Friction implements and thermochromic writing implements

Abstract

To prevent loosening of threaded engagement between a friction body and a body, and prevent the friction body from shaking and falling off from the body.SOLUTION: A friction tool 1 is provided with a main body 2 and a friction body 3 detachably attached to the upper portion of the main body 2.The main body 2 is provided with a base portion 21, a contact portion 22 provided on an upper portion of the base portion 21, a mounting portion 23 projecting axially upward from the contact portion, and a male thread portion 24 formed on the outer surface of the mounting portion 23. The friction body 1 is provided with a cylindrical holding portion 5, a female screw portion 51 formed on the inner surface of the holding portion 5, a friction portion fixed to the outside of the holding portion 5, and a pressure contact portion provided below the friction portion and located below a lower end of the holding portion. a pressure contact portion located below the portion. In a state in which the friction body is attached to the attachment portion, the male thread portion and the female thread portion are screwed together, and the contact portion and the pressure contact portion are pressed together.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a friction tool and a thermochromic writing instrument, and more particularly to a friction tool and a thermochromic writing instrument that can thermally change the color of a thermochromic image or handwriting formed on a surface using thermochromic ink by rubbing the thermochromic image or handwriting with the frictional heat generated during the rubbing. [Background technology]

[0002] Patent document 1 describes a configuration in which an erasing portion is integrally formed on the outer periphery of a cylindrical fitting portion by two-color molding, an eraser is provided with an internal thread formed on the inner wall of the fitting portion, an external thread is formed on the outer wall of the protruding portion at the rear end of the writing instrument, and the eraser is attached to the writing instrument via the internal thread of the fitting portion and the external thread of the protruding portion. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-203590 Summary of the Invention [Problem to be solved by the invention]

[0004] With the conventional erasers, the engagement between the internal thread of the eraser and the external thread of the protrusion may loosen during use, causing the eraser to wobble or fall off the writing implement.

[0005] The present invention aims to solve the above-mentioned conventional problems by providing a friction tool and a thermochromic writing implement that can prevent the screw connection between the friction body and the main body from loosening, and can prevent the friction body from wobbling or falling off the main body. In this invention, "upper" refers to the friction part side (upper side in the drawing), and "lower" refers to the opposite side. [Means for solving the problem]

[0006] The first invention of the present application is a friction tool that can thermally discolor a thermochromic image or handwriting formed on a surface to be written on using thermochromic ink by rubbing the thermochromic image or handwriting with the frictional heat generated during the friction, and that comprises a main body and a friction body that can be detachably attached to the upper part of the main body, and the main body comprises a base, a contact part provided on the upper part of the base, a mounting part that protrudes axially upward from the contact part, and a male thread part formed on the outer surface of the mounting part, and the friction body comprises a tubular holding part, a female thread part formed on the inner surface of the holding part, a friction part fixed to the outside of the holding part, and a pressure-contact part that is provided below the friction part and positioned below the lower end of the holding part, and when the friction body is attached to the mounting part, the male thread part and the female thread part are screwed together, and the contact part and the pressure-contact part are pressure-contacted.

[0007] The friction device of the first invention, with the above-described configuration, can prevent the threaded engagement between the friction body and the main body from loosening, and can prevent the friction body from wobbling or falling off the main body.

[0008] It is also preferable that the friction portion be fixed to the holding portion by two-color molding.

[0009] This allows the friction portion and the holding portion to be firmly fixed together, preventing the friction portion from coming off the holding portion even when strong friction occurs.

[0010] The thermochromic writing implement may also include a barrel that contains thermochromic ink and has a pen tip that can eject the thermochromic ink, and the barrel may be the main body of the friction implement.

[0011] This prevents the threaded engagement between the friction body and the barrel from loosening, and prevents the friction body from wobbling or falling off the barrel.

[0012] The thermochromic writing instrument may also include a barrel having a thermochromic ink built in and a nib capable of ejecting the thermochromic ink, and a cap removably attached to the nib side of the barrel, wherein the cap is the main body of the friction device.

[0013] This prevents the screw connection between the friction body and the cap from loosening, and prevents the friction body from wobbling or falling off the cap. [Effects of the Invention]

[0014] The friction tool of the present invention prevents the threaded engagement between the friction body and the main body from loosening, and can prevent the friction body from wobbling or falling off the main body. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 2 is a longitudinal cross-sectional view of the main part of the main body of the first and second embodiments of the present invention. [Figure 2] 1 is a longitudinal sectional view of a friction body according to a first embodiment of the present invention. [Figure 3] 1 is a perspective view of a friction body according to a first embodiment of the present invention. [Figure 4] 1 is a longitudinal sectional view of a main part showing a state in which a friction body according to a first embodiment of the present invention is attached to a main body. [Figure 5] FIG. 4 is a longitudinal sectional view of a friction body according to a second embodiment of the present invention. [Figure 6] FIG. 10 is a perspective view of a friction body according to a second embodiment of the present invention. [Figure 7] FIG. 10 is a longitudinal sectional view of a main part showing a state in which a friction body according to a second embodiment of the present invention is attached to a main body. DETAILED DESCRIPTION OF THE INVENTION

[0016] Two embodiments of the present invention will be described below with reference to the drawings. In the friction tool 1 and thermochromic writing tool 11 of the embodiments of the present invention, "upper" refers to the friction body side (upper side in the drawings), and "lower" refers to the opposite side.

[0017] First Embodiment 1 to 4 show a first embodiment of the present invention. Fig. 1 is a longitudinal cross-sectional view of a main body 2 of the first embodiment of the present invention, focusing on the vicinity of an attachment portion 23. The main body 2 of Fig. 1 is also used in a friction device of a second embodiment, which will be described later.

[0018] 2 and 3 are a longitudinal sectional view and a perspective view of the friction body 3 according to the first embodiment of the present invention. Fig. 4 is a longitudinal sectional view of the essential parts showing the state in which the friction body 3 shown in Figs. 2 and 3 is attached to the main body 2 shown in Fig. 1.

[0019] The friction implement 1 and thermochromic writing implement 11 of this embodiment are configured to include a main body 2 and a friction body 3 that is detachably attached to the top of the main body 2. The friction body 3 is used to rub a thermochromic image or handwriting formed on a surface to be written on using thermochromic ink, and the frictional heat generated at this time can thermocolorize the thermochromic image or handwriting.

[0020] Main unit The main body 2 is a cylindrical body (e.g., a cylinder) or a columnar body (e.g., a cylindrical body). Examples of materials that can be used to form the main body 2 include synthetic resins (e.g., synthetic resins such as polycarbonate (PC) resin, polypropylene (PP) resin, ABS resin, polybutylene terephthalate (PBT) resin, and nylon 6,6), metal, wood, paper, etc.

[0021] 1, in this embodiment, the main body 2 includes a cylindrical base portion 21. The upper portion of the base portion 21 includes a contact portion 22 with which the lower portion (pressure contact portion 42) of the friction body 3 contacts (presses) the contact portion 22. The main body 2 also includes a mounting portion 23 that protrudes axially upward from the contact portion 22, and a male thread portion 24 formed on the outer surface of the mounting portion 23.

[0022] Furthermore, an upward protrusion that protrudes upward may be provided on the surface of the abutting portion 22. This further prevents the screw engagement between the friction body and the main body from loosening, and prevents the friction body from wobbling or falling off the main body.

[0023] The upward protrusion is preferably a spherical protrusion. It may also be a rectangular prism, a ridge extending radially outward, or a resin residue (gate residue) formed at the gate. In particular, when the gate residue is an upward protrusion, it is possible to more effectively prevent loosening of the screw connection between the friction body 3 and the main body 2, and to stably attach the friction body. Furthermore, it is possible to position the gate residue in a location that is not visible to the user, thereby improving the aesthetics of the product.

[0024] At least one upward protrusion may be provided, but it is preferable to provide multiple upward protrusions. By providing multiple upward protrusions, the friction body 3 can be stably screwed onto the main body 2. In particular, it is more preferable to provide three upward protrusions, because all of the protrusions are reliably pressed against the pressure-contact portion 42, allowing the friction body to be stably attached.

[0025] Mounting part As shown in Fig. 1, in this embodiment, the attachment portion 23 is a cylindrical body that protrudes axially upward from the abutting portion 22. That is, an air vent 25 is provided inside the attachment portion 23. This makes it possible to prevent air compression when attaching the friction body 3. Note that the attachment portion 23 may also be a cylindrical body that does not have the air vent 25.

[0026] In this embodiment, the attachment portion 23 is formed integrally with the base portion 21. This allows the friction body 3 to be firmly attached to the main body 2, and allows stable friction of thermochromic images or handwriting. The base portion 21 and the attachment portion 23 may be configured as separate bodies (combination of separate parts). Furthermore, a male thread portion 24 is formed integrally with the attachment portion 23 on the outer surface thereof.

[0027] ·Friction body 2, the friction body 3 in this embodiment includes a cylindrical holding portion 5, a female thread portion 51 formed on the inner surface of the holding portion 5, a friction portion 4 fixed to the outside of the holding portion 5, and a pressure-contact portion 42 provided below the friction portion 4 and positioned below the lower end of the holding portion 5. Furthermore, an upper end hole 41 is formed in the upper end of the friction portion 4 so as to penetrate in the axial direction.

[0028] ·Holding part 2 to 4, in this embodiment, the holding part 5 is a cylinder having an inner hole 52 passing through in the axial direction. A female thread 51 is formed on the inner surface of the inner hole 52 of the holding part 5. The female thread 51 can be threaded onto the male thread 24 of the attachment part 23.

[0029] In this embodiment, the inner diameter of the female thread portion 51 of the holding part 5 (i.e., the inner diameter of the top of the threads of the female thread portion 51) is larger than the inner diameter of the upper part of the inner hole 52 and the inner diameter of the upper end hole 41. In other words, a step portion 53 is formed between the inner hole 52 of the holding part 5 and the female thread portion 51.

[0030] As a result, as shown in FIG. 4, when the friction body 3 is attached to the attachment part 23, the attachment part 23 fits behind the step part 53, and the air flow passage from the upper end hole 41 to the air vent hole 25 has approximately the same diameter, allowing air to circulate smoothly, preventing air compression when attaching the friction body 3 and making it easy to attach the friction body 3.

[0031] As shown in FIG. 4, a step 53 is formed between the inner hole 52 of the holding portion 5 and the female thread portion 51. This further improves the aesthetic appearance of the product because the end face of the attachment portion 23 is not visible when the user looks downward (into the inside of the friction tool 1 or the thermochromic writing instrument 11) from above (outside) the upper end hole 41.

[0032] As shown in FIG. 4, a step 53 is formed between the inner hole 52 of the holding part 5 and the female thread part 51, and the friction part 4 is further provided up to the upper surface of the friction body 3 (above the step 53), and the surface area and volume of the friction body can be increased, making it easier to rub the thermochromic image or handwriting.

[0033] When the inner diameter of the female thread portion 51 of the retaining portion 5 and the inner diameter of the upper portion of the inner hole 52 are substantially the same diameter, the inner diameter of the inner hole 52 may be larger than the inner diameter of the upper end hole 41. In other words, a step portion 53 may be formed between the upper end hole 41 and the inner hole 52 (female thread portion 51) of the retaining portion 5. This provides the same effect as described above.

[0034] The holding portion 5 is made of a material harder than the friction portion 4. Examples of materials that can be used to make the holding portion 5 include synthetic resins (e.g., synthetic resins such as polycarbonate (PC) resin, polypropylene (PP) resin, ABS resin, polybutylene terephthalate (PBT) resin, and nylon 6,6), metal, paper, etc. The holding portion 5 and the friction portion 4 are preferably integrally formed by two-color molding.

[0035] ·Friction part 2 to 4, in this embodiment, the friction portion 4 is integrally fixed to the exterior (outer periphery) of the holding portion 5 by two-color molding. More specifically, the friction portion 4 is integrally fixed to the holding portion 5 by two-color molding so as to continuously cover the outer periphery, upper surface, and lower surface of the holding portion 5. In other words, the friction portion 4 is made of a cylindrical body. Also, as shown in FIG. 2 or 3, the lower end portion of the holding portion 5 is not exposed on the lower surface side of the friction body 3.

[0036] An upper end hole 41 is formed in the axial direction at the upper end of the friction portion 4. As shown in Fig. 2, the upper end hole 41 communicates with an inner hole 52 of the holding portion 5. Furthermore, as shown in Fig. 4, when the friction body 3 is attached to the attachment portion 23 of the main body 2, the upper end hole 41 and the inner hole 52 communicate with the air hole 25 of the main body 2.

[0037] This prevents air compression when attaching the friction body 3, allowing for smooth assembly. The upper end hole 41 and the inner hole 52 have approximately the same diameter and both have a circular cross section. If there is a gap or the like that prevents air compression when attaching the friction body 3, the upper end hole 41, the inner hole 52, or the vent hole 25 may not be provided.

[0038] Pressure welding part 2 or 3, the friction portion 4 includes a pressure-contact portion 42 that is provided below the friction portion 4 and is located below the lower end of the holding portion 5. In this embodiment, the pressure-contact portion 42 continuously covers the lower surface of the holding portion 5. When the friction body 3 is attached to the attachment portion 23 of the main body 2, the abutment portion 22 and the pressure-contact portion 42 are in pressure contact with each other.

[0039] This causes a frictional force to act between the contact part 22 and the pressure contact part 42, preventing the screw connection between the friction body 3 and the main body 2 from loosening, and preventing the friction body 3 from wobbling or falling off from the main body 2.

[0040] The friction portion 4 (pressure-contact portion 42) is formed from a material having rubber elasticity, for example, a material containing an elastic synthetic resin (elastomer) such as silicone resin, SBS (styrene-butadiene-styrene copolymer) resin, SEBS (styrene-ethylene-butylene-styrene copolymer) resin, fluorine-based resin, chloroprene resin, nitrile resin, polyester-based resin, and ethylene propylene diene rubber (EPDM). The material of the friction portion 4 may contain multiple elastomers.

[0041] The material of the friction portion 4 may also be a mixture of an elastomer and a synthetic resin with relatively low elasticity.The material of the friction portion 4 is preferably a low-wear elastic material that generates less wear debris (eraser dust) due to wear, compared to a highly wear-resistant elastic material such as an eraser.In this embodiment, the friction portion 4 is a thermoplastic elastomer (e.g., polyester-based elastomer, styrene-based elastomer) and is obtained by injection molding (two-color molding).

[0042] A convex curved surface is formed around the upper edge of the friction portion 4. The friction portion 4 is used to rub a thermochromic image or handwriting formed on a surface to be written on using thermochromic ink, and the frictional heat generated during this process can thermocolorize the thermochromic image or handwriting.

[0043] Installation status Fig. 4 shows the friction body 3 attached to the attachment portion 23 of the main body 2. As shown in Fig. 4, the female thread portion 51 of the holding portion 5 of the friction body 3 and the male thread portion 24 of the attachment portion 23 are screwed together. When the screwing is complete, the pressure-contact portion 42 of the friction body 3 and the abutment portion 22 of the main body 2 are in a pressure-contact state.

[0044] When the main body 2 is a hollow cylindrical body, it can constitute a barrel used for the thermochromic writing instrument 11 or a cap used for the thermochromic writing instrument 11. The barrel used for the thermochromic writing instrument 11 is a barrel in the thermochromic writing instrument 11 that contains thermochromic ink inside and is equipped with a pen tip that can eject the thermochromic ink.

[0045] The cap used for the thermochromic writing instrument 11 is a cap that is attached to the nib side of the barrel of the thermochromic writing instrument 11, which contains thermochromic ink inside and has a nib that can eject the thermochromic ink.

[0046] In the present invention, the thermochromic ink is preferably a reversible thermochromic ink. Reversible thermochromic inks can be of various types, either alone or in combination, such as a thermal decolorization type that is decolorized from a colored state by heating, a color memory retention type that alternately retains the colored state or the decolorized state within a specific temperature range, or a thermal color development type that develops color from a decolorized state by heating and returns to the decolorized state by cooling from the colored state.

[0047] The friction tool 1 is capable of rubbing a thermochromic image or handwriting formed on a surface to be written on with thermochromic ink, and causing the thermochromic image or handwriting to change color with the frictional heat generated during the rubbing. The friction tool 1 comprises a main body 2 and a friction body 3 detachably attached to the upper part of the main body 2. The main body 2 comprises a base 21, a contact portion 22 provided on the upper part of the base 21, an attachment portion 23 protruding axially upward from the contact portion 22, and a male thread portion 24 formed on the outer surface of the attachment portion 23. The friction body 3 comprises a cylindrical holding portion 5, a female thread portion 51 formed on the inner surface of the holding portion 5, a friction portion 4 fixed to the outside of the holding portion 5, and a pressure-contact portion 42 provided below the friction portion 4 and positioned below the lower end of the holding portion 5. When the friction body 3 is attached to the attachment portion 23, the male thread portion 24 and the female thread portion 51 are screwed together, and the contact portion 22 and the pressure-contact portion 42 are pressure-contacted.

[0048] This causes a frictional force to act between the pressure contact portion 42 and the contact portion 22, preventing the screw connection between the friction body 3 and the main body 2 from loosening, and preventing the friction body 3 from wobbling or falling off the main body 2.

[0049] The friction part 4 is preferably fixed to the holding part 5 by two-color molding. This firmly fixes the friction part 4 and the holding part 5 together, preventing the friction part 4 from coming off the holding part 5 even during heavy use.

[0050] Alternatively, the thermochromic writing instrument 11 may include a barrel that contains thermochromic ink and has a pen tip that can eject the thermochromic ink, and the barrel may be the main body 2 of the friction instrument 1. This prevents the screw engagement between the friction body 3 and the barrel from loosening, and prevents the friction body 3 from wobbling or falling off the barrel.

[0051] The thermochromic writing implement may also include a barrel that contains thermochromic ink and has a pen tip that can eject the thermochromic ink, and a cap that is detachably attached to the pen tip side of the barrel, wherein the cap is the main body 2 of the friction implement 1. This prevents loosening of the screw connection between the friction body 3 and the cap, and prevents the friction body 3 from wobbling or falling off the cap.

[0052] Second Embodiment A second embodiment of the present invention is shown in Figures 5 to 7. Figures 5 and 6 are a longitudinal sectional view and a perspective view of a friction body 3 according to the second embodiment of the present invention. Figure 7 is a longitudinal sectional view of a main part showing a state in which the friction body 3 shown in Figures 5 and 6 is attached to the main body 2 shown in Figure 1.

[0053] The second embodiment of the present invention differs from the first embodiment in the configuration of the friction portion 4 and the holding portion 5 of the friction body 3. Specifically, the pressure contact portion 42 of the second embodiment is at least one protrusion that can be brought into pressure contact with the abutment portion 22. The other configurations of the second embodiment are substantially the same as those of the first embodiment, and therefore detailed description thereof will be omitted.

[0054] ·Friction part 5 to 7, in this embodiment, the friction portion 4 is integrally fixed to the holding portion 5 by two-color molding so as to cover not only the outer peripheral surface and the upper surface of the holding portion 5 but also a part of the lower surface. That is, the friction portion 4 is made of a cylindrical body. Also, as shown in FIG. 5 or 6, the lower end portion of the holding portion 5 is exposed on the lower surface side of the friction body 3. In other words, the lower end portion of the holding portion 5 is formed on the same plane as a part of the lower surface of the friction body 3.

[0055] Pressure welding part 5 or 6, the friction portion 4 includes a pressure contact portion 42 that is provided at the bottom of the friction portion 4 and is located below the lower end of the holding portion 5. In this embodiment, the pressure contact portion 42 is three protrusions that can be brought into pressure contact with the abutment portion 22.

[0056] When the friction body 3 is attached to the attachment portion 23 of the main body 2, the abutting portion 22 and the pressure contact portion 42 (protrusion) are pressed together. This causes a frictional force to act between the abutting portion 22 and the pressure contact portion 42 (protrusion), preventing the screw connection between the friction body 3 and the main body 2 from loosening, and preventing the friction body 3 from wobbling or falling off the main body 2.

[0057] At least one pressure-contact portion 42 (protrusion) may be provided, but it is preferable to provide a plurality of protrusions. Providing a plurality of protrusions allows the friction body 3 to be stably screwed onto the main body 2. In particular, as shown in Fig. 6, it is more preferable to provide three protrusions, since all of the protrusions are reliably pressure-contacted with the abutment portion 22, allowing the friction body to be stably attached.

[0058] 6, the pressure-contact portion 42 (protrusion) may be in the shape of a square pillar, a ridge extending radially outward, a resin residue portion (gate residue) formed in the gate portion, etc. In particular, when the pressure-contact portion 42 is in the form of a gate residue, loosening of the screw connection between the friction body 3 and the main body 2 can be further prevented, and the friction body can be stably attached. In addition, the gate residue can be located in a place that is not visible to the user, improving the aesthetic appearance of the product.

[0059] Furthermore, when the friction body 3 is attached to the attachment portion 23 of the main body 2, the pressure-contact portion 42 (protrusion) is pressed against the abutment portion 22, and the lower end of the holding portion 5 also abuts against the abutment portion 22. This allows the lower end of the holding portion 5 to function as a stopper during screwing, improving the rigidity of the friction body when attached. Furthermore, the friction body 3 can be screwed more firmly to the main body 2, and loosening of the screwing between the friction body 3 and the main body 2 is prevented, preventing the friction body 3 from wobbling or falling off the main body 2. [Explanation of symbols]

[0060] 1 Friction tool 11 Thermochromic writing implements 2 Main body (barrel, cap) 21 Base 22 Contact part 23 Mounting part 24 Male thread 25 ventilation holes 3 Friction body 4 Friction part 41 Upper end hole 42 Pressure welding part 5 Holding part 51 Female thread 52 Inner hole 53 Step part

Claims

1. A friction tool that can cause a thermochromic image or handwriting formed on a surface to be written on using a thermochromic ink to be rubbed and can cause the thermochromic image or handwriting to be thermally discolored by the frictional heat generated at the time, A main body and a friction body detachably attached to an upper part of the main body, the main body includes a base portion, an abutment portion provided on an upper portion of the base portion, an attachment portion protruding axially upward from the abutment portion, and a male thread portion formed on an outer surface of the attachment portion, The friction body is A cylindrical holding portion; A female screw portion formed on the inner surface of the holding portion; a friction portion integrally fixed to the holding portion by two-color molding so as to continuously cover the outer peripheral surface, the upper surface, and the lower surface of the holding portion; a pressure contact portion provided below the friction portion and positioned below a lower end of the holding portion, When the friction body is attached to the attachment portion, the male threaded portion and the female threaded portion are threadedly engaged with each other, and the abutment portion and the pressure-contact portion are pressure-contacted with each other.

2. The holding portion has an inner hole passing through in the axial direction, An upper end hole is formed in the axial direction at the upper end of the friction portion, The inner diameter of the female threaded portion is larger than the inner diameter of the upper portion of the inner hole and the inner diameter of the upper end hole, 2. The friction device according to claim 1, wherein a step is formed between the upper portion of the inner hole of the holding portion and the female thread portion.

3. A thermochromic writing instrument comprising a barrel having thermochromic ink built therein and a pen tip capable of ejecting the thermochromic ink, characterized in that the barrel is the main body of the friction tool described in claim 1 or 2.

4. A thermochromic writing instrument comprising a barrel having a thermochromic ink built therein and a nib capable of ejecting the thermochromic ink, and a cap removably attached to the nib side of the barrel, wherein the cap is the main body of the friction tool described in claim 1 or 2.

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