JP7688533B2 - Retractable writing instrument tip cover and retractable writing instrument equipped with said retractable writing instrument tip cover - Google Patents

Description

The present invention relates to a tip cover for a retractable writing instrument that is attached to the opening at the front end of the retractable writing instrument, and to a retractable writing instrument equipped with this tip cover for a retractable writing instrument.

2. Description of the Related Art Conventionally, retractable writing instruments include marker pens, ballpoint pens, mechanical pencils and the like, in which the writing lead protrudes and retracts from the front end of a barrel, as described in, for example, Patent Document 1.
With this type of conventional retractable writing pen, air can enter through the opening at the front end of the barrel due to the influence of wind or air currents, causing the tip of the marker pen to dry out.
Furthermore, writing instruments that are not displayed for test writing may be test written on, resulting in damage to the nib or a decrease in the durability of the nib.
Therefore, some conventional retractable writing instruments are sold with a cylindrical rubber stopper fitted over the opening at the front end.

JP 2020-179623 A

However, with the above-mentioned conventional technology, when the pen is knocked during test writing, the writing lead moving forward may push out the rubber stopper.

In view of the above problems, one aspect of the present invention has the following configuration.
A tip cover for a retractable writing instrument that is attached to an opening at the front end of a retractable writing instrument in which a writing lead protrudes and retracts from the front end of a barrel, the tip cover comprising a knob portion formed to protrude forward from the front end of the barrel, and an insertion portion formed to extend from the knob portion and be inserted into the opening, the insertion portion having a concave writing lead introduction portion such that the writing lead inserted into the writing lead introduction portion suppresses elastic deformation of the insertion portion radially inward in the barrel, and the insertion portion is formed so as to elastically bend radially inward in the barrel and be inserted into the opening from the front and return to its original radially outward in the barrel to contact the inner surface of the barrel .

The present invention is configured as described above, making it possible to make the tip cover, which is easy to attach, less likely to come off.

1A and 1B are full cross-sectional views showing an example of a tip cover according to the present invention attached to a retractable writing instrument, in which FIG. 1A shows the initial state and FIG. 2 is an enlarged cross-sectional view of a main portion of the retractable writing implement, in which the tip cover before attachment is shown in solid lines and the tip cover in the middle of attachment is shown in two-dot chain lines. FIG. FIG. 2 is a perspective view showing an example of a tip cover for a retractable writing instrument according to the present invention. 4A and 4B are enlarged views of the main part of the retractable writing implement, in which FIG. 4A shows the initial state and FIG. 13 is a full cross-sectional view showing another example of a tip cover according to the present invention attached to a multiple retractable writing instrument, with the marker tip advanced. 4 is a cross-sectional perspective view of a main portion of a barrel to which the tip cover is attached. FIG. 1 is an enlarged cross-sectional view of a key portion of a multiple retractable writing instrument equipped with the same tip cover, showing the state in which the marker tip has been advanced, (b) showing the state rotated 90 degrees around the axis from (a). 1 is an enlarged cross-sectional view of a key portion of a multiple retractable writing instrument equipped with the same tip cover, showing the state in which the ballpoint pen tip has been advanced, and (b) shows the state rotated 90 degrees around the axis from (a). FIG. 1A is a full cross-sectional view showing the end cover being attached to the barrel from the front side, and FIG. 1B is a full cross-sectional view showing the end cover being attached to the barrel from the rear side. 1 is an enlarged cross-sectional view of a key portion showing another example of a tip cover according to the present invention attached to a multiple retractable writing instrument and the writing lead advanced, (b) showing the state rotated 90 degrees around the axis from (a). This is an enlarged cross-sectional view of the essential parts showing another example of a tip cover according to the present invention being attached to a retractable writing instrument, in which the tip cover before attachment is shown in solid lines and the tip cover in the process of being attached is shown in dashed double-dashed lines.

This embodiment discloses the following features.
The first feature is that it is a tip cover for a retractable writing instrument that is attached to an opening at the front end of a retractable writing instrument that has a writing lead that protrudes and retracts from the front end of a barrel, and it has a knob portion formed to protrude forward from the front end of the barrel, and an insertion portion formed to extend from this knob portion and be inserted into the opening, and a concave writing lead introduction portion is provided in the insertion portion, so that the writing lead inserted into the writing lead introduction portion suppresses elastic deformation of the insertion portion radially inwardly of the barrel (see Figures 1 to 10).

The second feature is that the insertion portion is formed so that it elastically bends inward in the barrel diameter direction, is inserted into the opening from the front, and then returns to its original position outward in the barrel diameter direction to come into contact with the inner peripheral surface of the barrel (see Figures 2 and 4).

The third feature is that the insertion portion is made of a synthetic resin material that can elastically bend inward in the radial direction of the barrel.

The fourth feature is that the knob is formed so as to be inserted into the opening from the rear side (see FIG. 10 (b)).

The fifth feature is that the insertion portion includes a first insertion portion extending rearward from the knob portion and a second insertion portion extending forward from the knob portion (see FIG. 12).

The sixth feature is that the insertion portion is configured with multiple flexible pieces extending from the knob portion and spaced apart in the circumferential direction of the barrel (see Figures 3 and 9).

The seventh feature is that the flexible piece portions are provided on both sides in the axial direction of the barrel, and the knob portion is formed long in the axial direction intersecting the axial direction of the flexible piece portions on both sides (see Figure 11).

The eighth feature is that the retractable writing instrument is provided with the tip cover for the retractable writing instrument (see Figures 1 and 5).

The ninth feature is a retractable writing instrument equipped with the tip cover for the retractable writing instrument, in which a groove that fits into the inserted flexible piece is provided on the front end side of the inner circumferential surface of the barrel, and the writing lead is positioned to move outside the groove (see Figure 6).

<First embodiment>
Next, specific embodiments having the above-mentioned features will be described in detail with reference to the drawings.

In this specification, the barrel axis direction means the direction along the barrel centerline, and the barrel circumferential direction means the direction around the barrel centerline. Additionally, "front" means one side of the barrel axis direction in which the writing lead protrudes, and "rear" means the opposite side to the one side.
In this specification, the barrel diameter direction means the diameter direction of the barrel perpendicular to the center line of the barrel, the barrel diameter outer side means the direction away from the barrel center along the barrel diameter direction, and the barrel diameter inner side means the direction toward the barrel center along the barrel diameter direction.

FIG. 1 shows an example of a retractable writing instrument equipped with a tip cover for a retractable writing instrument according to the present invention.
This retractable writing instrument 1 comprises a barrel 10, a writing lead 20 that is movable forward and backward within the barrel 10, and an advancing/retracting mechanism 30 that moves the writing lead 20 forward and backward by external operation, and causes the front end of the writing lead 20 to retract at the front end side of the barrel 10.
A tip cover 40 is removably attached to the opening 10a at the front end of the retractable writing instrument 1.

The barrel 10 is constructed in an integral, generally cylindrical shape from a long cylindrical barrel body 11 and a tapered tubular tip portion 12 that is detachably screwed to the front end side of the barrel body 11 .
Other examples of the shaft tube 10 include a mode consisting of a single tubular member, and a mode consisting of three or more connected tubular members.

The tip portion 12 has an inner circumferential surface on the inner front end side that tapers in diameter toward the front, and more specifically, as shown in FIG. 2, has an inclined tapered surface 12a that gradually tapers in diameter toward the front.
This reduced diameter surface 12a is pressed against the tip cover 40, which will be described later, making it difficult for the tip cover 40 to come off.
As another example of the reduced diameter surface 12a, a surface whose diameter is reduced stepwise may be used.

The writing core 20 is a writing core for a felt-tip pen, in which a pen shaft 22 made of a fiber bundle is connected to the front end of a long, cylindrical inner batting 21 impregnated with ink via a cylindrical connecting member 23, and has a roughly bullet-shaped writing portion 20a. The writing core 20 is connected to the front end of a retractable mechanism 30.
Other examples of this writing lead 20 include a ballpoint pen refill having a ballpoint pen tip connected to the front end of an ink containing tube, a mechanical pencil refill, a marker pen refill, an electronic pen refill, etc.

The connecting member 23 is formed in a cylindrical shape, and the pen shaft 22 is inserted and fitted into it. The rear end side of this connecting member 23 is connected to the cylindrical case 24 around the padding 21. The outer diameter of the outer peripheral surface of the front end side of this connecting member 23 is appropriately set so as to fit into the writing lead introduction portion 42b.

The advance/retract mechanism 30 is a mechanism that advances the writing lead 20 and latches the writing part 20a at its front end by pushing forward the knock part 31, which protrudes rearward from the rear end of the writing instrument barrel 10, and releases this latched state by pushing the knock part 31 again. In the figure, the reference numeral 32 denotes a biasing member (a compression coil spring in the illustrated example) that biases the writing lead 20 rearward.
This advance/retract mechanism 30 can be applied to the structure of a known retractable writing instrument, such as the structure described in JP 2018-149787 A.

The tip cover 40 has a knob 41 formed to protrude forward from the front end of the barrel 10, and an insertion part 42 that extends rearward from the knob 41 and is formed to be inserted into the opening 10a.

The knob portion 41 is formed long in the barrel diameter direction intersecting the bending direction of the bending pieces 42a, 42a on both sides, and has flat surface portions 41b, 41b on one end side and the other end side in the bending direction, respectively.
Furthermore, the outer peripheral surface of the knob 41 in the illustrated example is formed with projections and recesses to prevent slipping (see FIG. 3).

The rear end surface 41a on the outer periphery of the knob 41 is formed in an annular shape larger than the inner diameter of the opening 10a so that it is in contact with or close to the front end of the barrel 10 over the entire circumference (see FIG. 3). The rear end surface 41a functions as a push-in restriction portion that prevents the knob 41 from being pushed into the opening 10a.

The inside of the knob 41 is formed in a concave shape that opens to the rear. This concave space is connected to the space inside the insertion part 42, and forms the writing lead introduction part 42b, which will be described later.

The insertion section 42 is extended rearward from the knob section 41 and is made up of multiple (two in the illustrated example) flexible pieces 42a spaced apart in the circumferential direction of the barrel, and the inner parts of these flexible pieces 42a form a concave writing lead introduction section 42b that is open to the rear.

The multiple flexible pieces 42a are formed so as to elastically bend inward in the direction of the barrel diameter and be inserted into the opening 10a from the front (see Figure 2), and then return to their original position outward in the direction of the barrel diameter to contact the inner surface of the barrel 10 (more specifically, the reduced diameter surface 12a).
The outer surface of each flexible piece 42 a is formed to fit along the inner circumferential surface including the reduced diameter surface 12 a on the front end side of the tip portion 12 .

The writing lead introduction portion 42 b is continuous from the inside of the multiple flexible pieces 42 a to the bottomed cylindrical inner surface of the knob portion 41 .
The dimensions between the inner surfaces and the inner diameter of this writing lead introduction portion 42b are appropriately set so that the writing lead 20 inserted from behind comes into contact with or comes close to the writing lead 20 from the radially inside.

To explain in detail, the rear end side of the inner circumferential surface of the writing lead introduction section 42b (specifically, each flexible piece 42a) is formed with an inclined guide surface 42a1 that narrows toward the front. The writing lead 20 inserted into the writing lead introduction section 42b is guided to the center by the guide surface 42a1 (see Figure 4).

A step 42a2 that narrows in diameter toward the front is formed on the rear end side of the inner circumferential surface of the writing lead introduction portion 42b (specifically, each flexible piece portion 42a) and in front of the guide surface 42a1.
When the writing core 20 is inserted into the writing core introduction portion 42b, the front end of the connecting member 23 abuts against or approaches the step 42a2 (see FIG. 4B). In this state, the outer circumferential surface of the connecting member 23 approaches or contacts the inner circumferential surface of the writing core 20 behind the step 42a2 in the writing core introduction portion 42b, and the writing portion 20a protruding from the connecting member 23 is inserted into the space in front of the step 42a2 in the writing core introduction portion 42b.

Next, the characteristic functions and effects of the retractable writing instrument 1 and tip cover 40 configured as described above will be described in detail.
First, when attaching the tip cover 40 to the tip side of the retractable writing instrument 1, as shown in Figure 2, the tip cover 40 is brought close to the opening 10a at the tip of the retractable writing instrument 1 from the front side, and the multiple flexible pieces 42a of the tip cover 40 are pinched with the fingers to narrow the opening 10a and inserted into the opening 10a.
At this time, by pinching and bending the bending pieces 42a, 42a on both sides with fingers and inserting the tip side into the opening 10a, the fingers are moved backward so that the fingers come into contact with the flat surface portions 41b, 41b on both sides. Therefore, the worker can stably pinch the knob portion 41 and push the tip cover 40 into the opening 10a.
The flexible piece 42a inserted into the opening 10a elastically returns to its original shape radially outward in the barrel and comes into contact with the inner circumferential surface of the tip 12, including the reduced diameter surface 12a (see FIG. 4(a)).

In this state, for example, when the advance/retract mechanism 30 is operated to advance the writing lead 20, the tip side of the writing lead 20 is inserted into the writing lead introduction portion 42b, and elastic deformation of the insertion portion 42 (more specifically, the multiple flexible piece portions 42a) toward the inside in the radial direction of the barrel is suppressed (see Figure 4 (b)).
In the illustrated example, the connecting member 23 fits between the flexible pieces 42a, 42a to suppress elastic deformation of the flexible pieces 42a, 42a in the radial direction of the barrel. However, as another example, the front end side of the pen shaft 22 may fit between the flexible pieces 42a, 42a to suppress elastic deformation of the flexible pieces 42a, 42a in the radial direction of the barrel.

Therefore, for example, even if the writing core 20 advances due to a knock operation on the advance/retract mechanism 30 and the writing part 20a at the front end of the writing core 20 pushes the tip cover 40 forward, the multiple flexible pieces 42a will bend inward and be pushed forward of the barrel 10, preventing the tip cover 40 from coming off.

<Second embodiment>
Next, other embodiments of the present invention will be described. Note that the retractable writing instrument 2 and tip cover 100 described below are partial modifications of the retractable writing instrument 1 and tip cover 40 described above, so the modifications will be mainly described in detail.

The retractable writing instrument 2 comprises a barrel 60, a plurality of writing leads 70, 80 arranged to be movable forward and backward within the barrel 60, and an advance/retract mechanism 90 that selectively advances and retracts the writing leads 70, 80 by external operation, thereby constituting a multiple retractable writing instrument (see Figure 5).
A tip cover 100 is attached to the front end of this retractable writing instrument 2 .

The barrel 60 is formed in a long, generally cylindrical shape, has a tapered tip 61 at its front end, and has a window 62 in the peripheral wall at its rear end that exposes the slide operating body 91 of the advance/retract mechanism 90.

The tip 61 has an opening 60a at its tip, and a concavely curved tapered surface 61a, the diameter of which gradually decreases forward, behind the opening 60a.
The reduced diameter surface 61a is pressed against the tip cover 100, which will be described later, to make it difficult for the tip cover 100 to come off.

More specifically, the reduced diameter surface 61a on the front end side of the inner circumferential surface of the barrel is provided with recessed grooves 61a1, 61a1 for fitting with the inserted flexible pieces 121, 121, respectively.
Each of the grooves 61a1 extends rearward from the inside of the opening 60a along the reduced diameter surface 61a.
The two grooves 61a1 are located on both sides of the barrel diameter direction that intersects with the direction in which the two writing leads 70, 80 are aligned in the barrel diameter direction. That is, the front end of each writing lead 70 (or 80) moves to a position away from the grooves 61a1 toward the outside in the intersecting barrel diameter direction.
By adopting such an arrangement, the writing portion 70a (or 80a) of the writing lead 70 (or 80) does not get caught on the flexible piece portion 121 during forward movement, but slides against the reduced diameter surface 61a and is guided toward the center of the writing lead introduction portion 130 (see Figures 7(a) and 8(a)).
As another example of the reduced diameter surface 61a, it is also possible to provide a surface whose diameter is reduced in a stepped manner.

Of the multiple writing cores, writing core 70 is a writing core for a marker pen, in which a pen shaft made of a fiber bundle is connected to the front end side of a long ink storage section that contains ink. The writing section 70a on the tip side of the pen shaft is formed into an approximately wedge shape, and is sometimes called a chisel tip.
The other writing core 80 is a long ballpoint pen refill, and has a writing portion 80a (ballpoint pen tip) at the front end side that rotatably holds a transfer ball.

The advance/retract mechanism 90 is a mechanism that, when one of the multiple slide operation bodies 91 is pushed forward, causes the writing lead 70 or 80 corresponding to this slide operation body 91 to protrude from the front end of the barrel 60. For example, the basic structure disclosed in JP 2012-200902 A can be applied to this advance/retract mechanism 90.

The tip cover 100 also includes a knob 110 that protrudes forward from the front end of the barrel 60, and an insertion portion 120 that extends rearward from the knob 110 and is adapted to be inserted into the opening 60a.

According to the illustrated example, the knob 110 is formed in a substantially cylindrical shape and has a locking protrusion 111 on its outer circumferential surface which can pass through the opening 60a and can be locked to the inner edge of the opening 60a.
A plurality of locking protrusions 111 (two equally spaced apart in the illustrated example) are provided at intervals in the circumferential direction.
Each locking protrusion 111 is formed so as to partially protrude outward in the circumferential and front-rear directions, and has an inclined surface 111a on the front end side that faces inward in the radial direction of the barrel. This inclined surface 111a makes it easy for the locking protrusion 111 to pass through the opening 60a from the rear (see FIG. 10B).

The multiple locking protrusions 111 have an outer diameter slightly larger than the inner diameter of the opening 60a, and pass through the opening 60a from the rear to the front by elastically contracting (see Figure 10).

The inside of the knob 110 is formed in a concave shape that is open to the rear (see FIG. 9). This concave space is continuous with the space inside the insertion portion 120, and forms the writing lead insertion portion 130.
The insertion portion 120 is extended rearward from the gripping portion 110 and is composed of multiple (two in the illustrated example) flexible pieces 121 spaced circumferentially of the barrel, and the inner portions of these flexible pieces 121 form a concave writing lead introduction portion 130 that is open to the rear.

The multiple flexible pieces 121 are formed so that they are elastically bent inward in the barrel diameter direction and inserted into the opening 60a from the front (see FIG. 10(a)), and then restored outward in the barrel diameter direction to contact the inclined inner peripheral surface of the barrel 60. That is, the outer surface of each flexible piece 121 is formed so as to fit along the reduced diameter surface 61a on the front end side of the tip 61.

The writing lead insertion portion 130 extends continuously from the inside of the multiple flexible pieces 121 to the cylindrical inner surface of the knob portion 110 with a bottom.
The dimensions between the inner surfaces and the inner diameter of this writing lead introduction portion 130 are appropriately set so that the writing portion 70a or 80a inserted from behind comes into contact with or approaches the writing portion 70a or 80a from the radially inner side.

Next, the effects of the retractable writing instrument 2 and tip cover 100 configured as described above will be described in detail.
First, when attaching the tip cover 100 to the tip side of the retractable writing instrument 2, as shown in Figure 10 (a), the tip cover 100 is brought close to the opening 60a at the tip of the retractable writing instrument 2 from the front side, and the multiple flexible pieces 121 of the tip cover 100 are pinched with the fingers to narrow the opening 60a and inserted into the opening 60a.
When the tip cover 100 is pushed rearward, the flexible pieces 121 elastically return to their original position radially outwardly of the barrel and come into contact with the inner circumferential surface of the tip portion 61, such as the reduced diameter surface 61a (see FIG. 7).

As another mounting method, as shown in FIG. 10(b), the tip cover 100 can be inserted into the barrel 60 from the rear side and the knob portion 110 of the tip cover 100 can be passed through the opening 60a to lock it in place.

When the tip cover 100 is attached, for example, if the writing lead 70 (or 80) is advanced by operating the advance/retract mechanism 90, the writing portion 70a (80a) of the writing lead is inserted into the writing lead introduction portion 130, and elastic deformation of the insertion portion 120 (more specifically, the multiple flexible pieces 121) inward in the barrel diameter direction is suppressed (see Figures 7(a)(b) and 8(a)(b)).

Therefore, for example, even if the writing lead 70 (or 80) is advanced by operating the advance/retract mechanism 90 and the writing portion 70a (80a) at the front end of the writing lead pushes the tip cover 100 forward, it is possible to prevent the tip cover 100 from coming off.
This in turn prevents air from entering the tip of the writing instrument, causing the pen tip to dry out or the writing instrument to be test written on.

<Other Modifications>
A tip cover 100' shown in FIG. 11 is obtained by replacing the knob portion 110 of the tip cover 100 with a knob portion 110'.
The knob portion 110' is formed in a flat plate shape that is long in the barrel diameter direction intersecting the bending direction of the bending pieces 121, 121 on both sides.
With tip cover 100', knob 110' can be easily pinched with fingertips f. Therefore, for example, by pinching and bending bending pieces 121, 121 on both sides with fingers and inserting the tip side into opening 60a, and then sliding the fingers backward, tip cover 100' can be pushed into opening 60a with the fingers.

Moreover, a tip cover 40' shown in FIG. 12 is configured such that the insert portion 42 of the tip cover 40 is a first insert portion, and a second insert portion 42' is added.
The first insertion portion 42 extends rearward from the knob portion 41 .
The second insertion portion 42 ′ is configured such that the first insertion portion 42 is reversed in front and rear, and extends forward from the knob portion 41 .
This tip cover 40' can be attached to a retractable writing instrument without having to worry about the front or rear orientation.

In the above embodiment, the insertion section is formed by a plurality of the flexible pieces. Alternatively, the insertion section may be formed in a cylindrical shape without any flexible pieces, and the peripheral wall may be elastically flexible inwardly in the radial direction and restored to its original shape outwardly in the radial direction.

In addition, in the illustrated example, the bottom of the cylindrical writing lead introduction part with a bottom is formed into a disk shape without holes, but the bottom may be provided with a through hole if necessary.

The present invention is not limited to the above-described embodiments, and may be modified as appropriate without departing from the spirit and scope of the present invention.

1, 2: Retractable writing implement 10, 60: Barrel 10a, 60a: Opening 20, 70, 80: Writing lead 40, 100, 100': Tip cover 41, 110, 110': Knob 41a: Rear end surface (push-in restriction portion)
42, 120: Insertion portion 42a, 121: Flexible piece portion 42b, 130: Writing lead introduction portion

Claims (8)

A tip cover for a retractable writing instrument is attached to an opening at the front end of the retractable writing instrument in which a writing core is retracted from the front end of a barrel,
The barrel has a knob portion formed to protrude forward from a front end thereof, and an insertion portion formed to extend from the knob portion and to be inserted into the opening,
A concave writing lead introduction portion is provided in the insertion portion, and elastic deformation of the insertion portion toward the inside in the barrel diameter direction is suppressed by the writing lead inserted into the writing lead introduction portion .
The tip cover for a retractable writing instrument is characterized in that the insertion portion is formed so as to elastically bend inward in the radial direction of the barrel to be inserted into the opening from the front and then return to its outward position in the radial direction of the barrel to contact the inner surface of the barrel . A tip cover for a retractable writing instrument is attached to an opening at the front end of the retractable writing instrument in which a writing core is retracted from the front end of a barrel,
The barrel has a knob portion formed to protrude forward from a front end thereof, and an insertion portion formed to extend from the knob portion and to be inserted into the opening,
A concave writing lead introduction portion is provided in the insertion portion, and elastic deformation of the insertion portion toward the inside in the barrel diameter direction is suppressed by the writing lead inserted into the writing lead introduction portion .
A tip cover for a retractable writing instrument, characterized in that the insertion portion comprises a first insertion portion extending rearward from the knob portion and a second insertion portion extending forward from the knob portion . A tip cover for a retractable writing instrument is attached to an opening at the front end of the retractable writing instrument in which a writing core is retracted from the front end of a barrel,
The barrel has a knob portion formed to protrude forward from a front end thereof, and an insertion portion formed to extend from the knob portion and to be inserted into the opening,
A concave writing lead introduction portion is provided in the insertion portion, and elastic deformation of the insertion portion toward the inside in the barrel diameter direction is suppressed by the writing lead inserted into the writing lead introduction portion .
A tip cover for a retractable writing instrument, characterized in that the insertion portion is configured by a plurality of flexible piece portions extending from the knob portion and spaced apart in the circumferential direction of the barrel. The flexible piece portion is provided on both sides in the barrel radial direction,
4. The tip cover for a retractable writing instrument according to claim 3, wherein the knob portion is formed to be elongated in a barrel diameter direction that intersects with the bending direction of the bending pieces on both sides . 5. The tip cover for a retractable writing instrument according to claim 1 , wherein the insertion portion is made of a synthetic resin material that is elastically bendable inwardly in the radial direction of the barrel . 6. The tip cover for a retractable writing instrument according to claim 1, wherein the knob portion is formed so as to be inserted into the opening from the rear side . A retractable writing instrument comprising the tip cover for a retractable writing instrument according to any one of claims 1 to 6. A retractable writing instrument equipped with the tip cover for a retractable writing instrument according to claim 3 or 4,
A retractable writing instrument characterized in that a groove is provided on the front end side of the inner surface of the barrel, into which the inserted flexible piece fits, and the writing lead is positioned so as to move outside the groove .

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