JP6756159B2 - Writing implements - Google Patents

Description

The present invention relates to a writing instrument having a writing instrument having a pen tip at the tip and accommodating ink inside, and an exterior body having the pen tip of the writing body protruding from the tip opening.

The cursive, which has a pen tip at the tip and stores ink inside, is provided with air exchange holes to prevent unexpected ink leakage and ink ejection failure from the pen tip due to internal and external pressure differences. (Patent Document 1).
Further, a writing instrument in which a cursive body having such an air exchange hole is housed in an outer body is also known (Patent Document 2).

Japanese Patent Application No. 11-148871 Jitsukaisho 60-178177

In the writing instrument described in Patent Document 2, if the air exchange hole of the refill which is the cursive is blocked by the outer body, problems of ink leakage and poor ink ejection occur. Therefore, the inside and outside of the outer body are changed. An air exchange means for communication is required, but if an attempt is made to adopt a means similar to the air exchange hole of the cursive described in Patent Document 1 and Patent Document 2, a hole is formed in the outer peripheral surface of the exterior body. There was a problem that the degree of freedom in design was hindered, such as impairing the decorativeness and luxury of the exterior body and making it look unattractive.
It is possible to design the assembly of parts so that the gap between the members between the exterior body and the writing instrument body opens to the outside of the exterior body, but due to variations in dimensions and changes in shape over time, the members, especially the exterior body, can be designed. And the position of the cursive changed, and the gap could not be secured.
In addition, when the pressure inside the exterior suddenly changes, such as when attaching or detaching the cap of the exterior, if the air exchange hole of the cursive is closed, the internal and external pressures can be kept the same instantly. Because there is no such thing, the inside of the writing body cannot be kept equal to the external pressure, and when attaching the cap, air is pushed in from the pen tip to retract the ink from the pen tip, causing ink ejection failure or ink when removing the cap. There is a possibility that ink may leak from the pen tip by pulling out the ink.

The present invention relates to a writing instrument having a writing instrument having a pen tip at the tip and supplying ink to be stored inside to the pen tip, and an exterior body having the pen tip of the writing body protruding from the tip opening. The cursive and the exterior have a circumferential close contact with each other, and an air exchange hole for the cursive is arranged on the pen tip side of the peripheral close portion, and the air exchange hole and the tip opening are provided. The gist of the cursive is that a protrusion is formed on the inner peripheral surface of the exterior body to ensure air flow between the air flow passage and the air exchange hole.

In the present invention, a protrusion for ensuring air flow between the air flow passage and the air exchange hole is formed between the air exchange hole and the tip opening and on the inner peripheral surface of the exterior body, so that the size of the cursive is Even if there are variations or changes in the shape of various contact parts due to the replacement of the cursive, the air flow passage can always be maintained between the air exchange hole of the cursive and the tip opening of the front shaft of the exterior. It is possible to prevent the occurrence of ink rubbing and ink leakage.

A vertical cross-sectional view of a state in which the cursive body 1 is housed in the exterior body 2 of the first embodiment. An enlarged view of part A in FIG. The vertical sectional view of the cursive 1 of the 1st Example. Vertical sectional view of the front axle 3. B-direction arrow view in FIG. FIG. 1 is a vertical cross-sectional view with the cap 13 attached. Enlarged view around the cap of FIG. Perspective view of the clip 18. The external view which shows the member of the cylinder part 14. FIG. 6 is an enlarged view of part C in FIG. The vertical sectional view of the 2nd Example in the state which attached the cap. The component development perspective view of the exterior body 2. The vertical sectional view of the front shaft of the 3rd Example.

The cursive of the present invention is provided with a pen tip at the tip and stores ink inside, and the stored ink is supplied to the pen tip to write or paint characters and figures. It is something that can be done.

As the pen tip, a ballpoint pen that holds a ball as a rotatable writing member protruding partly from the tip, a fountain pen, a small tube pen tip, a fiber pen (felt pen) using a fiber convergent, and a communication hole are used. It can be used as various pen tips that use ink, such as a plastic pen having a pen, an elastic pen tip having a perforated communication, and a brush tip.

The method of accommodating the ink inside the cursive and the method of supplying the ink to the pen tip may be either directly filled in the main body of the cursive or an ink accommodating member such as a refill may be used. As a result, it may be held in a so-called batting such as a fiber converging body or a continuous porous body. Further, the ink container itself can be replaced, or the ink can be replenished.

The cursive external member that houses the internal components such as the ink containing member may be a bottomed tubular member or a tubular body that opens at both ends with a plug member such as a tail plug attached, or a plurality of plug members. It is also possible to design the parts in a shape in which the parts are joined by screwing or over-fitting. As the material of these outer diameter members and internal components, various plastics such as polyethylene, polypropylene, acrylic resin, polyethylene terephthalate, and metals can be appropriately used, but materials made by reusing wood, used paper, etc. may be used. It is also possible to use a mixture of metal powder or the like. Of course, these materials may be a combination of parts made of a material selected according to the required characteristics of each part such as gas permeability, rigidity, and flexibility.

The method of communicating ink to the pen tip may be one in which a hole as an ink passage communicates to the pen tip or may be connected by a fiber converging body, and a temporary ink having a comb-shaped temporary ink reservoir. It may be provided with a reservoir member. In particular, as the method of supplying ink to the pen tip, an appropriate method is appropriately selected depending on the physical properties of the ink such as viscosity, surface tension, and solid content.

The air exchange hole of the cursive is located inside the exterior, but it needs to be arranged between the peripheral close portion between the exterior and the cursive and the opening at the tip of the exterior. In particular, if the outer body is covered with a cap to prevent the pen tip of the cursive from drying out, it is advantageous that the space inside the cap where the pen tip is located is narrow. The peripheral close portion of the pen is formed in a portion close to the pen tip, and in order to achieve the purpose of the air exchange hole, the air exchange hole is positioned on the pen tip side (opening side) from the peripheral close portion.

The cursive is fixed so that it does not move and rattle inside the hand-held exterior so that it can be easily used when it is used for writing. As the fixing method, an appropriate structure such as holding state, engagement, screwing, etc. can be adopted depending on the dimensions of the members.

The exterior body of the present invention may be any cursive body that can be written, and if the pen tip of the cursive body can be exposed to the outside, a part of the cursive body is covered. It may be something that is done. By using a bottomed cylinder made of a combination of one or more members, it is possible to cover most parts of the cursive other than the pen tip, so use an existing commercially available writing instrument. It is also possible to add new added value such as creating a new image on the appearance, adjusting the grip and weight, displaying the ink drying property and remaining amount, and adding functional parts such as clips. .. By providing a cap to cover the exterior body, it is possible to cover the entire cursive body.

A protrusion is formed on the inner peripheral surface of the exterior body at a position between the air exchange hole and the tip opening. As a result, even if the positional relationship of the parts changes due to the holding state of the cursive or the impact such as dropping, the outer peripheral surface of the cursive comes into contact with the protrusions, so that the part where the protrusions are not formed is written. It serves as a gap between the outer peripheral surface of the body and the inner peripheral surface of the front shaft, and the air flow passage from the air exchange hole of the cursive to the tip opening of the exterior body is always maintained. This makes it possible to prevent writing rubbing and ink leakage.
By making the contact area between the cursive and the protrusion smaller than the area of the air exchange hole of the cursive, even if the protrusion is arranged at the position of the air exchange hole, the air exchange hole Since there is no need to worry about completely blocking the air flow path, the air flow passage is maintained more reliably.

Further, when the cursive is housed in the exterior body, the rear end portion of the cursive body is urged forward by the repellent member arranged inside the exterior body, so that the repellent member Since the resilience can absorb variations in the total length of the cursive, it is possible to more reliably have a circumferential contact portion.

As the ink used, either a dye or a pigment can be used as the colorant, and water and / or various organic solvents can be used as the liquid medium. Adjust polysaccharides and resins, resins and resin emulsions for imparting fixability to the writing surface, surface tension, permeability, solubility, pigment dispersibility, etc. to adjust the viscosity and rheological properties of ink. Various surfactants, preservatives, fungicides, and other inks used for writing utensils can be used endlessly as appropriate.

An example will be described with reference to the drawings. The pen tip side of the cursive, which will be described later, is referred to as the front (the tip in the case of the end), and the breech side is referred to as the rear (the rear end in the case of the end). Further, the direction along the axis of the cursive, exterior body, front shaft, body ring, rear shaft, and other parts, which will be described later, is called the axial direction, and the direction of rotation around the axial direction is called the circumferential direction.

The ones shown in FIGS. 1 to 10 are the first embodiment of the present invention.
What is shown in FIG. 1 is a vertical cross-sectional view showing a state in which the cursive body 1 is fixed in the exterior body 2.
The exterior body 2 is composed of a front shaft 3, a body ring 4, and a rear shaft 5.
As shown in FIG. 2, which is an enlarged view of part A in FIG. 1, the front shaft 3 is a tubular member with both ends open, and a male screw portion 3a is formed on the outer peripheral surface on the rear end side. Then, a tapered portion 3b whose diameter is reduced from the male screw portion 3a toward the tip portion is formed.
The body ring 4 is a tubular member with both ends open, and a female screw portion 4a is formed on the inner peripheral surface on the tip side. Further, a male screw portion 4b is formed on the outer peripheral surface on the rear end side.
The rear shaft 5 is a tubular member whose front is open and whose rear is closed by a tail plug 6. A female screw portion 5a is formed on the inner peripheral surface on the tip side. The tail plug 6 is screwed by a male screw portion 6a formed on the outer peripheral surface of the tail plug 6 and a female screw portion 5b formed on the inner peripheral surface on the rear end side of the rear shaft 5. It is fixed to.
In the tail plug 6, a tubular portion 6b having a diameter smaller than that of the outer peripheral surface on which the male screw portion 6a is formed is formed toward the front.
In this embodiment, the body ring 4, the rear shaft 5, and the tail plug 6 are made of a metal material. Then, in order to improve the corrosion resistance and appearance, the surface treatment of plating and painting is performed, but in consideration of the reduction of parts cost and weight, the surface treatment of plating and painting is performed by molding with resin material. It doesn't matter.
The front shaft 3, the body ring 4, and the rear shaft 5 constituting the exterior body 2 are each fixed by screwing by a male screw portion and a female screw portion formed on the above-mentioned parts, and the cursive body 1 It becomes a bottomed cylinder that accommodates.

In the cursive 1 shown in FIG. 3, an ink occlusion body 8 for storing ink is arranged in the barrel 7, a tail plug 9 is attached to the rear end of the barrel 7, and an opening at the tip of the barrel 7 is used. The pen tip holder 11 for accommodating the pen tip 10 is fixed, and the rear end of the pen tip 10 is pierced into the ink occlusion body 8. An air exchange hole 7a is provided in front of the barrel 7.
By attaching a cap that covers the pen tip, the cursive body 1 can be used as a writing instrument with a cap by itself.

When accommodating the cursive 1 in the exterior body 2, the male screw portion 3a of the front shaft 3 and the female screw portion 4a of the body ring 4 are first fixed by screwing, and then the rear end portion of the rear shaft 5 is fixed. The female screw portion 5b and the male screw portion 6a of the tail plug 6 are fixed by screwing. The cursive 1 is inserted through the opening at the tip of the rear shaft 5, pushed into the tip of the tubular portion 6b arranged on the tail plug 6 of the rear shaft 5 until the rear end of the cursive 1 comes into contact, and screwed. The male threaded portion 4b of the body ring 4 and the female threaded portion 5a of the rear shaft 5 into which the cursive 1 is inserted are screwed together. At this time, a step portion formed continuously on the tapered portion 7b formed on the outer peripheral surface behind the pen tip of the cursive body 1 without interruption in the circumferential direction of the inner peripheral surface of the tapered portion 3b of the front shaft 3. The circumferential step portion 7c made of the same is in close contact with each other to form a circumferential close portion 12. Since the cursive 1 is in close contact with the circumferential close portion 12 and at the same time is in contact with the tip of the tubular portion 6b of the tail plug 6, the cursive 1 is sandwiched between the front shaft 3 and the rear shaft 5. , Fixed in the exterior body 2.
As a result, the pen tip 10 of the cursive body 1 is housed inside the exterior body 2 in a state of being exposed from the tip opening of the exterior body 2.

An air exchange hole 7a of the cursive 1 is located in front of the circumferential close portion 12 of the cursive 1 and the front shaft 3. Therefore, in front of the air exchange hole 7a, a continuous gap (air flow passage) is formed from the air exchange hole 7a to the tip opening of the exterior body 2. By forming this air flow passage, in the writing state, the air corresponding to the ejected ink is taken into the ink occlusion body 8 and the ink occlusion body 8 is kept so as not to be in the decompressed state. It is possible to prevent the ink from rubbing.

In the state where the cursive body 1 is housed in the exterior body 2 as in this embodiment, the writing body 1 is pressed forward in the exterior body 2 by the holding force generated for fixing the cursive body 1 and arranged. Therefore, the cursive 1 may move forward in front of the exterior body 2 due to variations in the dimensions of the cursive 1 or changes in the shapes of various contact portions due to replacement of the cursive 1.
However, as shown in FIGS. 4 and 5 which are vertical cross-sectional views showing the parts of the front shaft 3 of the exterior body 2 and FIG. 5 which is the arrow in the B direction of FIG. 4, in this embodiment, the tapered portion of the front shaft 3 On the inner peripheral surface of 3b, eight protrusions 3c are provided at equal intervals in the circumferential direction. The protrusion 3c is formed of a tapered surface 3d extending from the rear end toward the front toward the axis side and a straight surface 3e formed of a flat surface extending in the axial direction toward the front of the tapered surface 3d. Since the outer peripheral surface of the cursive 1 is guided along the tapered surface 3d of the protrusion 3c, the cursive 1 can be smoothly crowned with the front shaft 3.
When the cursive 1 moves forward, the outer peripheral surface of the cursive 1 comes into contact with the protrusion 3c to prevent the cursive 1 from moving further forward, and the portion where the protrusion 3c is not formed is formed. It serves as a gap between the outer peripheral surface of the cursive 1 and the inner peripheral surface of the front shaft 3, and the air flow passage from the air exchange hole 7a of the cursive 1 to the tip opening of the exterior body 2 is always maintained. This makes it possible to prevent writing rubbing and ink leakage. In this embodiment, the protrusions 3c are provided at eight points at equal intervals in the circumferential direction, but there is a gap for suppressing the forward movement of the cursive 1 and maintaining the air flow passage. If possible, the number of the protrusions 3c is not limited to eight, and may be appropriately set, and may be one. Further, the intervals of the protrusions 3c are not limited to equal intervals, and the intervals between the protrusions may be different. Further, the shape may be appropriately set depending on the cursive that also accommodates the protrusion shape. For example, it may have a semicircular spherical shape or a semi-elliptical spherical protrusion shape.
Further, in this embodiment, if the protrusion 3c is visible from the tip opening of the exterior body 2, the appearance is deteriorated, and it is difficult to process the tip core pin even in mold manufacturing. Therefore, the protrusion 3c is the tip of the exterior body 2. It has not reached the opening. However, the protrusion 3c may reach the tip opening.
The contact area between the cursive 1 and the protrusion 3c is set to be smaller than the area of the air exchange hole 7a of the cursive 1. As a result, even if the protrusion 3c is arranged at the position of the air exchange hole 7a, there is no concern that the air exchange hole 7a will be completely blocked, so that the air flow passage can be maintained more reliably.
It is also possible to accommodate another cursive with a different shape in the exterior body. For example, if you want to replace multiple cursives with similar outer shapes but different overall lengths, you can prepare other parts by preparing body rings with different overall lengths according to the total length of the cursives. Can be used in common. If the shape around the pen tip is different, a front shaft having a shape that matches the shape around the pen tip may be prepared.

As shown in FIG. 6, when the writing body 1 is housed in the exterior body 2, the cap 13 is attached to the pen tip 10 side of the exterior body 2 to prevent the pen tip 10 from drying when not writing. Can be done.
The cap 13 is composed of a tubular portion 14, a head crown 15, a clasp 16, a middle cap 17, and a clip 18.
The tubular portion 14 is made of brass and is a tubular member having both ends open. A folded portion 14a is formed inward at the tip opening, and the clip 18 is formed on the outer peripheral surface of the front end of the tubular portion 14. A mounting hole 14b for mounting the brass is provided.
The crown 15 and the clasp 16 are each provided with a screw portion, and are fixed to the cylinder portion 14 by sandwiching and screwing the folding portion 14a formed in the opening on the tip side of the cylinder portion 14. There is.
Further, the clasp 16 is also provided with a threaded portion on the inner peripheral surface of the rear end, and the tubular portion is formed by screwing the threaded portion provided on the outer peripheral surface of the inner cap 17 into the threaded portion. The middle cap 17 is fixed in 14.

FIG. 7 shows an enlarged view of the vicinity of the cap of FIG. Further, FIG. 8 is shown as a perspective view seen from the back side (cap body side) of the clip. FIG. 9 is an external view showing the members of the tubular portion 14.
The clip 18 is made of highly elastic metal, and the clip mounting portion 18a is fitted into the mounting hole 14b (see FIG. 9) of the tubular portion 14 for mounting. The clip mounting portion 18a is formed in a U shape including side surfaces 18c of the clip mounting portion extending rearward from both sides of the front end surface 18b of the clip mounting portion. Then, when the clip 18 is attached to the tubular portion 14 of the cap 13, a clip tip bottom surface portion 18d formed of a U-shaped end surface provided in front of the clip attachment portion 18a and a clip tip bottom surface portion 18d thereof. A clip tongue piece 18e provided behind 18d, extending rearward from the clip attachment portion 18a, and having its rear end bent toward the central axis side, and a bulge toward the barrel side provided at the rear end of the clip. The cylinder portion 14 is held at three points of the clip ball portion 18f. That is, the cylinder portion 14 is held at three points: the bottom surface portion 18d of the clip tip and the outer peripheral surface of the cylinder portion 14, the inner peripheral surface of the clip tongue piece portion 18e and the cylinder portion 14, and the outer peripheral surface of the clip ball portion 18f and the cylinder portion 14. ing. Therefore, no matter which direction a force acts on the clip 18, the clip 18 is securely fixed without rattling.
Further, since the tip of the clip tongue piece 18e is bent toward the center, the clip tongue piece 18e is bent in the direction of being inserted into the tubular portion 14, so that the bent portion serves as a guide for clipping. Since it is easy to fit into the mounting hole 14b of the cylinder portion 14, it is easy to fit into the mounting hole 14b of the clip of the tubular portion 14.
In order to reduce the weight of the exterior body, the wall thickness of the tubular portion 14 is processed to be as thin as possible, so that the contact area between the side surface 18c of the clip mounting portion and the inner wall surface of the mounting hole 14b of the tubular portion 14 is reduced, but the clip 18 In order to prevent rattling in the lateral direction of the clip, a notch having a width equal to the width of the rear end of the clip tongue piece 18e is formed in the clasp 16. As a result, the rear end side surface of the clip tongue piece 18e is installed in the cylinder so as to be gripped by the notch of the clasp 16, so that the tip of the clip tongue piece 18e is inside the notch of the clasp 16. Since it hits the wall surface, lateral rattling is suppressed.
The cylinder portion 14, the crown 15, the clasp 16, and the clip 18 are made of a metal material and are surface-treated by plating and painting in order to improve the corrosion resistance and the appearance, but the component cost is reduced and the weight is reduced. In consideration of the decrease in the amount of paint, the surface treatment may be performed by molding with a resin material, plating, and painting.

The fitting of the inner cap and the front shaft of the exterior body will be described with reference to FIGS. 6 and 10.
The inner cap 17 has a tubular shape with a bottom on the tip side, and a circumferential fitting projection 17a for fitting the cap 13 to the exterior body is provided on the rear end side of the inner cap 17. When attaching the cap 13, the fitting projection 17a provided on the rear end side of the middle cap 17 overcomes the circumferential fitting projection 3f provided on the outer peripheral surface of the front shaft 3, and after the cap 13 is attached. The cap 13 is removably attached to the exterior body 2 by abutting the front end surface of the fitting projection 17a of the middle cap 17 and the rear end surface of the fitting projection 3f of the front shaft in a light press-fitting state.
Further, on the inner peripheral surface of the inner cap 17, a continuous circumferential step portion (circumferential step portion 17b) without interruption in the circumferential direction and a circumferential step portion 17b adjacent to the rear of the circumferential step portion 17b. A continuous circumferential top (circumferential top 17c) is formed without interruption in the direction. Then, when the cap 13 is attached to the exterior body 2, the circumferential top portion 17c is continuously and continuously in close contact with the front shaft close portion 3g on the outer peripheral surface of the front shaft without interruption in the circumferential direction. Part 19 is formed. As a result, around the pen tip 10, the above-mentioned circumferential close portion 12 (consisting of close contact between the front shaft 3 and the cursive 1) and the circumferential close portion (consisting of close contact between the middle cap 17 and the front shaft 3) It is sealed by 19 and can prevent the pen tip 10 from drying.
Further, although polypropylene resin is adopted as the resin material of the inner cap 17, polyethylene terephthalate, acrylic, acrylonitrile butadiene styrene copolymer (ABS), acrylonitrile styrene copolymer (AS), polycarbonate, etc. It does not matter if you adopt.
Further, in this embodiment, the position of the protrusion 3c of the front shaft 3 is provided in front of the circumferential close portion 12 (consisting of the front shaft 3 and the cursive 1 in close contact with each other). In a molded product having protrusions on the inner surface, a phenomenon in which the outer surface corresponding to the protrusions is dented, so-called sink marks, occurs. If it is provided, unevenness is created in the front shaft close portion 3 g, and the sealed state with the cap cannot be maintained. Therefore, the position of the protrusion 3c is not limited as long as it is other than the circumferential close portion 12.

The second embodiment is shown in FIGS. 11 to 12.
In the first embodiment, the cursive 1 is in contact with the peripheral close portion 12 and at the same time is in contact with the tip of the tubular portion 6b of the breech block 6 screwed to the rear shaft 5. In the second embodiment, the repellent member 21 is provided between the rear end portion of the cursive body 1 and the breech block 20. The same applies to the first embodiment except that the repellent member 21 is provided, and the description thereof will be omitted.
A tubular portion 20b having a diameter smaller than that of the outer peripheral surface on which the male screw portion 20a is formed is formed on the tail plug 20 toward the front. A repellent member 21 made of a coil spring is arranged on the outer peripheral surface of the tubular portion 20b. The rear end portion of the repellent member 21 is in contact with the circumferential groove 20c formed between the outer peripheral surface on which the male screw portion 20a of the tail plug 20 is formed and the tubular portion 20b. By providing the circumferential groove 20c, the tail plug 20 can be lightened and the weight can be adjusted.
A circumferential protrusion (circumferential protrusion 20d) having a slightly larger outer diameter than the front portion is formed on the outer peripheral surface slightly forward from the root of the tubular portion 20b, and the outer diameter of the circumferential protrusion 20d is The repellent member 21 is formed to be slightly larger than the inner diameter of the rear end portion, and is slightly press-fitted and caught on the repellent member 21. Therefore, the repellent member 21 does not come off carelessly when assembling.
Then, in the state where the cursive body 1 is housed in the exterior body 2, the cursive body 1 abuts at the circumferential close portion 12 and at the same time abuts on the tip end portion of the repellent member 21 and is urged forward. Therefore, the cursive 1 is fixed in the exterior body 2.
By interposing the repellent force of the repellent member 21 between the cursives 1, the variation in the total length of the cursive 1 can be absorbed, so that the circumferential contact portion 21 can be more reliably provided.
The load that the repellent member 21 pushes the writing body 1 forward so that the pen tip 10 does not lose to the writing load and retract toward the rear end during writing is the case of a fiber core having a low writing load. In the case of a metal tip, resin tip or plastic pen tip of a ballpoint pen having a high writing load of 500 g or more, it is desirable that the weight is 1000 g or more. That is, a load of 500 g or more is always applied in the direction in which the inner peripheral surface of the exterior body 2 is in close contact with the outer peripheral surface of the cursive body 1.
Although the coil spring is used in this embodiment, rubber, a resin spring, an elastomer, or the like may be used.

FIG. 13 shows a third embodiment.
The third embodiment is a modification of the shape of the protrusion on the front shaft of the first embodiment. It is the same as that of the first embodiment except for the shape of the protrusion.
The protrusion 22a of the front shaft 22 of the third embodiment is formed in the shape of a rectangular parallelepiped extending in the axial direction from the front to the rear, but a groove 22b is formed from the rear end surface of the protrusion toward the front middle portion. As a result, the rear end portion 22c of the protrusion can be deformed to the inner peripheral surface side of the front shaft 3 by the amount of the space created by the groove portion 22b. Therefore, even if the shape of the outer peripheral surface is different, the protrusion 22a is deformed according to the different shape, so that various cursives 1 having different shapes can be accommodated.

1 Writing body 2 Exterior body 3 Front shaft 3a Male screw part 3b Tapered part 3c Protrusion 3d Tapered surface 3e Straight surface 3f Fitting protrusion 3g Front shaft close part 4 Body ring 4a Female thread part 4b Male thread part 5 Rear shaft 5a Female thread part 5b 6 Tail plug 6a Male thread part 6b Cylindrical part 7 Shaft cylinder 7a Air exchange hole 7b Tapered part 7c Circumferential step part 8 Ink occlusion 9 Tail plug 10 Pen tip 11 Pen tip holder 12 Circumferential close part 13 Cap 14 Cylinder part 14a Folded part 14b Mounting hole 15 Head crown 16 Clasp 17 Middle cap 17a Fitting protrusion 17b Circumferential step 17c Circumferential top 18 Clip 18a Clip mounting 18b Clip mounting front end 18c Clip mounting side 18d Clip tip bottom surface 18e Clip tongue piece 18f Clip ball 19 Circumferential close contact 20 Tail plug 20a Male thread 20b Cylindrical groove 20c Circumferential groove 20d Circumferential protrusion 21 Repellent member 22 Front shaft 22a Protrusion 22b Groove 22c Rear end

Claims (3)

A writing instrument having a writing instrument having a pen tip at the tip and supplying ink to be stored inside to the pen tip, and an exterior body in which the pen tip of the writing body is exposed in a state of protruding from the tip opening. The body has a circumferential close contact portion, and an air exchange hole for the cursive is arranged on the pen tip side of the peripheral close contact portion, and between this air exchange hole and the tip opening. A writing instrument having a protrusion on the inner peripheral surface of the exterior body to ensure air flow between the air flow passage and the air exchange hole. The writing instrument according to claim 1, wherein the contact area between the cursive and the protrusion is smaller than the area of the air exchange hole of the cursive. The first aspect of the present invention is that, when the writing body is housed in the outer body, the rear end portion of the writing body is urged forward by a repellent member arranged inside the outer body. Or the writing instrument according to claim 2.

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