JP6413572B2 - Writing instrument - Google Patents

Description

  In the present invention, the clip is connected to the shaft cylinder of the writing instrument so as to be rotatable about a fulcrum, the front end side of the clip is in contact with the outer peripheral surface of the shaft cylinder, and the rear end side of the clip is the outer periphery of the shaft cylinder. The present invention relates to a writing instrument that is constantly repelled away from the surface.

Conventionally, the clip is rotatably connected to the shaft tube of the writing instrument with a fulcrum as a center, and a coil spring is disposed between the rear end side of the clip and the shaft tube so that the tip end side of the clip is pivoted. There is known a writing instrument that is in constant contact with the outer peripheral surface of the cylinder and is always repelled so that the rear end side of the clip is separated from the outer peripheral surface of the shaft cylinder.
In such a writing instrument, it is necessary to repeatedly expand and contract the spring when the clip is opened and closed, and therefore it is necessary to prevent the coil spring from shifting or dropping when the clip is opened and closed. However, depending on the diameter of the shaft tube, the base portion of the coil spring may not be widely removed. In particular, when a clip is attached to a slide member of a multicolor ballpoint pen and a coil spring is disposed between the slide member and the clip, there is no space in the radial direction of the coil spring pedestal provided on the slide member. If it deviates, the sliding will be affected.
According to Patent Document 1, a structure is disclosed in which a protrusion is provided on the inner surface of the clip and the coil spring is fitted into the outer surface portion of the protrusion described above, thereby preventing the coil spring from shifting or dropping off.

JP 2010-179557 A

In the structure disclosed in Patent Document 1, the protrusion provided on the inner surface of the clip has a simple cylindrical shape, and the coil spring is fitted in the outer surface portion of the protrusion described above. Also guided by. When the clip is opened and closed, the entire inner diameter portion of the coil spring is guided, so that the contact position of the spring with the pedestal portion is moved back and forth. Therefore, the pedestal portion was shaved at the end of the spring cutting, or abnormal noise was generated by sliding. Also, if the spring does not move well forward due to the resistance of the pedestal and the end of the spring cut, when opening the clip, the coil spring is sandwiched between the protrusion on the back of the clip and the pedestal, and the opening and closing does not work well, The coil spring itself may be deformed, leading to a decrease in clip elasticity.
Further, the protrusion on the inner surface of the clip is configured to be perpendicular to the back surface of the clip, but is slightly inclined with respect to the rotation direction of the clip. When the clip is opened, the spring is compressed in the same direction as the rotation direction. However, since the protrusion is inclined from the rotation direction, the protrusion opens while hitting the inner surface of the spring in the process of rotation. Therefore, there is a risk that the opening / closing operation cannot be performed smoothly or abnormal noise is generated.

Therefore, in view of the above problems, the present invention is configured so that the clip support portion protruding from the outer peripheral portion of the shaft tube, the clip engaged with the clip support portion, and the rear portion of the clip are separated from the outer peripheral surface of the shaft tube. A coil spring for biasing is provided, and a side support plate protruding from both side surfaces of the clip is placed on the clip support portion to constitute a fulcrum that allows the clip to rotate, and the coil spring is located behind the fulcrum. In the writing instrument that is always urged so that the front side of the fulcrum of the clip is in contact with the outer peripheral surface of the shaft cylinder, the inner surface of the clip that is in contact with the coil spring is arranged on the inner side of the coil spring. the spring holding projections to enter the provided the cross-section of the spring holding projection, a longer direction of the axis and Cartesian than the axial direction of the writing instrument while said Koirusupu It is an Abstract that ring inner diameter and the spring holding projection axis and the circumscribed circle diameter in the direction Cartesian were substantially the same.

The present invention relates to a clip support portion protruding from an outer peripheral portion of a shaft tube, a clip engaged with the clip support portion, and a coil spring that urges a rear portion of the clip so as to be separated from the outer peripheral surface of the shaft tube. The clip support portion is covered with side support plates projecting on both side surfaces of the clip to form a fulcrum that allows the clip to rotate, and the coil spring is disposed behind the fulcrum. In addition, in the writing instrument always biased so that the front side of the fulcrum of the clip is in contact with the outer peripheral surface of the shaft cylinder, a spring holding projection that enters the inside of the coil spring is formed on the inner surface of the clip that contacts the coil spring. the provided a cross-section of the spring holding projections, while lengthening the direction of the axis and Cartesian than the axial direction of the writing instrument, the inner diameter and the split of the coil spring Since the circumscribed circle diameter in the direction axial center Cartesian fixings holding projections have substantially the same, when expansion and contraction of the coil spring, the coil spring inside diameter portion can have a clearance with respect to the spring holding projection to the axial direction on the other hand, movement in the direction of axial center Cartesian is restricted. Thereby, while the movement of the coil spring in the axial direction is suppressed as much as possible when the clip is opened and closed, it is possible to prevent the coil spring from being displaced or dropped from the base portion in the radial direction, and the clip can be opened and closed smoothly.
In addition, the angle formed by the straight line connecting the pivot point of the clip and the center of the end point of the coil spring end portion and the center line of the spring holding projection is approximately 90 degrees, so that the coil spring inner diameter portion and the holding projection Sliding resistance can be reduced, and it can be opened and closed smoothly without abnormal noise.
Further, by that the longer direction of Cartesian and axis than the axis of the writing instrument of the spring holding projection by providing ribs in the radial direction of the spring holding projection, further coil spring inside diameter portion and the sliding of the spring holding projections Dynamic resistance can be reduced, and smooth opening and closing without abnormal noise is possible.
Further, by chamfering or rounding the end surface of the rib provided on the spring holding projection, the sliding resistance between the coil spring inner diameter portion and the spring holding projection can be further reduced, and there is no abnormal noise. It can be opened and closed.

The front view which shows the structure of 1st Example of this invention. AA sectional view of FIG. The front view of the latching state of 1st Example of this invention AA sectional view of FIG. Front view of sliding case Rear end projection of sliding case AA sectional view of FIG. Front view of rear axle AA sectional view of FIG. Side view of slider Side view of slider with base Projection view of the top side of the clip Projection view of the inner bottom side of the clip AA sectional view of FIG. Sectional drawing in the clip open state of 1st Example of this invention Side view with clip and coil spring attached to slider with base Enlarged view around the coil spring with the clip closed BB sectional view of FIG. Enlarged view around the coil spring with the clip open BB sectional view of FIG. Diagram showing the axial direction of the spring holding projection

An example of the best configuration (Example 1) will be described. In the following description, the front refers to the pen tip side direction, and the rear refers to the side direction in which the clip is attached.
The shaft body 1 includes a front shaft 2, a rear shaft 3, and a sliding case 4. The front shaft 2 is attached to the rear shaft by means such as screwing, and a projection hole 2B in which a writing portion of the refill 5 protrudes and protrudes is formed at the front end of the front shaft 2. Further, the front shaft 2 is fitted with a grip 21 made of a rubber-like elastic body, but the front shaft 2 is covered with a grip made of a rubber-like elastic body by means of two-color molding or multicolor molding. You may do it. Providing a grip on the outer periphery of the front shaft 2 increases the grip feeling, improves the ease of writing, and further reduces fatigue.
The rear shaft 3 is formed with three window holes 3A in the longitudinal direction. In this example,
Three window holes 3A are formed, because the total number of refills 5 is three, and the number of window holes 3A formed varies depending on this number. In this example, the slider is composed of two sliders 6 and one slider 18 with a base.
The front and rear ends of the window hole 3A are closed by a closing portion 3E, and the slider 6 and the slider 18 with the base portion are inserted from the rear end of the rear shaft 3, pass through the rear shaft 3, and enter the window hole 3A.
A slider 6 is slidably disposed in the window hole 3A of the rear shaft 3. On both sides of the slider 6 in the longitudinal direction, drop prevention protrusions 18D are formed to prevent the slider 6 from dropping from the window hole 3A of the rear shaft 3.
One locking protrusion 6C and a release protrusion 6E are formed on the bottom surface of the slider 6.
When the user advances the slider 6, the slider 6 falls in the axial direction, and the locking projection 6 </ b> B of the slider 6 is in the locking recess 14 provided at the center of the beam-shaped partition wall 9 in the sliding case 4. Locked. At this moment, the pen tip 12 protrudes from the tip protrusion hole 2B of the front shaft 2 and writing is possible.
When the pen tip 12 protrudes, the refill restricting rib 15B provided from the rear shaft inner peripheral surface 3F near the through hole 15A provided in the restricting portion 15 in the rear shaft 3 toward the center of the through hole 15A, and the refill 5 Contact. By this contact operation, the nib 12 at the tip of the refill 5 is forced toward the protruding hole 2 </ b> B at the tip of the front shaft 2. Thereby, the pen tip 12 is protruded from the protrusion hole 2B without the refill 5 being bent in the front shaft 2. For example, when the refill 5 is a sharp unit, the feeding failure of the built-in sharp core 8 due to the bending of the sharp unit itself is prevented, and smooth centering becomes possible.
When the other slider 6 positioned at the rear in the protruding state of the tip of the refill 5 is advanced, the released protrusion 6E of the advanced slider 6 comes into contact with the released protrusion 6F of the slider 6 that is locked. When the slider 6 that has been locked moves outward in the radial direction, the locking is released, and at that moment, the slider 6 moves backward due to the resilience of the resilience member 13, and the tip of the refill 5 moves. It will be dead.
Further, a refill holding projection 6G protruding in the longitudinal direction is formed at the front end of the slider 6, and the refill holding projection 6G is inserted into the rear end portion of the refill 5 to hold the refill 5 in a press-fit manner. I can do it. The shape of the refill holding projection 6G is not limited to the present embodiment, and a press-fitting relationship may be provided by a rib or the like.
The refill 5 can be appropriately selected from a ballpoint pen refill, a sharp unit capable of feeding a sharp lead, and the like. In addition, when a ballpoint pen refill is selected as the refill 5, the resin pipe (ink receiving tube) is colored or colored in a color approximate to the internal ink by transfer printing, etc., and can be identified from the appearance of the user. You can also.
At the front end portion of the slider 6, a flange portion 6 </ b> H with which a rear end portion of a later-described elastic member 13 is in contact is formed.
Reference numeral 13 denotes an elastic member 13 such as a coil spring that biases the refill 5 and the slider 6 connected to the refill 5 backward.
A restricting portion 15 is formed at an intermediate portion of the rear shaft 3, and three through holes 15 </ b> A into which the refill 5 is loosely inserted are formed in the restricting portion 15. The refill 5 is urged rearward by locking one end of the member 13.

A sliding case 4 is attached to the rear end portion of the rear shaft 3. In this example, on the outer peripheral surface of the sliding case 4, engagement protrusions 4 </ b> A for engagement with the rear shaft 3 are provided at equal intervals. Further, the engagement protrusion 4A is engaged with a rear end portion of the window hole 3A provided on the outer peripheral surface of the rear shaft 3. In this engaged state, the front half 4B of the sliding case 4 is disposed inside the rear end of the rear shaft 3, while the rear half of the sliding case 4 protrudes from the rear end opening 3B of the rear shaft 3. The protruding rear half of the sliding case 4 is a knock portion 4C, and the entire sliding case 4 slides back and forth with respect to the rear shaft 3 by the knock operation. As a result, when the refill 5 is selected as a sharp unit, the length of the shaft body 1 is suppressed by effectively utilizing the sliding distance of the sharp core feedout in the window hole 3A. A partition 19 is formed by the beam-shaped partition wall 9 so as to divide the radial direction. The slider 6 attached to the rear end of the refill 5 slides back and forth in the section 19 so that the pen tip of the refill 5 and the tip portion of the sharp unit are immersed. The number of the sections 19 is three in this example, but changes depending on the number of the refills 5.
Moreover, although the sliding case 4 has comprised the bottomed cylinder shape, the cylinder part 4D is lose | eliminated from the intermediate part, and it is in the open state to radial direction. Specifically, a cutout portion 4E having a sectoral cross section is formed, and the cutout portion 4E is in an open state. That is, the notch 4E is used as a sliding surface, and the slider 6 slides in the sliding case 4. The pressing portion 6A of the slider 6 protrudes outward from the window hole 3A of the rear shaft 3, and the pressing portion 6A of the slider 6 slides in the window hole 3A of the rear shaft 3.

An attachment / detachment hole 10 is provided on the rear end surface of the sliding case 4 of the shaft body 1 to attach a decorative part such as an earphone jack accessory or a functional part such as an eraser, a fluorescent pen, a correction tool, or the like. It is possible.
As described above, two sliders 6 and one base-equipped slider 18 are disposed in the three window holes 3A provided on the rear shaft 3. The shape contacting the bottom surface side of the slider 18 with the base, that is, the sliding case 4 side is the same as the slider, and the operation at the time of locking or releasing is the same as that of the slider 6. However, on the top surface side of the slider 18 with the base portion, a clip support portion 18A that is exposed to the outside through the window hole of the rear shaft 3 is provided. The clip support portion 18A has a clip mounting protrusion 18B for mounting a clip 20 described later. After the clip 20 is attached, the clip attachment protrusion 18B becomes the fulcrum 22 when the clip 20 rotates. The clip mounting protrusion 18B has a substantially cylindrical shape. In addition, the clip mounting projection 18B is provided with a tapered portion 18C so that the height of the clip mounting projection 18B decreases as the distance from the axial center increases. This is because the clip mounting protrusion 18B can easily enter.

The clip 20 is formed of a clip main body 20A and a side plate 20B, and a side support plate 20B protrudes along both side surfaces of the clip main body 20A so as to face the left and right side surfaces of the clip mounting projection 18B. Yes. Each side support plate 20B is provided with a clip mounting hole 20C, which forms a pivot fulcrum 22 that engages with the clip mounting projection 18B and supports the clip 20 in a freely rotatable manner.
Further, in the vicinity of the clip mounting hole 20C, a tapered portion 20D is formed so as to be in surface contact with the tapered portion 18, and the clip mounting hole 20C serves as a guide when the clip mounting projection 18B is assembled. The assembling operation is easy.
In the present invention, the tapered portion 18 and the tapered portion 20D are formed, but they may be formed only on one of them.

Further, the clip 20 is set so that the thickness of the clip body 20A is smaller than the thickness of the side support plate 20B. With this thickness setting, the clip body 20A is easily elastically deformed with respect to the side support plate 20B, the side support plates 20B are opened away from each other, and the clip mounting projections 18B easily get over the side support plate 20B. It can be engaged with the hole 20C.
That is, when assembling the clip 20 to the slider 18 with the base portion, a force is applied to the side support plate 20B from the outer diameter direction of the shaft center toward the center, so that a force is applied to the side support plate 20B and the center of the clip main body 20A. Since the portion is concavely curved in an arc shape and the side support plate 20B is elastically deformed so as to be away from each other by the concave curvature, it can be easily engaged.
On the other hand, after the clip 20 is assembled to the slider 18 with the base, if the tip of the clip 20 is forcibly opened away from the shaft body 1, the clip 20 is pulled from the clip body 20 </ b> A to the rotation fulcrum 22. Since a force is applied to the inside of the plate 20B, the central portion of the clip main body 20A is curved in an anti-arc shape (convex shape), and the side support plate 20B is elastically deformed so as to be close to each other by this convex shape. 20 becomes difficult to come off.
In addition, the said effect becomes remarkable, so that the difference of the thickness A of the clip main body 20A and the thickness B of the side support plate 20B becomes large.
Furthermore, since the side support plate 20B is set to a sufficient thickness, the side support plate 20B is hardly damaged and can be used with confidence.

A flat surface portion 18D is provided on the outer peripheral portion of the slider 18 with base portion at the rear of the clip support portion 18A so as to face the inner bottom surface 23 of the clip body 20A. An end 24A of the coil spring 24 is in contact with the flat portion 18D.
Further, a spring holding projection 25 is provided behind the inner bottom surface 23 of the clip main body 20A so as to project toward the opposed flat portion 18D, and the end 24B of the coil spring 24 is the spring holding projection. 25 so as to cover 25 and prevent it from leaving the mounting position. That is, an urging force is generated in the coil spring 24 when the end 24A and the other end 24B that are in contact with the flat surface portion 18D are in contact with the inner bottom surface 10.
Due to the urging force of the coil spring 24, the rear portion of the clip 20 is repelled away from the outer peripheral surface of the shaft body 1 and the pivot fulcrum of the clip 20. The front portion of the cylinder 22 is repelled so as to contact the outer peripheral surface of the shaft cylinder 1 through the rotation fulcrum 22.
With this configuration, the clip 20 is pressed against the urging force of the coil spring 24 by pressing the rear portion of the clip 20 from the pivot fulcrum 22 in the axial direction of the shaft body 1. The front portion of the rotation fulcrum 22 is a clip that can be opened and closed to rotate away from the outer peripheral surface of the shaft body 1 via the rotation fulcrum 22.

The spring holding projection 25 is provided with a large diameter portion 26 on the outer peripheral surface close to the inner bottom surface 23, which is slightly larger than the inner peripheral diameter of the coil spring 24.
The large-diameter portion 26 is configured so that the end winding portion 24C of the coil spring 24 is pressed against the coil spring 24. When the clip 20 is assembled to the clip support portion 18A of the slider 18 with the base portion, the coil spring 24 is moved to the spring holding projection. By engaging with the clip support portion 18A after being extrapolated to 25 and held substantially integrally, the coil spring 24 is prevented from being detached and lost during assembly work. ing.
Further, the spring holding projection 25 does not project perpendicularly from the straight line WW representing the clip inner bottom surface 23 but has an angle. Specifically, the angle formed between the straight line YY indicating the center of the spring holding protrusion 25 and the straight line XX passing through the center flange of the end winding portion 24C of the coil spring 24 from the rotation fulcrum 22 of the clip 20 It is designed to be approximately 90 degrees. In other words, the spring holding projection 25 faces the tangential direction with respect to the rotation direction of the clip 20. More specifically, when the clip 20 is rotated, the locus of movement of the spring holding projection 25 is as indicated by an arc V, and the direction of the spring holding projection 25 is always directed to the tangential direction of the locus V.

Further, the spring holding projection 25 is formed with a slit 27 along the axis of the shaft cylinder 1, and when the clip 20 is attached to the slider 18 with the base, it is elastically deformed in the direction in which the clip attachment hole 20C is separated. It plays a role to make it easier.
The bottom surface 27A of the slit 27 is set on the same plane as the inner bottom surface 23 of the clip body 20A.
However, the present invention is not limited to this as long as the thickness of the clip body 20A on the bottom surface 27A of the slit 27 is smaller than the thickness of the side support plate 20B.
The same effect can be obtained even if the bottom surface 27A protrudes higher than the inner bottom surface 23, or is lower than the inner bottom surface 23 and is embedded in the clip main body 20A, or a through hole having the same shape as the bottom surface 27A is formed.

On the other hand, if the slit 27 is formed linearly along the axis of the shaft body 1, the width of the slit 27 is not limited, and a plurality of slits can be formed.
Furthermore, the opposing side surfaces 27B newly formed by forming the slits 27 may have a tapered shape in which the distance from each other toward the inner bottom surface 23 of the clip main body 20A decreases from the tip of the spring holding projection 25. It is also possible to improve releasability as a punch taper provided in the mold.

Further, a small-diameter portion 28 having an outer diameter smaller than that of the large-diameter portion 26 is formed on the distal end side in the projecting direction from the large-diameter portion 26 of the spring holding protrusion 25. The outer diameter of the small-diameter portion 28 has a tapered shape that gradually decreases toward the projecting tip portion, and the outer peripheral surface of the spring holding projection 25 and the inner peripheral surface of the coil spring 24 are the tip portion. The distance is closer.
Thereby, when the said clip 20 is formed by injection molding, a mold release property can also be improved as a taper taper provided in a metal mold | die.

Ribs 29 are provided along the spring holding projections 25 on both sides of the small diameter portion 28 in the direction of the clip side support plate 20B. The vicinity of the connection portion of the rib 29 with the clip 20 is approximately the same size as the circumscribed circle of the large-diameter portion 26 described above, but the rib 29 has a shape that is slightly reduced in diameter toward the tip. Yes. The purpose of this is also a draft angle to reduce interference with the mold during molding, but it is provided in consideration of the inner diameter tolerance of the coil spring 24. Further, the outer appearance portion of the rib 29 has a shape having an R (arc shape) as a whole, and the spring inner diameter portion and sliding resistance are reduced. That is, the vicinity of the connection portion of the rib 29 with the clip 20 has a dimensional relationship that is substantially the same as the inner peripheral diameter of the coil spring 24, but the circumscribed circle diameter of the rib 29 is slightly smaller than the inner peripheral diameter of the coil spring 24. May be.
As a result, when the coil spring 24 is extrapolated to the spring holding projection 25, the coil spring 24 contacts only the end turn portion 24C in the axial direction, but the end turn in the direction toward the clip side support plate 20B. The rib 29 is in contact with not only the portion 24C but also the intermediate portion 24D.

Next, the operation of the present invention will be described. When the slider 18 with the base portion to which the clip 20 is attached is slid forward, the flat portion 18D provided on the slider 18 with the base portion is immersed and locked inside the window hole 3A of the rear shaft 3. At this time, since the end portion 24A of the coil spring 24 is in contact with the plane portion 18D, the coil spring also enters the window hole 3A. However, when the end portion 24A of the coil spring 24 is displaced in the direction of the clip side indicator plate 20B and protrudes outward from the flat surface portion 18D, the window hole 3A and the coil spring 24A interfere with each other when the slider 18 with the base portion is immersed. There is a risk that it will not be locked smoothly, or if it is forcibly locked.
However, in the present invention, the rib 29 provided in the small diameter portion 28 prevents the coil spring 24 from moving in the direction of the clip side instruction plate 20B. Thereby, there is no possibility that the end 24A of the coil spring 24 on the side of the slider 18 with the base protrudes from the flat portion 18D of the slider 18 with the base. Therefore, smooth sliding is possible without contacting the window hole 3A and the end 24A of the coil spring 24.
Further, the angle YY formed by the straight line XX connecting the rotation fulcrum 22 of the clip 20 and the center of the end point of the coil spring end winding 24C and the center line of the spring holding projection 25 is approximately 90 degrees. When the clip 20 is rotated, the spring holding projection 25 is always directed in the tangential direction. As a result, the spring holding projection 25 is always oriented in the compression direction of the coil spring 24. That is, when the coil spring 24 is expanded and contracted, the inner diameter portion of the coil spring 24 and the spring holding projection 25 do not interfere with each other, thereby reducing the sliding resistance of the coil spring 24 and opening and closing smoothly without abnormal noise.

Although the spring holding projection 25 of the first embodiment has a substantially conical shape, it can also be formed in a conical shape having an elliptical bottom surface. The shorter side of the ellipse in the axial direction, and the direction of axial center Cartesian the long side of the ellipse, further circumscribed circle diameter of the long sides of the ellipse by substantially the same diameter than the circumference the coil spring The same effects as those of the first embodiment can be obtained. Naturally, the same effect can be obtained even when the bottom surface of the spring holding projection has a rhombic cone shape. In addition, various shapes such as a shape including a portion partially having an arc can be adopted, but the shape may be appropriately selected in consideration of the manufacturing cost.

DESCRIPTION OF SYMBOLS 1 Shaft body 2 Front shaft 2A Conical part 2B Projection hole 2C Screw part end surface 2D Front shaft appearance rear end surface 3 Rear shaft 3A Window hole 3B Rear end opening 3D Rear shaft front end surface 3E Closure part 3F Inner peripheral surface 4 Sliding case 4A Engagement protrusion 4B Front half 4C Knock part 4D Tube part 4E Notch part 4F Slider contact part 5 Refill 5C Removable part 6 Slider 6A Rear end pressing part 6B Notch 6C Locking protrusion 6E Release protrusion 6F Release protrusion 6G Refill holding Protrusion 6H Eaves part 7 Sharp unit 7A Tip part 8 Sharp core 9 Partition wall 10 Removable hole 12 Pen tip 13 Repellent member 14 Locking convex part 15 Restriction part 15A Through hole 15B Refill restriction rib 17 Insertion groove 18 Slider with base 18A Clip base 18B Clip mounting projection 19 Section 20 Clip 20A Clip body 20B Side support plate 20C Clip mounting hole 20D Upper part 21 Grip 22 Rotating fulcrum 23 Inner bottom surface 24 Coil spring 24A End part 24B End part 24C End winding part 24D Intermediate part 25 Spring holding projection 26 Large diameter part 27 Slit 27A Slit bottom surface 27B Both side face 28 Small diameter part 29 Rib V Clip Trajectory WW drawn by spring holding projection during rotation Straight line XX showing the inner bottom surface of the clip Straight line ZZ clip perpendicular to the straight line YY XX connecting the pivot end point to the end point of the spring end winding A straight line perpendicular to the bottom

Claims (4)

A clip support portion projecting from the outer peripheral portion of the shaft tube, a clip engaged with the clip support portion, and a coil spring for urging the rear portion of the clip away from the outer peripheral surface of the shaft tube, A side support plate projecting on both sides of the clip is placed on the clip support portion to form a fulcrum that allows the clip to rotate, and the coil spring is disposed behind the fulcrum and the clip In the writing instrument always urged so that the front side of the fulcrum is in contact with the outer peripheral surface of the shaft cylinder, a spring holding projection that enters the inside of the coil spring is provided on the inner surface of the clip that contacts the coil spring. the cross section of the spring holding projection, while lengthening the direction of the axis and Cartesian than the axial direction of the writing instrument, the inner diameter and the spring holding collision of the coil spring Writing instrument characterized by the axis and the circumscribed circle diameter in the direction Cartesian has substantially the same.   The writing instrument according to claim 1, wherein an angle formed by a straight line connecting the rotation fulcrum of the clip and the center of the end point of the spring end portion is approximately 90 degrees. Writing instrument according to claim 1 or 2 was longer direction of Cartesian and axis than the axis of the writing instrument by providing the rib in the radial direction before kissing pulling holding projections. The writing instrument according to claim 3, wherein the end face of the rib provided on the spring holding projection is chamfered or rounded.

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