JPH0653438B2 - A writing press writing instrument with a dryness prevention mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention is convenient to use because it does not require attachment and detachment of a cap, and when not in use, the cursive body is well sealed in the main body, and the number of parts is The present invention relates to a capless writing instrument having a drying prevention mechanism which can be manufactured at a low cost with a few structures.

(Prior art and its problems) Conventionally, there are roughly two types of capless writing instruments for the purpose of preventing dryness, one that makes the writing body difficult to dry and one that has a drying prevention mechanism in the main body. . The former uses ink that is difficult to dry or moves the position of the air hole to the rear and makes it smaller, but since it is not mechanically sealed, it cannot fully fulfill the purpose of preventing drying, Therefore, the cursive body (refill) is wrapped in an aluminum wheel etc. separately from the main body and sold, so there is a problem that the consumer cannot write a trial writing before buying. The latter employs various types of anti-drying mechanisms, but they all have insufficient sealability, and they are sold separately in a cursive (refill) package, and the number of parts is large and assembly is difficult. It had the drawback of being very expensive.

The applicant of the present invention has developed various capless writing instruments having a good anti-drying mechanism, which have good sealing properties and can be manufactured at low cost. The first one has good sealing properties and is inexpensive to manufacture with a small number of parts, but when using it, knock it by making the main body nearly horizontal and knocking down the end of the main body after use. It has been a problem that it has to be knocked toward, and has so-called "direction" (see Japanese Patent Laid-Open No. 59-142197, backward).
Therefore, as the second one, we developed a non-directional one, but as with the first one, there is a sliding cylinder, and a seal cylinder, a seal lid, and a mechanism for moving the cursive forward and backward are provided separately. There is a problem that the cost is slightly high and the appearance is impaired due to the sliding cylinder (see Japanese Patent Laid-Open No. 60-105599). As the third one, we developed a non-directional and non-sliding cylinder, but this one requires a considerable amount of cost to create the mechanism for bringing the seal lid into close contact with the seal cylinder and the groove on the back surface of the seal lid, and to make the tip shape It had the drawback that it could not be sharpened (see Japanese Patent Laid-Open No. 60-58896).

An object of the present invention is to solve each of the problems of the above-mentioned conventional technique, to be convenient to use, to have a good sealing property, to have a small number of parts, to have a simple structure and to be able to manufacture at low cost.

(Means for Solving Problems) In order to solve the above-mentioned technical problems, the present invention accommodates a writing body (refill) such as a felt-tip pen having a tip writing portion and an air hole, a water-based ballpoint pen, etc. in a main body. , A mechanism for advancing the cursive body by knocking, rotating, etc. and locking it to the main body at the forward position (writing possible position) in the main body, or releasing the lock to retract the cursive body for storage And a seal cylinder having a through hole for allowing the front part of the writing body to pass therethrough in the front part of the main body, and the seal cylinder is integrated with the seal cylinder through a hinge part in the vicinity of the tip, or When a separate seal lid is opened and closed (may be constantly biased in the opening direction), and an elastic seal body is attached to the back surface of the seal lid or the tip of the seal tube to close the seal lid. Seal the tip hole of the seal tube. Thus, between the seal cylinder and the cursive body, the tip writing portion of the cursive body presses against each other at a position rearward of the air hole when stored in the seal cylinder.
An elastic seal ring such as a ring is provided so that the tip writing portion and the air hole of the writing body are sealed between the seal lid and the seal ring when the writing body is stored, while either or both of the sealing tube and the main body are sealed. A groove, a through hole, a rib or the like is provided to allow a filamentous member such as a filament of synthetic fiber to pass therethrough, and the filamentous member connects the interlocking member that advances and retracts as the writing instrument advances and retracts, and the seal lid, One of the interlocking member and the cursive body is constantly urged in the backward direction by a push spring or a tension spring, and the interlocking member and the cursive body are slackened even after the seal lid is opened as the interlocking member and the cursive body advance. Can move forward, and after the slack of the filamentous member disappears as the interlocking member retracts, the filamentous member pulls the seal lid by the interlocking member that tries to retract further by the force of the spring. Thereby sealing the sealing tube front end hole, it is characterized in that so as to prevent further retraction of the interlock member.

(Operation) With the configuration of the present invention as described above, when the cursive body is stored in the main body when not in use, the thread-like member passes between the seal cylinder and the main body to connect the seal lid and the interlocking member. Therefore, the retracting force of the interlocking member caused by the spring causes the seal lid to be pulled and pressed against the tip hole of the seal tube, and the seal lid or elastic member provided at the tip of the seal tube causes the tip hole of the seal tube to move. Is sealed. On the other hand, at a position rearward of the air hole of the cursive body, a seal ring made of an elastic member such as an O-ring exists between the seal cylinder and the cursive body and is in pressure contact with both of them, so that the tip of the cursive body and the air hole are separated from each other. Both are sealed by a seal lid and a seal ring. In this state, the interlocking member receives a retracting force further directly or indirectly by the force of the spring or the like, but the thread-like member is taut between the seal lid and the member interlocking with the cursive body. Has prevented the retreat.

Next, when the writing body is advanced through the writing body advancing mechanism, the interlocking member advances and the pulling force by the filamentous member loosens to allow the seal lid to move in the opening direction. It is opened by the biasing force in the opening direction or by being pushed by the tip of the cursive body. When the writing body is further advanced, the writing tip portion projects from the tip of the main body to enable writing, and the writing body is locked to the main body at the advanced position. At this time, the filamentous member is slack in the main body.

When you finish writing and unlock the cursive body at the forward position,
By the urging force of the spring or the like in the backward direction, the interlocking member retracts together with the writing body and the tip writing portion of the writing body is sunk into the tip end hole of the seal cylinder, and then pulled by the thread member connected to the interlocking member, The seal lid also closes the end hole of the seal cylinder to seal it.

If a filament made of synthetic fiber is used, the filamentous member will slacken as the interlocking member advances, but even if slack occurs in the front part of the seal tube, it will be entangled with the tip of the cursive body or the slack part will become entangled in the main body. There is no such thing. Further, the writing body may be provided with a part of the forward / backward moving mechanism, and the rear end of the writing body itself may be used as a knock rod. Also, if the writing body does not come out when the locking at the forward position is released, in this case, since the writing body is prevented from retreating by the thread member, the retreat of the knock rod portion is prevented. Even if it is not limited, the function of bringing the seal lid into close contact with the seal cylinder front end hole is not lost when the filamentous member is slightly stretched.

(Example) Next, the Example of this invention is described with drawing.

FIG. 1 is a plan sectional view of a writing instrument showing a first embodiment of the present invention, and FIG. 2 is a side sectional view when it is rotated 90 degrees in the state of FIG. The seal state stored in the main body is shown.

In the figure, 1 is a front shaft, and 2 is a rear shaft, which are screwed together to form an integral body. The cursive body 3 is accommodated in the main body, and the cursive body 3 has a tip writing portion 3a, an air hole 3b,
It has a small diameter portion 3c, a large diameter portion 3d, and a male screw portion 3e behind the large diameter portion 3d. The cylindrical body 4 is fitted on the outside of the large-diameter portion 3d of the writing body 3. The cylindrical body 4 has a large diameter portion 4a for receiving the spring 15, a female screw portion 4b in the large diameter portion 4a, and a large diameter portion 4
Small cut grooves 4c, 4c are provided at the rear end of a (see FIG. 6). The male screw portion 3e of the writing body 3 is screwed into the female screw portion 4b of the cylindrical body 4 to integrate them. The method of integrating both of them does not have to be screwing. For example, a material having a strong friction resistance such as a rubber band is attached to the inner surface of the cylindrical body 4 or the outer circumference of the large diameter portion 3d of the writing body 3, The cursive body 3 may be pressed into the cylindrical body 4. Further, the cylindrical body 4 may be a ring-shaped one instead of the cylindrical body as long as it has a portion for holding it so as to interlock with the writing body 3.

As the cursive body 3 advances, the cylindrical body 4 and the ring-shaped object are pushed forward by the cursive body 3, and as the cursive body 3 retracts, the cylindrical body 4 and the ring-shaped object retreat by the springs 15. Need only be detachably attached to the cylindrical body 4 or a ring-shaped object.

The knock bar 5 is fitted in the rear shaft 2 behind the cursive body 3,
The front portion of the knock rod 5 serves as a receiving portion 5a that receives the rear end of the writing body 3. The knock rod 5 is provided with an inverted U-shaped slit 5b that is long in the axial direction, and the tongue piece 5c is elastically held by the knock rod 5. A protrusion 5d is provided on the outer periphery of the tongue piece 5c closer to the tip than the central portion. (See FIG. 9).
A wide hole 5e is provided in a portion of the knock rod 5 opposite to the tongue piece 5c. A convex portion 2a for mounting the clip 6 is provided on a part of the outer periphery of the rear end of the rear shaft 2, and a slit (long length) just enough to allow the protrusion 5d of the knock rod 5 to pass through the portion of the rear shaft 2 hidden by the clip 6 is formed. Hole 2b is provided. Then, when the knock rod 5 moves forward and backward, the protrusion 5d becomes the rear shaft 2.
The inside of the long hole 2b can be moved forward and backward. Protrusion 5
Due to d, the knock bar 5 does not rotate with respect to the rear shaft 2.

Next, a concave portion is provided on the back side of the rear end of the clip 6, and the concave portion is press-fitted into the convex portion 2a of the rear shaft 2 to integrate the clip 6 with the rear shaft 2. An engaging portion 6a, which is wider than the slit 2b of the rear shaft 2, is provided on the back side of the substantially central portion of the clip 6. The rear end surface (the surface that does not engage with the protrusion 5d) of the locking portion 6a is tapered or rounded so that it does not get caught when the main body is pulled out from a pocket or the like. A hinge portion 6b is provided in front of the locking portion 6a so that when the tip portion of the clip 6 is pressed with a finger, the tip end of the clip 6 is inclined inward. A pushing portion 6c is provided on the back side near the tip of the clip 6, but since the width of the pushing portion 6c is narrower than that of the slit 2b of the rear shaft 2, the pushing portion 6c.
The tip end portion of c can be sunk in the slit 2b. In addition, from the tip of the clip 6 to the front end of the hinge portion 6b, the taper wall 6d is provided on the back side of both side surfaces of the clip 6.
Is provided so that the clip 6 can be easily inserted into a pocket such as clothes. The pushing portion 6c is also rounded so that the pushing portion 6c does not get caught.

Next, the seal cylinder 7 is provided inside the front portion of the front shaft 1,
The tip of the seal cylinder 7 is a small diameter portion 7a, and the tip of the small diameter portion 7a is thinned and tapered as shown in the drawing. In the seal cylinder 7, the tip writing portion 3 of the writing body 3 is provided.
a, a through hole 7c through which the small-diameter portion 3c passes is provided, and the through-hole 7c is formed at the tip of the small-diameter portion 7a of the seal cylinder 7 at the tip hole 7d.
Is open. The small diameter portion 7a of the seal cylinder 7 has a cylindrical portion 8a of the seal body 8 made of an elastic member such as silicon rubber.
Is covered. In the seal body 8, the lid portion 8c and the cylindrical portion 8a are connected via the hinge portion 8b. The lid portion 8c has a donut shape, and a circular protrusion 9a protruding from the back surface of the seal lid 9 is fitted into the inner hole of the lid portion 8c so as not to separate the both. (See FIGS. 7 and 8) The seal lid 9 has the shape shown in FIGS. 7 and 8, and has a groove 9b having a slightly tapered inlet on its top surface.

On the other hand, the two grooves 7 are also provided in the portion of the seal cylinder 7 that contacts the front shaft 1.
b and 7b are provided (see FIGS. 2, 4, and 5). The groove 9b of the seal lid 9 or the groove 7b of the seal cylinder may be a through hole, or two ribs may be aligned to form a valley-shaped portion. When the seal cylinder 7 is provided with ribs, a groove is carved in the front shaft 1 to fit the two ribs of the seal cylinder 7 into the groove, and as a result, a through hole may be formed between the two ribs. Good. Further, instead of providing the groove in the seal cylinder 7, the groove may be provided in the front shaft 1.

Next, the O-ring 10, which is a seal ring, is fitted in the rear large-diameter portion of the seal cylinder 7, and the washer 11 for preventing the O-ring from slipping out is fixed in the seal cylinder 7. This washer 1
1 is not always necessary, and the washer 11 may be omitted by forming inward protrusions at three locations behind (rightward in the drawing) the O-ring in the seal cylinder 7. .

Finally, a filamentous member 12 is prepared. The filamentous member 12 is a filament of synthetic fiber, which does not change due to low temperature or high temperature, is thin and strong, is particularly resistant to pulling due to friction or shock, and hardly stretches. Let's choose the one that doesn't sag and sticks. Heat is applied to both ends of this thread member to form a thread ball (pilling), and the spring 15 is used to seal the seal cylinder 7 and the large diameter portion 4 of the cylindrical body 4.
After being fitted between a, the thread ball 12a at one end of the thread member 12 is fitted and hooked in the cut groove 4c at the rear end of the large diameter portion 4a, passed through one groove 7b of the seal tube 7, and the top surface of the seal lid 9 is inserted. Through the other groove 7b of the seal cylinder 7 and then the thread ball 12a at the other end into the other cut groove 4c at the rear end of the large diameter portion 4a of the cylindrical body 4 and the spring 15 is compressed. So that it can be fitted (see FIGS. 5 and 6).

Then, the male threaded portion 3e of the writing body 3 of FIG. 5 is screwed into the female threaded portion 4b of the cylindrical body 4 of FIG. , Fix it. Next, by inserting the knock bar 5 having the writing body receiving portion 5a and screwing the rear shaft 2 into the front shaft 1, the states shown in FIGS. 1 and 2 are obtained. In the case of this screwing, the writing body 3 is not rotated by the receiving portion 5a, but a protrusion is provided on the outer periphery of the large diameter portion 4a of the cylindrical body 4, while a groove is provided in the tip shaft 1 to fit both. If combined, the rotation of the cylindrical body 4 can be completely prevented.

Although the seal cylinder 7 does not have to be fixed in the front shaft 1,
When replacing the cursive body 3, it is necessary to avoid any trouble.

Next, the operation will be described. In the state shown in FIGS. 1 and 2, the cylindrical body 4,
Although the cursive body 3 is retracted together, the thread member 12
Since the thread balls 12a, 12a at both ends of the thread member 12 are fitted and caught in the cut grooves 4c, 4c at the rear end of the large diameter portion 4a of the cylindrical body 4, the central portion of the thread member 12 passes through the groove 9b of the seal lid 9. The cylindrical body 4 is prevented from moving backward. The receiving portion 5a of the knock rod 5 contacts the rear end of the writing body 3 by its own weight, and there is a gap between the protrusion 5d of the knock rod 5 and the rear end of the elongated hole 2b of the rear shaft 2. This gap disappears when the tip of the writing instrument is raised, and instead the same gap is formed between the rear end of the writing body 3 and the receiving portion 5a. This gap is for preventing the retreat of the cylindrical body 4 and the writing body 3, and therefore improves the close contact between the seal lid 9, the seal body 8 and the tip of the small diameter portion 7a of the seal cylinder 7. Even if the filamentous member 12 is stretched to some extent, it is absorbed by the gap.

FIGS. 3 and 4 show a state in which the writing rod 3 is pushed in the forward position in the main body by pushing the knock rod 5 from the states shown in FIGS. 1 and 2 to enable writing by the tip writing portion 3a. Is shown. The seal lid 9 is opened by the rising force of the lid portion 8c of the seal body 8 due to its own force, and the thread member 12 is slack in the main body. The projection 5d provided on the tongue piece 5c of the knock rod 5 engages with the locking portion 6a of the clip 6 to lock the writing body 3 at the forward position. The spring 15 is contracted by the distance that the cylindrical body 4 has advanced. Write in this state.

After the writing is finished, when the tip of the clip 6 is pushed toward the center, the front part of the clip 6 bends inward through the hinge portion 6b, so that the pushing portion 6c tries to enter the elongated hole 2b of the rear shaft 2 and the tongue is pushed. Push the tip of the piece 5c to sink it. Then, the protrusion 5d also sinks, and the engagement with the locking portion 6a of the clip 6 is released, so that the cylinder 15 and the writing body 3 are both retracted by the spring 15 and the state shown in FIGS. It returns to the state of FIG. And FIG. Even if the tip portion of the clip 6 is not pressed with a finger, if the clip is inserted into the pocket, and even if the cloth is thin, it can be disengaged by passing it between the protrusion 5d and the engaging portion 6a. Therefore, cursive 3 is clip 6
It is stored and sealed in the main body in the same way as when pressing the tip of the.

In the first embodiment, the filamentous member 12 is attached to the cylindrical body 4, and the cylindrical body 4 and the writing body 3 are detachable. Therefore, when the writing body 3 is out of ink, the writing body 3 shown in FIGS.
In the state shown in the figure, the rear shaft 2 is rotated to disengage it from the front shaft 1 (even in this case, since the writing body 3 is not rotated by the receiving portion 5a of the knock rod 5, the thread member 12 does not twist), the cylindrical body 4 The cursive body 3 can be easily removed by turning the cursive body 3 while holding the large diameter portion 4a. Therefore, the old cursive can be removed and a new cursive can be attached. That is, the cursive (refill) can be exchanged.

FIG. 10 and FIG. 11 are side sectional views showing a second embodiment of the present invention, respectively, in a state corresponding to FIGS. 2 and 4 of the first embodiment, that is, a sealed state in which a cursive is stored. And a writing state in which the cursive body is advanced.
A plan sectional view showing a state corresponding to FIGS. 1 and 3 of the first embodiment before being rotated by 90 degrees is omitted.

In the second embodiment, the writing member and the knock rod are integrated by attaching a thread member to a part of the knock rod, and the knock rod is pushed to lock the writing body in the forward position, and the writing member is unlocked to write. As the body recedes, the knock bar also recedes. The same parts as those in the first embodiment will be described using the same reference numerals.

In FIGS. 10 and 11, H is a main body shaft, and inside the front portion of the main body shaft H, as in the first embodiment, a seal cylinder 7, a seal body 8, a seal lid 9, a seal ring (O ring) 10,
A washer 11 is provided. Tip writing part 3 of cursive body 3
a is the small diameter portion 7 of the seal cylinder 7 in the housed state of FIG.
It is located slightly rearward (rightward in the figure) from the tip of a, and the air hole (provided at the tip of the small diameter portion 3c) is located in front of the O-ring 10 (leftward in the figure). The front part of the is inserted into the seal cylinder 7. Next, the knock rod 5 is prepared. Two knocking portions 5f, 5f are provided at the tip of the knock rod 5.
Is provided, and the thin cut grooves 5 are formed on the protrusions 5f and 5f.
g and 5g are cut.

A spring 15 is interposed between the main body shaft H and the rear end flange portion 3f of the writing body 3 housed in the seal cylinder 7 and the seal cylinder 7, and the tip end of the knock bar 5 is further brought into contact with the rear end of the flange portion 3f. The seal lid 9 and the knock rod 5 are connected to each other with the spring 15 slightly compressed by the thread member 12. That is, the filamentous member 1
The thread ball 12a at one end of 2 is attached to the protrusions 5f, 5 of the knock rod 5.
Fitted in one of the cut grooves 5g, 5g of f, the thread member 12 is fitted in one groove 7b of the seal cylinder large diameter portion, then fitted in the groove 9b on the top surface of the seal lid 9, and further in the seal cylinder large diameter portion. The other groove 7b
, The spring 15 is contracted, and the other end of the thread member 1 is inserted into the cut groove 5g of the other protrusion 5f of the knock rod 5.
Set by fitting 2a.

In the second embodiment as well, the mechanism in which the knock bar 5 locks the writing body 3 in the forward position at the rear portion of the body axis H and releases the locking is the same as that in the first embodiment. is there. Although the projection on the tongue of the knock rod can be further retracted in the slit of the main body shaft, the thread-like member 12 causes the knock rod 5 to move.
Since the projection 5f and the closed seal lid 9 are taut, the knock bar 5 and the writing body 3 do not retract even by the retracting force of the spring 15. Since the seal lid 9 is pressed against the tip of the small diameter portion 3a of the seal tube, the seal lid 9 is well sealed.

In this embodiment, the member interlocking with the cursive body is a knock bar. In this embodiment, the internal mechanism to be inserted into the body shaft H is first assembled outside, and then the protrusion 5d of the knock rod 5 is sunk from the rear of the body shaft H while the protrusion 5d is aligned with the slit 2b. The entire internal mechanism is inserted into the main body shaft H and assembled. The seal cylinder 7 may be loosely fitted to the main body shaft H.

Since the operation of the second embodiment is the same as that of the first embodiment, it will be omitted.

Although some embodiments have been described above, the present invention is not limited to the above embodiments. For example, the rear end of the cursive body itself may be used as a knock bar, and a mechanism for locking and unlocking at the forward position may be attached to a part of the cursive body. In this case, a thread-like member connects the seal lid and a part of the writing body. A method of detachably attaching the cylindrical body and the cursive body may be arbitrary. That is, as long as the interlocking member such as the cylindrical body or the ring is pushed by the writing body to move forward and retract by the force of the spring, the method of detachably attaching the writing body to the interlocking member may be arbitrary. Alternatively, the clip may be a molded product of synthetic resin, and the front portion of the locking portion may be thinned to facilitate bending inward. The seal body and the seal lid may be integrally molded, and the side that seals the seal tube (back side) may be made of soft synthetic resin, and the side that is pressed or pulled by the thread member (top surface) may be made of hard synthetic resin. Further, the seal body and the seal lid may or may not always be biased toward the opening direction and may swing. As for the member that advances and retracts as the cursive body moves backward and forward, the filamentous member may be connected to any advancing and retracting mechanism as long as it is a portion that advances and retracts without rotating. In addition, the integration of each component, the material, the shape, etc. may be arbitrary, and the design can be changed.

(Effects of the Invention) According to the present invention, the following effects are achieved.

(1) It is convenient to use because the cursive body is well sealed when not in use, without the need to attach and detach the cap.

(2) Since the number of parts is small and each part can be made inexpensive, the structure is simple and automatic assembly by machine is possible.
It can be produced at low cost.

(3) It can be used for both refill replacement and disposable items.

(4) If the cursive is stored in the main body when it is inserted into the pocket, it will not cause ink to smear on clothes even if the cursive storage operation is forgotten and inserted into the pocket.

(5) It is suitable for both felt-tip pens and water-based ballpoint pens, and popular products, intermediate products, and high-class products can be made according to the application.

[Brief description of drawings]

1 and 2 are a plan sectional view and a side sectional view of a writing instrument showing a first embodiment of the present invention, showing a sealed state in which a writing body is housed in a main body, and FIGS. 3 and 4 are the same. A plan sectional view and a side sectional view showing a writable state, FIGS.
The figure is an explanatory view of the main part, and FIGS. 10 and 11 are the second of the present invention.
It is a sectional side view which shows the different operation state of an Example. 1 ... Front axis, 2 ... Rear axis, 2b ... Slit, 3 ... Writing body, 3a ... Tip writing section, 3b ... Air hole, 4 ... Cylindrical body, 5 ... Knock rod, 5c ... … Tongue, 5d …… projection,
6 ... clip, 6a ... locking part, 7 ... seal cylinder, 7
c ... Through hole, 7d ... Tip hole, 8 ... Seal body, 9 ...
... Seal lid, 10 ... Seal ring, 12 ... Filiform member, 15 ... Spring.

Claims (4)

[Claims] 1. An advancing / retracting mechanism for accommodating a writing body having a tip writing portion and an air hole in a main body, advancing the writing body to lock at the writing position, and releasing the locking to retract to the storage position. A seal tube having a through hole through which the front part of the writing body passes is provided in the front part of the main body, and a seal lid for sealing the tip hole of the seal tube is attached to the front end of the seal tube so as to be openable and closable. In addition, between the seal cylinder and the cursive body, a seal ring of an elastic member that presses the tip of the cursive body against each other at a position behind the air hole when the cursive body is housed in the seal cylinder is provided, and the cursive body moves forward and backward. The reciprocating interlocking member and the seal lid are composed of a thread-like member, and either the interlocking member or the writing body is constantly biased in the retreating direction by a spring, and the thread-like member is passed between the main body and the seal cylinder. Means provided, front As the interlocking member and the cursive body advance, the thread member sags even after the seal lid opens, and the interlocking member and the cursive body can move forward. As the interlocking member retreats, the thread member loses its slack and the thread member seals. Is a capless writing instrument having a drying prevention mechanism, which is configured to be pulled to seal the tip end hole of the seal cylinder and prevent the interlocking member from further retracting. 2. A capless writing instrument having a dry prevention mechanism according to claim 1, wherein the interlocking member and the writing body are detachable. 3. A capless writing instrument having a dry prevention mechanism according to claim 1, wherein the interlocking member and the writing body are integrated. 4. A mechanism for advancing and retracting the cursive body includes a projection on a tongue provided on a part of a knock rod and elastically supported, and a projection provided on a portion hidden by a clip of a main body. Slit, a locking portion provided on the back surface of the clip that is wider than the slit and that engages with the projection, and when the tip portion of the clip is bent inward by pressing with a finger, presses the tongue piece to engage with the projection. The capless writing instrument having a dry prevention mechanism according to claim 1, comprising a narrow pressing portion having a width wider than that of the slit for releasing engagement with the stopper.