JP6192964B2 - Thermochromic writing instrument - Google Patents

Description

The present invention accommodates a writing body containing thermochromic ink in a shaft cylinder so as to be movable in the front-rear direction, and pushes the knock body at the rear end of the shaft cylinder to move the pen tip of the writing body to the shaft. A thermochromic writing instrument which is configured so as to be able to protrude and retract from a front end hole of a cylinder, and provided with a friction body capable of rubbing the handwriting of the thermochromic ink on the outer surface of the shaft cylinder and thermally changing the handwriting by frictional heat generated at that time About.

Conventionally, in Patent Document 1, a writing body is accommodated in a shaft cylinder so as to be movable in the front-rear direction, an operation portion is provided on an outer surface of the shaft tube, and the pen tip of the writing body is operated by operating the operation portion. It is configured to be able to protrude and retract from the front end hole of the shaft cylinder, the thermochromic ink is accommodated in the cursive body, a pen tip capable of discharging the thermochromic ink is provided at the front end of the cursive body, A thermochromic writing instrument is disclosed in which a friction body capable of thermally changing the handwriting of the thermochromic ink by rubbing the handwriting of the thermochromic ink on the outer surface is provided.

International Publication No. 2008/105227 Pamphlet

When the thermochromic writing instrument of Patent Document 1 is stored in a pencil case, a pen stand, or a pocket of clothes when not in use, the friction body is always exposed to the outside. Contact with other articles (for example, the outer surface of other writing instruments, the inner surface of a pen case, the bottom surface of a pen stand, or the inner surface of a pocket of clothes), dust or dirt adheres to the surface of the friction body, and the surface of the friction body becomes dirty. There is a problem that the paper surface becomes dirty when the surface of the paper (writing surface) is rubbed with the dirty friction body.

The present invention solves the above-mentioned conventional problems, and an object of the present invention is to provide a thermochromic writing instrument that can prevent the friction body from becoming dirty when not in use.

In the present invention, “front” refers to the pen tip side, and “rear” refers to the opposite side. In the present invention, the pen tip protruding state refers to a state in which the pen tip protrudes forward from the front end of the shaft cylinder, and the pen tip immersed state refers to a state in which the pen tip is inserted into the shaft cylinder from the front end of the shaft cylinder.

1st invention of this application accommodates the writing body 6 in the axial cylinder 2 so that a movement in the front-back direction is possible, accommodates thermochromic ink in the inside of the writing body 6, and puts the writing body 6 on the front end of the writing body 6. A nib 61 capable of ejecting thermochromic ink is provided; a knock body is provided at the rear end of the shaft cylinder 2; The pendulum is provided with a retracting mechanism for pressing the knock body forward from the pen tip protruding state so as to be in a pen tip immersing state, and the outer surface of the shaft cylinder 2 is rubbed with the handwriting of the thermochromic ink. A thermochromic writing instrument provided with a frictional body 5 made of a low-abrasion elastic material capable of thermally discoloring the handwriting by the generated frictional heat, wherein the frictional body 5 is placed near the knocking body at the rear end of the shaft cylinder 2. In the pen tip immersion state, the rear end of the knock body is Behind the body 5 a rear end, and the requirements to be protruded higher than the pen tip protruding state.

In the thermochromic writing instrument 1 of the first invention, the friction body 5 is provided in the vicinity of the knock body 9 at the rear end of the shaft cylinder 2, and the rear end of the knock body 9 is the friction body 5 in the pen tip immersion state. When protruding from the rear end larger than the pen tip protruding state, when not in use (that is, in the pen tip immersed state), other articles (eg, other writing instrument outer surfaces, pen cases, pen stands, or clothes) And the like, the rear end of the knock body 9 comes into contact with the other article, the friction body 5 can be prevented from coming into contact with the other article, and the surface of the friction body 5 becomes dirty. Can be prevented.

In addition, the thermochromic writing instrument 1 of the first invention has a writing surface using the friction body 5 because the knock body 9 is immersed in the shaft cylinder 2 when in use (that is, in a state where the pen tip protrudes). The handwriting of the above thermochromic ink can be easily rubbed. The knock body 9 is immersed in the shaft cylinder 2 when the knock body 9 is completely immersed in the shaft cylinder 2 or most of the knock body 9 is immersed in the shaft cylinder 2 and the knock body. A part of 9 is projected outside.

The second invention of the present application is that, in the thermochromic writing instrument 1 of the first invention, the friction body 5 is provided on the outer peripheral edge of the rear end of the shaft tube 2.

In the thermochromic writing instrument 1 of the second invention, the friction body 5 is provided at the outer peripheral edge of the rear end of the shaft cylinder 2 so that the shaft cylinder is removed from the writing use state (pen tip protruding state) when the friction body is used. After inverting 2 back and forth, the friction body 5 can be quickly pressed against the handwriting on the writing surface simply by tilting the shaft cylinder 2 from the vertical state with respect to the writing surface.

3rd invention of this application requires that the said friction body 5 is cyclically | annularly provided in the outer-periphery edge part of the axial cylinder 2 in the thermochromic writing instrument 1 of the said 2nd invention.

The third thermochromic writing instrument 1 needs to confirm the circumferential position of the friction body 5 when the friction body is used by providing the friction body 5 in an annular shape at the outer peripheral edge of the rear end of the shaft tube 2. The friction body 5 can be quickly pressed against the handwriting on the writing surface.

According to a fourth invention of the present application, in the thermochromic writing instrument 1 of the first, second, or third invention, in the pen tip protruding state, a tangent line b that contacts the friction body 5 and the knock body 9; It is a requirement that the angle formed with the axis is set to 45 degrees or more.

In the thermochromic writing instrument 1 of the fourth invention, in the pen tip protruding state, by setting the angle formed by the axis and the tangent line b contacting the friction body 5 and the knock body 9 to 45 degrees or more, The friction body 5 can be easily pressed against the writing surface by slightly tilting the shaft cylinder 2 from the vertical state with respect to the writing surface, and the shaft cylinder on the friction body 5 side can be held in the same manner as when writing. 2 can be gripped. If the angle formed between the tangent line b contacting the friction body 5 and the knock body 9 and the axis is less than 45 degrees, the shaft cylinder 2 needs to be considerably inclined from the perpendicular state to the writing surface. There is a possibility that the shaft cylinder 2 on the friction body 5 side cannot be gripped by the same holding method as when writing.

According to a fifth invention of the present application, in the thermochromic writing instrument 1 according to any one of the first to fourth inventions, the outer surface of the shaft tube 2 in front of the friction body 5 is radially outward from the friction body 5. It is a requirement that the convex portion 43 projecting is provided.

The thermochromic writing instrument 1 according to the fifth aspect of the invention is not used by providing a convex portion 43 projecting radially outward from the friction body 5 on the outer surface of the shaft cylinder 2 in front of the friction body 5. Even when stored in other articles (for example, the outer surface of other writing instruments, a pen case, a pen stand, or a pocket of clothes, etc.) The friction body 5 is disposed between the knock body 9 and the knock body 9 or the convex portion 43 in contact with the other article, the contact of the friction body 5 with the other article can be avoided, and the surface of the friction body 5 is stained. Can be prevented.

In the thermochromic writing instrument 1 according to the fifth aspect of the present invention, when not in use (that is, in the pen tip immersion state), the friction body 5 is positioned radially inward from the tangent line a where the knock body 9 and the protrusion 43 are in contact. That is, a configuration in which the friction body 5 does not protrude radially outward from the tangent line a where the knock body 9 and the convex portion 43 contact is preferable. As a result, the friction body 5 can be prevented from coming into contact with the other article, and the surface of the friction body 5 can be prevented from becoming dirty.

The thermochromic writing instrument of the present invention can prevent the friction body from becoming dirty when not in use.

It is a longitudinal cross-sectional view of the pen tip immersion state (friction body protection state) of the 1st Embodiment of this invention. It is a longitudinal cross-sectional view of the pen tip protrusion state (friction body use possible state) of the 1st Embodiment of this invention. FIG. 3 is an enlarged vertical sectional view of a main part of FIG. 2. It is an exploded view which shows the intrusion mechanism of the 1st Embodiment of this invention. It is a longitudinal cross-sectional view of the pen tip immersion state (friction body protection state) of the 2nd Embodiment of this invention.

<First Embodiment>
A first embodiment of the present invention is shown in FIGS.
The thermochromic writing instrument 1 according to the present embodiment includes a shaft tube 2, a writing body 6 accommodated in the shaft tube 2, and a pen tip 61 of the writing body 6 that can be projected and retracted from a front end hole 31 of the shaft tube 2. And a frictional mechanism 5 provided at the rear end of the shaft cylinder 2.

The shaft cylinder 2 includes a front shaft 3 and a rear shaft 4 that is detachably connected to the rear end of the front shaft 3.

Front shaft The front shaft 3 is a molded body of a synthetic resin having a tapered cylindrical shape. A front end hole 31 is provided in the front end of the front shaft 3 in the front-rear direction. A male thread portion is integrally formed on the outer surface of the rear end opening of the front shaft 3.

Rear shaft The rear shaft 4 is a cylindrical synthetic resin molded body. A rear end hole 41 is provided in the rear end of the rear shaft 4 in the front-rear direction. A stepped portion 73 is integrally formed on the inner surface of the rear end portion of the rear shaft 4. A cam portion 7 is integrally formed on the inner surface in front of the rear end hole 41 of the rear shaft 4. On the outer surface of the rear shaft 4, a convex portion 43 that protrudes radially outward is integrally formed. A clip 42 is integrally extended in front of the convex portion 43. On the inner surface of the front end opening of the rear shaft 4, a female thread is integrally formed. The female screw portion and the male screw portion of the front shaft 3 can be screwed together.

Cursive body The cursive body 6 includes a pen tip 61, an ink storage tube 62 in which the pen tip 61 is press-fitted and fixed to the front end opening, a thermochromic ink filled in the ink storage tube 62, and It consists of a follower (for example, a high-viscosity fluid) that fills the rear end of the thermochromic ink and moves forward as the thermochromic ink is consumed.

The nib 61 is, for example, either a metal ballpoint pen tip having a ball rotatably held at its front end or a synthetic resin nib holder holding the rear outer surface of the ballpoint pen tip. It may be. Further, a tail plug provided with a vent hole through which the ink containing tube 62 and the outside can be vented may be attached to the rear end opening of the ink containing tube 62.

The retracting mechanism is a knock-type retracting mechanism using a rotating cam mechanism, and a rotating member 8 that engages with the cam portion 7 formed on the inner surface of the shaft cylinder 2 and abuts against the rear end of the writing body 6. , A knocking body 9 that engages with the rotating member 8 and protrudes rearward from the rear end hole 41 of the shaft cylinder 2, and a resilient body 10 that is accommodated in the shaft cylinder 2 and biases the writing body 6 backward ( For example, a compression coil spring). The retracting mechanism of the present embodiment is a double knock type in which both the pen tip protruding operation and the pen tip retracting operation push the knock body 9 forward.

Friction body A friction body 5 made of a low-abrasion elastic material is fixed to the rear end of the rear shaft 4. The friction body 5 is annularly provided at the outer peripheral edge of the rear end of the rear shaft 4 and has an inner hole 51 at the center thereof. The elastic material is an elastic material that hardly generates wear debris at the time of friction. For example, a synthetic resin (rubber or elastomer) having elasticity is preferable. Specifically, silicone resin, SBS resin (styrene- Examples thereof include butadiene-styrene copolymers), SEBS resins (styrene-ethylene-butylene-styrene copolymers), fluorine resins, chloroprene resins, nitrile resins, polyester resins, ethylene propylene diene rubber (EPDM), and the like. By rubbing the handwriting of the thermochromic ink on the writing surface using the friction body 5, the handwriting of the thermochromic ink can be discolored by the frictional heat generated at that time.

The rear end hole 41 of the shaft cylinder 2 and the inner hole 51 of the friction body 5 communicate with each other, and the knock body 9 protrudes greatly rearward from the inner hole 51 of the friction body 5 in the pen tip immersion state. The friction body 5 is formed in the vicinity of the knock body 9 at the rear end of the shaft cylinder 2. Further, the angle α formed between the tangent line b in contact with the friction body 5 and the knock body 9 and the axis is set to 45 degrees or more. Further, a convex portion 43 is formed on the outer surface of the shaft cylinder 2 in front of the friction body 5 so as to protrude radially outward from the friction body 5. The convex portion 43 is a base portion of the clip 42 in the present embodiment. In the pen tip immersion state, the friction body 5 is positioned radially inward from a tangent line a that contacts the knock body 9 and the protrusion 43.

In the thermochromic writing instrument 1 of the present embodiment, the friction body 5 is provided in the vicinity of the knock body 9 at the rear end of the shaft tube 2, and the rear end of the knock body 9 is located behind the friction body 5 in the pen tip immersion state. By projecting beyond the end beyond the tip of the pen tip, when not in use (i.e., in the pen tip immersion state), other articles (eg, other writing instrument outer surfaces, pen cases, pen stands, or clothes Even if it is stored in a pocket or the like, it can be avoided that the rear end of the knock body 9 comes into contact with the other article, the friction body 5 comes into contact with the other article, and the surface of the friction body 5 becomes dirty. Can be prevented.

In the thermochromic writing instrument 1 of the present embodiment, the friction body 5 is provided on the outer peripheral edge of the rear end of the shaft cylinder 2, so that the shaft cylinder 2 is changed from the writing use state (pen tip protruding state) when the friction body is used. After reversing back and forth, the friction body 5 can be quickly pressed against the handwriting on the writing surface simply by tilting the shaft cylinder 2 from the vertical state with respect to the writing surface.

The thermochromic writing instrument 1 of the present embodiment confirms the circumferential position of the friction body 5 when the friction body is used by providing the friction body 5 in an annular shape at the outer peripheral edge of the rear end of the shaft tube 2. There is no need, and the friction body 5 can be quickly pressed against the handwriting on the writing surface.

The thermochromic writing instrument 1 of the present embodiment is configured such that, in the pen tip protruding state, the angle between the tangent line b contacting the friction body 5 and the knock body 9 and the axis is set to 45 degrees or more. The friction body 5 can be easily pressed against the writing surface by slightly tilting the tube 2 from the vertical state with respect to the writing surface, and the shaft cylinder 2 on the friction body 5 side can be held in the same manner as when writing. Can be gripped.

The thermochromic writing instrument 1 of the present embodiment is provided with a convex portion 43 that protrudes radially outward from the friction body 5 on the outer surface of the shaft cylinder 2 in front of the friction body 5. (In other words, in the state where the pen tip is immersed), even if stored in other articles (for example, the outer surface of other writing instruments, a pen case, a pen stand, a pocket of clothes, etc.) and stored, The friction body 5 is disposed between the knock body 9 or the protrusion 43 and the other article can be prevented from contacting the other article, and the surface of the friction body 5 can be prevented from becoming dirty. it can.

When the thermochromic writing instrument 1 of the present embodiment is not in use (i.e., in the pen tip immersion state), the friction body 5 is located radially inward from the tangent line a where the knock body 9 and the convex portion 43 contact, i.e., The friction body 5 does not protrude outward in the radial direction from the tangent line a where the knock body 9 and the convex portion 43 contact. Thereby, it can avoid that the friction body 5 contacts the said other goods further, and can prevent that the friction body 5 surface gets dirty.

<Second Embodiment>
A second embodiment of the present invention is shown in FIGS. 5 and 4 (FIG. 4 is common to the first embodiment).
The present embodiment is a modification of the convex portion 43 of the first embodiment.

The thermochromic writing instrument 1 according to the present embodiment includes a shaft tube 2, a writing body 6 accommodated in the shaft tube 2, and a pen tip 61 of the writing body 6 that can be projected and retracted from a front end hole 31 of the shaft tube 2. And a frictional mechanism 5 provided at the rear end of the shaft cylinder 2.

The shaft cylinder 2 includes a front shaft 3 and a rear shaft 4 that is detachably connected to the rear end of the front shaft 3.

Front shaft The front shaft 3 is a molded body of a synthetic resin having a tapered cylindrical shape. A front end hole 31 is provided in the front end of the front shaft 3 in the front-rear direction. A male thread portion is integrally formed on the outer surface of the rear end opening of the front shaft 3.

Rear shaft The rear shaft 4 is a cylindrical synthetic resin molded body. A rear end hole 41 is provided in the rear end of the rear shaft 4 in the front-rear direction. A stepped portion 73 is integrally formed on the inner surface of the rear end portion of the rear shaft 4. A cam portion 7 is integrally formed on the inner surface in front of the rear end hole 41 of the rear shaft 4. On the outer surface of the rear shaft 4, a convex portion 43 that protrudes radially outward is integrally formed in an annular shape. A clip 42 extends to one end in front of the convex portion 43. On the inner surface of the front end opening of the rear shaft 4, a female thread is integrally formed. The female screw portion and the male screw portion of the front shaft 3 can be screwed together.

Cursive body The cursive body 6 includes a pen tip 61, an ink storage tube 62 in which the pen tip 61 is press-fitted and fixed to the front end opening, a thermochromic ink filled in the ink storage tube 62, and It consists of a follower (for example, a high-viscosity fluid) that fills the rear end of the thermochromic ink and moves forward as the thermochromic ink is consumed.

The nib 61 is, for example, either a metal ballpoint pen tip having a ball rotatably held at its front end or a synthetic resin nib holder holding the rear outer surface of the ballpoint pen tip. It may be. Further, a tail plug provided with a vent hole through which the ink containing tube 62 and the outside can be vented may be attached to the rear end opening of the ink containing tube 62.

The retracting mechanism is a knock-type retracting mechanism using a rotating cam mechanism, and a rotating member 8 that engages with the cam portion 7 formed on the inner surface of the shaft cylinder 2 and abuts against the rear end of the writing body 6. , A knocking body 9 that engages with the rotating member 8 and protrudes rearward from the rear end hole 41 of the shaft cylinder 2, and a resilient body 10 that is accommodated in the shaft cylinder 2 and biases the writing body 6 backward ( For example, a compression coil spring). The retracting mechanism of the present embodiment is a double knock type in which both the pen tip protruding operation and the pen tip retracting operation push the knock body 9 forward.

Friction body A friction body 5 made of a low-abrasion elastic material is fixed to the rear end of the rear shaft 4. The friction body 5 is annularly provided at the outer peripheral edge of the rear end of the rear shaft 4 and has an inner hole 51 at the center thereof. The elastic material is an elastic material that hardly generates wear debris at the time of friction. For example, a synthetic resin (rubber or elastomer) having elasticity is preferable. Specifically, silicone resin, SBS resin (styrene- Examples thereof include butadiene-styrene copolymers), SEBS resins (styrene-ethylene-butylene-styrene copolymers), fluorine resins, chloroprene resins, nitrile resins, polyester resins, ethylene propylene diene rubber (EPDM), and the like. By rubbing the handwriting of the thermochromic ink on the writing surface using the friction body 5, the handwriting of the thermochromic ink can be discolored by the frictional heat generated at that time.

The rear end hole 41 of the shaft cylinder 2 and the inner hole 51 of the friction body 5 communicate with each other, and the knock body 9 protrudes greatly rearward from the inner hole 51 of the friction body 5 in the pen tip immersion state. The friction body 5 is formed in the vicinity of the knock body 9 at the rear end of the shaft cylinder 2. Further, the angle α formed between the tangent line b in contact with the friction body 5 and the knock body 9 and the axis is set to 45 degrees or more. Further, a convex portion 43 is formed on the outer surface of the shaft cylinder 2 in front of the friction body 5 so as to protrude radially outward from the friction body 5. The convex portion 43 is a base portion of the clip 42 in the present embodiment. In the pen tip immersion state, the friction body 5 is positioned radially inward from a tangent line a that contacts the knock body 9 and the protrusion 43.

In the thermochromic writing instrument 1 of the present embodiment, the friction body 5 is provided in the vicinity of the knock body 9 at the rear end of the shaft tube 2, and the rear end of the knock body 9 is located behind the friction body 5 in the pen tip immersion state. By projecting beyond the end beyond the tip of the pen tip, when not in use (i.e., in the pen tip immersion state), other articles (eg, other writing instrument outer surfaces, pen cases, pen stands, or clothes Even if it is stored in a pocket or the like, it can be avoided that the rear end of the knock body 9 comes into contact with the other article, the friction body 5 comes into contact with the other article, and the surface of the friction body 5 becomes dirty. Can be prevented.

In the thermochromic writing instrument 1 of the present embodiment, the friction body 5 is provided on the outer peripheral edge of the rear end of the shaft cylinder 2, so that the shaft cylinder 2 is changed from the writing use state (pen tip protruding state) when using the friction body. After reversing back and forth, the friction body 5 can be quickly pressed against the handwriting on the writing surface simply by tilting the shaft cylinder 2 from the vertical state with respect to the writing surface.

The thermochromic writing instrument 1 of the present embodiment confirms the circumferential position of the friction body 5 when the friction body is used by providing the friction body 5 in an annular shape at the outer peripheral edge of the rear end of the shaft tube 2. There is no need, and the friction body 5 can be quickly pressed against the handwriting on the writing surface.

The thermochromic writing instrument 1 of the present embodiment is configured such that, in the pen tip protruding state, the angle between the tangent line b contacting the friction body 5 and the knock body 9 and the axis is set to 45 degrees or more. The friction body 5 can be easily pressed against the writing surface by slightly tilting the tube 2 from the vertical state with respect to the writing surface, and the shaft cylinder 2 on the friction body 5 side can be held in the same manner as when writing. Can be gripped.

The thermochromic writing instrument 1 of the present embodiment is provided with a convex portion 43 that protrudes radially outward from the friction body 5 on the outer surface of the shaft cylinder 2 in front of the friction body 5. (In other words, in the state where the pen tip is immersed), even if stored in other articles (for example, the outer surface of other writing instruments, a pen case, a pen stand, a pocket of clothes, etc.) and stored, The friction body 5 is disposed between the knock body 9 or the protrusion 43 and the other article can be prevented from contacting the other article, and the surface of the friction body 5 can be prevented from becoming dirty. it can.

When the thermochromic writing instrument 1 of the present embodiment is not in use (i.e., in the pen tip immersion state), the friction body 5 is located radially inward from the tangent line a where the knock body 9 and the convex portion 43 contact, i.e., The friction body 5 does not protrude outward in the radial direction from the tangent line a where the knock body 9 and the convex portion 43 contact. Thereby, it can avoid that the friction body 5 contacts the said other goods further, and can prevent that the friction body 5 surface gets dirty.

<Thermochromic ink>
In the first and second embodiments, 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 first and second embodiments, the shape of the curve plotting the change in the color density due to the temperature change is higher than the color change temperature range, contrary to the case where the temperature is raised from the lower temperature side than the color change temperature range. The color changes by following a different route depending on whether the color is lowered from the color, and the color develops 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 ). However, a color memory holding type thermochromic ink that can be stored and held in a specific temperature range [temperature range between t _{2 and} t ₃ (substantially two-phase holding temperature range)] is applied. When the value of the temperature width indicating the degree of hysteresis (that is, the hysteresis width) is small, only one of the two states before and after the color change can exist. When the value of the temperature range indicating the degree of hysteresis is large, it is easy to maintain each state before and after the color change.

In the first and second embodiments, the discoloration temperature of the thermochromic ink friction body 5 due to frictional heat is set to 25 ° C. to 95 ° C. (preferably 36 ° C. to 95 ° C.). That is, the high temperature side color change point [complete color erasing 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 color change point [complete color development temperature ( It is effective to set (t ₁ )] within a 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 the handwriting by the reversible thermochromic ink can be easily changed in color by the frictional heat generated by the friction body 5.

<Infestation mechanism>
In the first and second embodiments, the retracting mechanism is a knock-type retracting mechanism using a rotating cam mechanism, which engages with the cam portion 7 formed on the inner surface of the shaft cylinder 2 and the writing body 6. A rotating member 8 that contacts the rear end, a knocking body 9 that engages with the rotating member 8 and protrudes rearward from the rear end hole 41 of the shaft cylinder 2, and is accommodated in the shaft cylinder 2 and the writing body 6 is moved rearward It consists of a projectile 10 (for example, a compression coil spring) that urges it. The intrusion mechanism of the first and second embodiments is a double knock type in which both the pen tip protruding operation and the pen tip retracting operation push the knock body 9 forward.

In the first and second embodiments, as shown in FIG. 4A, the front end of the knock body 9 is provided with cam teeth 71 that engage with the rear end of the protrusion 81 of the rotating member 8. . The outer surface of the front end portion of the knock body 9 is provided with a guide protrusion 91 that can slide in the cam groove 72 of the cam portion 7 in the front-rear direction, whereby the rotation of the knock body 9 relative to the cam portion 7 is prevented. As shown in FIG. 4B, the outer surface of the rotating member 8 includes four protrusions 81 extending in the longitudinal direction. The protrusion 81 is engaged with the cam teeth 71 and the cam groove 72 of the cam portion 7. As shown in FIG. 4C, the cam portion 7 includes a plurality of serrated cam teeth 71 projecting forward and cam grooves 72 formed between the cam teeth 71.

In the first and second embodiments, when the knocking body 9 is pushed forward against the rearward biasing by the projectile body 10 from the penpoint immersion state, the front end of the knocking body 9 is The rotating member 8 is pressed forward, and the protrusion 81 of the rotating member 8 moves forward along the cam groove 72. As the rotating member 8 moves forward, the rotating member 8 presses the rear end of the writing body 6 forward, and the pen tip 61 projects from the front end hole 31 to the outside. At this time, the rotating member 8 rotates by a certain angle with respect to the cam portion 7 by the contact between the cam teeth 92 of the knock body 9 and the protrusion 81 of the rotating member 8. Thereby, the protrusion 81 of the rotating member 8 is engaged with the cam teeth 71 of the cam portion 7, and the pen tip protruding state is maintained.

In the first and second embodiments, when the knock body 9 is pushed forward against the rear urging force of the elastic body 10 from the pen tip protruding state, the front end of the knock body 9 moves the rotating member 8 forward. The rotating member 8 is rotated by a certain angle with respect to the cam portion 7 by the contact between the cam teeth 92 of the knock body 9 and the protrusion 81 of the rotating member 8. Accordingly, the engagement state between the protrusion 81 and the cam teeth 71 of the cam portion 7 is released, and the protrusion 81 is rearward along the cam groove 72 of the cam portion 7 by the rear biasing by the elastic body 10. Move to. As the rotary member 8 moves rearward, the writing body 6 moves rearward and enters the pen tip immersion state. The protrusion 81 is locked to the stepped portion 73 behind the cam portion 7 so that the pen tip immersion state is maintained.

DESCRIPTION OF SYMBOLS 1 Thermochromic writing instrument 2 Shaft 3 Front shaft 31 Front end hole 4 Rear shaft 41 Rear end hole 42 Clip 43 Convex part 5 Friction body 51 Inner hole 6 Writing body 61 Pen tip 62 Ink storage pipe 7 Cam part 71 Cam tooth 72 Cam Groove 73 Step 8 Rotating member 81 Projection 9 Knock body 91 Guide projection 92 Cam tooth 10 Ejection body a Tangent b Tangent

Claims (2)

A cursive body is accommodated in the shaft cylinder so as to be movable in the front-rear direction, a thermochromic ink is accommodated in the cursive body, and a pen tip capable of discharging the thermochromic ink is provided at the front end of the cursive body A knocking body is provided at the rear end of the shaft tube, and the knocking body is pushed forward from the pen tip immersing state to be in a pen tip protruding state, and the knocking body is pushed forward again from the pen tip protruding state. It is equipped with a retracting mechanism that makes the pen tip immersive by operating, and has a low wear property that can rub the handwriting of the thermochromic ink on the outer surface of the shaft tube and thermally discolor the handwriting with frictional heat generated at that time. A thermochromic writing instrument provided with a friction body made of an elastic material,
In the pen tip protruding state, the knock body rear end protrudes rearward from the friction body rear end,
The friction body is provided in the vicinity of the knock body at the rear end of the shaft cylinder, and in the pen tip immersion state, the rear end of the knock body is projected rearward from the rear end of the friction body and larger than the pen tip protruding state ,
On the outer surface of the rear shaft, a clip projecting radially outward is integrally extended,
The friction body is provided in an annular shape on the outer peripheral edge of the rear end of the shaft cylinder behind the base of the clip,
The thermochromic writing instrument characterized in that, in the pen tip protruding state, an angle formed by a tangent line contacting the friction body and the knock body and an axis is set to 45 degrees or more . Provided on the outer surface of the shaft cylinder in front of the friction body is an annular convex portion projecting radially outward from the friction body, and the clip extends forward from the convex portion. The thermochromic writing instrument according to claim 1 , wherein the friction body is located radially inward from a tangent line that contacts the knock body and the convex portion .

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