Mounting structure in a writing instrument, writing instrument and soft component

Abstract

The mounting structure is a mounting structure for a writing instrument, which includes: a first component; and a second component inserted into an insertion hole located at the end of the first component. The second component includes: a small-diameter portion; a large-diameter portion located in front of the small-diameter portion; and a first outer step portion located between the small-diameter portion and the large-diameter portion. The insertion hole includes a small-diameter hole and an inner step portion located in front of the small-diameter hole. The small-diameter portion is inserted into or loosely inserted into the small-diameter hole. The first outer step portion abuts against the inner step portion. The small-diameter hole has a barb portion protruding from the inner surface of the small-diameter hole. The barb portion can be deformed by contacting the small-diameter portion when the second component is inserted.

Description

Technical Field

[0001] This invention relates to mounting structures for writing instruments, writing instruments, and soft components. Background Technology

[0002] Patent document 1 discloses a pen refill retaining structure, which is a pen refill retaining structure that inserts and fixes the pen refill from the opening at the front end of the cylinder. In this structure, a pen refill retaining hole with a circular cross-section at the front end of the cylinder is provided with a mountain-shaped protrusion along the length direction at constant intervals, and the height of the protrusion increases towards the rear.

[0003] According to this pen refill locking structure, for pen refills with a circular or elliptical cross-section, the top of the protrusion behind the pen refill bites into the pen refill and locks it in place. For pen refills with a rectangular cross-section such as a square or rectangle, the adjacent inclined surfaces of the adjacent protrusions clamp the pen refill near each edge and lock it in place. Therefore, it is possible to lock the pen refill without performing machining such as stepping or grooving.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Utility Model Application Publication No. 1-161078 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] In the configuration disclosed in Patent Document 1, when the pen refill (second component) is inserted from the front end of the shaft (first component), the top of the protrusion behind it presses the pen refill into the shaft in a biting state. Therefore, inserting the pen refill requires a large force, which may make it difficult to easily insert the pen refill into the front end of the shaft.

[0009] Furthermore, in the configuration disclosed in Patent Document 1, since the top of the protrusion behind it is pressed into the outer surface of the pen refill in a biting state, an axially extending scratch is formed on the outer surface of the pen refill. Therefore, when an axially forward force is applied to the pen refill (i.e., a force in the direction of pen tip detachment), the desired locking performance cannot be obtained, and the pen tip may easily detach.

[0010] The present invention was made in view of the above insights, and its object is to provide an installation structure in a writing instrument that facilitates the insertion of components and, on the other hand, prevents the components from falling off after insertion.

[0011] Methods for solving problems

[0012] The mounting structure of the present invention is a mounting structure for a writing instrument, which includes: a first component; and a second component inserted into an insertion hole provided at the end of the first component. The second component includes: a small-diameter portion; a large-diameter portion disposed in front of the small-diameter portion; and a first outer step portion disposed between the small-diameter portion and the large-diameter portion. The insertion hole includes: a small-diameter hole portion; and an inner step portion disposed in front of the small-diameter hole portion. The small-diameter portion is inserted into or loosely inserted into the small-diameter hole portion. The first outer step portion abuts against the inner step portion. The small-diameter hole portion has a barb portion protruding from the inner surface of the small-diameter hole portion. The barb portion can be deformed by contacting the small-diameter portion when the second component is inserted.

[0013] According to the present invention, the barb can deform by contacting the small-diameter portion of the second component during insertion, thus not creating significant resistance during insertion and allowing for smooth insertion. Furthermore, after insertion, when an axially forward force (i.e., a force in the direction of the second component's detachment) is applied to the second component, the barb returns to its pre-insertion (pre-deformation) state, thus biting into the outer surface of the small-diameter portion of the second component and reliably securing it. In other words, insertion of the second component is easy, and it does not detach after insertion.

[0014] Furthermore, according to the present invention, since the inner stepped portion functions as a stop for positioning during the insertion of the second component, the second component can be easily inserted into the desired position. Additionally, even if the user applies excessive force to the second component, the second component will not be buried under the first component.

[0015] Preferably, the barb portion is located at the rear end of the inner surface of the small-diameter hole. Thus, the small-diameter hole functions as a guide for through-insertion of the small-diameter portion, making it easier to insert the small-diameter portion and thus easier to insert the second component.

[0016] Preferably, the insertion hole also includes a large-diameter hole located in front of the inner stepped portion, the large-diameter portion being inserted into or loosely fitted into the large-diameter hole. This allows for clamping the front of the second component, thus ensuring the stability of the second component.

[0017] Preferably, multiple barbs are arranged in a circumferential, equally spaced pattern on the small-diameter hole. This allows the barbs to bite into the outer surface of the second component in a circumferential, equally spaced pattern, thus more reliably securing the second component.

[0018] Preferably, the cross-section of the front end of the barb portion is R-shaped. This allows the barb portion to be easily formed.

[0019] Preferably, the second component has a locking groove behind the first outer step portion, and a second outer step portion at the rear end of the locking groove. The barb portion is locked into the second outer step portion, and the second component is axially locked to prevent detachment. Therefore, when an axially forward force (i.e., a force in the direction of the second component falling off) is applied to the second component after its insertion, the force to return it to its pre-tipping state acts on the barb portion. At this time, the barb portion hooks onto the second outer step portion provided on the outer surface of the small-diameter portion, thus more reliably preventing the second component from falling off after its insertion.

[0020] Preferably, the first component is the writing instrument body, the second component is the pen tip, and the insertion hole is located at the front of the writing instrument body. This ensures a smooth connection between the pen tip and the ink reservoir, allowing ink to be supplied smoothly from the ink reservoir to the pen tip. Furthermore, even if the user applies excessive pressure to the pen tip during use, the pen tip will not be submerged in the writing instrument.

[0021] Preferably, the first component is the shaft or cap of the writing instrument, and the second component is a flexible component. The insertion hole is located at the tail end of the shaft or the closed end of the cap. Therefore, even if the user applies excessive force to the flexible component during use, the flexible component will not be buried in the writing instrument.

[0022] Invention Effects

[0023] According to the present invention, the component is easy to insert, and on the other hand, the component will not fall off after insertion. Attached Figure Description

[0024] Figure 1 This is a schematic longitudinal sectional view of the writing instrument according to the first embodiment of the present invention.

[0025] Figure 2 This is an enlarged longitudinal sectional view showing the main part of the pen tip insertion process of the present invention, and a diagram showing the state before pen tip insertion.

[0026] Figure 3 This is an enlarged longitudinal sectional view showing the main part of the pen tip insertion process of the present invention, and a diagram showing the state of pen tip insertion.

[0027] Figure 4 This is an enlarged longitudinal sectional view showing the main part of the pen tip insertion process of the present invention, and a diagram showing the state after the pen tip is inserted.

[0028] Figure 5 This is a cross-sectional perspective view of the shaft cylinder according to the first embodiment of the present invention, showing the state before the pen tip is inserted.

[0029] Figure 6 yes Figure 2The AA-line sectional view of the shaft cylinder is a diagram showing the cross-sectional shape of the barb portion of the shaft cylinder according to the first embodiment of the present invention.

[0030] Figure 7 yes Figure 2 The AA-line sectional view of the shaft cylinder is a diagram showing the cross-sectional shape of the barb portion of the shaft cylinder according to the second embodiment of the present invention.

[0031] Figure 8 This is an enlarged longitudinal sectional view showing the main part of the pen tip after insertion according to the third embodiment of the present invention.

[0032] Figure 9 This is an enlarged longitudinal sectional view showing the main part of the pen tip after insertion according to the fourth embodiment of the present invention.

[0033] Figure 10 This is a schematic longitudinal sectional view of the writing instrument according to the fifth embodiment of the present invention.

[0034] Figure 11 This is an enlarged longitudinal sectional view showing the main part of the insertion process of the flexible component of the present invention, and a diagram showing the state of the flexible component before insertion.

[0035] Figure 12 This is an enlarged longitudinal sectional view showing the main part of the insertion process of the flexible component of the present invention, and a diagram showing the state of the flexible component during insertion.

[0036] Figure 13 This is an enlarged longitudinal sectional view showing the main part of the insertion process of the flexible component of the present invention, and a diagram showing the state of the flexible component after insertion.

[0037] Figure 14 This is a cross-sectional perspective view of the shaft sleeve according to the fifth embodiment of the present invention, showing the state of the soft component before insertion.

[0038] Figure 15 yes Figure 11 The BB-line sectional view of the shaft cylinder is a diagram showing the cross-sectional shape of the barb portion of the shaft cylinder according to the fifth embodiment of the present invention.

[0039] Figure 16 yes Figure 11 The BB-line sectional view of the shaft cylinder is a diagram showing the cross-sectional shape of the barb portion of the shaft cylinder according to the sixth embodiment of the present invention.

[0040] Figure 17 This is an enlarged longitudinal sectional view of the main part showing the state of the soft component after insertion according to the seventh embodiment of the present invention.

[0041] Figure 18This is an enlarged longitudinal sectional view of the main part showing the state of the soft component after insertion according to the eighth embodiment of the present invention.

[0042] Figure 19 This is a schematic longitudinal sectional view of a part of the writing instrument according to the ninth embodiment of the present invention.

[0043] Figure 20 This is a schematic longitudinal sectional view of a part of the writing instrument according to the tenth embodiment of the present invention.

[0044] Figure 21 This is a schematic longitudinal sectional view of a part of the writing instrument according to the eleventh embodiment of the present invention. Detailed Implementation

[0045] Hereinafter, the first to fourth embodiments of the present invention will be described with reference to the accompanying drawings. It should be noted that in the pen tip mounting structure of the first to fourth embodiments, "front" refers to the side of the pen tip 12 in the writing instrument, and "rear" refers to the opposite side. In the pen tip, "front" refers to the side of the writing section 121, and "rear" refers to the opposite side.

[0046] Figure 1 This is a schematic longitudinal sectional view of the writing instrument 10 of the present invention, showing the state in which the cap 14 is installed. Figures 2 to 4 This is an enlarged longitudinal sectional view showing the main parts of the pen tip insertion process of the present invention, and is shown sequentially from before pen tip insertion to after pen tip insertion.

[0047] Figure 5 This is a cross-sectional perspective view of the shaft cylinder 11 according to the first embodiment of the present invention, showing the state before the pen tip is inserted. Figure 6 and Figure 7 yes Figure 2 The AA-line sectional view of the shaft cylinder 11 is a diagram showing the cross-sectional shape of the barb portion 115 of the shaft cylinder 11 according to the first and second embodiments of the present invention.

[0048] Figure 8 This is an enlarged longitudinal sectional view of the main part showing the state of the pen tip after insertion according to the third embodiment of the present invention. The shape of the outer surface of the pen tip 12 is different from that of other embodiments. Figure 9 This is an enlarged longitudinal sectional view showing the main part of the pen tip after insertion according to the fourth embodiment of the present invention. The shape of the outer surface of the pen tip 12 and the front of the shaft cylinder 11 is different from that of the other embodiments.

[0049] <First Implementation Method>

[0050] The present invention is a pen tip mounting structure in which a pen tip 12 (second component) is inserted into a pen tip insertion hole 111 (insertion hole) located at the front of the main body (first component) of the writing instrument 10. Figure 1 The writing instrument 10 of this embodiment mainly consists of a cap 14, a pen tip 12, an ink reservoir 13, and a shaft 11. The pen tip 12 is inserted into the front end of the shaft 11, and the ink reservoir 13 is housed inside. The cap 14 may have an airtight component 15 inside to prevent ink evaporation from the pen tip 12. The pen tip 12 is inserted into the pen tip insertion hole 111 of the shaft 11 (front shaft 11a). In addition, in order to replace the ink reservoir 13 or replenish ink to the ink reservoir 13 while the front shaft 11a is removed from the rear shaft 11b, the front shaft 11a and the rear shaft 11b can be detachably engaged.

[0051] The writing instrument 10, in the case of a thermochromic writing instrument containing thermochromic ink, may also include a soft part 16. The soft part 16 can rub the thermochromic ink marks, and use the frictional heat generated at this time to make the thermochromic ink marks change color.

[0052] <Shaft>

[0053] like Figure 1 As shown, the shaft cylinder 11 is a bottomed cylindrical body manufactured by injection molding or extrusion molding of synthetic resin, with one end open and the other end closed. Examples of synthetic resin materials include polypropylene, polyethylene, polystyrene, polycarbonate, polyethylene terephthalate, polyacetal, acrylic acid, nylon, acrylonitrile-styrene copolymer (AS resin), and acrylonitrile-butadiene-styrene copolymer (ABS resin). The shaft cylinder 11 consists of a front shaft 11a and a rear shaft 11b, which are axially locked together to prevent disengagement. The front shaft 11a consists of a pen tip insertion hole 111, a flange, and a fitting portion. The large-diameter portion 122 of the pen tip 12 is inserted into the pen tip insertion hole 111. The flange can axially abut against the open end of the rear shaft 11b. The fitting part can be axially locked to the fitting part on the inner surface of the opening of the rear axle 11b, and a first annular sealing part is formed on the outer surface of the fitting part to airtightly fit with the second annular sealing part on the inner circumferential surface of the fitting part of the rear axle 11b.

[0054] like Figure 2 As shown, the pen tip insertion hole 111 has the following on its inner surface: a large-diameter hole portion 112 on the open side, a small-diameter hole portion 113 disposed behind the large-diameter hole portion 112, and an inner stepped portion 114 that is perpendicular to the axis disposed between the large-diameter hole portion 112 and the small-diameter hole portion 113. The large-diameter portion 122 of the pen tip 12 is inserted or loosely inserted into the large-diameter hole portion 112. The small-diameter portion 123 of the pen tip 12 is inserted or loosely inserted into the small-diameter hole portion 113.

[0055] The small-diameter hole 113 has a barb portion 115 that protrudes radially inward from the inner surface of the small-diameter hole 113. For example... Figure 3As shown, the barb portion 115 can deform upon contact with the small-diameter portion 123 during pen tip insertion. That is, in this embodiment, the barb portion 115 tilts axially and rearward through the outer surface of the small-diameter portion 123 of the pen tip 12 as the pen tip 12 is inserted. This allows the small-diameter portion 123 to be easily inserted. In other words, it does not create significant resistance during pen tip 12 insertion, allowing for smooth insertion of the pen tip 12.

[0056] On the other hand, after the 12-point nib is inserted (see reference) Figure 4 When an axial forward force is applied to the pen tip 12 (i.e., the force in the direction in which the pen tip 12 falls off), the force required to return the pen tip 12 to its pre-tilting state acts on the barb portion 115. In other words, the barb portion 115 must be restored to its pre-penstling state (before the pen tip 12 is inserted: see [reference]). Figure 2 The barb 115 engages with the outer surface of the small diameter portion 123 of the nib 12, reliably securing the nib 12. This means that the nib 12 is easy to insert, and it will not fall off after insertion.

[0057] like Figure 2 As shown, in this embodiment, the barb portion 115 is provided at the rear end of the inner surface of the small-diameter hole portion 113. Thus, the small-diameter hole portion 113 functions as a guide for the small-diameter portion 123 to be inserted through it, making it easier for the small-diameter portion 123 to be inserted into the small-diameter hole portion 113, and making it easier to insert the pen tip 12.

[0058] like Figure 5 or Figure 6 As shown, in this embodiment, multiple barbs 115 are arranged circumferentially at equal intervals in the small-diameter hole 113, and the cross-section of the radially inner front end of each barb 115 is R-shaped. Of course, the barbs 115 may not be evenly spaced. Furthermore, at least one barb 115 needs to be formed and engaged with the outer surface of the small-diameter hole 123. In this embodiment, the barbs 115... Figure 2 In the state before pen tip insertion shown, the axial thickness t is 0.1 mm, the protrusion length L from the small diameter hole to the radially inward side is 0.5 mm, and the circumferential width W is 0.6 mm. Preferably, 0.01 mm < t < 1.0 mm, 0.1 mm < W < 3.0 mm, and 0.1 mm < L < 2.0 mm. By setting the size of the barb within these ranges, pen tip 12 can be inserted more easily, and on the other hand, pen tip 12 will not fall off after insertion.

[0059] A plurality of (specifically eight) airflow grooves 117 extending axially are provided at equal intervals on the inner surface of the large-diameter hole 112 and the inner surface of the small-diameter hole 113. Through these airflow grooves 117, an axial airflow path is formed between the outer surface of the pen tip 12 and the inner surface of the shaft cylinder 11. As a result, airflow is smooth, and ink is smoothly supplied from the ink reservoir 13 to the pen tip 12.

[0060] like Figure 4 As shown, when the pen tip 12 is inserted, the inner step portion 114 abuts against the first outer step portion 124 of the pen tip 12, which will be described later. Thus, the inner step portion 114 functions as a stop for positioning the pen tip 12 during insertion, allowing the pen tip 12 to be easily inserted into the desired position. Furthermore, the pen tip 12 and the ink reservoir 13 are connected without any misalignment, and ink is smoothly supplied from the ink reservoir 13 to the pen tip 12. Additionally, even if the user applies excessive pen pressure to the pen tip 12 during writing, the pen tip 12 will not be buried in the writing instrument.

[0061] In addition to the type in which the ink reservoir 13 for holding ink is housed within the cylinder 11, the writing instrument 10 of the present invention can also be of the type in which ink directly housed within the cylinder 11 is guided to the nib 12 via the ink reservoir 13. Furthermore, as needed, an ink retention component (e.g., a comb-shaped ink retention component) that temporarily retains remaining ink corresponding to changes in the internal pressure of the ink reservoir, and a guiding component that guides ink from the ink reservoir 13 to the nib 12 can also be provided. Furthermore, it can be either a cap-type or a nib-emerging (press-type) type.

[0062] <Pen Tip>

[0063] The pen tip 12 has a large-diameter portion 122 on its outer surface, a small-diameter portion 123 disposed behind the large-diameter portion 122, and a first outer stepped portion 124 disposed between the large-diameter portion 122 and the small-diameter portion 123. The large-diameter portion 122 is cylindrical and has a writing portion 121 at its front end. The small-diameter portion 123 is cylindrical and is connected to the ink reservoir 13. The first outer stepped portion 124 abuts against the inner stepped portion 114 of the pen tip insertion hole 111 when the pen tip 12 is inserted.

[0064] One end of the pen tip 12 protrudes forward from the front opening of the cylinder 11 as the writing section 121. The other end of the pen tip 12 (small diameter section 123) is pierced and connected to the front end of the ink reservoir 13. For example, as Figure 3As shown, the writing part 121 is machined into a chisel shape. Of course, the writing part 121 is not limited to a chisel shape, and can also be machined into other shapes corresponding to the purpose, such as a cannonball shape, a rectangular shape, a square prism shape, or a plate shape. It should be noted that the form of the writing instrument 10 of the present invention is not limited to the example shown in the figure, and can also be a double-ended writing instrument with pen tips 12 of different shapes installed at both ends of the ink reservoir 13.

[0065] The pen tip 12 is made of a resin-processed fiber (e.g., a resin-processed polyester fiber), with one end protruding outward as the writing part 121, and the other end connected to one end of the ink-absorbing body 13 in a piercing shape. Of course, the pen tip 12 only needs to be able to flow ink. Specifically, examples include: a fiber pen tip made of a fused-in-fiber material, a felt pen tip made of a felt body, a plastic pen tip in which multiple linear resins (monofilaments formed by extrusion molding of synthetic resin) are fused together to form an axial ink flow path inside, a pen tip (porous tip) made of a porous body of synthetic resin with continuous bubbles, and a brush pen tip, etc., which utilize capillary force. Alternatively, the pen tip 12 can be a tip formed by pressing and deforming a ball-holding part near the front end of a metal tube from the outer surface to the inner surface, or a tip formed by cutting a metal material using a drill bit or the like, or a tip with a resin ball receiving seat provided inside a metal or plastic tip. It should be noted that the ball can be made of materials such as superhard alloy, stainless steel, ruby, ceramic, resin, or rubber, with a diameter of 0.3 to 3.0 mm, preferably 0.3 to 1.5 mm, and more preferably 0.4 to 1.0 mm.

[0066] <Ink Absorber>

[0067] The ink absorber 13 can be impregnated with ink, and specifically, examples include: fiber bundle processed bodies (e.g., thermally welded fiber bundle processed bodies, resin processed fiber bundle processed bodies, resin processed felt bodies, needle-punched felt bodies) or porous bodies (e.g., continuous air bubbles of synthetic resin such as sponge). In addition, the outer peripheral surface of the ink absorber 13 can also be coated with a synthetic resin film.

[0068] like Figure 1 or Figure 2As shown, the front end face of the ink reservoir 13 abuts axially with the abutment wall 116 provided on the front shaft 11a. Furthermore, the rear end face of the ink reservoir 13 abuts axially with the second abutment wall (not shown) provided on the rear shaft 11b. Preferably, the long side dimension of the ink reservoir 13 is set to be greater than the long side dimension between the abutment wall 116 and the second abutment wall. Therefore, the ink reservoir 13 within the shaft cylinder 11 can achieve stable writing performance by being axially clamped by the abutment wall 116 and the second abutment wall.

[0069] <Soft components>

[0070] like Figure 1 As shown, in this embodiment, the soft component 16 is axially secured to the top of the cap 14. Of course, the mounting structure and position of the soft component 16 are not limited to this embodiment. For example, besides providing the soft component 16 made of elastic material on the outer surface of the rear end of the shaft cylinder 11 through pressing, engaging, screwing, fitting, bonding, or two-color molding, it is also possible to integrally form the shaft cylinder 11 or the cap 14 using elastic material.

[0071] Preferably, the elastic synthetic resin constituting the soft component 16 is not made of a highly abrasive elastic material (such as rubber), but is made of a low-abrasive elastic material that produces almost no abrasion residue (rubber residue) during friction.

[0072] The elastic material constituting the soft component 16 is preferably a synthetic resin (rubber, elastomer) with elasticity, such as silicone resin, SBS resin (styrene-butadiene-styrene copolymer), SEBS resin (styrene-ethylene-butene-styrene copolymer), fluorinated resin, chloroprene resin, nitrile resin, polyester resin, ethylene propylene diene rubber (EPDM), or a mixture of two or more rubber elastic materials, as well as a mixture of rubber elastic material and synthetic resin.

[0073] <Ink>

[0074] In this embodiment, the ink contained in the ink absorber 13 is a thermochromic ink. The thermochromic ink is preferably a reversible thermochromic ink. Reversible thermochromic inks can be configured individually or in combination with various types, including: a heat-curing type that decolorizes from a colored state by heating; a color storage and retention type that stores and retains the colored or decolorized state alternately within a specific temperature range; and a heat-curing type that develops color from a decolorized state by heating and reverts to a decolorized state by cooling, etc.

[0075] As a pigment contained in reversible thermochromic ink, for example, a reversible thermochromic pigment containing a reversible thermochromic composition encapsulated in microcapsules is preferably used, the reversible thermochromic composition containing at least three essential components: (a) an electron-donating color-developing organic compound, (b) an electron-accepting compound, and (c) a reaction medium that determines the temperature at which the reaction (color development reaction) of the chemical combination of the two occurs.

[0076] It should be noted that the ink used in this invention is not limited to thermochromic inks; other ink compositions besides thermochromic inks may also be used. For example, writing ink, correction fluid, liquid paste, cosmetic liquid, etc., may be appropriately selected depending on its intended use as a liquid ejector. Among writing inks, oil-based inks, water-based inks, etc., are not particularly limited.

[0077] <Second Implementation Method>

[0078] Figure 7 yes Figure 2 The AA-line sectional view of the shaft sleeve 11 is a diagram showing the shape of the barb portion 115 of the shaft sleeve 11 according to the second embodiment of the present invention. In the second embodiment of the present invention, the cross-sectional shape of the barb portion 115 is different from that of the first embodiment. Specifically, the cross-section of the radially inner front end portion is a sharp shape.

[0079] The other structures of the second embodiment are largely the same as those of the first embodiment, therefore detailed descriptions are omitted. For example... Figure 7 As shown, according to this embodiment, the barbs 115 bite into the outer surface of the pen tip 12 in a circumferential, equally spaced manner, which can more reliably lock the pen tip 12 in place. In addition, the cross-section of the radially inner front end of the barbs 115 is sharp, so the barbs 115 bite into the outer surface of the pen tip 12 more deeply, and the pen tip 12 is more firmly locked in the axial direction.

[0080] Of course, the cross-section of the front end of the barb 115 is not limited to a sharp shape or the aforementioned R shape; it can also be a rectangular shape, an inverted R shape with a concave radial inner front end, or other shapes corresponding to the pen tip. In addition, the barb 115 can also be a burr formed when resin enters the gap between the mating surfaces of the mold (pin) during the injection molding of the shaft 11.

[0081] <Third Implementation Method>

[0082] Figure 8 This is an enlarged longitudinal sectional view showing the main part of the pen tip 12 after insertion according to the third embodiment of the present invention. In the third embodiment of the present invention, the shape of the pen tip 12 rearward from the first outer step portion 124 differs from that in the first embodiment. Specifically, as Figure 8As shown, the pen tip 12 has a locking groove 125 behind the first outer step portion 124, and a second outer step portion 126 at the rear end of the locking groove 125. The barb portion 115 is locked into the second outer step portion 126, and the pen tip 12 is axially locked in place. The locking groove 125 is preferably formed in a circumferential shape in the small diameter portion 123.

[0083] The other structures of the third embodiment are largely the same as those of the first embodiment, so detailed descriptions are omitted. According to this embodiment, similarly to the first embodiment, when an axially forward force (i.e., a force in the direction of the pen tip 12 falling off) is applied to the pen tip 12 after it is inserted, a force to return it to its pre-tilting state acts on the barb portion 115. At this time, as... Figure 8 As shown, the barb 115 hooks onto the second outer step 126 provided on the outer surface of the small diameter portion 123, which can more reliably prevent the pen tip 12 from falling off after the pen tip 12 is inserted. In addition, the locking groove 125 is formed in a circumferential shape in the small diameter portion 123, so that when the pen tip 12 is inserted into the shaft cylinder 11, it is not necessary to position the rotation direction of the pen tip 12, and the pen tip 12 can be easily inserted.

[0084] <Fourth Implementation Method>

[0085] Figure 9 This is an enlarged longitudinal sectional view showing the main part of the pen tip 12 after insertion according to the fourth embodiment of the present invention. In the fourth embodiment of the present invention, the shape of the shaft cylinder 11, which is further forward than the small-diameter hole portion 113, differs from that in the third embodiment. Specifically, as... Figure 9 As shown, the large-diameter hole of the shaft cylinder 11 is omitted, and the inner stepped part 114 is provided at the front end of the shaft cylinder.

[0086] Furthermore, in the fourth embodiment of the present invention, the outer surface shape of the pen tip 12 differs from that in the third embodiment. Specifically, as shown in... Figure 9 As shown, the pen tip 12 has a locking groove 125 on the surface of its small diameter portion behind the outer stepped portion, and a second outer stepped portion 126 is provided at the rear end of the locking groove 125. The writing portion 121 is shaped like a cannonball. Furthermore, when the pen tip 12 abuts against the first outer stepped portion 124 and the inner stepped portion 114, an air passage hole 127 is formed between the first outer stepped portion 124 and the inner stepped portion. This allows for smooth airflow, ensuring a smooth supply of ink from the ink reservoir 13 to the pen tip 12.

[0087] The other structures of the fourth embodiment are largely the same as those of the third embodiment, so detailed descriptions are omitted. According to this embodiment, the pen tip 12 can be held closer to the front of the writing section 121, thus enabling stable writing.

[0088] The pen tip mounting structure constructed as described above functions as follows.

[0089] The pen tip mounting structure of the present invention is a pen tip mounting structure formed by inserting a pen tip 12 into a pen tip insertion hole 111 provided at the front of the main body of the writing instrument 10. The pen tip 12 has a small diameter portion 123, a large diameter portion 122 provided in front of the small diameter portion 123, and a first outer step portion 124 provided between the small diameter portion 123 and the large diameter portion 122. The pen tip insertion hole 111 has a small diameter hole portion 113 and an inner step portion 114 provided in front of the small diameter hole portion 113. The small diameter portion 123 is inserted or loosely inserted into the small diameter hole portion 113. The first outer step portion 124 abuts against the inner step portion 114. The small diameter hole portion 113 has a barb portion 115 protruding from the inner surface of the small diameter hole portion 113. The barb portion 115 can be deformed by contacting the small diameter portion 123 when the pen tip is inserted.

[0090] According to the present invention, the barb portion 115 can deform by contacting the small-diameter portion 123 of the pen tip 12 during pen tip insertion, thus not becoming a large obstacle during pen tip insertion and allowing for smooth insertion of the pen tip 12. On the other hand, when an axially forward force (i.e., a force in the direction of pen tip 12 falling off) is applied to the pen tip 12 after pen tip insertion, the barb portion 115 returns to its state before pen tip insertion (before deformation), so the barb portion 115 bites into the outer surface of the small-diameter portion of the pen tip 12, reliably locking the pen tip 12. That is, pen tip 12 is easy to insert, and on the other hand, the pen tip 12 will not fall off after insertion.

[0091] Furthermore, according to the present invention, since the inner step portion 114 functions as a stop for positioning during pen tip insertion, the pen tip 12 can be easily inserted into the desired position. Additionally, the pen tip 12 and the ink reservoir 13 are connected without any poor connection, and ink is smoothly supplied from the ink reservoir 13 to the pen tip 12. Furthermore, even if the user applies excessive pen pressure to the pen tip 12 during use of the writing instrument 10, the pen tip 12 will not be submerged in the writing instrument 10.

[0092] Preferably, the barb portion 115 is provided at the rear end of the inner surface of the small-diameter hole portion 113. Thus, the small-diameter hole portion 113 functions as a guide for the small-diameter portion 123 to be inserted through it, making it easier to insert the small-diameter portion 123 into the small-diameter hole portion 113 and making it easier to insert the pen tip 12.

[0093] The preferred pen tip insertion hole 111 also has a large-diameter hole 112 located in front of the inner stepped portion 114, and the large-diameter portion 122 is inserted into or loosely fitted into the large-diameter hole 112. As a result, the pen tip 12 can be held further forward, thus enabling stable writing.

[0094] Preferably, multiple barbs 115 are provided in a circumferential, equally spaced manner on the small-diameter hole portion 113, and the cross-section of the front end of the barb 115 is R-shaped. Thus, the barbs 115 bite into the outer surface of the pen tip 12 in a circumferential, equally spaced manner, enabling more reliable locking of the pen tip 12. Furthermore, the R-shaped cross-section of the front end of the barb 115 facilitates its formation.

[0095] Preferably, the pen tip 12 has a locking groove 125 behind the first outer step portion 124, and a second outer step portion 126 at the rear end of the locking groove 125. The barb portion 115 is locked into the second outer step portion 126, and the pen tip 12 is axially locked in place. Therefore, when an axial forward force (i.e., a force in the direction of pen tip 12 falling off) is applied to the pen tip 12 after insertion, the force to return it to its pre-tilting state acts on the barb portion 115. At this time, the barb portion 115 hooks onto the second outer step portion 126 provided on the outer surface of the small diameter portion, which more reliably prevents the pen tip 12 from falling off after insertion.

[0096] Furthermore, this invention only applies to the shaft 11 of the writing instrument 10 described above. That is, a shaft 11 of a writing instrument 10, wherein the writing instrument 10 has a pen tip insertion hole 111 at its front end for inserting a pen tip 12, wherein the outer surface of the pen tip 12 has a large-diameter portion 122, a small-diameter portion 123 disposed behind the large-diameter portion 122, and a first outer step portion 124 disposed between the large-diameter portion 122 and the small-diameter portion 123; the inner surface of the pen tip insertion hole 111 has a large-diameter hole portion 112, and a small-diameter portion 123 disposed behind the large-diameter hole portion 112. The pen tip 122 consists of a small-diameter hole 113 and an inner stepped portion 114 disposed between the large-diameter hole 112 and the small-diameter hole 113. The large-diameter portion 122 is inserted into the large-diameter hole 112, and the small-diameter portion 123 is inserted into or loosely inserted into the small-diameter hole 113. The first outer stepped portion 124 abuts against the inner stepped portion 114. The small-diameter hole 113 has a barb portion 115 protruding from the inner surface of the small-diameter hole 113. The barb portion 115 can be deformed by contacting the small-diameter portion 123 when the pen tip 12 is inserted. As a result, the pen tip 12 is easy to insert, and the pen tip 12 will not fall off after insertion. In addition, the pen tip 12 will not be buried in the writing instrument 10 when writing.

[0097] Hereinafter, the fifth to eighth embodiments of the present invention will be described with reference to the accompanying drawings. It should be noted that in the mounting structure of the soft component in the fifth to eighth embodiments, "front" refers to the side of the soft component 22 in the writing instrument, and "rear" refers to the opposite side. In the soft component, "front" refers to the side of the friction part 221, and "rear" refers to the opposite side.

[0098] Figure 10 This is a schematic longitudinal sectional view of the writing instrument 20 of the present invention, showing the state in which the cap 24 is installed. Figures 11 to 13 This is an enlarged longitudinal sectional view showing the main part of the insertion process of the flexible component 22 of the present invention, and is shown sequentially from before the insertion of the flexible component to after the insertion of the flexible component.

[0099] Figure 14 This is a cross-sectional perspective view of the shaft sleeve 21 according to the fifth embodiment of the present invention, showing the state before the soft component is inserted. Figure 15 and Figure 16 yes Figure 11 The BB-line sectional view of the shaft cylinder 21 is a diagram showing the cross-sectional shape of the barb portion 215 of the shaft cylinder 21 according to the fifth and sixth embodiments of the present invention.

[0100] Figure 17 This is a magnified longitudinal sectional view of the main part showing the state of the soft component after insertion according to the seventh embodiment of the present invention. The shape of the outer surface of the soft component 22 is different from that of other embodiments. Figure 18 This is an enlarged longitudinal sectional view of the main part showing the state of the soft component after insertion according to the eighth embodiment of the present invention. The shape of the outer surface of the soft component 22 and the front of the shaft cylinder 21 is different from that of the other embodiments.

[0101] <Fifth Implementation Method>

[0102] The present invention is a soft component mounting structure formed by inserting a soft component 22 (second component) into the tail end of the shaft 21 (first component) or the closed end of the cap (first component) of the writing instrument 20. Figure 10 The writing instrument 20 of this embodiment shown mainly consists of a cap 24, a pen tip 26, an ink reservoir 23, a shaft 21 (first shaft 21a, second shaft 21b), and a flexible component 22. The pen tip 26 is inserted into the front end of the shaft 21, and the ink reservoir 23 is housed inside. The cap 24 may have an airtight component 25 inside to prevent ink evaporation from the pen tip 26. The pen tip 26 is inserted into a pen tip insertion hole in the shaft 21 (first shaft 21a). Furthermore, in order to replace the ink reservoir 23 or replenish ink to the ink reservoir 23 while the first shaft 21a is removed from the second shaft 21b, the first shaft 21a and the second shaft 21b can be easily engaged and disengaged.

[0103] The writing instrument 20 is a thermochromic writing instrument containing thermochromic ink. The soft part 22 can rub the thermochromic ink marks, and the frictional heat generated at this time causes the thermochromic ink marks to change color.

[0104] <Shaft>

[0105] like Figure 10As shown, the shaft cylinder 21 is a bottomed cylindrical body manufactured by injection molding or extrusion molding of synthetic resin, with one end open and the other end closed. Examples of synthetic resin materials include polypropylene, polyethylene, polystyrene, polycarbonate, polyethylene terephthalate, polyacetal, acrylic acid, nylon, acrylonitrile-styrene copolymer (AS resin), and acrylonitrile-butadiene-styrene copolymer (ABS resin). The shaft cylinder 21 is composed of a first shaft 21a and a second shaft 21b, which are axially locked together to prevent disengagement. The first shaft 21a consists of a pen tip insertion hole, a flange, and a fitting portion. The second shaft 21b consists of a flexible component insertion hole 211 and a fitting portion. The inner side of the flexible component insertion hole 211 of the second shaft 21b is closed by a center bolt 27. The large-diameter portion 222 of the flexible component 22 is inserted into the flexible component insertion hole 211. The flange can abut against the open end of the second shaft 21b axially. The fitting part can be axially locked to the fitting part on the inner surface of the opening of the second shaft 21b, and a first annular sealing part is formed on the outer surface of the fitting part to airtightly fit the second annular sealing part on the inner circumferential surface of the fitting part of the second shaft 21b.

[0106] like Figure 11 As shown, the soft component insertion hole 211 has a large-diameter hole 212 with an open side, a small-diameter hole 213 located behind the large-diameter hole 212, and an inner stepped portion 214 perpendicular to the axis between the large-diameter hole 212 and the small-diameter hole 213 on its inner surface. The large-diameter portion 222 into which the soft component 22 is inserted or loosely inserted is inserted into the large-diameter hole 212. The small-diameter portion 223 into which the soft component 22 is inserted or loosely inserted is inserted into the small-diameter hole 213.

[0107] The small-diameter hole 213 has a barb portion 215 that protrudes radially inward from the inner surface of the small-diameter hole 213. For example... Figure 12 As shown, the barb portion 215 can deform upon contact with the small-diameter portion 223 during insertion of the soft component. That is, in this embodiment, the barb portion 215 tilts axially and rearward through the outer surface of the small-diameter portion 223 of the soft component 22 as the soft component 22 is inserted. This allows the small-diameter portion 223 to be easily inserted. In other words, it does not create significant resistance during insertion of the soft component 22, allowing for smooth insertion.

[0108] On the other hand, after the soft component 22 is inserted (see reference) Figure 13 When an axial forward force is applied to the soft component 22 (i.e., a force in the direction in which the soft component 22 falls off), the force required to return the hook portion 215 to its state before tipping over acts on it. In other words, the hook portion 215 needs to be restored to its state before the soft component 22 was inserted (before the hook portion 215 deformed: see...). Figure 11In this state, the barb 215 bites into the outer surface of the small-diameter portion 223 of the soft component 22, reliably locking the soft component 22 in place. That is, the soft component 22 is easy to insert, and on the other hand, the soft component 22 will not fall off after insertion.

[0109] like Figure 11 As shown, in this embodiment, the barb portion 215 is provided at the rear end of the inner surface of the small-diameter hole portion 213. Thus, the small-diameter hole portion 213 functions as a guide for the small-diameter portion 223 to be inserted through it, making it easier for the small-diameter portion 223 to be inserted into the small-diameter hole portion 213, and making it easier to insert the soft component 22.

[0110] like Figure 14 or Figure 15 As shown, in this embodiment, multiple barbs 215 are arranged circumferentially and at equal intervals in the small-diameter hole 213, and the cross-section of the radially inner front end of each barb 215 is R-shaped. Of course, the barbs 215 may not be evenly spaced. Furthermore, at least one barb 215 needs to be formed and engaged with the outer surface of the small-diameter hole 223. In this embodiment, the barbs 215... Figure 11 In the state before insertion of the soft component shown, the axial thickness t is 0.1 mm, the radially inward protrusion length L from the small diameter hole 213 is 0.5 mm, and the circumferential width W is 0.6 mm. Preferably, 0.01 mm < t < 1.0 mm, 0.1 mm < W < 3.0 mm, and 0.1 mm < L < 2.0 mm. By setting the dimensions of the barb portion 215 within these ranges, the soft component 22 can be inserted more easily, and on the other hand, the soft component 22 will not fall off after insertion.

[0111] A plurality of axially extending air passages 217 are provided at equal intervals on the inner surface of the large-diameter bore 212 and the inner surface of the small-diameter bore 213. These air passages 217 form an axial air passage between the outer surface of the flexible component 22 and the inner surface of the shaft cylinder 21. This ensures smooth airflow, preventing air compression within the shaft cylinder during insertion of the flexible component 22, thus allowing for smooth insertion.

[0112] like Figure 13 As shown, when the flexible component 22 is inserted, the inner step portion 214 abuts against the first outer step portion 224 of the flexible component 22, which will be described later. Thus, the inner step portion 214 functions as a stop for positioning the flexible component 22 during insertion, allowing it to be easily inserted into the desired position. Furthermore, even if the user applies excessive force to the flexible component 22 during use, the flexible component 22 will not be buried in the writing instrument 20.

[0113] In addition to the type in which the ink reservoir 23 for holding ink is housed within the cylinder 21, the writing instrument 20 of the present invention can also be of the type in which ink directly housed within the cylinder 21 is guided to the nib 26 via the ink reservoir 23. Furthermore, depending on the need, an ink retention component (e.g., a comb-shaped ink retention component) may be provided to temporarily retain remaining ink corresponding to changes in the internal pressure of the ink reservoir, and a guiding component may be provided to guide ink from the ink reservoir 23 to the nib 26. Furthermore, it can be either a cap-type or a nib-emerging (press-type) type.

[0114] <Soft components>

[0115] The flexible component 22 has a large-diameter portion 222 on its outer surface, a small-diameter portion 223 disposed behind the large-diameter portion 222, and a first outer step portion 224 disposed between the large-diameter portion 222 and the small-diameter portion 223. The large-diameter portion 222 is cylindrical and has a friction portion 221 at its front end. The small-diameter portion 223 is also cylindrical. Furthermore, the first outer step portion 224 abuts against the inner step portion 214 of the flexible component insertion hole 211 when the flexible component 22 is inserted.

[0116] One end of the soft component 22 protrudes forward from the front opening of the shaft sleeve 21 as a friction part 221. For example, as Figure 12 As shown, the friction part 221 is machined into a projectile shape. Of course, the friction part 221 is not limited to a projectile shape, and can also be machined into a chisel shape, a rectangular shape, a square prism shape, a plate shape, or other shapes corresponding to the purpose. It should be noted that the form of the writing instrument 20 of the present invention is not limited to the example shown in the figure, and it can also be a writing instrument in which the friction body is inserted into the top (closed end side) of the cap.

[0117] Preferably, the elastic synthetic resin constituting the soft component 22 is not made of a highly abrasive elastic material (such as rubber), but is made of a low-abrasive elastic material that produces almost no abrasion residue (rubber residue) during friction.

[0118] The elastic material constituting the soft component 22 is preferably a synthetic resin (rubber, elastomer) with elasticity, such as silicone resin, SBS resin (styrene-butadiene-styrene copolymer), SEBS resin (styrene-ethylene-butene-styrene copolymer), fluorinated resin, chloroprene resin, nitrile resin, polyester resin, ethylene propylene diene rubber (EPDM), or a mixture of two or more rubber elastic materials, as well as a mixture of rubber elastic material and synthetic resin.

[0119] <Ink Absorber>

[0120] The ink absorber 23 can be impregnated with ink, and specifically, examples include: fiber bundle processed bodies (e.g., thermally welded fiber bundle processed bodies, resin processed fiber bundle processed bodies, resin processed felt bodies, needle-punched felt bodies) or porous bodies (e.g., continuous air bubbles of synthetic resin such as sponge). In addition, the outer peripheral surface of the ink absorber 23 can also be coated with a synthetic resin film.

[0121] like Figure 10 or Figure 11 As shown, the stopper 27 abuts axially with the abutment wall 216 provided on the second shaft 21b. The rear end face of the ink reservoir 23 abuts axially with the abutment wall provided on the first shaft 21a. Furthermore, the front end face of the ink reservoir 23 abuts axially with the end face of the stopper 27. The length of the ink reservoir 23 is preferably set to be greater than the length between the abutment wall and the stopper 27. Therefore, the ink reservoir 23 within the shaft cylinder 21 can achieve stable writing performance by being axially clamped by the abutment wall and the stopper 27.

[0122] <Pen Tip>

[0123] like Figure 10 As shown, in this embodiment, the pen tip 26 is axially locked into the pen tip insertion hole of the first shaft 21a. Of course, the mounting structure and position of the pen tip 26 are not limited to this embodiment. For example, the pen tip 26 can be installed on the outer surface of the rear end of the shaft cylinder 21 by pressing, locking, screwing, fitting, bonding, or two-color molding. One end of the pen tip 26 protrudes outward from the front opening of the shaft cylinder 21 as a writing part. The other end of the pen tip 26 is connected to the end of the ink reservoir 23 in a piercing manner. For example, as... Figure 10 As shown, the writing part is machined into a chisel shape. Of course, the writing part is not limited to a chisel shape; it can also be machined into other shapes corresponding to the purpose, such as a cannonball shape, a rectangular shape, a square prism shape, or a plate shape. It should be noted that the form of the writing instrument 20 of the present invention is not limited to the example shown in the figure; it can also be a double-ended writing instrument with different shaped pen nibs 26 installed at both ends of the ink reservoir 23. In this case, the soft part 22 is inserted into the top (closed end side) of the cap 24.

[0124] The pen tip 26 is made of a resin-processed fiber (e.g., a resin-processed polyester fiber), with one end protruding outward as a writing part, and the other end connected to one end of the ink reservoir 23 in a piercing manner. Of course, the pen tip 26 can simply be used to allow ink to flow. Specifically, examples include: a fiber pen tip made of a fused-in thermoplastic fiber, a felt pen tip made of a felt body, a plastic pen tip that forms an axial ink flow path internally by fusing multiple linear resins (monofilaments formed by extrusion molding of synthetic resin), a pen tip (porous tip) made of a porous body of synthetic resin with continuous air bubbles, and a brush pen tip, etc., utilizing capillary force. Alternatively, the pen tip 26 can also be a tip formed by a ball-holding part that holds a ball by pressing and deforming the front end of a metal tube from the outer surface inward, or a tip formed by a ball-holding part formed by cutting metal material using a drill bit, or a tip with a resin ball receiver inside a metal or plastic tip. It should be noted that the ball bearings can be made of materials such as superhard alloy, stainless steel, ruby, ceramic, resin, and rubber, with a diameter of 0.3 to 3.0 mm, preferably 0.3 to 1.5 mm, and more preferably 0.4 to 1.0 mm.

[0125] <Ink>

[0126] In this embodiment, the ink contained in the ink absorber 23 is a thermochromic ink. The thermochromic ink is preferably a reversible thermochromic ink. Reversible thermochromic inks can be configured individually or in combination with various types, including: a heat-curing type that decolorizes from a colored state by heating; a color storage and retention type that stores and retains the colored or decolorized state alternately within a specific temperature range; and a heat-curing type that develops color from a decolorized state by heating and reverts to a decolorized state by cooling, etc.

[0127] As a pigment contained in reversible thermochromic ink, for example, a reversible thermochromic pigment encapsulating a reversible thermochromic composition in microcapsules is preferably used, the reversible thermochromic composition containing at least three essential components: (a) an electron-donating color-developing organic compound, (b) an electron-accepting compound, and (c) a reaction medium that determines the temperature at which the reaction (color development reaction) of the chemical combination of the two occurs.

[0128] It should be noted that the ink used in this invention is not limited to thermochromic inks; other ink compositions besides thermochromic inks may also be used. For example, writing ink, correction fluid, liquid paste, cosmetic liquid, etc., may be appropriately selected depending on its intended use as a liquid ejector. Among writing inks, oil-based inks, water-based inks, etc., are not particularly limited.

[0129] <Sixth Implementation Method>

[0130] Figure 16 yes Figure 11 The BB-line cross-sectional view of the shaft sleeve 21 is a diagram showing the shape of the barb portion 215 of the shaft sleeve 21 according to the sixth embodiment of the present invention. In the sixth embodiment of the present invention, the cross-sectional shape of the barb portion 215 is different from that of the fifth embodiment. Specifically, the cross-section of the radially inner front end portion is a sharp shape.

[0131] The other structures of the sixth embodiment are largely the same as those of the fifth embodiment, therefore a detailed description is omitted. Figure 16 As shown, according to this embodiment, the barbs 215 bite into the outer surface of the soft component 22 in a circumferential, equally spaced manner, which can more reliably lock the soft component 22 in place. In addition, the cross-section of the radially inner front end of the barb 215 is sharp, so the barb 215 bites into the outer surface of the soft component 22 more deeply, and the soft component 22 is more firmly locked in the axial direction to prevent it from falling off.

[0132] Of course, the cross-section of the front end of the barb 215 is not limited to a sharp shape or the aforementioned R shape; it can also be a rectangular shape, an inverted R shape with a concave radial inner front end, or other shapes corresponding to the pen tip. In addition, the barb 215 can also be a burr formed when resin enters the gap between the mating surfaces of the mold (pin) during the injection molding of the shaft 21.

[0133] <Seventh Implementation Method>

[0134] Figure 17 This is an enlarged longitudinal sectional view showing the main portion of the soft component 22 after insertion according to the seventh embodiment of the present invention. In the seventh embodiment of the present invention, the shape of the soft component 22 rearward from the first outer step portion 224 differs from that in the fifth embodiment. Specifically, as... Figure 17 As shown, the soft component 22 has a locking groove 225 behind the first outer step portion 224, and a second outer step portion 226 at the rear end of the locking groove 225. The barb portion 215 is locked into the second outer step portion 226, and the soft component 22 is axially locked in place. The locking groove 225 is preferably formed in a circumferential shape in the small diameter portion 223.

[0135] The other structures of the seventh embodiment are largely the same as those of the fifth embodiment, therefore detailed descriptions are omitted. According to this embodiment, similarly to the fifth embodiment, when an axially forward force (i.e., a force in the direction in which the soft component 22 detaches) is applied to the soft component 22 after it has been inserted, a force to return it to its state before tipping acts on the hook portion 215. At this time, as... Figure 17As shown, the barb portion 215 hooks onto the second outer step portion 226 provided on the outer surface of the small diameter portion 223, which can more reliably prevent the soft component 22 from falling off after it is inserted. In addition, the locking groove 225 is formed in a circumferential shape in the small diameter portion 223, so that when the soft component 22 is inserted into the shaft cylinder 21, it is not necessary to position the rotation direction of the soft component 22, and the soft component 22 can be easily inserted.

[0136] <Eighth Implementation Method>

[0137] Figure 18 This is an enlarged longitudinal sectional view showing the main portion of the soft component 22 after insertion according to the eighth embodiment of the present invention. In the eighth embodiment of the present invention, the shape of the shaft sleeve 21, which is further forward than the small-diameter bore 213, differs from that in the seventh embodiment. Specifically, as... Figure 18 As shown, the large-diameter hole 212 of the shaft cylinder 21 is omitted, and the inner step portion 214 is provided at the front end of the shaft cylinder 21.

[0138] Furthermore, in the eighth embodiment of the present invention, the outer surface shape of the soft component 22 differs from that in the seventh embodiment. Specifically, as... Figure 18 As shown, the flexible component 22 has a locking groove 225 on the surface of its small diameter portion behind the first outer step portion 224, and a second outer step portion 226 is provided at the rear end of the locking groove 225. The friction portion 221 is shaped like a projectile. Furthermore, when the flexible component 22 abuts against the first outer step portion 224 and the inner step portion 214, an air passage hole 227 is formed between the first outer step portion 224 and the inner step portion 214. This ensures smooth airflow, preventing air compression inside the shaft cylinder during insertion of the flexible component 22, allowing for smooth insertion of the flexible component 22.

[0139] The other structures of the eighth embodiment are substantially the same as those of the seventh embodiment, so detailed descriptions are omitted. According to this embodiment, the soft part 22 can be clamped closer to the front of the friction part 221, thus enabling stable friction.

[0140] The mounting structure of the soft component as described above functions as follows.

[0141] The mounting structure for the soft component of the present invention is a structure in which a soft component 22 is inserted into the tail end of the shaft cylinder 21 or the closed end of the cap 24 of the writing instrument 20. A soft component insertion hole 211 is provided at the tail end of the shaft cylinder 21 or the closed end of the cap 24. The soft component 22 includes a small-diameter portion 223, a large-diameter portion 222 disposed in front of the small-diameter portion 223, and a first outer step portion disposed between the small-diameter portion 223 and the large-diameter portion 222. 224, the soft component insertion hole 211 has a small diameter hole 213 and an inner step 214 provided in front of the small diameter hole 213. The small diameter hole 223 is inserted or loosely inserted into the small diameter hole 213. The first outer step 224 abuts against the inner step 214. The small diameter hole 213 has a barb 215 protruding from the inner surface of the small diameter hole 213. The barb 215 can be deformed by contacting the small diameter hole 223 when the soft component is inserted.

[0142] According to the present invention, the barb portion 215 can deform by contacting the small-diameter portion 223 of the soft component 22 during insertion, thus not becoming a large obstacle during insertion of the soft component 22, allowing for smooth insertion of the soft component 22. On the other hand, after insertion, if an axially forward force (i.e., a force in the direction in which the soft component 22 will fall off) is applied to the soft component 22, the barb portion 215 will return to its state before insertion (before deformation). Therefore, the barb portion 215 bites into the outer surface of the small-diameter portion 223 of the soft component 22, reliably locking the soft component 22. In other words, insertion of the soft component 22 is easy, and the soft component 22 will not fall off after insertion.

[0143] Furthermore, according to the present invention, the inner step portion 214 functions as a stop for positioning during the insertion of the soft component, thus allowing the soft component 22 to be easily inserted into the desired position. Additionally, even if the user applies excessive force to the soft component 22 during use, the soft component 22 will not be buried in the writing instrument 20.

[0144] Preferably, the barb portion 215 is provided at the rear end of the inner surface of the small-diameter hole portion 213. Thus, the small-diameter hole portion 213 functions as a guide for the small-diameter portion 223 to be inserted through it, making it easier for the small-diameter portion 223 to be inserted into the small-diameter hole portion 213, and making it easier to insert the soft component 22.

[0145] The preferred soft component insertion hole 211 also includes a large-diameter hole 212 located in front of the inner stepped portion 214, and the large-diameter portion 222 is inserted into or loosely fitted into the large-diameter hole 212. As a result, the soft component 22 can be clamped further forward, thus enabling stable friction.

[0146] Preferably, multiple barbs 215 are provided circumferentially at equal intervals in the small-diameter hole portion 213, and the cross-section of the front end of the barb 215 is R-shaped. Therefore, the barbs 215 bite into the outer surface of the soft component 22 in a circumferentially at equal intervals, enabling more reliable locking of the soft component 22. Furthermore, the R-shaped cross-section of the front end of the barb 215 facilitates its formation.

[0147] Preferably, the soft component 22 has a locking groove 225 behind the first outer step portion 224, and a second outer step portion 226 at the rear end of the locking groove 225. The barb portion 215 is locked into the second outer step portion 226, thus preventing the soft component 22 from detaching in the axial direction. Therefore, when an axial forward force is applied to the soft component 22 after insertion (i.e., a force in the direction in which the soft component 22 will fall off), the force to return it to its pre-tipping state acts on the barb portion 215. At this time, the barb portion 215 hooks onto the second outer step portion 226 provided on the outer surface of the small diameter portion 223, more reliably preventing the soft component 22 from falling off after insertion.

[0148] Furthermore, this invention only applies to the shaft 21 of the writing instrument 20 described above. That is, a shaft 21 of a writing instrument, which is the shaft 21 of a writing instrument 20 having a soft component insertion hole 211 at its front end for inserting a soft component 22. The outer surface of the soft component 22 has a large-diameter portion 222, a small-diameter portion 223 disposed behind the large-diameter portion 222, and a first outer step portion 224 disposed between the large-diameter portion 222 and the small-diameter portion 223. The inner surface of the soft component insertion hole 211 has a large-diameter hole portion 212 and a... The large-diameter hole 212 is followed by a small-diameter hole 213, and an inner step 214 is provided between the large-diameter hole 212 and the small-diameter hole 213. The small-diameter part 223 is inserted into or loosely inserted into the small-diameter hole 213. The first outer step 224 abuts against the inner step 214. The small-diameter hole 213 has a barb 215 protruding from the inner surface of the small-diameter hole 213. The barb 215 can deform by contacting the small-diameter part 223 when the soft part is inserted. As a result, the soft part 22 is easy to insert. On the other hand, the soft part 22 will not fall off after being inserted. In addition, the soft part 22 will not be buried in the writing instrument 20 during friction.

[0149] Furthermore, this invention is a writing instrument, characterized in that it has a mounting structure for the soft component, forming thermochromic handwriting. Additionally, this invention is a soft component, characterized in that it, together with the soft component insertion hole 211, constitutes the mounting structure for the soft component.

[0150] <Implementation Methods 9 through 11>

[0151] Hereinafter, the ninth to eleventh embodiments of the present invention will be described with reference to the accompanying drawings. It should be noted that in the mounting structure of the ninth to eleventh embodiments, "front" refers to the end 321 side of the second component 32, and "rear" refers to the opposite side therefrom.

[0152] Figure 19 This is a schematic longitudinal sectional view of a part of the writing instrument 30 according to the ninth embodiment of the present invention. Figure 20 This is a schematic longitudinal sectional view of a part of the writing instrument 30 according to the tenth embodiment of the present invention. Figure 21 This is a schematic longitudinal sectional view of a part of the writing instrument 30 according to the eleventh embodiment of the present invention. Figure 19 In the diagram, the top represents the front, and the bottom represents the back. Figure 20 , 21 In the diagram, the top represents the back, and the bottom represents the front.

[0153] In any of the ninth to eleventh embodiments of the present invention, the mounting structure is formed by mounting the second component 32 through the insertion hole 311 provided at the end of the first component 31. The writing instrument 30 of the ninth to eleventh embodiments is mainly the same as that of, for example, the first to eighth embodiments, and is composed of a cap, a pen tip, an ink reservoir, a shaft, and a soft component.

[0154] The writing instrument 30 has a first component 31 and a second component 32. Figure 19 In the ninth embodiment shown, the first component 31 is the shaft or cap of the writing instrument 30, and the second component 32 is the tail plug of the shaft or the crown of the cap. Figure 20 In the tenth embodiment shown, the first component 31 is a cap, and the second component 32 is a rubber seal. Figure 21 In the eleventh embodiment shown, the first component 31 is a cap, and the second component 32 is an inner cap.

[0155] The first component 31 is a cylindrical body with an open end, manufactured by injection molding or extrusion molding of synthetic resin. An insertion hole 311 is provided in the first component 31. The large-diameter portion 322 of the second component 32 is inserted into the insertion hole 311. Examples of synthetic resin materials include polypropylene, polyethylene, polystyrene, polycarbonate, polyethylene terephthalate, polyacetal, acrylic acid, nylon, acrylonitrile-styrene copolymer (AS resin), acrylonitrile-butadiene-styrene copolymer (ABS resin), and other synthetic resins.

[0156] The insertion hole 311 has a small-diameter hole 313 on its inner surface and an inner stepped portion 314 connected to the small-diameter hole 313 and perpendicular to the axis. The small-diameter portion 323 of the second component 32 is inserted or loosely inserted into the small-diameter hole 313. The insertion hole 311 may also have a large-diameter hole on its inner surface. In this case, the large-diameter portion 322 of the second component 32 is inserted or loosely inserted into the large-diameter hole.

[0157] The small-diameter bore 313 has a barb 315 protruding radially inward from its inner surface. The barb 315 can deform upon contact with the small-diameter portion 323 during insertion of the second component 32. That is, in this embodiment, the barb 315 tilts axially rearward through the outer surface of the small-diameter portion 323 of the second component 32 as the second component 32 is inserted. This allows the small-diameter portion 323 to be easily inserted. In other words, it does not create significant resistance during insertion of the second component 32, allowing for smooth insertion of the second component 32.

[0158] On the other hand, when a forward axial force (i.e., a force in the direction of the second component 32 falling off) is applied to the second component 32 after it is inserted, a force is applied to the barb portion 315 to return it to its state before it tipped over. In other words, the barb portion 315 is to be restored to its state before the second component 32 was inserted (before the barb portion 315 deformed). Thus, the barb portion 315 hooks onto the second outer step portion 326 provided on the outer surface of the small diameter portion 323 of the second component 32 (described later), which can more reliably prevent the second component 32 from falling off after it is inserted. That is, the second component 32 is easy to insert, and it will not fall off after insertion. The barb portion 315 can also bite into the outer surface of the small diameter portion 323 of the second component 32 to lock the second component 32 in place.

[0159] In this embodiment, the barb portion 315 is provided at the rear end of the inner surface of the small-diameter hole portion 313. Thus, the small-diameter hole portion 313 functions as a guide for the small-diameter portion 323 to be inserted through it, making it easier for the small-diameter portion 323 to be inserted into the small-diameter hole portion 313, and making it easier to insert the second component 32.

[0160] In this embodiment, multiple barbs 315 are arranged at equal intervals around the small-diameter hole 313, and the cross-section of the radially inner front end of each barb 315 is R-shaped. Of course, the barbs 315 may not be evenly spaced. Furthermore, at least one barb 315 may be formed and engaged with the outer surface of the small-diameter hole 323. The dimensions of the barbs 315 can be set similarly to those of the barbs 115 and 215 in the first to eighth embodiments.

[0161] A plurality of (specifically eight) airflow grooves 317 extending axially are provided at equal intervals on the inner surface of the small-diameter hole 313. Through these airflow grooves 317, an axial airflow path is formed between the outer surface of the second component 32 and the inner surface of the first component 31. As a result, airflow is smooth, and the air in the first component 31 is not compressed when the second component 32 is inserted, allowing for smooth insertion of the second component 32.

[0162] When the second component 32 is inserted, the inner step portion 314 abuts against the first outer step portion 324 of the second component 32, which will be described later. Thus, the inner step portion 314 functions as a stop for positioning the second component 32 during insertion, allowing it to be easily inserted into the desired position. Furthermore, even if the user applies excessive force to the second component 32, it will not be buried in the writing instrument 30.

[0163] The second component 32 has a large-diameter portion 322 on its outer surface, a small-diameter portion 323 disposed behind the large-diameter portion 322, and a first outer stepped portion 324 disposed between the large-diameter portion 322 and the small-diameter portion 323. The large-diameter portion 322 is cylindrical or cylindrical. The small-diameter portion 323 is cylindrical. The first outer stepped portion 324 abuts against the inner stepped portion 314 of the insertion hole 311 when the second component 32 is inserted. The second component 32 is made of synthetic resin. The type of synthetic resin can be appropriately determined according to the intended use of the second component 32.

[0164] The second component 32 has a locking groove 325 behind the first outer step portion 324, and a second outer step portion 326 at the rear end of the locking groove 325. The barb portion 315 is locked into the second outer step portion 326, and the second component 32 is axially locked in place. The locking groove 325 is preferably formed in a circumferential shape in the small diameter portion 323.

[0165] In the ninth embodiment, the second component 32 (tail plug or crown) seals the end of the first component 31. In the tenth embodiment, the second component 32 (rubber seal) seals the tip 33 of the ballpoint pen. In the eleventh embodiment, the second component 32 (inner cap) prevents ink from evaporating from the tip 33 of the highlighter.

[0166] As described in the first to eleventh embodiments above, the first component of the present invention can be various components of a writing instrument, such as the writing instrument body, the shaft, and the cap. Furthermore, the second component of the present invention can be various components of a writing instrument, such as the pen tip, the soft component, the end cap, the crown, the rubber seal, and the inner cap. Additionally, the terms "front" and "rear" in the present invention can be varied depending on the first and second components.

[0167] Symbol Explanation

[0168] 10, 20, 30 writing instruments

[0169] 11, 21 shaft cylinder

[0170] 31 First Component

[0171] 11a front axle

[0172] 11b rear axle

[0173] 21a First Axis

[0174] 21b Second Axis

[0175] 111 nib insertion hole

[0176] 211 Flexible Part Insertion Hole

[0177] 311 insertion hole

[0178] 112, 212 large diameter holes

[0179] 113, 213, 313 small diameter holes

[0180] 114, 214, 314 Inner Step Section

[0181] 115, 215, 315 barbed section

[0182] 116, 216 abutting wall section

[0183] 117, 217, 317 air circulation slots

[0184] 12 nibs

[0185] 22 Soft parts

[0186] 32 Second Component

[0187] 121 Writing Department

[0188] 221 Friction Section

[0189] 321 end

[0190] 122, 222, 322 large diameter part

[0191] 123, 223, 323 small diameter sections

[0192] 124, 224, 324 First outer step section

[0193] 125, 225, 325 locking slots

[0194] 126, 226, 326 Second outer step section

[0195] 127, 227 air vents

[0196] 13, 23 Ink Absorbers

[0197] 33 nib

[0198] 14, 24 hats

[0199] 15, 25 airtight components

[0200] 16 soft parts

[0201] 26 nib

[0202] 27 medium bolt

Claims

1. A mounting structure for a writing instrument, the writing instrument comprising: First component; and The second component is inserted into an insertion hole located at the end of the first component. in, The second component includes: a small-diameter portion; a large-diameter portion disposed in front of the small-diameter portion; and a first outer step portion disposed between the small-diameter portion and the large-diameter portion. The insertion hole includes: a small-diameter hole portion; and an inner stepped portion disposed in front of the small-diameter hole portion and formed circumferentially on the first component. The small-diameter portion is inserted or loosely inserted into the small-diameter hole. The first outer step portion abuts against the inner step portion. The small-diameter hole portion has a barb portion protruding from the inner surface of the small-diameter hole portion. The barb portion can tilt axially rearward by contacting the small-diameter portion during the insertion of the second component. After the second component is inserted, when an axial forward force is applied to the second component, the barb portion bites into the outer surface of the small-diameter portion of the second component. The barbs are provided in a circumferential, equally spaced manner in the small-diameter hole. The barb portion is a plate-shaped portion in which the axial thickness is less than the radially inward protrusion length in the state before the second component is inserted.

2. The installation structure according to claim 1, wherein, The barb portion is located at the rear end of the inner surface of the small-diameter hole.

3. The installation structure according to claim 1, wherein, The insertion hole also includes a large-diameter hole located in front of the inner stepped portion. The large-diameter portion is inserted or loosely fitted into the large-diameter hole.

4. The installation structure according to claim 1, wherein, The front end of the barb has an R-shaped cross-section.

5. The installation structure according to claim 1, wherein, The second component has a locking groove behind the first outer step portion, and a second outer step portion is provided at the rear end of the locking groove. The barb portion is locked to the second outer step portion, and the second component is axially locked to prevent disengagement.

6. The installation structure according to claim 1, wherein, The axial thickness t, the radially inward protrusion length L, and the circumferential width W of the barb portion are 0.01mm < t < 1.0mm, 0.1mm < W < 3.0mm, and 0.1mm < L < 2.0mm, respectively.

7. The mounting structure according to any one of claims 1 to 6, wherein, The first component is the main body of the writing instrument. The second component is the pen tip. The insertion hole is located at the front of the writing instrument body.

8. The mounting structure according to any one of claims 1 to 6, wherein, The first component is the shaft or cap of the writing instrument. The second component is a soft component. The insertion hole is located at the tail end of the shaft or the closed end of the cap.

9. A writing instrument, characterized by It has the mounting structure described in claim 8, forming thermochromic pen marks.

10. A soft component characterized by, Together with the insertion hole, it constitutes the mounting structure as described in claim 8.

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