; The body has a radially outwardly protruding collar portion at its axial center portion, and the collar portion is sandwiched between the rear end portion of the first head crown mounting portion and the diameter-reduced portion. It is required that the friction part and the preliminary friction part can be attached by reversing front and back.

The thermochromic writing instrument according to the second aspect of the invention, comprising: the barrel; a crown detachably attached to the rear end of the barrel by screwing; a first head crown mounting portion protruding toward the head, the outer surface of the first head crown mounting portion having a first male screw portion, the head crown being provided with a barrel mounting hole opening forward; The inner surface of the barrel mounting hole has a first female thread portion that can be screwed into the first male thread portion, and the crown has a reduced diameter portion protruding radially inward at the rear end thereof. The friction body is provided with a friction part and a preliminary friction part at both ends, and the friction body is provided with a collar part protruding radially outward in the axial center part, and the collar part is attached to the first crown attachment part. The friction body is held between the rear end portion and the reduced diameter portion, and the friction body is retained by the crown. Stable and appropriate friction can be achieved without any friction, and the installed friction portion can be easily replaced with a spare friction portion.

The present invention has a commercial value because the friction body does not wobble during friction and stable and appropriate friction can be achieved, and the mounted friction body can be easily replaced with a spare friction body or friction part. can provide a thermochromic writing instrument with a high

It is a front view showing a 1st embodiment of the present invention. FIG. 2 is an enlarged vertical cross-sectional view of a main portion of FIG. 1; FIG. 2 is an exploded view showing a state of friction body replacement in FIG. 1; FIG. 2 is a perspective view of a friction body and a preliminary friction body of FIG. 1; It is a front view which shows 2nd Embodiment of this invention. FIG. 6 is an enlarged vertical cross-sectional view of a main portion of FIG. 5; FIG. 6 is an exploded view showing the state of friction body replacement in FIG. 5; FIG. 6 is a perspective view of the friction body and preliminary friction body of FIG. 5;

Two embodiments of the present invention will be described below with reference to the drawings.

<First embodiment>
1 to 4 show a first embodiment of the invention. FIG. 1 is a front view of a thermochromic writing instrument 1 according to a first embodiment of the present invention, showing a state in which the nib (writing body) does not protrude. FIG. 2 is an enlarged longitudinal sectional view of the rear end portion of the thermochromic writing instrument 1 of this embodiment. FIG. 3 is an exploded view showing the state when replacing the friction body 4 of this embodiment. FIG. 4 is a perspective view of the friction body 4 of this embodiment.

The thermochromic writing instrument 1 of the present embodiment is a multi-core retractable writing instrument, and has a slide operation portion on the outer surface of the side wall of the shaft cylinder 3. By sliding the slide operation portion or the clip portion as an operation portion, the writing body can be moved. The tip of the pen is protruded and retracted from the opening at the tip of the barrel 3 . The writing material is housed in the barrel 3, and a writing instrument can be constructed in which the writing tip of the writing piece appears and retracts from the tip opening of the barrel 3 by the operation of the retraction mechanism. A plurality of (specifically, three) writing bodies are accommodated in the barrel 3 so as to be movable in the front-rear direction, and each writing body is moved backward by an elastic body (specifically, a compression coil spring). energized.

In addition to this, the retraction mechanism is a rear end knock type in which the pen tip is retracted by pushing forward the operation part provided at the rear end of the barrel, and the operation part protruding from the outer surface of the side wall of the barrel Examples include a side-knock type in which the pen tip appears and retracts when pressed, and a rotary type in which the pen tip appears and retracts by rotating the operating portion at the rear portion of the barrel.

Cursive The cursive consists of a pen tip, an ink storage tube in which the pen tip is press-fitted and fixed to the front end opening, thermochromic ink filled in the ink storage tube, and the rear end of the thermochromic ink. a follower (such as a high viscosity fluid) which is filled in the thermochromic ink and advances as the thermochromic ink is consumed. Of the writing bodies applied to the thermochromic writing instrument 1 of the present embodiment, the writing bodies containing the thermochromic ink composition are accommodated in the barrel 3 in one or more pieces.

The pen tip may, for example, consist of only a metal ball-point pen tip that rotatably holds a ball at its front end, or may consist of a synthetic resin pen tip holder that holds the rear outer surface of the ball-point pen tip. Further, a tail plug having a ventilation hole that allows ventilation between the ink storage tube and the outside is attached to the rear end opening of the ink storage tube. A spring is housed inside the nib that pushes forward the ball at the front end. The spring has a configuration in which a rod portion is provided at the front end portion of a compression coil spring, and the front end of the rod portion is in contact with the rear surface of the ball. When not writing, the forward bias of the spring brings the ball into close contact with the inner surface of the inward front edge of the front end of the ballpoint pen tip, preventing ink from leaking out and evaporating from the front end of the pen tip.

- Thermochromic ink In the present invention, the thermochromic ink is preferably a reversible thermochromic ink. Reversible thermochromic ink is a heat decoloring type in which the color is decolored by heating from a colored state, a color memory retention type in which the colored state or decolored state is alternately stored in a specific temperature range, or a decolored state is heated. Various types can be used alone or in combination, such as a heat coloring type that develops color by heating and returns to a decolored state by cooling from the developed state.

In addition, the coloring material contained in the reversible thermochromic ink is a conventionally known (a) electron-donating color-forming organic compound, (b) an electron-accepting compound, and (c) a coloring reaction that causes both of them to occur. A reversible thermochromic microcapsule pigment in which a reversible thermochromic composition containing at least the three essential components of a reaction medium that determines the temperature is encapsulated in microcapsules is preferably used.

Axle As shown in FIGS. 1 and 3, the thermochromic writing instrument 1 of the present embodiment includes a front barrel 3a formed of a tapered cylindrical body and a rear end portion of the front barrel 3a screwed or press-fitted. and a cylindrical rear shaft 3b to be attached. The front end of the front barrel 3a is axially penetrated with an opening through which the tip of a cursive pen can protrude. The front axle 3a and the rear axle 3b are made of synthetic resin (for example, polycarbonate or the like) or metal.

For example, three (selectable from 2 to 6) elongated window holes 33 extending in the front-rear direction are radially penetrating through the rear side wall of the rear axle 3b. The three window holes 33 are formed, for example, at regular intervals in the circumferential direction.

A rear end portion of the barrel 3 is provided with a first crown mounting portion 31 protruding rearward, and a first male screw portion 32 is provided on the outer surface of the first crown mounting portion 31 . The crown 2 is detachably attached to the first crown attachment portion 31 by screwing.

Head crown As shown in Fig. 2 or 3, a head crown 2 is detachably attached to the rear end of the thermochromic writing instrument 1 of the present embodiment by screwing. The head crown 2 is provided with a barrel mounting hole 21 that opens forward, and has a first female screw portion 23 on the inner surface of the barrel mounting hole 21 .

The crown 2 is provided with a rearwardly-opening friction body mounting hole 22 and has a second internal thread portion 24 on the inner surface of the friction body mounting hole 22 . The crown 2 is detachably attached by screwing to a second crown attachment portion 41 provided at the front end of the friction body 4 . A preliminary friction body 4a is accommodated inside the mounted barrel 3 and crown 2. As shown in FIG.

In the thermochromic writing instrument 1 of the present embodiment, it is preferable that the outer surface of the crown 2 is formed with a rotary operation portion including a width across flat portion and a knurl portion. By rotating the rotating operation part, the threaded state between the barrel 3 and the crown 2 is released, and the barrel 3 and the crown 2 can be easily attached and detached. The rotary operation part may be, for example, a width across flat part such as a hexagon or an octagon that can be spanned, or a knurled part.

- Friction body The thermochromic writing instrument 1 includes a friction body 4 . In the present embodiment, it is preferable that the friction body 4 incorporates thermochromic ink therein and is provided at the rear end of the writing instrument from which the thermochromic ink can be discharged from the writing body.

In the present embodiment, the elastic material constituting the friction body 4 is preferably an elastic synthetic resin (rubber, elastomer), such as silicone resin, SBS resin (styrene-butadiene-styrene copolymer), SEBS resin ( styrene-ethylene-butylene-styrene copolymer), fluororesin, chloroprene resin, nitrile resin, polyester resin, ethylene propylene diene rubber (EPDM) or a mixture of two or more rubber elastic materials, and a rubber elastic material Mixtures with synthetic resins and the like are included. The elastic synthetic resin that constitutes the friction body 4 is not a high-wear elastic material (such as an eraser), but a low-wear elastic material that produces almost no wear residue (eraser residue) during friction. The friction body 4 can be a writing instrument set by combining the writing instrument and the friction instrument which is a separate member of arbitrary shape.

The friction body 4 may be formed from a mixture of polypropylene resin and a styrene-based thermoplastic elastomer, or a mixture of polypropylene resin and a polypropylene-based thermoplastic elastomer. A material that has a blending ratio of 1:1 to 1:4 by weight, does not contain abrasives, plasticizers, or fillers, and has a durometer hardness A specified in JIS K6251 of 70° to 100°. It is formed from a low-wear elastic material that does not contain a plasticizer and has a pencil-drawn line erasability (erasure rate) of 70% or less as defined in JIS S 6050-2002. As a result, the friction body 4 is effective because erasable scum is less likely to occur during rubbing and the heat discoloration is excellent.

The friction body 4 is made of a low-wear elastic material that produces almost no abrasion residue (eraser residue) when rubbed, but it may wear out or break gradually depending on the type or condition of the surface to be rubbed or the method of friction. have a nature. The worn or damaged friction body 4 cannot perform appropriate friction, and it may be difficult to rub the handwriting of the thermochromic ink, and heat discoloration of the handwriting of the thermochromic ink by the frictional heat generated at that time. .

In addition, when there is handwriting written with a pencil or the like on the rubbing surface of the friction body 4, or when the rubbing surface is dirty, scum or stains of the lead of the pencil or the like are transferred to the friction body 4, and the friction body 4 is rubbed. The body 4 may become soiled. With the soiled friction body 4, when rubbing another paper surface, the dirt adhered to the friction body 4 may be transferred to the paper surface, and the paper surface may be soiled.

When the friction body 4 is worn, damaged, or soiled, it is possible to perform appropriate friction again by replacing the worn, damaged, or soiled friction body 4 with a new friction body 4 .

The thermochromic writing instrument 1 of this embodiment comprises a friction body 4 detachably attached to the rear end of the crown 2 by screwing, and a preliminary friction body 4a housed inside the barrel 3 and inside the crown 2. , and the friction body 4 is replaceable with a spare friction body 4a.

Both the friction body 4 and the preliminary friction body 4a are provided with a second crown mounting portion 41 which protrudes forward and is detachably mounted in the friction body mounting hole 22. As shown in FIG. A second male screw portion 42 is provided on the outer surface of the second crown mounting portion 41 .

In order to obtain the same friction performance before and after replacement of the friction body 4, it is preferable that the friction body 4 and the preliminary friction body 4a have the same shape. As a result, even after the friction body 4 is worn and replaced with the preliminary friction body 4a, the same constant friction performance as before the replacement can be obtained, and stable writing performance can be maintained. Further, when the friction range is changed by the shape of the friction body, it is preferable that the friction portions of the friction body 4 and the preliminary friction body 4a have different shapes. This allows a single writing instrument to rub both a wide area and a narrow area.

The friction body 4 preferably has an air flow path 43 in the axial direction. As a result, even if an infant swallows the friction body 4 by mistake, the air flow path 43 of the friction body 5 can be ventilated and the airway can be secured, thereby avoiding an accident of suffocation.

In the thermochromic writing instrument 1 of the present embodiment, it is preferable that the outer surface of the friction body 4 is formed with a rotary operation portion including a width across flat portion and a knurl portion. By rotating the rotary operation portion, the screwed state between the friction body 4 and the crown 2 is released, and the friction body 4 and the crown 2 can be easily attached and detached. The rotary operation part may be, for example, a width across flat part such as a hexagon or an octagon that can be spanned, or a knurled part.

The thermochromic writing instrument 1 configured as described above operates as follows.

When the friction body 4 is used (that is, during friction), as shown in FIG. The barrel attachment hole 21 of the crown 2 is attached to the first head crown attachment portion 31 of the barrel 3 by screwing. As a result, since the friction body 4 is stably attached to the thermochromic writing instrument 1, the friction body does not wobble during friction, and stable and appropriate friction can be achieved.

On the other hand, when replacing the friction body 4, as shown in FIG. 21 is removed from the first crown mounting portion 31 of the barrel 3 . Since the friction body 4 and the crown 2 and the crown 2 and the barrel 3 are detachably attached by screwing, they can be easily disassembled.

Further, as the barrel mounting hole 21 of the crown 2 is removed from the first crown mounting portion 31 of the barrel 3, the preliminary friction body 4a that has been housed inside the barrel 3 and the crown 2 is removed. is removed. As a result, the worn, damaged, or soiled friction body 4 can be easily replaced with the spare friction body 4a.

Further, the friction body 4 that has been worn, damaged, soiled, or the like can be accommodated inside the barrel 3 and crown 2 in which the preliminary friction body 4a was accommodated. As a result, the internal space between the barrel 3 and the crown 2 can be used as a storage space for the used friction elements 4 until they are discarded.

As described above, according to the thermochromic writing instrument 1 of the present embodiment, stable and appropriate friction can be achieved without the friction body 4 shaking during friction, and the friction body 4 attached to the crown 2 can be Since it can be easily replaced with the preliminary friction body 4a, the friction performance of the thermochromic writing instrument can be maintained for a long period of time, and a thermochromic writing instrument with high commercial value can be provided.

<Second embodiment>
5 to 8 show a second embodiment of the invention. This is a modified example of the first embodiment, and differs from the first embodiment in that it is provided with a friction body 5 which is an integral unit of the friction body 4 and the preliminary friction body 4a and which has friction portions at both ends. is. Another difference is that the method of mounting the friction body 5 of the second embodiment is that the crown 2 and the shaft tube 3 are sandwiched between them. Since other configurations and effects are the same as those of the first embodiment, description thereof will be omitted.

FIG. 5 is a front view of the thermochromic writing instrument 1 according to the second embodiment of the present invention, showing a state in which the pen tip (writing body) is not protruding. FIG. 6 is an enlarged longitudinal sectional view of the rear end portion of the thermochromic writing instrument 1 of this embodiment. FIG. 7 is an exploded view showing a state in which the friction portion 5a and the preliminary friction portion 5b of the friction body 5 of this embodiment are exchanged. FIG. 8 is a perspective view of the friction body 5 of this embodiment.

· Crown The crown 2 is provided with a diameter-reduced portion 25 protruding radially inward at its rear end. The friction body 5, which will be described later, is provided with a friction part 5a and a preliminary friction part 5b projecting rearward from the diameter-reduced part 25 at both ends, and a collar part projecting radially outward at the axial center of the friction body 5. be done. The collar portion is sandwiched between the rear end portion of the first crown mounting portion 31 and the reduced diameter portion 25, so that the friction body 5 is retained by the crown 2, and the friction portion 5a and the preliminary friction portion 5b are reversed back and forth. can be installed by

Friction body The friction body 5 is provided with a friction part 5a and a preliminary friction part 5b projecting rearward from the diameter-reduced part 25 at both ends, and a collar part 51 projecting radially outward from the center part in the axial direction of the friction body 5. is provided, and the collar portion 51 is sandwiched between the rear end portion of the first crown mounting portion 31 and the reduced diameter portion 25, so that the friction body 5 is prevented from coming off by the crown 2, and the friction portion 5a and preliminary friction The portion 5b can be attached by reversing the front and back.

In order to obtain the same friction performance before and after mounting the friction portion 5a and the preliminary friction portion 5b with the front and rear reversed, it is preferable that the friction portion 5a and the preliminary friction portion 5b have the same shape. Further, when the friction range is changed by the shape of the friction body, it is preferable that the friction portion 5a and the preliminary friction portion 5b have different shapes.

A first insertion portion 52 that can be inserted into the first crown mounting portion 31 of the barrel 3 is provided on the friction portion 5a side of the outer surface of the friction body 5, and the preliminary friction portion 5b side of the barrel 3 is provided. A second insertion portion 53 is provided that can be inserted into the first crown mounting portion 31 . Thereby, the first insertion portion 52 or the second insertion portion 53 can be inserted into the first crown mounting portion 31 of the barrel 3 . Also, the first insertion portion 52 or the second insertion portion 53 can be inserted into the reduced diameter portion 25 of the crown 2 . Moreover, it is preferable that the outer diameter of the first insertion portion 52 and the outer diameter of the second insertion portion 53 are equal.

The friction body 5 preferably has an air flow path 54 in the axial direction. As a result, even if an infant accidentally swallows the friction body 5, the air passage 54 of the friction body 5 can be ventilated to secure the airway, thereby avoiding suffocation accidents.

As for the friction body 5, it is preferable that the flange portion 51 of the friction body 5 is directly held between the rear end portion of the first head crown mounting portion 31 and the reduced diameter portion 25 without locking a holder or the like to the friction body 5. . As a result, it is possible to eliminate the step of mounting the friction body in the through-hole of the holder, reduce the number of parts, and reduce the cost.

The thermochromic writing instrument 1 configured as described above operates as follows.

When the friction body 5 is used (that is, during friction), as shown in FIG. The friction body 5 is held by the crown 2 and held between the rear end portion of the crown mounting portion 31 and the reduced diameter portion 25 . As a result, since the friction body 5 is stably attached to the thermochromic writing instrument 1, the friction body does not wobble during friction, and stable and appropriate friction can be achieved.

When replacing the friction portion 5a and the preliminary friction portion 5b of the friction body 5, the barrel mounting hole 21 of the crown 2 is removed from the first crown mounting portion 31 of the barrel 3, as shown in FIG. be Since the crown 2 and the barrel 3 are detachably attached by screwing, they can be easily disassembled.

Further, as the barrel mounting hole 21 of the crown 2 is removed from the first crown mounting portion 31 of the barrel 3, the friction body 5 can also be removed. As a result, the friction portion 5a and the preliminary friction portion 5b can be reversed and attached, and the friction portion 5a that has been worn, damaged, or soiled can be easily replaced with the preliminary friction portion 5b.

Further, the friction body 5 that has been worn, damaged, soiled, or the like has a friction portion 5a and a preliminary friction portion 5b in the same member. As a result, there is no need to store preliminary friction bodies in the internal space between the barrel 3 and the crown 2, and no storage space for used friction bodies is required.

As described above, according to the thermochromic writing instrument 1 of the present embodiment, stable and appropriate friction can be achieved without the friction body 5 shaking during friction, and the friction body 5 attached to the crown 2 can be Since the friction portion 5a can be easily replaced with the preliminary friction portion 5b, the friction performance of the thermochromic writing instrument can be maintained for a long period of time, and a thermochromic writing instrument with high commercial value can be provided.

1 thermochromic writing instrument 2 head crown 21 barrel mounting hole 22 friction body mounting hole 23 first female threaded portion 24 second female threaded portion 25 reduced diameter portion 3 barrel 3a front shaft 3b rear shaft 31 first head crown mounting Part 32 First male threaded part 33 Window hole 4 Friction body 4a Preliminary friction body 41 Second head crown attachment part 42 Second male threaded part 43 Air flow path 5 Friction body 5a Friction part 5b Preliminary friction part 51 Flange 52 Second 1 inserting portion 53 second inserting portion 54 air flow path

Claims (5)

A thermochromic ink is contained inside a barrel, and the thermochromic ink can be discharged from a pen tip at the front end of the barrel, and a handwriting of the thermochromic ink is printed at the rear end of the barrel. A thermochromic writing instrument comprising a friction body capable of thermally discoloring handwriting of the thermochromic ink by rubbing and frictional heat generated at that time,
the barrel, the head crown detachably attached to the rear end of the barrel by screwing, the friction body detachably attached to the rear end of the crown by screwing, and the interior of the barrel. and a preliminary friction body housed inside the crown,
The barrel is provided with a rearwardly protruding first crown mounting portion, the outer surface of the first crown mounting portion has a first male screw portion, and the crown is mounted with a forwardly opening barrel. a hole is provided, and the inner surface of the barrel mounting hole has a first female thread portion that can be screwed into the first male thread portion;
The crown is provided with a rearwardly-opening friction body mounting hole, and the inner surface of the friction body mounting hole has a second female screw portion. a crown mounting portion is provided, the outer surface of the second crown mounting portion has a second external thread portion, the second crown mounting portion can be mounted in the friction body mounting hole by screwing; A thermochromic writing instrument, wherein the friction body is replaceable with the preliminary friction body. A thermochromic ink is contained inside a barrel, and the thermochromic ink can be discharged from a pen tip at the front end of the barrel, and a handwriting of the thermochromic ink is printed at the rear end of the barrel. A thermochromic writing instrument comprising a friction body capable of thermally discoloring handwriting of the thermochromic ink by rubbing and frictional heat generated at that time,
comprising the barrel, a head crown detachably attached to the rear end of the barrel by screwing, and the friction body,
The barrel is provided with a rearwardly protruding first crown mounting portion, the outer surface of the first crown mounting portion has a first male screw portion, and the crown is mounted with a forwardly opening barrel. a hole is provided, and the inner surface of the barrel mounting hole has a first female thread portion that can be screwed into the first male thread portion;
The crown is provided with a diameter-reduced portion protruding radially inward at its rear end, the friction body is provided with a friction portion and a preliminary friction portion at both ends, and the friction body is provided with a radially outward portion at an axial center portion. The collar portion is sandwiched between the rear end portion of the first crown mounting portion and the reduced diameter portion, the friction body is retained by the crown, and the friction portion and the A thermochromic writing utensil characterized in that the preliminary friction part can be attached by reversing the front and back. 3. The thermochromic writing instrument according to claim 2, wherein said friction portion and said preliminary friction portion have the same external shape. A first insertion portion that can be inserted into the first crown mounting portion of the barrel is provided on the friction portion side of the outer surface of the friction body, and the first insertion portion of the barrel is provided on the preliminary friction portion side. A second insertion part is provided that can be inserted into one crown mounting part, and the first insertion part or the second insertion part is inserted into the first crown mounting part of the barrel. 4. The thermochromic writing instrument according to claim 3, wherein said first insertion portion or said second insertion portion is inserted into said reduced diameter portion of said crown. 5. The friction tool according to claim 4, wherein the outer diameter of the first insertion portion and the outer diameter of the second insertion portion are equal.

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