Writing instrument and writing section replacement unit

Abstract

The present invention provides a writing instrument that makes it possible to easily select a usage method in which writing defects such as line breakage or patchiness of writing (drawn line) can be suppressed or a usage method in which writing including patchiness etc. can be obtained. Provided is a writing instrument which comprises a container main body 2 for accommodating a writing ink, a writing body 7 disposed so as to block an opening part 2c of the container main body, and a cap member 4 removably fitted in the opening part and covering the writing body, and which is capable of writing on a writing surface via effusion of the ink in the container main body from the writing body, wherein: the container main body is provided with a bottom part 2a, a trunk part 2b that is continuous with the bottom part and that extends upward, and an opening part 2c that is continuous with the trunk part and that extends diagonally upward; and the angle of intersection of an axis line Ax1 of the container main body that is orthogonal to the surface of the bottom part in the container main body and an axis line Ax2 of the opening part that passes through the center of the opening part is obtuse.

Description

Technical Field

[0001] This invention relates to a writing instrument that can easily select a usage method capable of suppressing the occurrence of writing defects such as blurs and line skips in handwriting (drawn lines), and a usage method capable of obtaining handwriting including blurs, etc., and a writing part replacement unit preferably used in this writing instrument.

Background Art

[0002] A writing instrument is disclosed in Patent Document where a liquid such as paint, drawing ink, or ink is contained in a container, and the liquid is exuded from a writing part having a relatively large area with continuous pores formed in a synthetic resin material attached to the mouth of the container. In the writing instrument disclosed in this Patent Document 1, the container for containing a liquid such as ink has a planar bottom surface on which the container can be placed on a horizontal surface, and a body portion is formed continuously from this bottom surface and having an outer diameter that decreases upward. And the above-described writing part is attached so as to cover the mouth portion formed at the upper end of the body portion.

[0003] Similar to the writing instrument disclosed in the above-described Patent Document 1, writing instruments that contain a liquid such as ink in a container and exude the liquid from a writing part such as a rubber sponge having a relatively large area attached to the mouth of the container are disclosed in Patent Documents 2 and 3. In the writing instruments disclosed in these Patent Documents 2 and 3, the container is described as being teardrop-shaped. That is, the container body forms a substantially spherical shape, and a cylindrical mouth portion is formed by slightly protruding slenderly from a part thereof, and a writing part made of a sponge or the like is attached so as to cover this mouth portion.

[0004] In each of the writing instruments disclosed in these patent documents, the axis of the mouth portion to which the container body and the writing part are attached is formed on the same straight line. That is, this writing instrument has a structure premised on writing in a posture such that the writing part faces downward with respect to, for example, the paper surface on a desk. This allows for a smooth supply of ink from the container body to the downward-facing writing section, enabling the smooth supply of the necessary amount of ink to a relatively large area of ​​cursive writing. Therefore, it is possible to provide a writing instrument that does not produce smudging, skipped lines, or uneven lines in the handwriting (lines). [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2006-123305 [Patent Document 2] Japanese Patent Publication No. 2013-240895 [Patent Document 3] Japanese Patent Publication No. 2013-240896 [Overview of the project] [Problems that the invention aims to solve]

[0006] In recent years, with improvements in the structure of writing instruments and the development of ink compositions, there has been an increase in proposals for writing instruments that enable writing on a writing surface by allowing paints, pigments, inks, etc., to seep out from a writing part such as a sponge with a relatively large surface area, as disclosed in the aforementioned patent documents, and demand for such instruments is also increasing.

[0007] Accordingly, various proposals have been made for this type of writing instrument, with the aim of obtaining a writing instrument that prevents smudging, skipping lines, and uneven lines in the writing by improving the ink supply to the writing part, as mentioned above. However, on the other hand, there is a potential demand for using the aforementioned writing instruments that can produce thick strokes and lines to obtain unique strokes and lines that include smudging and other variations.

[0008] This invention aims to meet the aforementioned demands and primarily aims to provide a writing instrument that allows for easy selection between a usage method that suppresses handwriting defects such as smudging and skipped lines, and a usage method that produces handwriting that includes smudging and other defects. [Means for solving the problem]

[0009] The writing instrument according to this invention, made to solve the aforementioned problems, comprises a container body for containing writing ink, a writing body positioned to close the mouth of the container body, and a cap member detachably attached to the mouth and covering the writing body, and is a writing instrument that enables writing on a writing surface by causing the ink in the container body to seep out from the writing body, wherein the container body is provided with a bottom, a body that stands upright above the bottom and is continuous with the bottom, and a mouth that stands up diagonally above the body and is continuous with the body, and the angle of intersection between the axis of the container body perpendicular to the surface of the bottom and the axis of the mouth passing through the center of the mouth constitutes an obtuse angle. The writing instrument is positioned with its opening closed by a support ring that supports the writing instrument along its periphery, and the inner surface of the support ring has a plurality of small protrusions that project towards the writing instrument along its circumference. It is characterized by being present.

[0010] In this case, it is desirable that the container body contains a stirring ball for the writing ink, and that the diameter of the stirring ball is larger than the diameter of the opening facing inward of the container, which supports the writing body and is attached to the mouth of the writing section.

[0011] Furthermore, it is desirable that the writing element attached to close the opening be made of a flexible foamed material, and that the writing ink also contains titanium dioxide.

[0012] On the other hand, in the writing instrument according to this invention, preferably, the container body and the cap member attached to the mouth of the container body are covered in a tightly sealed state by a packaging sheet. Furthermore, the packaging sheet is provided with a slit so that a portion of the packaging sheet covering the cap member can be peeled off by the slit, and the slit is formed parallel to the bottom of the container body, along the smallest cross-sectional portion of the container body between the body and the opening of the container body.

[0013] Furthermore, in the writing instrument according to this invention, an additional writing unit that receives ink seeping from the writing body and supplies the ink to the writing surface can be detachably attached as an attachment to the mouth of the container body.

[0014] Furthermore, a writing section replacement unit preferably used in the writing instrument according to this invention comprises: a writing section removal cap member that screws onto the mouth of the container body and has an opening on its top surface; a writing section extraction member formed in a cylindrical shape, with one end inserted into the opening of the writing section removal cap member, and having a flexible portion at the one end that bends in the axial direction, and having a locking portion formed on the flexible portion that can engage with a writing section attached to the mouth of the container body; a bending suppression rod that is inserted into the axial hole of the cylindrical writing section extraction member to suppress the bending movement of the flexible portion in the axial direction; and a spring that surrounds the writing section extraction member and is mounted between the top surface of the writing section removal cap member and the other end of the writing section extraction member. [Effects of the Invention]

[0015] According to the writing instrument of this invention described above, the angle of intersection between the axis of the container body perpendicular to the bottom surface of the container body and the axis passing through the center of the mouth of the container body constitutes an obtuse angle. Therefore, for example, when writing with the bottom of the container body facing upwards on a vertical writing surface, sufficient ink can be supplied to the writing instrument placed at the mouth of the container body. Furthermore, when writing with the bottom of the container facing downwards, the supply of ink to the writing instrument can be restricted.

[0016] Therefore, by selecting the posture of the container body during writing, it is possible to provide a writing instrument that can select a usage method that suppresses the occurrence of writing defects such as blurring and line skipping in the handwriting (drawn lines), and a usage method that can actively obtain handwriting including blurring. Further, by attaching an additional writing unit as an attachment to the above-described writing instrument, the additional writing unit can receive the ink leaking from the writing body of the writing instrument and apply a unique writing style to the writing surface.

[0017] Furthermore, according to the writing part replacement unit used in the writing instrument according to this invention, the writing part attached to the mouth part of the container body constituting the writing instrument can be easily removed by the writing part extraction member in a state where the bending suppression rod is attached. Therefore, it is possible to cope with damage to the writing body and replenishment of the ink in the container body as a shaft cylinder, and contribute to the continuous use of the writing instrument.

Brief Description of the Drawings

[0018] [Figure 1] Shows the external configuration of the entire writing instrument according to this invention, (A) is a front view, (B) is a side view, (C) is a rear view, (D) is a top view, and (E) is a bottom view. [Figure 2] Similarly shows the external configuration of the entire writing instrument, (A) is a perspective view seen along the right side from the front, and (B) is a perspective view seen along the rear from the right side. [Figure 3] Similarly is an enlarged longitudinal sectional view of the entire writing instrument in a state of being cut at the central part. [Figure 4] Shows the external configuration of the writing instrument covered with a packaging sheet, (A) is a perspective view in a state of covering the whole, and (B) is a perspective view in a state of peeling off a part of the packaging sheet from the cut end. [Figure 5] Shows an assembly drawing of the writing part attached to the mouth part of the container body, (A) is a perspective view seen from the writing body side of the front, (B) is a central sectional view, and (C) is a perspective view seen from the rear side. [Figure 6]The individual components of the valve seat member are shown, with (A) being a side view, (B) a longitudinal section view, (C) a perspective view from the front, and (D) a perspective view from the rear. [Figure 7] The individual components of the valve body are shown, with (A) being a front view, (B) a side view, (C) a perspective view from the front, and (D) a perspective view from the rear. [Figure 8] The individual components of the cursive writing are shown, with (A) being a perspective view from the front, (B) being a perspective view from the back, and (C) being a central vertical cross-section. [Figure 9] Figure 8 shows the cursive writing instrument in a partially deformed state when attached to a writing instrument; (A) is a front view, (B) is a side view, and (C) is a central vertical cross-section. [Figure 10] The individual components of the cursive writing support ring are shown, with (A) being a rear view, (B) being an oblique view from the rear, and (C) being a central cross-sectional view. [Figure 11] The individual components of the cap are shown, with (A) being a perspective view from the front, (B) being a central cross-sectional view, and (C) being a perspective view from the rear. [Figure 12] The images show the writing instrument in use. (A) is a side view showing an example of writing with the bottom of the container facing upwards, and (B) is a side view showing an example of writing with the bottom of the container facing downwards. [Figure 13] Figures 1 to 12 show a writing instrument with the first additional writing unit attached as an attachment. These are perspective views of the writing instruments shown in Figures 1 to 12. [Figure 14] The image also shows the writing instrument with the first additional writing unit attached, with (A) being a front view, (B) a central cross-sectional view, and (C) a rear view. [Figure 15] The first additional writing unit is shown, with (A) being a top view, (B) a front view, (C) a central cross-sectional view, and (D) a right side view. [Figure 16] The individual components of the holder constituting the first expansion writing unit are shown, with (A) being a front view, (B) a perspective view from the front, (C) a rear view, (D) a perspective view from the rear, and (E) a central cross-sectional view. [Figure 17] This is a perspective view of a writing instrument with a second additional writing unit attached as an attachment. [Figure 18] The image also shows the writing instrument with the second additional writing unit attached, with (A) being a front view, (B) a central cross-sectional view, and (C) a rear view. [Figure 19] The individual components of the holder constituting the second additional writing unit are shown, with (A) being a front view, (B) a perspective view from the front, (C) a rear view, (D) a perspective view from the rear, and (E) a central cross-sectional view. [Figure 20] This is a perspective view of a writing instrument with a third additional writing unit attached as an attachment. [Figure 21] The image also shows the writing instrument with the third additional writing unit attached, with (A) being a front view, (B) a central cross-sectional view, and (C) a rear view. [Figure 22] This shows the third additional writing unit, with (A) being a front view and (B) being a central cross-sectional view. [Figure 23] This is a perspective view of the deployed state of the third additional writing unit. [Figure 24] This is a central cross-sectional view of the third additional writing unit in its deployed state. [Figure 25] This shows the writing instrument with the fourth additional writing unit attached as an attachment; (A) is a front view and (B) is a side view. [Figure 26] The image also shows the writing instrument with the fourth additional writing unit attached; (A) is a cross-sectional view of the center, and (B) is a perspective view from the front. [Figure 27] This shows the fourth additional writing unit, with (A) being a rear view, (B) a central cross-sectional view, and (C) a perspective view from above. [Figure 28] The overall configuration of the writing section replacement unit is shown, with (A) being a perspective view and (B) being an exploded perspective view. [Figure 29] The overall configuration of the writing section replacement unit is shown, with (A) being a left side view, (B) a front view, (C) a right side view, and (D) a longitudinal cross-sectional view. [Figure 30] The cap component for removing the writing section, which constitutes the writing section replacement unit, is shown in (A) a perspective view with the top surface facing the viewer, and (B) a perspective view with the top surface facing the rear. [Figure 31] This is a perspective view showing the individual components of the writing section extraction member that makes up the writing section replacement unit. [Figure 32] The initial state of the writing instrument with the writing section replacement unit attached is shown, with (A) being a perspective view and (B) being a longitudinal cross-section. [Figure 33] The first state in which the writing instrument has the writing section replacement unit attached is shown, with (A) being a perspective view and (B) being a longitudinal cross-section. [Figure 34] The second state, in which the writing instrument is fitted with a writing section replacement unit, is shown, with (A) being a perspective view and (B) being a longitudinal cross-section. [Figure 35] The images show the writing section removed from the writing instrument using the writing section replacement unit; (A) is a perspective view and (B) is a longitudinal cross-section. [Figure 36] The final state after removing the writing section from the writing section replacement unit is shown; (A) is a perspective view and (B) is a longitudinal cross-section. [Modes for carrying out the invention]

[0019] The writing instrument according to this invention will be described based on the embodiment shown in the figure. Figures 1 to 3 show the overall configuration of the writing instrument according to this invention, with Figure 3 being an enlarged cross-sectional view. Therefore, the overall configuration of the writing instrument according to this invention will first be explained based on Figure 3. In the following diagrams, the same parts are indicated by the same reference numerals. However, in some diagrams, due to space limitations, representative parts are indicated by different reference numerals. Details of each part will be explained by referring to the reference numerals used in the diagrams showing the individual component configurations.

[0020] The writing instrument 1 according to this invention is equipped with a bottle-shaped container body 2 for containing writing ink (not shown), as shown in Figures 1 to 3. The container body 2 is made of a flat plate with an elliptical bottom 2a (see Figure 1(E)) so that it can be placed on a horizontal surface, and a body portion 2b is formed that stands upright at the top, continuous with the bottom 2a. This body portion 2b constitutes an inclined body portion 2b1 in which the upright surface on the front side of the container body 2, that is, the upright surface on the left side of the container body 2 as shown in Figure 3, decreases in diameter towards the center of the container body 2 as it rises upward. Furthermore, the upright surface on the back side of the container body 2, that is, the upright surface on the right side of the container body 2 as shown in Figure 3, constitutes an upright body portion 2b2 that is substantially perpendicular to the bottom portion 2a mentioned above.

[0021] Furthermore, a neck portion 2b3 is formed at the upper part of the upright body portion 2b2, which curves toward the front side of the container body 2, and a cylindrical mouth portion 2c is integrally formed along the curved surface of this neck portion 2b3, rising diagonally upward. As a result, the intersection angle between the axis Ax1 of the container body 2, which is perpendicular to the surface of the bottom portion 2a of the container body 2, and the axis Ax2 of the opening portion 2c, which passes through the center of the opening portion 2c, is obtuse. In the illustrated example, the intersection angle between the axis Ax1 of the container body 2 and the axis Ax2 of the opening portion 2c is set to approximately 120 degrees.

[0022] Furthermore, the mouth portion 2c is configured to be located directly above the inclined body portion 2b1, which, as explained earlier, narrows in diameter towards the center of the container body 2 as it rises upward. This ensures that the weight balance is considered so that the center of gravity of the entire writing instrument 1, including the writing section 3 which will be described later and attached to the mouthpiece 2c, does not shift to the front side of the container body 2 on which the mouthpiece 2c is formed. In addition, multiple finger-receiving recesses 2d are formed on the front and back sides of the container body 2, allowing the fingertips to be placed when the container body 2 is grasped. These finger-receiving recesses 2d function as an anti-slip feature when the container body 2 is grasped.

[0023] The container body 2 is preferably molded from a flexible synthetic resin. This results in a squeeze container that can be deformed by lightly pressing the left and right sides of the container body 2 with a hand or the like.

[0024] Furthermore, a writing section 3, which is attached to the mouth 2c of the container body 2, contains a writing body 7, which will be described later, that allows writing by releasing ink from inside the container body 2, and is positioned in a state that closes the mouth 2c. Then, a cap member 4 that covers the writing body 7 is detachably attached using a male screw 2e formed on the circumferential surface of the cylindrical part that constitutes the mouth 2c, thereby forming the writing instrument 1.

[0025] Figure 4 shows the external appearance of the writing instrument 1 covered with the packaging sheet 11, and in Figure 4, the packaging sheet 11 is shown with hatching. The packaging sheet 11 is made of a heat-shrinkable resin sheet molded into a cylindrical shape, for example, and is tightly fitted to the outer casing of the writing instrument 1. Figure 4(A) shows the entire writing instrument 1 covered with the packaging sheet 11, indicating that the product (writing instrument 1) is unused. Figure 4(B) shows the product (writing instrument 1) ready for use, with the cap release sheet 11b separated from the body side sheet 11a using the dotted lines 11c on the packaging sheet 11.

[0026] Furthermore, it is desirable that the dashed cuts 11c made in the packaging sheet 11 be pre-formed in a portion of the heat-shrinkable resin sheet. When the resin sheet is heat-shrinkable and in close contact with the container body 2, the position of the dashed cuts 11c is set to be parallel to the bottom 2a of the container body 2, along the smallest cross-sectional portion of the container body 2 between the body portion 2b and the opening portion 2c of the container body 2 as shown in Figure 3. By setting the position of the dashed cut 11c in this way, the majority of the outer casing of the container body 2, which has a special shape, can be covered by the body-side sheet 11a. Therefore, by pre-printing the product name and logo of the writing instrument 1 on the heat-shrinkable resin sheet corresponding to the main body sheet 11a, it becomes possible to provide a writing instrument 1 with the product name and logo displayed, utilizing the large area of ​​the main body sheet 11a.

[0027] Figure 5 shows a writing section 3 attached to the mouth 2c of the container body 2. This writing section 3 consists of a valve seat member 5 which is cylindrical and has a valve opening on its front surface, a valve body member 6 which is housed within the valve seat member 5 and has a valve body that is biased by a spring, a sheet-like writing body 7 which is attached to the front side of the valve seat member 5 and positioned to cover the mouth 2c of the container body 2, and a writing body support ring 8 which attaches the peripheral edge of the writing body 7 to the valve seat member 5. In the following, each of the aforementioned components constituting the writing section 3 will be described based on the drawings showing their individual components.

[0028] Figure 6 shows the individual components of the valve seat member 5 that constitutes the writing section 3. The valve seat member 5 is formed in a cylindrical shape overall, with its front portion closed and a valve opening 5a in its center. The area around this valve opening 5a is tapered, with the inner diameter decreasing towards the front side. The frustoconical valve body 6c of the valve body member 6, which will be described later, is fitted onto this valve opening 5a to close the valve. The outer circumferential surface of the valve seat member 5 is formed to have the same diameter along the axial direction, forming a fitting portion 5b into the mouth 2c of the container body 2. A tapered portion 5c is formed along the rear half of the tapered portion 5c, slightly reducing the outer diameter. This tapered portion 5c functions as a guide when attaching the writing portion 3 to the mouth 2c of the container body 2.

[0029] On the front side of the fitting portion 5b of the valve seat member 5, a flange portion 5d with a larger diameter than the fitting portion 5b is formed, and this flange portion 5d abuts against the front end of the mouth portion 2c of the container body 2 and serves the function of positioning the writing portion 3. Furthermore, an annular locking portion 5e is formed within the opening at the rear end of the valve seat member 5, protruding inward. This annular locking portion 5e functions as a stopper to prevent the valve body member 6, which will be described later, from falling out when it is installed inside the valve seat member 5. Furthermore, an annular projection 5f is formed on the front side of the valve seat member 5, which supports the writing instrument 7 (described later) from its rear side and serves to position the writing instrument 7.

[0030] Figure 7 shows the individual components of the valve body member 6 that constitutes the writing section 3. The valve body member 6 is integrally molded from elastic synthetic resin and is equipped with three spring bodies 6b that extend spirally upward from a ring body 6a. These spring bodies 6b are arranged at 120-degree intervals in the circumferential direction of the ring body 6a, and a frustoconical valve body 6c is formed at the upper end of each spring body 6b. A valve stem 6d is molded in the center of the valve body 6c so as to protrude from it.

[0031] The outer diameter of the ring body 6a is approximately equal to the inner diameter of the cylindrically formed valve seat member 5, and is slightly larger than the inner diameter of the annular locking portion 5e. Therefore, by inserting and pushing the valve stem 6d of the valve body member 6 from the annular locking portion 5e side at the rear end of the valve seat member 5, the rear ring body 6a overcomes the annular locking portion 5e of the valve seat member 5 and is housed inside the valve seat member 5. The ring body 6a of the valve body member 6 is then positioned inside the valve seat member 5 while locked to the annular locking portion 5e of the valve seat member 5 [see Figure 5(B)]. As a result, the valve body 6c contacts the valve opening 5a, closing the valve, while the central valve stem 6d protrudes slightly forward from the valve opening 5a. In other words, the writing section 3 is equipped with a stopper (valve valve) 3a formed by the valve opening 5a of the valve seat member 5 and the valve body 6c of the valve body member 6.

[0032] Figure 8 shows the individual components of the cursive writing font 7 that make up the writing section 3. This cursive font 7 is formed using a flexible foamed sheet material. This foamed sheet material can preferably be open-cell urethane or polyethylene, or even rubber sponge; however, from the viewpoint of durability, foamed urethane is preferred. This cursive writing 7 is made from the aforementioned foam sheet material cut into a circular shape, and in accordance with the shape of the front side of the valve seat member 5, a spherical convex portion 7a is formed in the center, a short cylindrical portion 7b is formed around the periphery of the spherical convex portion 7a, and an annular flange portion 7c is formed outward at the end of the cylindrical portion 7b. Furthermore, the portion of the cursive writing 7 that forms the spherical protrusion 7a in the center retains the same thickness as the aforementioned foamed sheet material, while the short cylindrical portion 7b and flange portion 7c around its periphery are formed, for example, by press working, so that they are thinner than the spherical protrusion 7a.

[0033] Figure 9 shows the cursive writing font 7 shown in Figure 8 in a state where a part of it has been deformed after being attached to the writing section 3 shown in Figure 3. In other words, on the back side of the aforementioned spherical protrusion 7a, a recess 7d is formed, which is deformed by the tip of the valve stem 6d that protrudes from the central part of the valve seat member 5, as shown in Figure 9(C). Furthermore, on the back side of the spherical protrusion 7a, an annular recess 7e is formed along the inside of the cylindrical portion 7b, surrounding the aforementioned central recess 7d. This is deformed when the annular projection 5f that protrudes from the front side of the valve seat member 5 comes into contact with it. Furthermore, on the front side of the annular flange portion 7c, numerous recesses 7f are formed by multiple small protrusions 8d that are formed on the support ring 8 side, which is deformed by being pressed by the cursive writing support ring 8 described later. In addition, on the back side of the flange portion 7c, a groove 7g is formed, which is deformed by being pressed by the valve seat member 5.

[0034] Figure 10 shows the individual components of the writing support ring 8 that constitutes the writing section 3. The support ring 8 supports the surface-shaped cursive writing instrument 7 along its periphery by pressing the periphery of the cursive writing instrument 7, which is attached to the front surface of the valve seat member 5, along the front side periphery of the valve seat member 5. This support ring 8 is molded from a resin material and has a tapered surface 8a whose outer diameter slightly decreases from the back side to the front side. Inside it, an annular first stage 8b and a second stage 8c are molded concentrically, with their inner diameters decreasing from the back side to the front side.

[0035] Furthermore, the second stage portion 8c has a series of small protrusions 8d that project toward the rear side, formed continuously along its circumference. Therefore, the writing body 7, which is pressed against the front surface of the valve seat member 5 by this support ring 8, is supported by the multiple small protrusions 8d so as not to loosen. The writing portion 3 shown in Figure 5 is formed by welding this support ring 8 along the flange portion 5d of the valve seat member 5. The writing section 3 is then attached to the mouth 2c of the container body 2 using the tapered portion 5c of the valve seat member 5, and fitted into the mouth 2c of the container body 2 by the fitting portion 5b of the valve seat member 5 [see Figure 3].

[0036] Figure 11 shows the individual components of the cap member 4. This cap member 4 has a cylindrical shape with its end closed by a top surface 4a, and its outer circumferential surface is continuously provided with numerous knurled grooves 4b that are groove-shaped indentations along the axial direction. Furthermore, a female thread 4c is provided on the inner circumferential surface on the opening side, and a ring-shaped projection ring 4d is formed on the back side of the top surface 4a, located behind the female thread 4c, projecting in the axial direction.

[0037] As shown in Figure 3, the cap member 4 is attached to the mouth 2c of the container body 4 by screwing the female thread 4c of the cap member 4 onto the male thread 2e of the mouth 2c. This allows the writing instrument 1 to be stored with the writing tip 7 of the writing section 3 covered. At this time, the protruding ring 4d inside the cap member 4 comes into contact with the writing body support ring 8 of the writing section 3, sealing the writing body 7, thereby suppressing the evaporation of the ink solvent from the writing body 7.

[0038] In the aforementioned writing instrument 1, as shown in Figure 3, writing ink (not shown) is contained within the container body 2 along with a stirring ball 9. The stirring ball 9 is made of hard ball or glass ball, and it is preferable to select a ball diameter D1 of the stirring ball 9 that is larger than the opening diameter D2 of the writing section 3 that supports the writing body 7 and is attached to the mouth 2c, which faces inward into the container. In other words, in this embodiment, as shown in Figure 3, the ball diameter D1 of the stirring ball 9 is selected to be larger than the inner circumference diameter D2 of the annular locking portion 5e of the valve seat member 5. This allows the large-diameter, heavy stirring ball 9 to effectively stir the sedimentation of the coloring agent in the writing ink used in this type of writing instrument, which has a relatively wide line width. This helps to prevent unevenness in the writing line (uneven coloring, etc.).

[0039] A preferred writing ink to be contained in the container body 2 is an ink composition comprising at least pigment particles, wet silica, hydrated kaolin, a flocculation control agent, and water, wherein the pigment particles contain titanium dioxide, and the content of the flocculation control agent is 0.05% to 1.0% by mass, based on the total mass of the writing ink.

[0040] Examples of pigment particles include inorganic pigments such as metal oxides or metal salts, and organic pigments such as organic dye pigments or lake pigments. Among inorganic pigment particles, metal oxide particles are particularly preferred. Titanium dioxide is particularly preferred because, being white, it can be combined with complementary pigments, as described later, to achieve a wide range of colors. Furthermore, using titanium dioxide with an alumina surface treatment is particularly preferred because it improves dispersion stability. In addition, glossy, lustrous pigments, such as aluminum pigments, can also be used as pigments. The average particle size of the pigment particles is preferably 0.1 μm to 10 μm. The average particle size described herein can be measured by the particle size (D50) at 50% volume accumulation of the particle size distribution measured by laser diffraction using a laser diffraction particle size distribution analyzer (product name "MicrotracHRA9320-X100", Nikkiso Co., Ltd.). Unless otherwise specified, this refers to the average particle size based on volume. The pigment particle content in the ink composition is preferably 10 to 40% by mass, based on the total mass of the ink composition. If the pigment particle content is within the above numerical range, a decrease in ink ejection performance can be prevented, and the opacity of the ink composition and the writing formed using it can be maintained.

[0041] Wet silica is amorphous silica synthesized by a wet process, consisting of aggregated primary particles of several to tens of nanometers in size, and secondary particles of several to tens of micrometers in size, which are difficult to form as primary particles through dispersion. In this invention, wet silica has a higher specific surface area and more silanol groups on its surface compared to dry silica, and therefore forms a loose crosslinking network through interaction with pigment particles. As a result, it can form loose, bulky aggregates with flocculation control agents and flocculation dispersants, and by including wet silica in the ink composition, the dispersion stability of pigment particles is improved, and the redispersibility of the aggregates can be further improved. On the other hand, when dry silica is used, dispersion stability can be maintained, but even a small amount of addition causes structural viscosity, increasing the ink viscosity, which is undesirable. Furthermore, when paper is used as the writing surface, wet silica exhibits a strong sealing effect, preventing pigment particles from penetrating between the paper fibers, and when used in combination with hydrated kaolin, as described later, it enhances the color development of the writing. The average particle size of wet silica is preferably 1 μm to 5 μm. If the average particle size of wet silica is within the above range, stable dispersion in the ink composition is possible, and a high effect of suppressing pigment sedimentation can be obtained. The content of wet silica in the ink composition is preferably 1% to 3% by mass, based on the total mass of the ink composition.

[0042] The flocculation control agent binds to the relatively low-density aggregates formed by the wet silica described above, and further disperses hydrated kaolin and extenders, described later, in the ink composition to create bulky aggregates. This flocculation control agent prevents the ink composition from becoming a hard cake and improves redispersibility by creating bulky aggregates. As the flocculation control agent, for example, a cellulose derivative can be used, and two or more cellulose derivatives can be used in combination. Examples of cellulose derivatives include carboxymethylcellulose, methylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, hydroxypropylethylcellulose, and their salts. The content of the flocculation control agent in the ink composition is preferably 0.1 to 0.5% by mass, based on the total mass of the ink composition.

[0043] Hydrated kaolin is a flat or plate-shaped natural clay mineral mainly composed of aluminum silicate containing crystal water, obtained by refining kaolin clay, a natural clay mineral. In the present invention, as described above, hydrated kaolin has a flat or plate-shaped particle form. Therefore, when paper is used as the writing surface, the inclusion of hydrated kaolin in the ink composition provides a strong sealing effect, preventing pigment particles from penetrating between the paper fibers and further enhancing the color development of the writing. Furthermore, because hydrated kaolin is uniformly dispersed in the ink composition within relatively low-density aggregates formed by pigment particles, wet silica, and a flocculation control agent, it creates bulky aggregates despite their relatively low density, thus improving redispersibility compared to the case where calcined kaolin is used. Furthermore, due to its flat or plate-like particle shape, hydrated kaolin is placed parallel to the paper surface when writing, preventing scratching of the paper even when writing over it, thus allowing writing without damaging the paper. The average particle size of hydrated kaolin is preferably 0.5 μm to 2 μm. If the average particle size of hydrated kaolin is within the above range, the redispersibility of the ink composition and the color development of the writing can be improved, and the paper surface can be prevented from being damaged. The content of hydrated kaolin in the ink composition is preferably 5% to 15% by mass, based on the total mass of the ink composition. If the content of hydrated kaolin is within the above range, the ink viscosity will not become too high, hard cake formation will not occur, and the paper surface can be prevented from being damaged when writing. Furthermore, the opacity of the ink composition and the writing formed using it can be maintained.

[0044] In addition, other components such as resins, flocculants / dispersants, extenders, complementary pigments, surfactants, preservatives, wetting agents, defoamers, rust inhibitors, pH adjusters, bubble inhibitors, bubble absorbers, shear viscosity reducers, and viscosity modifiers may be added as needed, provided they do not affect the performance of the ink as a writing instrument ink.

[0045] The viscosity of the ink composition is preferably 1 to 20 mPa·s. The viscosity of the composition can be measured using a rotational viscometer (TV-20, manufactured by TOKIMEC) at 25°C and 10 rpm. If the viscosity of the ink composition is within the above numerical range, the ink ejection performance when used in writing instruments such as markers can be improved, and the writing performance on non-permeable recording media such as films can also be improved.

[0046] As described above, the writing section 3 of the writing instrument 1 in this embodiment is equipped with an internal stopper (valve valve) 3a [see Figure 5(B)] consisting of the valve opening 5a of the valve seat member 5 and the valve body 6c of the valve body member 6. Therefore, by pressing the writing tip 7 against the writing surface, the valve stem 6d of the valve member 6 can be retracted against the biasing force of the spring body 6b via the writing tip 7. This releases the seal of the valve body 6c on the valve opening 5a, and the ink in the container body 2 is supplied to the writing tip 7 through the opened stopper 3a and absorbed. Then, the ink seeps out from the writing tip 7 toward the writing surface, and writing is performed.

[0047] Figure 12 shows an example of the writing instrument 1 according to this invention in use. In this example, (A) shows the case where writing is performed with the bottom 2a of the container body 2 facing upwards relative to the vertical writing surface 15, and (B) shows the case where writing is performed with the bottom 2a of the container body 2 facing downwards relative to the vertical writing surface 15.

[0048] As shown in Figure 12(A), when writing with the bottom 2a of the container body 2 facing upwards on a vertical writing surface 15, sufficient ink can be supplied to the writing instrument 7 positioned at the mouth 2c of the container body 2. This makes it possible to draw while suppressing handwriting defects such as smudging and skipped lines. Furthermore, as shown in Figure 12(B), when writing with the bottom 2a of the container body 2 facing downwards on a vertical writing surface 15, the supply of ink to the writing instrument 7 can be restricted. This makes it possible to obtain drawings that include smudging or other imperfections in the handwriting (lines).

[0049] In the above-described embodiment, the writing section 3 attached to the mouth 2c of the container body 1 is equipped with an inner stopper (valve valve) 3a including a valve opening 5a and a valve body 6c. However, the writing instrument according to this invention does not necessarily require the inner stopper, and can also be used in a direct-ink type writing instrument in which the ink in the container body 1 directly permeates the writing instrument 7.

[0050] Next, Figures 13 to 27 show an example in which an additional writing unit is provided, which is detachably attached as an attachment to the writing instrument 1 described above, and which receives the ink seeping from the writing body 7 of the writing instrument 1 and makes it possible to supply the ink to the writing surface. First, Figures 13 to 16 show an example of a first additional writing unit attached to the writing instrument 1 as an attachment. This first additional writing unit consists of a roller writing unit 21 attached to the mouth 2c of the container body of the writing instrument 1.

[0051] As shown in Figures 13 and 14, the roller writing unit 21 includes a holder 22 attached to the mouth 2c of the container body 2 of the writing instrument 1, a support rod 23 locked to the holder 22, a writing roller 24 rotatably supported by the support rod 23, and an ink transfer roller 25 interposed between the writing roller 24 and the holder 22 to send ink supplied from the writing instrument 1 to the writing roller 24.

[0052] As shown in Figure 16 in its individual component configuration, the holder 22 is entirely molded from a resin material. The front half of the holder 22 has an arc-shaped recess 22a in which the ink transfer roller 25 is housed, while the rear half of the holder 22 is cylindrical, and its inner surface is fitted with an internal thread 22b. The female thread 22b is screwed into the male thread 2e (see Figure 3) provided on the mouth portion 2c of the container body of the writing instrument 1, thereby allowing the holder 22 to be detachably attached to the mouth portion 2c of the writing instrument 1.

[0053] The inner bottom surface of the recessed portion 22a on the front side of the holder 22 has five linearly arranged openings 22c, each opening 22c passing through to the back side of the holder 22. A small projection 22d (see Figure 16(E)) is provided surrounding the central opening 22c on the back side. When the holder 22 is attached to the mouth 2c of the container body, the small projection 22d acts to push back the valve member 6 via the writing tip 7 of the writing instrument 1, thereby opening the aforementioned inner stopper 3a [see Figure 5(B)]. As a result, ink from the writing instrument 1 is supplied to the roller writing unit 21 via the writing tip 7.

[0054] The recessed portion 22a of the holder 22 is provided with a linear opening communication groove 22e connecting five openings 22c, and an arc groove 22f is provided along the recessed portion 22a in each of the openings 22c, intersecting the opening communication groove 22e. The opening communication groove 22e and each arc groove 22f work together to evenly supply the ink supplied from the writing instrument 1 to the ink transfer roller 25 housed in the recessed portion 22a. Furthermore, on both outer sides in the longitudinal direction of the recessed portion 22a of the holder 22, a pair of parallel locking protrusions 22g are formed, extending in the front-rear direction of the holder 22, and a locking groove 22h is formed between the pair of locking protrusions 22g, into which the aforementioned support rod 23 is fitted and attached.

[0055] The support rod 23 is formed by bending a round metal rod into a U-shape, and its central bend 23a is curved in an arc shape. This arc-shaped curved central bend 23a is positioned along the side of the holder 22. Furthermore, the tips of each leg portion 23b of the support rod 23, which is supported by the locking groove 22h, are bent inward toward each other, and these bent portions 23c are inserted into the shaft hole 24a of the writing roller 24 as shown in Figure 13, thereby rotatably supporting the writing roller 24. The ink transfer roller 25, which has a smaller diameter than the writing roller 24, is housed in the aforementioned recessed portion 22a formed in the holder 22, and its front side contacts the writing roller 24, thereby preventing it from falling out of the holder 22 and allowing it to be rotatably held by the holder 22.

[0056] The ink transfer roller 25 is molded from a flexible, ink-impregnable material, such as a rubber sponge. The writing roller 24 can preferably be made of a cylindrical base material with felt or similar material wrapped around its outer surface. Then, by positioning the writing roller 24 of the roller writing unit 21 downwards and rolling the writing roller 24 on the writing surface, ink from the writing instrument 1 can be supplied to the writing roller 24 via the ink transfer roller 25, which is rolled by the writing roller 24. This makes it possible to write on the writing surface using the entire length of the writing roller 24.

[0057] Figures 17 to 19 show an example of a second additional writing unit attached to the writing instrument 1 as an attachment. This second additional writing unit consists of a thick brush unit 31 attached to the mouth 2c of the container body of the writing instrument 1. As shown in Figures 17 and 18, this thick brush unit 31 consists of a holder 32 that is detachably attached to the mouth 2c of the container body 2 of the writing instrument 1, and a writing brush 33 made of bundled natural or synthetic fibers formed into a rectangular prism shape attached to the front end of the holder 32.

[0058] As shown in Figure 19 in its individual component configuration, the holder 32 is entirely molded from a resin material. The front half of the holder 32 has an opening 32a for attaching the writing brush 33, and the rear half of the holder 32 is formed in a cylindrical shape, with an internal thread 32b on the inner surface of the cylinder. The female thread 32b is screwed into the male thread 2e (see Figure 3) provided on the mouth portion 2c of the container body of the writing instrument 1, thereby allowing the holder 32 to be detachably attached to the mouth portion 2c of the writing instrument 1.

[0059] The rectangular opening 32a for the writing brush 33, formed on the front side of the holder 32, has three openings 32c at its inner bottom, and each opening 32c penetrates to the back side of the holder 32. A small projection 32d (see Figure 19(E)) is provided to surround the central opening 32c on the back side. When the holder 32 is attached to the mouth 2c of the container body, the small projection 32d acts to push back the valve member 6 via the writing tip 7 of the writing instrument 1, thereby opening the aforementioned inner stopper 3a [see Figure 5(B)]. As a result, ink from the writing instrument 1 is supplied to the thick brush unit 31 side via the writing tip 7.

[0060] The base end of the writing brush 33, which is formed by bundling natural or chemical fibers into a rectangular prism shape, is fitted into the rectangular brush mounting opening 32a on the front side of the holder 32. In this case, the strength of the attachment of the writing brush 33 to the holder 32 can be improved by using adhesive as needed. In this embodiment, by positioning the writing brush 33 of the aforementioned thick brush unit 31 downwards, ink from the writing instrument 1 is supplied to the writing brush 33 through the opening 32c provided in the holder 32. This makes it possible to write on the writing surface using the writing brush 33.

[0061] Although the writing brush 33 described above uses a bundle of natural or synthetic fibers formed into a rectangular prism shape, similar effects can be obtained by using a rectangular prism shape made of open-cell rubber sponge or the like instead of natural or synthetic fibers as the writing brush 33.

[0062] Figures 20 to 24 show an example of a third additional writing unit attached to the writing instrument 1. This third additional writing unit consists of a fine brush unit 41 attached to the mouth 2c of the container body of the writing instrument 1. As shown in Figures 20 and 21, this fine brush unit 41 consists of first to third subholders 42-44 that are detachably attached to the mouth 2c of the container body 2 of the writing instrument 1, and a writing brush 45 formed by bundling natural or chemical fibers and attaching them to the tip via each subholder 42-44 to create a tapered round brush shape.

[0063] As shown in Figures 23 and 24, which depict the first to third subholders 42 to 44 in their individual configurations after unfolding, the first to third subholders 42 to 44 are each molded from a resin material. The first subholder 42 has an opening with a female thread 42a in the center of its front side, and its back side is formed in a cylindrical shape with a large-diameter female thread 42b on the inner surface of the cylinder. This female thread 42b is screwed into the male thread 2e (see Figure 3) provided on the mouth 2c of the container body of the writing instrument 1, thereby allowing the fine brush unit 41 to be detachably attached to the mouth 2c of the writing instrument 1.

[0064] The second subholder 43 is equipped with a shaft 43b having a central shaft hole 43a, and a short cylindrical body 43c surrounding the shaft 43b is formed in the front half, with an internal thread 43d on the inner surface of the cylindrical body 43c. The shaft 43b protruding from the rear half of the second subholder 43 is also equipped with an external thread 43e. Furthermore, the third subholder 44 is provided with an axial hole 44a for housing and supporting a writing brush 45 consisting of a tapered round brush, which will be described later. The front half of the third subholder 44 is tapered, narrowing slightly towards the tip. In addition, a male screw 44b is provided on the outer circumference of the rear half of the third subholder 44. Furthermore, as described above, the writing brush 45 is formed by bundling natural or synthetic fibers together into a tapered, round brush shape (a so-called bullet shape), and an ink introduction hole 45a is formed along the axis of the rear half thereof.

[0065] Figure 22 shows the assembled state of the fine brush unit 41, which is formed by connecting the first to third sub-holders 42 to 44 and attaching the writing brush 45 to the tip. An example of the assembly process will be explained based on Figure 24. First, the male thread 43e on the second subholder 43 is screwed into the female thread 42a formed in the center of the front surface of the first subholder 42, thereby connecting the second subholder 43 to the first subholder 42.

[0066] Next, the tip of the writing brush 45 is inserted into the shaft hole 44a from the rear side of the third subholder 44, and the male thread 44b on the third subholder 44 is screwed into the female thread 43d on the cylindrical body 43c of the second subholder 43. This allows the third subholder 44 to be connected to the second subholder 43. This connecting operation pushes the writing brush 45 in the third sub-holder 44 into the shaft hole 44a of the third sub-holder 44 by the tip of the shaft 43b of the second sub-holder 43. As described above, the shaft hole 44a of the third sub-holder 44 is formed in a tapered shape that narrows slightly towards the tip, so the tip of the writing brush 45 protrudes from the third sub-holder 44, and the rear half of the writing brush 45 is fitted into the shaft hole 44a of the third sub-holder 44 without any looseness.

[0067] The fine brush unit 41 assembled according to the above procedure is attached to the writing instrument 1 by screwing the female thread 42b on the first subholder 42 into the male thread 2e (see Figure 3) on the mouth 2c of the container body of the writing instrument 1, as described above. At this time, as shown in Figure 22(B), the rear end of the shaft 43b of the second subholder 43 protrudes into the first subholder 42, and this rear end of the shaft 43b pushes back the valve member 6 via the writing tip 7 of the writing instrument 1, causing the aforementioned stopper 3a [see Figure 5(B)] to open. Therefore, ink from the writing instrument 1 is supplied to the fine brush unit 41 via the writing body 7, and the ink is supplied to the writing brush 45 through the shaft hole 43a of the second subholder 43 and the ink introduction hole 45a provided in the writing brush 45. This makes it possible to write on the writing surface with the writing brush 33.

[0068] Although the aforementioned writing brush 45 uses natural or synthetic fibers bundled together and shaped into a tapered, rounded brush, similar effects can be obtained by using an open-cell rubber sponge or the like, shaped into a tapered, rounded brush, instead of the natural or synthetic fibers, as the writing brush 45.

[0069] Figures 25 to 27 show an example of a fourth additional writing unit attached to the writing instrument 1 as an attachment. This fourth additional writing unit consists of a sputtering unit 51 attached to the mouth 2c of the container body of the writing instrument 1. This sputtering unit 51 consists of a unit holder 52 that is detachably attached to the mouth 2c of the container body 2 of the writing instrument 1, and a hand rotary tool 54 that is attached to the unit holder 52 and has a rotating brush 53 positioned near the mouth 2c of the container body 2.

[0070] As shown in Figure 27(B), the unit holder 52 is formed in an L-shape from, for example, a resin material, with a cylindrical portion 52a at its top and a female thread 52b on the inner surface of the cylindrical portion 52a. The writing instrument 1 is attached to the unit holder 52 by screwing the male thread 2e (see Figure 3) on the mouth portion 2c of the container body of the writing instrument 1 into this female thread 52b (see Figure 26). Furthermore, an opening 52c for mounting a hand rotary tool 54 is formed in the L-shaped bent bottom of the unit holder 52, and the rotating brush 53 of the hand rotary tool 54, which is attached to this opening 52c, is positioned directly in front of the cylindrical portion 52a of the unit holder 52.

[0071] A metal mesh 52d is positioned on the front side of the cylindrical portion 52a formed in the unit holder 52, and this metal mesh 52d is supported by a retaining ring 52e that is screwed into the front side of the cylindrical portion 52a. Furthermore, the retaining ring 52e has a rotating brush 53 in the center, with an umbrella-shaped portion 52f that protrudes from one side towards the front side of the metal mesh 52d, integrally formed with the retaining ring 52e, and a notched opening 52g [see Figure 25] formed on the other side so as to be flush with the front side of the metal mesh 52d.

[0072] The aforementioned hand rotary tool 54 has an elongated cylindrical outer shell, and its bottom forms a battery case 54a in which dry cell batteries are housed. A micromotor housing chamber 54b is formed at the top of the battery case 54a. The aforementioned rotating brush 53 is attached to the tip of the rotating drive shaft 54c of the micromotor, which is positioned upward from the micromotor housing chamber 54b. In this embodiment, the hand rotary tool 54 is attached to the unit holder 52 by fitting the micromotor housing chamber 54b into the hand rotary tool mounting opening 52c.

[0073] In the sputtering unit 51 described above, the writing instrument 1 can be attached to the unit holder 52 by screwing the male thread 2e provided on the mouth portion 2c of the container body of the writing instrument 1 into the female thread 52b in the cylindrical portion 52a formed in the unit holder 52. As described above, when the writing instrument 1 is attached to the sputtering unit 51, the metal mesh 52d positioned in the unit holder 52 pushes back the valve member 6 via the writing tip 7 of the writing instrument 1, opening the aforementioned stopper 3a [see Figure 5(B)]. As a result, ink from the writing instrument 1 seeps out through the writing tip 7 towards the metal mesh 52d.

[0074] In this state, by rotating the micromotor of the hand rotary tool 54, the rotating brush 53 attached to the tip of the rotating drive shaft 54c rotates to the right (clockwise) when viewed from the tip side. As a result, the tip of the rotating brush 53 is subjected to centrifugal force and spreads circumferentially, causing a portion of the rotating brush 53 to rotate while in contact with the surface of the metal mesh 52d. Consequently, the ink that seeps out onto the metal mesh 52d is sputtered (flyed) in a direction along the surface of the metal mesh 52d, creating a unique speckled pattern on the writing surface.

[0075] Furthermore, in the sputtering unit 51 described above, the retaining ring 52e that holds the metal mesh 52d in place on the front side has a notched opening 52g formed therein, as described above. This notched opening 52g reduces the degree to which it interferes with the flight of ink particles that are ejected along the surface direction of the metal mesh 52d, and contributes to the normal sputtering operation of the ink.

[0076] Figures 28 to 36 show a writing section replacement unit 61 according to this invention, which is detachably attached to the mouth 2c of the container body 2 of the writing instrument 1 shown in Figures 1 to 12. The writing section replacement unit 61 then functions to allow the writing section 3 attached to the mouth 2c to be easily removed. As shown in Figures 28 and 29, the writing section replacement unit 61 is composed of a cap member 62 for removing the writing section, a writing section extraction member 63, a deflection suppression rod 64, and a coil-shaped spring 65.

[0077] Figure 30 shows the individual components of the cap member 62 for removing the writing section. This cap member 62 has an opening 62b in the center of its top surface 62a, into which one end of the writing section extraction member 63 is inserted from the outside of the top surface 62a. Furthermore, the outer surface of the cap member 62 for removing the writing section is continuously provided with numerous knurled grooves 62c along the axial direction.

[0078] Furthermore, the inner circumferential surface of the opening side of the cap member 62 for removing the writing section is provided with an internal thread 62d, and a ring-shaped projection ring 62e is formed on the back side of the top surface 62a, located behind the internal thread 62d, projecting in the axial direction. In other words, the cap member 62 for removing the writing section has an opening 62b in the center of the top surface 4a of the cap member 4 described with reference to Figure 11, and all other components except the opening 62b are the same as those of the cap member 4 shown in Figure 11.

[0079] Figure 31 shows the individual components of the writing section extraction member 63. The main part of this writing section extraction member 63 is made up of a cylindrical shaft 63a, and a pair of slits 63b are provided at one end of the shaft 63a at positions 180 degrees opposite each other on the cylindrical wall, extending axially from the end. As a result, one end of the writing section extraction member 63 has a flexible portion 63c that can bend in the axial direction, facing each other.

[0080] Furthermore, a locking portion 63d is formed at the tip of the flexible portion 63c, with a larger diameter than that of the shaft body 63a, and this locking portion 63d is provided with a tapered portion 63e that decreases in diameter towards the tip. Furthermore, the other end of the writing section extraction member 63 has an annular flange portion 63f formed in a direction perpendicular to the shaft, and this flange portion 63f is provided with an axial hole 63g (see Figure 28) that communicates with the cylindrical shaft body 63a.

[0081] Figure 28 shows the individual components of the deflection-suppressing rod 64. This deflection-suppressing rod 64 consists of a cylindrical shaft 64a with a constant axial diameter, and a disc-shaped head 64b formed at the end of the shaft 64a. The shaft rod 64a is configured to be inserted into the shaft hole 63g of the writing section extraction member 63 with a small gap. The length of the shaft rod 64a is set such that when the shaft rod 64a is inserted until the head 64b of the bending suppression rod 64 contacts the flange portion 63f of the writing section extraction member 63, the tip of the shaft rod 64a reaches the tip of one end of the writing section extraction member 63 [see Figure 29(D)]. This configuration prevents the flexible portion 63c of the writing section pull-out member 63 from bending in the axial direction.

[0082] Figure 28 shows the individual configuration of the coil spring 65, which is mounted surrounding the writing section pull-out member 63. In this case, the spring 65 is mounted from the tapered portion 63e side of the writing section pull-out member 63 toward the flange portion 63f side at the other end. Then, by inserting the tapered portion 63e of the writing section removal member 63, which does not have the bending suppression rod 64 attached, into the opening 62b made in the writing section removal cap member 62 from the top surface 62a side, the locking portion 63d is inserted into the opening 62b while bending toward the axis.

[0083] As a result, the spring 65 is mounted between the top surface 62a of the cap member 62 for removing the writing section and the flange portion 63f of the writing section removal member 63, surrounding the writing section removal member 63. Furthermore, the locking portion 63d of the writing section removal member 63 is located inside the writing section removal cap member 62 and locks into the opening 62b. Therefore, the locking portion 63d acts as a retainer, preventing the writing section removal member 63 from coming off the writing section removal cap member 62.

[0084] Figures 32 to 36 illustrate the steps involved in attaching the writing section replacement unit 61, configured as described above, to the mouth 2c of the container body 2 of the writing instrument 1, and removing the writing section 3 that is attached to the mouth 2c. First, Figure 32 shows the initial state in which the writing section replacement unit 61 is attached to the mouth 2c of the container body 2. When attaching the writing section replacement unit 61 to the mouth 2c of the container body 2, a cut portion 7h is formed by making an incision in the center of the writing body 7 of the writing section 3 shown in Figure 5, which is attached to the mouth 2c of the container body 2. It is desirable that this cut portion 7h be an opening into which the tip of the writing section extraction member 63 can be inserted.

[0085] Next, with the bending suppression rod 64 removed from the writing section extraction member 63, the writing section removal cap member 62 is screwed onto the mouth 2c of the container body 2, as shown in Figure 33. In this state, the writing section extraction member 63 is pushed towards the writing section removal cap member 62 against the elastic force of the spring 65, causing the tapered portion 63e formed at the tip of the writing section extraction member 63 to bend axially due to the action of the aforementioned bending portion 63c, and to enter the valve opening 5a of the writing section 3 [see Figure 5(B)]. As a result, the locking portion 63d of the writing section withdrawal member 63 is inserted into the valve seat member 5 of the writing section 3, the axial deflection of the tapered portion 63e is returned to its original position, and the locking portion 63d locks into the valve opening 5a of the writing section 3.

[0086] As shown in Figure 34, by inserting the bending suppression rod 64 into the shaft hole 63g of the writing section removal member 63 and loosening the screw of the writing section removal cap member 62 that screws onto the mouth 2c of the container body 2, the writing section removal cap member 62 gradually separates from the mouth 2 of the container body 2. On the other hand, since a deflection-suppressing rod 64 is inserted into the writing section extraction member 63, the locking portion 63d remains locked to the valve opening 5a. Consequently, the spring 65 contracts axially, and the adjacent coils come into contact, stopping the contraction of the spring 65. This causes the locking portion 63d of the writing section extraction member 63 to pull the writing section 3 out of the opening 2c of the container body 2.

[0087] Figure 35 shows the state in which the writing section 3 has been pulled out from the mouth 2c of the container body 2 due to the aforementioned pulling action. At this time, the cap member 62 for removing the writing section comes off from the mouth 2c of the container body 2, which it was screwed onto, and the writing section 3 is locked and attached to the writing section removal member 63 side of the writing section replacement unit 61. In this state, the bending suppression rod 64 is pulled out from the writing section removal member 63, and then, as shown in Figure 36, the writing section removal member 63 is pulled out from the writing section removal cap member 62, thereby removing the writing section 3 from the writing section removal member 63.

[0088] In this case, the locking portion 63d formed on the writing section extraction member 63 engages with the tapered valve opening 5a of the writing section 3, as shown in Figure 5. Therefore, when the bending suppression rod 64 is pulled out, the locking portion 63d easily bends axially due to the action of the aforementioned bending portion 63c by the tapered valve opening 5a. Consequently, the writing section 3 can be easily removed from the writing section extraction member 63.

[0089] According to the aforementioned writing section replacement unit 61, when the writing tip 7 of the writing section 3 becomes worn out, or when the ink in the container body 2 runs out and needs to be refilled, the writing section 3 can be easily removed from the container body 2. Then, by attaching a new writing section 3 to the opening 2c of the container body 2, the writing instrument can be used continuously. [Explanation of Symbols]

[0090] 1 writing implements 2. Container body 2a bottom 2b Torso 2c Mouth 2d finger rest recess 3 Writing section 3a Inner plug (valve) 4 Cap Member 4a Top surface 5 Valve seat member 5a Benguchi 5e Annular locking section 6 Valve body member 6b Spring body 6c valve body 6d valve stem 7 Cursive 7a Spherical protrusion 7h Resection area 8. Cursive writing support rings 9. Mixing ball 11 Packaging sheets 11a Main unit side sheet 11b Release sheet on the cap side 11c cut 15 Writing surface 21. First additional writing unit (Roller script unit) 31. Second additional writing unit (thick brush unit) 41. Third additional writing unit (fine brush unit) 51. Fourth additional writing unit (sputtering unit) 61. Writing section replacement unit 62 Cap component for removing the writing section 62b aperture 63. Writing section removal member 63c Flexible section 63d Locking part 63g shaft hole 64. Deflection suppression rod 64a shaft rod 64b Disc-shaped head 65 Coil springs

Claims

1. A writing instrument comprising a container body for containing writing ink, a writing body positioned to close the mouth of the container body, and a cap member detachably attached to the mouth and covering the writing body, wherein writing is made possible on a writing surface by causing the ink in the container body to seep out from the writing body, The container body is provided with a bottom, a body portion that rises upright above the bottom and is continuous with the body, and a mouth portion that rises diagonally upward and is continuous with the body. The angle of intersection between the axis of the container body perpendicular to the bottom surface of the container body and the axis of the opening passing through the center of the opening constitutes an obtuse angle. The writing instrument is positioned with its opening closed by a support ring that supports the writing instrument along its periphery. Multiple small protrusions are formed on the inner surface of the support ring, projecting outwards towards the writing instrument along its circumference. A writing instrument characterized in that a mixing ball for writing ink is housed inside the container body, and the diameter of the mixing ball is larger than the diameter of the opening facing inward of the container of the writing part that supports the writing body and is attached to the mouth.

2. The writing instrument according to claim 1, characterized in that the writing body attached to close the mouth is made of a flexible foam material.

3. The writing instrument according to claim 1, characterized in that the writing ink contains titanium dioxide.

4. The container body and the cap member attached to the opening of the container body are covered in close contact with a packaging sheet, and the packaging sheet has a cut in it so that a portion of the packaging sheet covering the cap member can be peeled off at the cut. The writing instrument according to claim 1, characterized in that the aforementioned cut is formed parallel to the bottom of the container body, along the smallest cross-sectional portion of the container body between the body and the mouth of the container body.

5. The writing instrument according to claim 1, characterized in that an additional writing unit, which receives ink seeping from the cursive writing instrument and enables the supply of said ink to the writing surface, is detachably attached as an attachment to the mouth of the container body.

6. A cap member for removing the writing section, which is screwed onto the mouth of the container body and has an opening on its top surface, A writing section removal member is formed in a cylindrical shape, with one end inserted into the opening of the cap member for removing the writing section, and the one end is provided with a flexible portion that bends in the axial direction, and the flexible portion has a locking portion that can be locked into the writing section attached to the mouth of the container body, A bending suppression rod, which is inserted into the axial hole of the cylindrical writing section extraction member, suppresses the bending motion of the bending portion in the axial direction, Between the top surface of the cap member for removing the writing section and the other end of the writing section extraction member, a spring is mounted surrounding the writing section extraction member, A writing instrument writing section replacement unit according to claim 1, characterized by comprising the above.

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