Writing instrument and ink storage member

Abstract

To provide a writing instrument capable of easily and quickly refilling an ink occlusion body with ink.SOLUTION: A writing instrument 1 includes a barrel 2, an ink occlusion body 6 arranged within the barrel 2 and impregnated with ink, an ink refill portion 10 arranged rearward of the ink occlusion body 6 and having an air hole 12 and an ink ejection hole 13, and an ink storage member 20 attachable to the rear end of the barrel 2 and capable of containing ink, and is configured such that when the ink storage member 20 is attached to the rear end of the barrel 2, ink in the ink storage member 20 can be supplied to the ink occlusion body 6 through the ink ejection hole 13 of the ink refill portion 10.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a writing instrument and an ink storage member. [Background technology]

[0002] Writing instruments are known that have an ink occlusion body that is disposed in a barrel and is impregnated with ink, and a writing core that is a pen tip that ejects ink induced from the ink occlusion body (for example, Patent Document 1). Examples of such writing instruments include paint markers, oil-based markers, water-based markers, and underline markers. From the viewpoint of environmental protection, when the ink induced from the ink occlusion body runs out through use and writing with the writing instrument becomes impossible, it is preferable that the ink occlusion body can be refilled with ink.

[0003] The writing instrument described in Patent Document 1 has a barrel, an ink occlusion body disposed inside the barrel, and a plug that holds the pen tip. To refill the ink, the plug is removed from the barrel, and a refilling tool containing ink is inserted into the front end of the barrel, so that ink can be supplied to the ink occlusion body. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2019-142006 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the writing instrument described in Patent Document 1, touching the pen tip when removing the stopper may result in soiling of the fingers, etc. Also, because the rear end of the barrel is closed, the air in the ink occlusion body is not properly replaced with the supplied ink when ink is supplied, and the supplied ink may overflow from the ink occlusion body and, ultimately, the barrel. If the ink is supplied slowly from the refill tool, ink overflow can be prevented, but refilling may take too long.

[0006] An object of the present invention is to provide a writing instrument that allows ink to be easily and quickly replenished into an ink occlusion body. [Means for solving the problem]

[0007] According to one aspect of the present invention, a writing instrument is provided which comprises a barrel, an ink absorbing body disposed within the barrel and impregnated with ink, an ink refill section disposed rearward of the ink absorbing body and having an air hole and an ink ejection hole, and an ink storage member which can be attached to the rear end of the barrel and is capable of containing ink, and which is configured so that when the ink storage member is attached to the rear end of the barrel, the ink in the ink storage member can be supplied to the ink absorbing body through the ink ejection hole of the ink refill section.

[0008] According to another aspect of the present invention, there is provided an ink storage member for a writing instrument, which is attachable to the rear end of a barrel having an ink refill section having an air hole and an ink ejection hole, and an ink absorbing body impregnated with ink disposed therein, and which contains ink, and which is configured so that when attached to the rear end of the barrel, the ink is supplied to the ink absorbing body through the ink ejection hole of the ink refill section.

[0009] The air vent may be provided closer to the central axis of the barrel than the ink ejection hole. The air vent may be provided on the central axis. The ink ejection holes may be provided concentrically around the central axis. The ink occlusion body may be configured to have at least two types of capillary forces. Effect of the Invention

[0010] According to the aspects of the present invention, a common effect is achieved in that a writing instrument is provided that allows ink to be replenished into the ink occlusion body easily and quickly. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a perspective view of a writing instrument according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a vertical cross-sectional view of the writing instrument of FIG. [Diagram 3] FIG. 3 is an exploded perspective view of the writing instrument of FIG. [Figure 4] FIG. 4 is a vertical cross-sectional view of the ink storage member. [Diagram 5] FIG. 5 is another vertical cross-sectional view of the ink storage member. [Figure 6] FIG. 6 is an enlarged vertical cross-sectional view of the rear end portion of the barrel. [Figure 7] FIG. 7 is a cross-sectional view of the ink refill section. [Figure 8] FIG. 8 is a partial cross-sectional perspective view of the barrel showing the ink refill section. [Figure 9] FIG. 9 is another partial perspective cross-sectional view of the barrel showing the ink refill section. [Figure 10] FIG. 10 is a perspective view of the lead holding member. [Figure 11] FIG. 11 is a vertical cross-sectional view of the lead holding member. [Figure 12] FIG. 12 is a cross-sectional view taken along line DD in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Corresponding components are designated by common reference numerals throughout the drawings.

[0013] FIG. 1 is a perspective view of a writing instrument according to an embodiment of the present invention, FIG. 2 is a vertical cross-sectional view of the writing instrument of FIG. 1, and FIG. 3 is an exploded perspective view of the writing instrument of FIG.

[0014] The writing instrument 1 comprises a cylindrical barrel 2, a cylindrical front barrel 3 which fits inside the front end of the barrel 2, a lead retaining member 4 which fits inside the front end of the lead barrel 3, a writing lead 5 held by the lead retaining member 4, an ink occluder 6 which is disposed inside the barrel 2 and is impregnated with ink, and a cylindrical ink storage member 20 which screws into the rear end of the barrel 2. An ink refill section 10 is formed on the inner surface of the barrel 2 near the rear end. The barrel 2 may be referred to as including the lead barrel 3 and further including the ink storage member 20.

[0015] In this specification, in the axial direction of the writing instrument 1, the side of the writing lead 5 is defined as the "front" side, and the side opposite the writing lead 5 is defined as the "rear" side. In the explanation of each component, the front and rear are defined based on the assembled state of the writing instrument 1. Furthermore, unless otherwise specified, the central axis refers to the central axis of the writing instrument 1, i.e., the barrel 2.

[0016] The writing instrument 1 is a writing instrument configured to eject ink induced from the ink occlusion body 6 from the writing core 5, and is specifically a marking pen. The writing core 5 is composed of a porous body such as a sintered body, a fiber bundle, a foam, a sponge body, a felt body, and a porous body. The writing core 5 is a substantially U-shaped member, and both ends of the U-shape are inserted into the ink occlusion body 6. The ink in the ink occlusion body 6 is guided to the entire writing core 5 by capillary force, making it possible to eject the ink during writing. Note that the writing instrument 1 may be a paint marker, an oil-based marker, a water-based marker, or the like, as long as it is a writing instrument configured to eject ink induced from the ink occlusion body 6 from the writing core 5, and the shape of the writing core 5 may be formed arbitrarily according to the type of writing instrument.

[0017] When the ink induced from the ink occlusion body 6 runs out due to writing and writing with the writing instrument 1 becomes impossible, the ink can be replenished into the ink occlusion body 6. Specifically, the ink storage member 20 is removed from the rear end of the barrel 2, and a new ink storage member 20 filled with ink is fitted in its place. The ink storage member 20 will be described with reference to Figs. 4 and 5.

[0018] Fig. 4 is a vertical cross-sectional view of the ink storage member 20, and Fig. 5 is another vertical cross-sectional view of the ink storage member 20. In Figs. 4 and 5, the upper side is the front side. Fig. 4 shows the ink storage member 20 in an unused state. One end, i.e., the rear end, of the ink storage member 20 is closed, and ink 25 can be stored inside. The other end, i.e., the front end, of the ink storage member 20 is open. A cover member 30 is fitted to the front end of the ink storage member 20 in an unused state to prevent the ink 25 from leaking.

[0019] FIG. 5 shows the ink storage member 20 with the cover member 30 removed. The front end of the ink storage member 20 is formed with a small diameter portion 21 that is smaller in diameter than the rear portion. The outer circumferential surface of the small diameter portion 21 is formed with a male screw portion 22. As shown in FIG. 3, the threads of the male screw portion 22 are not formed in a continuous spiral shape, but are formed as discontinuous threads arranged on a continuous spiral trajectory. That is, the threads of the male screw portion 22 are formed at equal intervals along the spiral direction by a length corresponding to a predetermined rotation angle around the central axis. By forming the threads regularly, a plurality of sets of threads aligned in the axial direction are formed at equal intervals along the circumferential direction. As shown in FIG. 5, the inner circumferential surface of the front end of the ink storage member 20 is formed with an annular protrusion 23. In addition, as shown in FIG. 6 described later, the inner circumferential surface of the rear end of the shaft tube 2 is formed with a female screw portion 7 that can be screwed with the male screw portion 22 of the ink storage member 20 and has a similar shape.

[0020] Referring to FIG. 4, a closure member 31 is formed on the inside of the front end surface of the lid member 30 to fit with the inner peripheral surface of the front end of the ink storage member 20. The closure member 31 is a cylindrical protrusion extending rearward, and a fitting protrusion 32 is formed in an annular shape on the outer peripheral surface of the closure member 31. A female thread portion (not shown) that can be screwed with the male thread portion 22 of the ink storage member 20 is formed on the inner peripheral surface of the lid member 30. When the ink storage member 20 and the lid member 30 are screwed together, the fitting protrusion 32 of the closure member 31 inserted inside the ink storage member 20 and the annular protrusion 23 of the ink storage member 20 overcome each other while undergoing elastic deformation, thereby completing the screwing. As a result, the sealing performance between the ink storage member 20 and the closure member 31 is improved, and ink leakage from the ink storage member 20 is prevented. In addition, by screwing the lid member 30 to the ink storage member 20 filled with ink, the ink storage member 20 can be stored, transported, etc. in an unused state.

[0021] 1 and 2, the outer peripheral surface of the ink storage member 20 is formed so as to be flush with, i.e., integral with, the outer peripheral surface of the barrel 2 when attached to the barrel 2. The outer peripheral surface of the cover member 30 is also formed so as to be flush with, i.e., integral with, the outer peripheral surface of the ink storage member 20.

[0022] To refill the ink, the cover member 30 is removed from the unused ink storage member 20 with the front end facing upward to prevent ink leakage. Next, the ink storage member 20 that has already been attached is removed from the barrel 2, and instead, an unused ink storage member 20 is attached to the barrel 2 by screwing with the writing core 5 of the writing instrument 1 facing upward. Next, when the writing instrument 1 is tilted so that the writing core 5 faces downward, the ink 25 inside the ink storage member 20 moves into the barrel 2 by gravity and further passes through the ink refill section 10. The ink 25 that has passed through the ink refill section 10 is supplied to the ink occluder 6, completing the refill of the ink. The ink refill section 10 will be described with reference to Figs. 6 to 9.

[0023] FIG. 6 is an enlarged vertical cross-sectional view of the rear end of the barrel 2. FIG. 7 is a horizontal cross-sectional view of the ink refill section 10. Specifically, FIG. 7(A) is a cross-sectional view taken along line AA in FIG. 6, FIG. 7(B) is a cross-sectional view taken along line BB in FIG. 6, and FIG. 7(C) is a cross-sectional view taken along line CC in FIG. 6. FIG. 8 is a partial cross-sectional perspective view of the barrel showing the ink refill section 10, and FIG. 9 is another partial cross-sectional perspective view of the barrel showing the ink refill section 10. Specifically, FIGS. 8 and 9 are perspective views of the barrel 2 cut out in the vicinity of the ink refill section 10, and FIG. 8 is a perspective view of the ink refill section 10 as viewed from the rear side of the barrel 2, and FIG. 9 is a perspective view of the ink refill section 10 as viewed from the front side of the barrel 2.

[0024] A female screw portion 7 that can be screwed with the male screw portion 22 of the ink storage member 20 is formed near the rear end of the barrel 2. The female screw portion 7 has a plurality of threads that are arranged in the same spiral shape, aligned in the axial direction, and formed at equal intervals along the circumferential direction, similar to the male screw portion 22 of the ink storage member 20. As described above, an ink refill portion 10 is formed on the inner surface near the rear end of the barrel 2. The ink refill portion 10 has a partition wall 11 that crosses the inner surface of the barrel 2, and the partition wall 11 is provided with an air hole 12 and two ink discharge holes 13 that penetrate the partition wall 11 in the axial direction. Three ribs 8 are formed in front of the partition wall 11 and are arranged at equal intervals along the circumferential direction. The ribs 8 have a slope 9 facing forward. The ink occlusion body 6 inserted into the barrel 2 from the front is guided toward the center by the slope 9 of the rib 8 so that the central axes of the barrel 2 and the ink occlusion body 6 coincide with each other. As a result, the ink occlusion body 6 is fixed to the barrel 2 so as to be sandwiched between the ribs 8.

[0025] As shown in FIG. 8 in particular, a first cylindrical wall 14 is formed in a cylindrical shape from the partition wall 11 toward the rear, and a second cylindrical wall 15 is formed in a cylindrical shape so as to surround the first cylindrical wall 14. The central axes of the first cylindrical wall 14 and the second cylindrical wall 15 are aligned with the central axis of the barrel 2. A fitting space 16 is defined between the outer peripheral surface of the second cylindrical wall 15 and the inner peripheral surface of the barrel 2. When the ink storage member 20 is attached to the barrel 2, the small diameter portion 21 of the ink storage member 20 fits into the fitting space 16, filling the fitting space 16. This prevents the ink that flows from the ink storage member 20 into the barrel 2 when refilling the ink from accumulating around the second cylindrical wall 15, and allows all the ink to be impregnated into the ink occlusion body 6.

[0026] 7(B), a circular through hole 11a having a diameter equal to the inner diameter of the first cylindrical wall 14 is formed in the partition wall 11. A cylindrical vent hole 12 is defined by the through hole 11a penetrating the interior of the first cylindrical wall 14 and the partition wall 11. Therefore, the vent hole 12 is provided on the central axis of the barrel 2, and communicates with the front and rear of the partition wall 11.

[0027] As shown in FIG. 7B, two arc-shaped through holes 11b are formed around the through hole 11a of the partition wall 11, corresponding to a part of the cylindrical space defined between the first cylindrical wall 14 and the second cylindrical wall 15. The two through holes 11b are arranged symmetrically with respect to the central axis. As shown in FIG. 7C, two donut-shaped abutment protrusions 17 are formed from the partition wall toward the front. The two abutment protrusions 17 are equally divided by a slit 18 extending in the radial direction and arranged symmetrically. The diameter of the circumscribed circle of the two abutment protrusions 17 is formed to be smaller than the outer diameter of the ink occlusion body 6. The two through holes 11b penetrate the corresponding abutment protrusions 17 in the axial direction. Two ink ejection holes 13 are defined by the cylindrical space defined between the first cylindrical wall 14 and the second cylindrical wall 15, and the two through holes 11b penetrating the partition wall 11 and the abutment protrusions 17. Therefore, the two ink ejection holes 13 are provided concentrically around the central axis of the barrel 2, and communicate with the front and rear of the partition wall 11. When the writing instrument 1 is in an assembled state, the front end face of the abutment protrusion 17 is completely covered by the rear end face of the ink occluder 6, so that the outlet of the ink ejection hole 13 abuts against the ink occluder 6.

[0028] As described above, in order to refill the ink, an unused ink storage member 20 is screwed to the barrel 2 with the writing core 5 of the writing instrument 1 facing upward, and then the writing instrument 1 is tilted so that the writing core 5 faces downward. As a result, the ink inside the ink storage member 20 passes through the ink discharge hole 13 of the ink refill section 10 by gravity and is supplied to the inside of the ink occlusion body 6 from the rear end surface of the ink occlusion body 6. In detail, as the writing instrument 1 is tilted, the ink descends along the wall surface of the ink storage member 20. The ink discharge hole 13 is provided farther from the central axis of the barrel 2 or the ink storage member 20 than the ventilation hole 12, i.e., is provided radially outward from the ventilation hole 12, so that the ink continues to descend through the ink discharge hole 13 before passing through the ventilation hole 12. In particular, the front end face of the contact protrusion 17, which is the outlet of the ink ejection hole 13, abuts against the ink occlusion body 6, specifically the fibrous body 6b described later, so that the ink that has passed through the ink ejection hole 13 can be supplied directly to the ink occlusion body 6.

[0029] A through hole 11a provided in the partition 11, which is the entrance of the ventilation hole 12, is separated from the ink occlusion body 6 by the contact protrusions 17 and is therefore connected to a slit 18 between the two contact protrusions 17. The slit 18 is connected to the inside of the barrel 2, specifically, to the space between the inner peripheral surface of the barrel 2 and the outer peripheral surface of the ink occlusion body 6, so that the ventilation hole 12 is connected to the inside of the barrel 2.

[0030] As described above, when ink is supplied to the rear end surface of the ink occlusion body 6, the ink gradually permeates from the rear to the front. As the ink permeates, the air in the ink occlusion body 6 also gradually moves from the rear to the front and is discharged from the front end surface of the ink occlusion body 6. The air pushed out from the front end surface of the ink occlusion body 6 passes through the space between the inner peripheral surface of the barrel 2 and the outer peripheral surface of the ink occlusion body 6, and flows into the ink storage member 20 through the ventilation hole 12. In other words, when ink is supplied into the ink occlusion body 6 through the ink discharge hole 13, the air in the ink occlusion body 6 equivalent to the volume of the ink flows into the ink storage member 20 through the ventilation hole 12. Since the flow direction of the ink and the flow direction of the air are the same in the ink occlusion body 6, ink can be quickly replenished.

[0031] Furthermore, refilling the ink in the writing instrument 1 can be done simply by removing the ink storage member 20 that is attached to the rear end of the writing instrument 1 and that is already empty of ink, and simply attaching an unused ink storage member 20. Therefore, unlike the writing instrument described in Patent Document 1, there is no need to remove the plug having the pen tip, so there is no risk of fingers getting dirty with the writing core 5, and there is no need to worry about ink spilling during the refilling process. Therefore, with the writing instrument 1, refilling the ink can be done easily and quickly.

[0032] The cross-sectional area of ​​the ink ejection hole 13 is formed to be smaller than that of the ventilation hole 12. Therefore, assuming that the same ink passes through, the capillary force in the ink ejection hole 13, which has a smaller cross-sectional area and is a narrower flow path, is greater than the capillary force in the ventilation hole 12, which has a larger cross-sectional area and is a wider flow path. Therefore, when the ink passes through the ink ejection hole 13, the flow of the ink can be promoted by the action of the capillary force.

[0033] As described above, the writing instrument 1 is configured such that when the ink storage member 20 is attached to the rear end of the barrel 2, the refill ink in the ink storage member 20 can be supplied to the ink occluder 6 through the ink discharge hole 13 of the ink refill section 10. The ink refill section 10 may be disposed behind the ink occluder 6, and therefore may be disposed inside the ink storage member 20, not inside the barrel 2. The ink refill section 10 may be configured as a separate body and may be inserted into the barrel 2 or the ink storage member 20. The shape, number and arrangement of the ventilation hole 12 and the ink discharge hole 13 can be arbitrarily selected, so long as the ventilation hole 12 is disposed closer to the central axis of the barrel 2 than the ink discharge hole 13 so that the ink passes through the ink discharge hole 13 first when the writing instrument 1 is tilted. The ventilation hole 12 is preferably disposed on the central axis, but may be deviated from the central axis. The ink ejection holes 13 are preferably provided concentrically around the central axis of the barrel 2, but do not have to be provided concentrically.

[0034] Ink supplied to the ink occluder 6 from the ink storage member 20 via the ink refill unit 10 permeates the entire ink occluder 6 due to the action of capillary force within the ink occluder 6. This eliminates uneven ink ejection during writing, making it possible to use the ink without waste. Taking into account the difference in fluidity between air and ink, it is preferable that the ink occluder 6 have at least two types of capillary force. The ink occluder 6 will be described below.

[0035] As shown in Fig. 2, the ink occlusion body 6 is composed of an outer skin 6a and a fibrous body 6b which is a bundle of long fibers arranged in the longitudinal direction. Examples of the fibers include natural fibers, animal hair fibers, fibers made of polyacetal resin, acrylic resin, and polyester resin. The ink occlusion body 6 is formed into a cylindrical shape as a whole by the outer skin 6a surrounding the fibrous body 6b. At both ends of the ink occlusion body 6, the fibrous body 6b is cut and aligned, and the exposed fibrous body 6b forms a circular end face.

[0036] The outer cover 6a is a sheet-like member. The outer cover 6a may be made of a material that does not have capillary force, such as a synthetic resin film, or may be made of a material that has capillary force, such as a nonwoven fabric. By making the outer cover 6a of a breathable material such as a nonwoven fabric, air can be discharged from the inside of the ink occluder 6 to the outside when refilling the ink.

[0037] In the fibrous body 6b, numerous flow paths for ink and air are formed by the minute gaps between the fibers. As described above, when ink is supplied from the ink occlusion body 6 to the ink occlusion body 6, i.e., the fibrous body 6b, the ink penetrates into the minute gaps between the fibers. In the minute gaps, the ink penetrates into the entire fibrous body 6b by capillary force. At this time, by adjusting the density of the fibers constituting the fibrous body 6b, i.e., the size of the gaps between the fibers, the size of the capillary force can be adjusted and the penetration of the ink can be promoted. The density of the fibers constituting the fibrous body 6b can be adjusted, for example, by the thickness of the fibers.

[0038] When the fibrous body 6b is made of thicker and thinner fibers, the fibrous body 6b has two types of capillary force. However, when the fibrous body 6b is made of fibers of different thicknesses, the fibers are not mixed, but are unevenly distributed with fibers of the same thickness. The portion made of thicker fibers has larger gaps than the portion made of thinner fibers, and therefore the capillary force is smaller. According to the ink occlusion body 6 made of the fibrous body 6b made of fibers of two types of thicknesses, the supplied ink is preferentially sucked into the gaps between the thinner fibers, which have a stronger capillary force, and the gaps between the thicker fibers become air passages, facilitating the discharge of air. The fibrous body 6b may be made of fibers of three or more types of thicknesses.

[0039] Experiments conducted using specific examples regarding the presence or absence of the ink refill part 10 of the writing instrument 1 and the difference in the fibers constituting the fibrous body 6b of the ink occlusion body 6 will be described below.

[0040] A cylindrical ink occluder 6 had an outer diameter of 6.5 mm and a total length of 60 mm, and Examples 1 to 8 and Comparative Examples 1 and 2 were prepared as follows. In Examples 1 to 8, the ink occluder was set to a writing instrument having an ink refill section, i.e., a writing instrument having two types of flow paths, an air hole and an ink ejection hole. In Comparative Examples 1 and 2, the ink occluder was set to a writing instrument not having an ink refill section, i.e., a writing instrument with no barrier between the ink storage member and the ink occluder.

[0041] <Example> Example 1: An ink occlusion body obtained by enclosing a fibrous body consisting of 11,000 fibers of 3 dtex and 460 fibers of 2 dtex in an outer skin made of a PET film was set in a writing implement having an ink refill section. Example 2: An ink occlusion body obtained by enclosing a fibrous body consisting of 12,000 fibers of 3 dtex and 500 fibers of 2 dtex in an outer skin made of a PET film was set in a writing implement having an ink refill section. Example 3: An ink occlusion body obtained by enclosing a fibrous body consisting of 10,000 fibers of 3 dtex and 400 fibers of 2 dtex in an outer skin made of a PET film was set in a writing implement having an ink refill section. Example 4: An ink occlusion body obtained by enclosing a fibrous body consisting of 10,000 fibers of 3 dtex and 50 fibers of 15 dtex in an outer skin made of a PET film was set in a writing implement having an ink refill section. Example 5: An ink occlusion body obtained by enclosing a fibrous body consisting of 9,000 fibers of 3 dtex, 460 fibers of 2 dtex, and 50 fibers of 15 dtex in an outer skin of a PET film was set in a writing implement having an ink refill section. Example 6: An ink occlusion body obtained by surrounding a fibrous body consisting of 12,000 fibers of 3 dtex with an outer skin made of nonwoven fabric was set in a writing implement having an ink refill section. Example 7: An ink occlusion body obtained by enclosing a fibrous body consisting of 12,000 fibers of 3 dtex in an outer skin made of a PET film was set in a writing implement having an ink refill section. Example 8: An ink occlusion body obtained by enclosing a fibrous body consisting of 14,000 fibers of 3 dtex in an outer skin consisting of a PET film was set in a writing implement having an ink refill section. <Comparative Example> Comparative Example 1: An ink occlusion body obtained by enclosing a fibrous body consisting of 12,000 fibers of 3 dtex in an outer skin made of a PET film was set in a writing implement having no ink refill section. Comparative Example 2: An ink occlusion body obtained by enclosing a fibrous body consisting of 14,000 fibers of 3 dtex in an outer skin made of a PET film was set in a writing implement having no ink refill part.

[0042] <Experimental Method> The ink occlusion body was soaked with 1.7g of ink in advance, and 1.3g of ink was ejected by writing. Next, an unused ink storage member was attached to the barrel, and 1.2g of ink was supplied to the ink occlusion body. The time it took for the supplied ink to completely soak into the ink occlusion body was measured.

[0043] <Experimental Results> The ink impregnation times in Examples 1 to 8 were 25 seconds in Example 1, 20 seconds in Example 2, 30 seconds in Example 3, 15 seconds in Examples 4 to 6, 45 seconds in Example 7, and 40 seconds in Example 8. The ink impregnation times in Examples 1 to 8 were all within 1 minute, and in particular, the ink impregnation times in Examples 1 to 6 were all good, being within 30 seconds. On the other hand, in Comparative Examples 1 and 2, a portion of the ink remained unimpregnated even after 600 seconds had elapsed in both Comparative Examples 1 and 2.

[0044] Examples 7 and 8 differ from Comparative Examples 1 and 2 corresponding to the ink refill part only in the presence or absence of the ink refill part, but as described above, there is a large difference in the ink soaking time, and the effectiveness of the ink refill part is clear. In detail, the ink forms a concave film due to surface tension inside the barrel behind the ink occluder or on the inner surface of the ink storage member. In this state, when the writing instrument is tilted to move the ink forward, in Comparative Examples 1 and 2 not having the ink refill part, the ink does not come into contact with the ink occluder appropriately, and therefore the ink does not easily penetrate into the ink occluder appropriately. On the other hand, in Examples 1 to 8 having the ink refill part 10, when the entrance of the ink discharge hole 13 comes into contact with the ink liquid surface, the ink is sucked into the ink discharge hole 13 by the action of capillary force. As a result, the ink is discharged from the exit of the ink discharge hole 13 and is efficiently supplied to the ink occluder 6 in sequence.

[0045] In Examples 4 to 6, the ink impregnation time was the shortest at 15 seconds, and the reason is as follows. That is, the ink occluders of Examples 4 and 5 contain thicker 15 dtex fibers compared to other Examples, and the gaps between the fibers are larger compared to other fibers. Therefore, inside one ink occluder, there are two types of capillary force: a stronger capillary force due to a narrower gap between fibers such as 3 dtex, and a weaker capillary force due to a wider gap between fibers of 15 dtex. As a result, the flow of the ink being supplied and the flow of the air being discharged are efficiently performed. In Example 6, since the outer skin is made of nonwoven fabric, air can be well discharged from the inside to the outside of the ink occluder 6 when refilling the ink, and the flow of the ink being supplied and the flow of the air being discharged are efficiently performed. The ink occluders of Examples 1 to 3 contain 2 dtex fibers and 3 dtex fibers, and do not contain 15 dtex fibers. Therefore, the ink soaking time is longer than that of the ink occlusion bodies of Examples 4 and 5 containing 15 dtex fibers, but the flow of the supplied ink and the flow of the exhausted air are efficient.

[0046] For the above reasons, it is preferable that the ink occlusion body is configured to have at least two types of capillary force. The two types of capillary force may be capillary forces obtained due to differences in the fibers that make up the fibrous body, or the effect obtained from the material of the outer skin, such as nonwoven fabric, may also be referred to as capillary force. In other words, the fibrous body may contain one type of fiber and be formed of a material such as nonwoven fabric as the outer skin, thereby having two or more types of capillary force.

[0047] As described above, since the effect of the ink refill section can be obtained regardless of the configuration of the ink occlusion body, the ink occlusion body may be configured not only from a fibrous body made of fibers, but also from a porous body such as a sponge, resin particles, and a sintered body.

[0048] Fig. 10 is a perspective view of the lead holding member 4, Fig. 11 is a vertical cross-sectional view of the lead holding member 4, and Fig. 12 is a cross-sectional view taken along line DD in Fig. 11. The lead holding member 4 has a main body portion 40 formed in a trapezoidal flat plate shape, a fitting portion 41 provided at the rear of the main body portion 40 and configured to fit into the front end of the front barrel 3, a holding groove 42 provided on the outer periphery of the main body portion 40 and the fitting portion 41 and configured to fit a substantially U-shaped writing lead 5, and a visible portion 43 provided on the side of the main body portion 40.

[0049] The visible portion 43 is composed of a through hole 44 provided in the main body portion 40, and three beam members 45 extending in the longitudinal direction of the core holding member 4 inside the through hole 44. As shown in Fig. 12, each of the beam members 45 has a rectangular cross section having approximately the same width and height.

[0050] Providing the beam members 45 in the through holes 44 prevents the lead holding member 4 from bending excessively due to the writing pressure applied during writing. In other words, the flexibility of the lead holding member 4 can be adjusted by adjusting the number, shape, width, etc. of the beam members 45. Furthermore, when writing with the writing instrument 1 which is a marking pen, the user can visually recognize the characters written in the writing direction through the visible portion 43, particularly the through holes 44. The beam members 45 are provided to extend in the longitudinal direction of the through holes 44, but may be provided to extend in an oblique direction or in a lateral direction rotated by 90 degrees.

[0051] The lead holding member 4 is preferably made of a synthetic resin material having a compression set at 120°C of less than 80% and a Shore A hardness of 60 to 95. Specifically, it is a styrene-based elastomer selected from the group consisting of styrene-ethylene-propylene-styrene (SEPS) in which styrene is replaced with p-methylstyrene, styrene-ethylene-ethylene-propylene-styrene (SEEPS) in which styrene is replaced with p-methylstyrene, and styrene-ethylene-butadiene-styrene (SEBS) in which styrene is replaced with p-methylstyrene. By using a styrene-based elastomer for the lead holding member 4, it is possible to obtain appropriate elasticity during writing and to prevent damage to the writing lead 5 due to excessive writing load. [Explanation of symbols]

[0052] 1 writing implements 2 shaft cylinder 3 front axis 4 Core holding member 5 writing lead 6 Ink occluder 10 Ink refill section 11 Bulkhead 12 Ventilation holes 13 Ink ejection hole 14 First cylindrical wall 15 Second cylindrical wall 16 Fitting space 17 Contact projection 18 Slit 20 Ink storage member 21 Small diameter section 22 Male thread 23 Annular protrusion 25 Ink

Claims

1. The device comprises a barrel, an ink-absorbing body disposed within the barrel and impregnated with ink, an ink refill section located behind the ink-absorbing body and having vent holes and ink discharge holes, and an ink storage member that can be attached to the rear end of the barrel and is capable of holding ink. A writing instrument characterized in that when the ink storage member is attached to the rear end of the barrel, the ink in the ink storage member can be supplied to the ink storage body through the ink discharge hole of the ink replenishment section.

2. The writing instrument according to claim 1, wherein the ventilation holes are located closer to the central axis of the barrel than the ink ejection holes, and the ink ejection holes are arranged concentrically around the central axis.

3. An ink storage member for a writing instrument, which can be attached to the rear end of a barrel and contains ink, having an ink refill section with ventilation holes and an ink discharge hole, and an ink-absorbing material that impregnates ink, located inside, An ink storage member characterized in that, when attached to the rear end of the barrel, the ink is supplied to the ink storage body through the ink discharge hole of the ink replenishment section.

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