JP2011173407A - Retractable writing utensil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To overcome the problem that, since a retractable writing utensil which performs opening and closing of a lid body using opposition contact of a writing utensil body and a lid body generates a sliding friction force in the writing utensil body when closing lid body, it is necessary to set an elastic force high which lowers the writing utensil body with an increase in knock load that much in advance operation of the writing utensil body. <P>SOLUTION: At a retreat operation of the writing utensil body, the lid body is locked by a locking mechanism, locking of the lid body is canceled after writing utensil body retreats, and rotation blocking of the lid body is carried out while maintaining a non-contact state of the lid body with the writing utensil body. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention accommodates a writing instrument main body having a nib at the tip in an exterior body so as to be movable back and forth, and interlocks with a lid disposed at the front end opening of the exterior body as the writing instrument body is advanced or retracted by operation. In addition, the present invention relates to a retractable writing instrument that opens and closes a front end opening of an exterior body and causes a pen tip to project from the front end of the exterior body.

  Conventionally, a writing instrument body having a pen tip at the tip is housed in the exterior body so as to be movable back and forth, and the writing instrument body is moved forward or backward by operation, and the lid disposed at the distal end opening of the exterior body is interlocked, The retractable writing instrument, which opens and closes the tip opening of the exterior body and projects the pen tip from the front end of the exterior body, does not separate the body from the body of the writing instrument. The pen nib can be housed and sealed with a single touch even though it does not have to worry about losing it, so ink drying from the pen nib is suppressed, and a fresh handwriting can be obtained over a long period of time. It suppresses contacting with the thing.

Such an in / out type writing instrument applies an opening / closing driving force to the lid member by utilizing the forward / backward movement of the writing instrument body for accommodating the pen tip protruding for writing in the exterior body.
For example, Japanese Patent Application Laid-Open No. 2008-110527 (Patent Document 1) discloses a cam portion and a lid body of a writing instrument body that accompany advancing operation of the writing instrument body when the pen tip projects from the tip of the exterior body. When the lid of the writing instrument body comes into contact, the lid rotates, the tip of the exterior body opens, and the pen tip can be ejected. When the cam portion of the lid body comes into contact with the lid body, the lid body rotates to close the tip of the exterior body.
In addition, what is disclosed in Japanese Utility Model Publication No. 06-015728 (Patent Document 2) is that when the pen tip is protruded from the tip of the exterior body by a coil spring that constantly applies force in the direction of closing the lid. With the advancement of the writing instrument body, the writing instrument body pushes open the lid against the spring force of the coil spring, opens the tip of the exterior body, allows the pen tip to be discharged, and closes the lid When the writing instrument main body retreats and the pen tip is retracted, the lid closes due to the spring force of the coil spring when the writing instrument main body is retracted. It becomes a state.

JP 2008-110527 A Japanese Utility Model Publication No. 06-015728

  In the thing of patent document 1, since the lid is opened and closed using the contact between the writing instrument body and the lid, the writing instrument book needs a force to rotate the lid even when the lid is closed. In addition, sliding friction occurs between the writing instrument body and the lid. Therefore, it is necessary to set a large elastic force for lowering the writing instrument body, and there is a problem that the knock load becomes higher in the forward movement of the writing instrument body.

  In the thing of patent document 2, since force is always given in the direction which obstruct | occludes a cover body with a coil spring, it is not necessary to make the rotation operation | movement which closes a cover body by operation | movement of a writing instrument main body, and the part of a writing instrument main body is the part. Although the burden on the operation is reduced, the lid is kept open by the contact between the lid and the writing instrument body, so that sliding friction occurs between the writing instrument body and the lid that is about to move. Since it becomes a load, it is necessary to set a large elastic force to lower the writing instrument body, and this elastic force is a load required when trying to protrude the pen tip. There was a problem that would become high.

  The present invention accommodates a writing instrument body having a pen tip at the tip in an exterior body so as to be able to move back and forth, and a lid that releases and closes the distal end opening of the exterior body by rotational movement at the distal end of the exterior body, An elastic member that urges the lid in the rotational direction to close the front end opening of the exterior body is disposed, and an inner cam portion provided on the inner side of the lid body and an outer cam portion formed at the tip of the writing instrument body are opposed to each other. In contact with the forward movement of the writing instrument body, with the lid pushed open against the elastic force of the elastic body, the lid is locked by the locking mechanism and the tip of the exterior body is released. The lid body and the writing instrument main body are in a non-contact state while maintaining the state, and when the writing instrument main body is retracted, the locking mechanism for the lid body is released, and the lid body is the tip of the exterior body after the pen tip is retracted. The gist of the pen-shaped writing instrument that closes the opening.

  Since the present invention always applies force in the direction of closing the lid with the elastic body, it is not necessary to make a rotating operation to close the lid by the operation of the writing instrument body, and the burden on the operation of the writing instrument body is accordingly reduced. While being reduced, the lid body and the writing instrument body are brought into a non-contact state when the writing instrument body is retracted by maintaining the lid body in the open state, and sliding friction is generated in the writing instrument body. In addition, the elastic force for returning the writing instrument body can be set weak. Therefore, it is possible to keep the knock load low in the forward movement of the writing instrument body.

The longitudinal cross-sectional view which shows an example. The I section enlarged view of FIG. The perspective view which shows the components of a cover body. FIG. 2 is a view corresponding to FIG. 2 showing an open state of the lid. FIG. 2 is a view corresponding to FIG. 2 showing a closing process of the lid. FIG. 2 is a view corresponding to FIG. Perspective view showing parts of lid Perspective view showing parts of annular member Side view of II section enlarged in FIG. A perspective view of a cross section showing a part of an annular elastic body Perspective view of the tip cross-section showing the parts of the exterior body Perspective view of the tip showing the parts of the writing instrument body FIG. 6 is a view corresponding to FIG. 6 for explaining the rotation of the lid and the forward movement of the writing instrument body. FIG. 6 is a view corresponding to FIG. 6 for explaining the rotation of the lid and the forward movement of the writing instrument body. FIG. 6 is a view corresponding to FIG. 6 for explaining the rotation of the lid and the backward movement of the writing instrument body. FIG. 6 is a view corresponding to FIG. 6 for explaining the rotation of the lid and the backward movement of the writing instrument body. Another example equivalent to FIG. Vertical section showing the pen tip The perspective view which shows the components of the lid of another example The perspective view which shows the pen tip part of another example FIG. 15 is a view corresponding to FIG. 15 for explaining the rotation of the lid and the backward movement of the writing instrument body. FIG. 16 is a view corresponding to FIG. 16 for explaining the rotation of the lid and the backward movement of the writing instrument body.

The writing instrument body is a member that has a pen tip at the tip and contains ink therein. As the nib, a ballpoint nib, a fiber converging body, a porous nib such as urethane, or a synthetic resin nib having a communication hole can be used as appropriate. In the present invention, since the writing instrument main body and the lid are not in contact with each other, the chance that the pen nib and the lid unexpectedly come into contact with each other is suppressed as much as possible. Even if it is used, it is possible to avoid damaging or crushing the nib as much as possible.
In addition, as a method for storing ink in the writing instrument main body, the ink storage body such as a fiber converging body may be impregnated or may be stored directly in the main body without using the ink storage body. As for the ink used, a dye and / or a pigment can be used as a colorant, and water or an organic solvent can be appropriately used as a medium.

  For the operation of advancing the writing instrument body and causing the pen tip to protrude from the front end of the exterior body, a known method such as a knock member disposed at the rear end of the retractable writing instrument or a slide mechanism on the side can be appropriately employed. It is. Further, an elastic member such as a coil spring can be arranged between the members to help drive by operation and to seal the lid member.

  As a method of locking the writing instrument main body in the pen tip protruding state, a cam member having a rotor is provided at the rear of the writing instrument main body, and a so-called debit cam that locks by rotation of the cam member, or a cam on the clip. So-called heart cams that are provided and locked by rubbing with the writing instrument body, those having a structure such that a protrusion is provided on the writing instrument body and the writing instrument body itself is locked by rotating the locking part of the exterior body, etc. You can choose.

The lid that closes the distal end opening of the exterior body in a state where the writing instrument body that is not in use is accommodated in the exterior body opens the distal end opening of the exterior body by rotation, and the lid body and the hinge A door that opens to the outside or the inside that is connected, or an opening portion of the exterior body that slides to open and close by rotating about a rotating shaft that is arranged near the center of gravity of the member can be used. When the lid body is sealed so that it is pressed against the inner edge of the opening of the exterior body, the lid member unexpectedly even when the internal pressure in the sealed chamber inside the lid body increases due to an increase in environmental temperature, etc. Will be prevented from opening. Furthermore, by making the rotation radius as small as possible, the writing instrument itself can be made thin. If the lid body is sealed so that it is pressed against the inner edge of the opening of the exterior body, the space in which the lid body is accommodated when the lid body is opened and closed may be a space in which the pen tip is accommodated. However, when using an ink with an organic solvent as a medium, it is preferable that the space where the pen tip is present is small when the lid is closed, and the inside of the sealed space is reduced by making the rotation radius of the lid as small as possible. Also, drying of the nib is suppressed. At this time, 500 mm ³ or less is desirable as a good sealed space capable of suppressing the drying of the nib.
In addition, at least one member is made of an elastic material such as synthetic resin, rubber, or elastomer at a contact portion between the lid and the opening of the exterior body (or the member forming the opening). It is preferable to do. In particular, when it is formed of butyl rubber, it is excellent in chemical resistance and gas resistance, so that it is sealed well.
Moreover, it is preferable to use a polypropylene with little gas permeation | transmission in order to suppress the nib drying in sealed space in a closed state for a cover body. Especially in the case of knock type, the clip is attached to the knock side and the pen tip is often stored with the pen tip facing downward, and the solvent vapor evaporated from the pen tip is heavier than air and accumulates from the lower side in the sealed space. Gas permeation from the lid side has a great influence on the nib drying. Therefore, the use of polypropylene with little gas permeation has a great effect on the nib drying.
However, since the lid always slides in accordance with the appearance of the pen tip, it is preferable to use polyacetal in the sense of improving the sliding of the lid and improving the durability.
In other words, when using an ink whose main solvent is an organic solvent that tends to cause nib drying, polypropylene is a good material choice, and when using an ink etc. whose main solvent is water that is difficult to dry the nib Polyacetal is a good material choice. Of course, other thermoplastic resins can be appropriately selected and used.
When the lid is moved by moving the writing instrument back and forth, and the lid is in contact with the inner edge of the opening of the exterior body so as to be sealed, the inside of the sealed space that seals the pen tip when the lid is closed Since the operating range of the lid is provided, the sealed space becomes large. In such a case, particularly when an ink using an organic solvent as a medium is used, the air in the sealed space in contact with the pen tip is large, and the pen tip is quickly dried. Therefore, by enlarging the air holes provided in the writing instrument body and increasing the evaporation of vapor from the writing instrument body containing the ink (ink impregnated in the ink occlusion body), the vapor in the sealed space around the pen tip Can be filled quickly, and drying of the nib can be suppressed.

With the elastic member, the lid is urged in the rotation direction that closes the front end opening of the exterior body. As an elastic member, it can employ | adopt suitably by devising the installation place which each functions, such as a leaf | plate spring, a string wound spring, a coil spring, and an elastic structure.
If you try to close the lid with the retracting force of the writing instrument body, you will need the force to retract the writing instrument body accordingly, so either directly or through a member, the relevant part between the writing instrument body and the lid It is also possible to provide an elastic member and assist the backward movement of the writing instrument body when the pen tip is stored.

The driving means for transmitting the forward movement of the writing instrument body in contact with the lid body and imparting the rotational movement to the lid body causes the inclined surface provided in the writing instrument body to abut against the lid body, and the forward force of the writing instrument body is inclined to the inclined surface. A so-called cam mechanism that changes the direction to a component force that works in the normal direction is used. By making the inclined surface of the writing instrument main body into a plurality of inclined surfaces with different angles or a concave curved inclined surface, the force in the normal direction can be approximated to the tangent of the rotating orbit of the contact, and the necessary load Can be adjusted to a low load without changing as much as possible.
The inclined surface can be integrally formed as an edge portion of a wall disposed on the outer front portion of the writing instrument body, or another member can be fixed to the writing instrument body as a member that can be fixed or separated without separation. . In addition, the projection of the lid that contacts the inclined surface may have a corner shape or a circular shape. However, if the curved surface such as a circular shape or an elliptical shape is used as a peripheral wall, the protrusion can contact without being caught. It is possible to suppress an increase in load.
In addition, by providing the position of the protrusion when the lid is closed at a position as far as possible from the sealed part, the contact point between the protrusion and the inclined surface of the writing instrument body and the opening of the exterior body The distance between them can be increased, and a relatively long pen tip can be provided.
Further, by providing the position of the protrusion as far as possible from the rotation center, the rotation radius can be kept long, so that a large load is not required to rotate the lid. However, if the rotation radius is increased, a large internal space is required for the exterior body in which the lid body is accommodated, so that the exterior body becomes thick and it may be difficult for the user to use. Therefore, the distance between the rotation center and the protrusion is preferably 15 mm or less.
As for the ink used, a dye and / or a pigment can be used as a colorant, and water or an organic solvent can be appropriately used as a medium.
In addition, the larger the size of the protrusion, the greater the durability of repeated driving. However, since the rotation radius may be changed small, the maximum diameter is about 0.4 mm to 5.0 mm while maintaining the durability. Is preferably small.

As a locking mechanism that locks the lid in the open state, when the lid is opened, a part of the edge of the lid or an undercut placed on the rotation track of the locking part such as a protrusion It can be said that the bumping over the projection by the projection (or the step portion accompanying the recess) is preferable in terms of reliable locking, but a sliding wall to which the lid is pressed may be formed.
Also, here, as a method of applying a rotational force to the lid, a linear elastic force such as a coil spring is converted into a rotational force by a cam mechanism with the lid and / or its peripheral members. The position where the force is received is located outside the rotation center of the lid, and this point is aligned with the rotation center of the lid in the direction in which the force is applied by the elastic member. If it exists in a position, a rotational force will not be provided to a cover body. Therefore, by changing the position of the lid or the elastic member (including another intervening member) and moving to this position, a state in which no rotational force is applied to the lid is formed even if a force is applied. Can do. However, at this time, if the inertial force due to the rotation of the lid is not stopped, the lid may rotate even if no rotational force is applied, and the locking may not be stable. It is necessary to devise measures to stop the rotation of the lid, such as making contact or forming a contact wall between the lid and the repellent member (or interposition member) so as to make surface contact at a point where no force is applied. .

  In addition to the method of forcibly rotating the lid, the unlocking method for the lid can be achieved by moving the lid and / or a member that is locking the lid, but is locked. It can be said that the method of moving the member is preferable in terms of the certainty of sealing and releasing by the stable rotational movement of the lid, and the fact that a large force necessary for releasing is not required. Since the lid can be unlocked by using a method to change the position where the rotational force is applied to the lid, the lock can be released by slightly disrupting the balance, thus reducing the force at the time of release. Things are possible.

Example 1
An example is shown in FIGS. It is assumed that a low-viscosity ink using a fiber converging body as a nib and water and / or an organic solvent as a medium is impregnated and used in an ink occlusion body which is a fiber converging body.
A writing instrument main body 3 having a pen tip 2 at the tip is housed in an outer body 1 which forms the outermost shape of the writing instrument and is held by a hand so as to be movable back and forth. The exterior body 1 is basically a cylindrical body provided with through holes having openings at the front and rear ends, the front end opening 1a is a pen tip discharge port, and the rear end opening 1b is a protrusion of an operating member. Mouth. An annular elastic body 5 that is in sliding contact with a lid 4 to be described later is fitted and fixed to the front end opening 1a. When the lid 4 closes the front end opening 1a, the lid 4 is annular. It is in circumferential contact with the elastic body 5 to block external ventilation.

A clip 6 for a protrusion locking mechanism of the writing instrument body 3 is integrally fixed to the rear of the exterior body 1 on the side of the exterior body 1, and a gear member 7 is rotatably fixed to the inside of the tip of the clip 6. ing.
A rear protrusion 3b is formed on the rear side wall of the writing instrument body 3 at the same axial position as the front protrusion 3a, and protrudes out of the exterior body 1 through a slit hole 1c provided in a side portion of the exterior body 1. At the position where the writing instrument main body 3 is advanced and the pen tip 2 protrudes, the front protrusion 3a is locked to the gear member 7 arranged on the inner side of the tip of the clip 6 to maintain the pen tip protruding state. When the writing instrument main body 3 is further advanced, the rear protrusion 3b rotates the gear member 7, the engagement between the front protrusion 2a and the gear member 7 is released, and the writing instrument main body 3 can be retracted. The writing instrument body 3 receives a rear urging force by a coil spring 8 that abuts against the shoulder 3c. When the locking between the front protrusion 2a and the gear member 7 is released, the pen tip 2 is immersed in the exterior body 1. The writing instrument main body 3 moves backward to the position to be in the state.
In the present embodiment, polypropylene having good gas moldability and good moldability is used as the outer package 1, and the outer diameter is 11.5 mm. The clip 6 is made of polycarbonate that is hard and has a strong repulsive force when bent, and has excellent durability. Since the gear member 7 is in sliding contact with the writing instrument main body 3 and serves as a cam for releasing the locking of the writing instrument main body 3, polyacetal having self-lubricating properties and excellent frictional wear properties is used.

  An ink storage body 9 impregnated with ink is housed inside the writing instrument body 3, and the rear end of the pen tip 2 is connected to the front end of the ink storage body 9 in an embedded manner so that the ink communicates. The writing instrument body 3 is made of polypropylene with low gas permeation and good moldability. Further, at the rear part of the writing instrument main body 3, there is a tail plug 10 which is detachably attached by screwing and is airtightly attached, and the ink occlusion body 9 is interposed in the internal space of the tail plug 10. A plurality of ribs 10 a extend in the longitudinal direction on the inner wall of the tail plug 10, and air passages are formed between the tail plug 10 and the inner wall of the writing instrument main body 3 and the ink occlusion body 9 and at the rear end. At the same time, the ink occlusion body 9 is sandwiched between the ribs 10a, and the ink occlusion body 9 is removed together with the tail plug 10 when the tail plug 10 is removed. By doing so, when the ink impregnated in the ink occlusion body 9 is consumed or less, or the ink is used up, the ink occlusion body 9 is taken out together with the tail plug 10, and the ink is impregnated again. The occlusion body 9 can be replaced with an ink occlusion body impregnated with ink. Further, the ink occlusion body 9 has an outer skin so that the hand is not soiled even when touched during replacement.

Further, the outer shape of the writing instrument main body 3 is mainly composed of a small-diameter portion 3d that accommodates the nib 2 and a large-diameter portion 3e that mainly accommodates the ink occlusion body 9, with a shoulder portion 3c therebetween. Is formed. As described above, the shoulder 3c is a portion that receives the urging force when the writing instrument body 3 is moved into the pen tip by the coil spring 8. A plurality of ribs are formed between the shoulder 3c and the small diameter portion 3d, and the bending of the small diameter portion 3d is suppressed. And between the inner wall of the exterior body 1 and the small diameter part 3d of the writing instrument main body 3, the cyclic | annular elastic body 11 is fitted in the state which airtightly contacted both. As a result, an airtight contact between the lid 4 and the annular elastic body 5 fitted and fixed in the front end opening 1a of the exterior body 1 described above is formed, and an internal space for accommodating the pen nib 2 in an airtight manner is formed. .
Further, the nib 2 is caulked and held by a metal nib holder 2a, and the nib 2 is fixed by being press-fitted into the tip inner hole of the small diameter portion 3d. In addition, an air circulation groove (not shown) is formed inside the small diameter portion 3d of the writing instrument body 2 so that air can be exchanged.

As shown in FIG. 2 which is an enlarged view of a portion I in FIG. 1 (for convenience of explanation, members and parts hidden in the lid body 4 are indicated by broken lines in the sectional view), the front end opening of the exterior body 1 is shown. A lid 4 is rotatably mounted near the portion 1a. As shown in FIG. 3, which is a perspective view showing the members, the lid body 4 has a lid portion 4 a and a side wall portion 4 b that can close the front end opening 1 a of the exterior body 1, and the side wall portion 4 b has an exterior body. A rotating shaft 4c that abuts on a bearing portion (not shown) formed on the inner wall of 1 is provided in a convex state outward. The rotating shaft 4c is rotatably attached by being connected by a bearing portion of the exterior body 1. A portion between the side wall portions 4b is a space portion, and forms a passage through which the pen tip 2 and the writing instrument body 3 can pass when the lid body 4 rotates to open the front end opening portion 1a of the exterior body 1. Is.
Further, an inner cam portion 4 d is formed as an inward projection on the inner wall portion of the side wall portion 4 b of the lid 4. The inner cam portion 4d is a portion that abuts against the writing instrument main body 3 as the writing instrument main body 3 moves forward. By the impingement, the writing instrument main body 3 presses the lid body 4 to forcibly rotate the lid body 4 and The front end opening portion 1a and the space portion of the lid body 4 meet, and the pen tip 2 protrudes.
Since the lid body 4 has an inner cam portion 4d that is in sliding contact with the writing instrument main body 3 and rotates the lid body 4, polyacetal is used which is self-lubricating and excellent in frictional wear.

  Both ends are fixed to the rotating shaft 4c of the lid body 4 and the exterior body 1 and a string spring 12 as a resilient member is disposed, and the lid body 4 exerts a force in a direction to close the front end opening 1a of the exterior body 1. (In the case of a string-wound spring, “elasticity” in the present invention is a force in the direction of contracting the string-wound spring. This is called resilience.) That is. The lid 4 is in contact with the stopper 1d formed on the inner wall of the exterior body 1 while maintaining the closed state while closing the front end opening 1a while the string spring 12 is wound.

As materials for the ring-shaped elastic body 5 and the ring-shaped elastic body 11 that keep the space in the cap airtight, other than butyl rubber, isobutylene rubber, butadiene rubber, styrene-butadiene rubber, nitrile rubber, chloroprene rubber, butyl rubber, ethylene propylene rubber, chlorosulfone Polyethylene, chlorinated polyethylene, acrylic rubber, silicone rubber, acrylonitrile butadiene rubber, urethane rubber, fluoro rubber, epichlorohydrin rubber, polysulfide rubber, olefin thermoplastic elastomer, styrene thermoplastic elastomer rubber or elastomer, etc. Examples of such a mixture include chemical resistance to ink and gas permeability that affects sealing performance, but butyl rubber is excellent in both chemical resistance and gas permeability. So good sealing It is possible. In particular, since halogenated butyl rubber has a small compression set, the elastic deformation at the time of sliding tends to return to its original shape when stationary, and good sealing and sliding can be performed.
Further, by disposing the annular elastic body 11 at a position close to the lid 4, the accommodation space of the pen tip 2 is made small, and the nib drying in the accommodation space is suppressed as much as possible. In particular, in the case of the thin nib 2, the size of the accommodation space of the nib 2 greatly affects the drying of the nib in the accommodation space, so that the nib drying is more effectively suppressed.

By applying a hardly volatile liquid material to the sliding contact portion of each member, it is possible to suppress friction during sliding contact. The hardly volatile liquid material may have a freezing point of −22 ° C. or lower, a boiling point of 145 ° C. or higher, and a viscosity of 10 to 500,000 MPa · s (20 ° C.). Synthetic lubricating oil, mineral oil, glycerin, Soybean oil, rapeseed oil, corn oil, safflower oil, rice oil, cottonseed oil, sesame oil, peanut oil, olive oil, palm oil and other vegetable oils composed of unsaturated fatty acids such as linoleic acid, linolenic acid and oleic acid Synthetic lubricating oils include hydrocarbon synthetic lubricating oils such as Α-olefin (poly-Α-olefin), polybutene (polyisobutylene), alkylbenzene, diester (dibasic acid ester), polyol ester (hindered). Esters) and other fatty acid ester synthetic lubricants, silicone oils, silicate esters, and silanes Fluorine synthetic lubricating oils such as lubricating oils, chlorofluorocarbons, perfluoropolyethers, fluoroesters, phenyl ethers, phosphates, and the like. These can be used alone or in combination. Moreover, what gelatinized these may be used.
In particular, when synthetic resin, rubber, elastomer, or the like is used for the members that make up the sliding contact portion, it is chemically stable against solvents such as ink, and has releasability and non-adhesive properties. , Straight silicone oils such as polydimethylsiloxane, polymethylhydrogensiloxane, polymethylphenylsiloxane, and cyclic dimethylsiloxane that have low surface tension and are easy to spread on the surface of the material, and the side chain and / or both ends are modified with organic groups Amino modification, epoxy modification, carbinol modification, mercapto modification, carboxyl modification, methacryl modification, polyether modification, phenol modification, silanol modification, aralkyl modification, fluoroalkyl modification, long chain alkyl modification higher fatty acid ester modification, higher fatty acid content Modified silicone oil such as . In addition, straight silicone oils such as polydimethylsiloxane, polymethylhydrogensiloxane, polymethylphenylsiloxane, and cyclic dimethylsiloxane are less susceptible to environmental changes and the like because their viscosity changes with temperature are small.
In addition to these portions, these hardly volatile liquid materials can be disposed on a member that is desired to impart liquid tightness or reduce sliding resistance.
In this embodiment, polydimethylsiloxane having a freezing point of −50 ° C. or less, a boiling point of 200 ° C., and a viscosity of 10,000 mPa · s (20 ° C.) is applied to the sliding contact portion of each member. Therefore, airtightness and a low friction coefficient of sliding are realized.

FIG. 4 shows a state in which the lid body 4 opens the front end opening 1a and the pen tip 2 protrudes. It is shown as a diagram corresponding to FIG.
As the writing instrument body 3 advances, the writing instrument body 3 and the inner cam portion 4d of the lid body 4 come into contact with each other, and the writing instrument body 3 presses the lid body 4 against the elastic force of the string spring 12 to force the lid body 4 to move. Rotate. During the rotation, the locking projection 4e provided at the end of the lid 4 gets over the projection 1e provided on the inner wall of the exterior body 1 and the rotation of the lid 4 is completed. The lid is kept open by fitting the concave and convex against the repellency. The writing instrument main body 3 further moves forward, releases the contact with the inner cam portion 4d of the lid body 4, and causes the pen tip 2 to protrude from the front end opening 1a of the exterior body 1. At the position where the pen tip 2 protrudes, the front protrusion 3a provided at the rear of the writing instrument body 3 is engaged with the gear member 7 arranged on the inner side of the tip of the clip 6, and the pen tip protruding state is maintained.

FIG. 5 shows a state in which the writing instrument body 3 is retracted halfway. It is shown as a diagram corresponding to FIG.
When the writing instrument main body 3 is further advanced from the protruding locking state of the nib 2, the rear projection 3b rotates the gear member 7, the locking between the front projection 2a and the gear member 7 is released, and the writing instrument main body 3 is a coil spring. Starts retreating with a resilience of 8.
At the stage where the writing instrument body 3 starts to retract, the lid body 4 is locked and does not rotate. When the writing instrument body 3 is further retracted, the release protrusion 3 f provided at the tip of the writing instrument body 3 comes into contact with the inside of the lid portion 4 a of the lid body 4, and the writing instrument body 3 pushes the portion of the lid body 4, thereby 4 rotates in a direction to close the front end opening 1 a of the exterior body 1, gets over the protrusion 1 e, and becomes closed by the elastic force of the string spring 12. The writing instrument main body 3 is retracted and stored in a non-contact manner with the lid 4 when the lid 4 gets over the protrusion 1e.

(Example 2)
FIG. 6 shows another example. It is shown as a figure corresponding to FIG. For convenience of explanation, the exterior body 1 and the annular elastic body 5 are shown in a longitudinal section.
The difference from the above example is that the coil spring 12 is not applied to the lid body 4 in the direction of closing the front end opening 1a of the exterior body 1, and instead, the coil spring that biases the writing instrument body 3 backward. 8 is used.
That is, the annular elastic body 11 is arranged so as to be movable back and forth, and the annular member 13 formed of synthetic resin is arranged on the front side of the annular elastic body 11 so as to be movable back and forth together with the annular elastic body 11. 8 is applied to the lid body 4 via the annular elastic body 11 and the annular member 13, and rotational force is applied to the lid body 4.

As shown in FIG. 7, which is a perspective view of the lid body 4, the lid body 4 includes a spherical lid portion 4 a that can close the front end opening 1 a of the exterior body 1, and a side wall portion 4 b that includes a rotating shaft 4 c that protrudes outward. And have. A portion between the side wall portions 4b of the lid body 4 is a space portion. When the lid body 4 is rotated 90 degrees to open the front end opening 1a of the exterior body 1, the pen tip 2 and the writing instrument body 3 are It forms a passage that can pass through.
Further, an inner cam portion 4d that is an inward projection is formed inside the side wall portion 4b, and a protruding outer cam portion 4f is formed outside. The inner cam portion 4d is a portion that comes into contact with the writing instrument body 3 as the writing instrument body 3 advances.
In the present embodiment, the inner cam portion 4d and the lid portion 4a are provided at the farthest positions on the side wall portion 4b. By forming the inner cam portion 4d and the lid portion 4a as far as possible, a wide space is provided between the lid portion 4a and the contact point between the writing instrument body 3 and the inner cam portion 4d of the lid body 4. In the closed state of the lid 4, the distance in the longitudinal direction from the most advanced position of the pen tip 2 to the contact point between the writing instrument body 3 and the inner cam portion 4 d of the lid 4 can be earned. A long nib 2 can be provided at the tip of the main body 3. Further, the distance from the inner cam portion 4d to the rotating shaft 4c can be increased, and the lid body 4 can be rotated with a smaller knock load.
Since the inner cam portion 4d is a part that receives a load from the writing instrument body 3 and rotates the lid body 4, if the inner cam portion 4d is too small, it may be damaged during operation, and the lid body 4 is made of thermoplastic resin. When making, the cross-sectional area of the protrusion is preferably 0.2 mm ² or more. However, when the protrusion is enlarged, the contact point between the inner cam portion 4d and the writing instrument main body 3 moves to the rotation axis 4c side of the lid body 4 during the rotation of the lid body 4. Since the distance changes short, it is preferable to make the distance that the contact point moves as small as possible in terms of reducing the knock load. Therefore, it is preferable that the diameter of the protrusion is about 0.4 mm to 5.0 mm and the moving distance of the contact point is within 3 mm.
Further, the outer cam portion 4f has a cam slope 4g. The cam slope 4g receives the forward biasing force by the coil spring 8 via the annular member 13, and the lid 4 receives a force in the rotational direction. Yes.
The lid 4 has a stopper 4 h outside the side wall 4 b, and the stopper 4 h abuts against the annular member 13 to define the end point of rotation of the lid 4.
The lid 4 is made of polyacetal that has self-lubricating properties and excellent friction and wear properties.
And since the cover body 4 is U-shaped in shape, the side wall part 4b of the cover body 4 is easily bent inward at the time of injection molding of parts. In order to prevent this bending, the gate which is the resin inflow port of the mold is arranged so as to come to the outer central portion of the lid portion 4a. Further, in order to eliminate the influence of rubbing between the lid 4 and the front end opening 1a, the periphery of the portion that remains as a gate is a recess (not shown). Furthermore, the diameter of the gate is relatively large, and in molding, the thermoplastic resin can be sufficiently retained in pressure after flowing, so that there is less bending after molding, so the gate diameter is 0.5 mm. It should be ~ 0.8mm.

As shown in FIG. 8 which is a perspective view of the annular member 13 and FIG. 9 which is an enlarged view of the portion II in FIG. 8 viewed from the side, the annular member 13 is connected to the annular elastic body 11. It has the side wall part 13b which provides the part 13a and the front urging | biasing force to the cover body 4. As shown in FIG. A contact surface 13c is provided at the front end of the side wall portion 13b. The contact surface 13c includes an inclined surface 13d, a locking groove 13e in which the outer cam portion 4f of the lid body 4 falls and locks when the lid body 4 is opened, and a protrusion. 13f. The side wall portion 13 transmits the elastic force of the rear coil spring 8 to the outer cam portion 4f of the lid body 4 through the contact surface 13c, and in the direction of closing the front end opening 1a of the exterior body 1 to the lid body 4. Giving rotational force.
Further, the inner shape of the connecting portion 13a is formed with an inner hole portion 13f through which the small diameter portion 3d of the writing instrument main body 3 can pass, but it can be point-contacted with the small diameter portion 3d of the writing instrument main body 3 having a circular cross section. Moreover, the middle hole portion 13f has a shape in which a corner portion of a quadrangle is curved.
Since the annular member 13 is a member that is in sliding contact with the lid 4 and rotates the lid 4, polyacetal that is self-lubricating and excellent in frictional wear is used.

  As shown in FIG. 10, which is a longitudinal sectional perspective view of the annular elastic body 11, the annular elastic body 11 has the exterior body 1 with the lid 4 closing the front end opening 1 a of the exterior body 1 on the outside. An outer sealing rib 11a that is in airtight contact with the inner surface of the outer surface and an outer inclination preventing rib 11b that prevents the annular elastic body 11 from being excessively inclined when sliding in the exterior body 1. Inside the elastic body 11, there is an inner sealing rib 11 c that is in airtight contact with the writing instrument body 3. The inner sealing rib 11c is a double rib, and the above-mentioned hardly volatile liquid material stays between the ribs, so that the sealing with the writing instrument main body 3 is ensured and the sliding resistance is kept low. Yes. Further, by shifting the formation positions of the outer sealing rib 11a and the inner sealing rib 11c back and forth in the axial direction, the inner sealing due to the bending to the inner side of the outer sealing rib 11a due to the contact with the exterior body 1 and the contact with the writing instrument main body 3 is achieved. Since the outward bending of the ribs 11c does not collide with each other in the radial direction, the sliding resistance when the writing instrument body 3 moves and when the annular elastic body 11 moves backward is reduced.

  As shown in FIG. 11, which is a longitudinal sectional perspective view of the distal end portion of the exterior body 1, the exterior body 1 has a bearing portion 1 f to which a rotating shaft 4 c of the lid body 4 is rotatably attached. The bearing portion 1 f is provided with walls on the front and left and right sides of the rotating shaft 4 c so that the lid 4 does not move in the forward direction and the radial direction of the exterior body 1. The rear side of the rotating shaft 4c is an open part without a wall. This is because the lid body 4 facilitates insertion and placement from the rear side when the lid body 4 is disposed on the exterior body 1. The rearward movement restriction of the lid body 4 is performed on the contact surface 13 c of the annular member 13 disposed behind the lid body 4.

As shown in FIG. 12, which is a perspective view of the tip portion of the writing instrument body 3, a concave curved surface 3 g that abuts against the inner cam portion 4 d of the lid body 4 and gives a rotational force to the lid body 4 on the front end surface of the writing instrument body 3. Is provided. The concave curved surface 3g of the writing instrument body 3 is a concave curved surface having two first and second curvature radii. From the rear to the front of the writing instrument main body, the curvature radius of the first curved surface is 17 mm. The curved surface has a curvature radius of 2.2 mm, and the two curved surfaces are smoothly connected so as not to have an angle as much as possible. The inner cam portion 4d of the lid 4 moves from the second curved surface to the first curved surface on the concave curved surface.
Further, a release protrusion 3f that contacts the inner hole portion 13g of the annular member 13 is provided on the outer surface of the small diameter portion 3d of the writing instrument body 3, and a scraping portion 3h is provided on the opposite side of the release protrusion 3f. Yes.
An air groove 3i is provided between the front end opening 1a and the pen tip holder 2a in the writing tool body 3 so that gas can pass through the inside and outside of the writing tool body 3. By creating the air groove 3i on the release protrusion 3f side, the thickness of the writing tool body 3 on the release protrusion 3f side is reduced, and when the writing tool body 3 is formed by injection molding, the release protrusion 3f is not further damaged. Easy to make.

The annular elastic body 11, the exterior body 1, and the writing instrument main body 3 seal the rear end of the pen tip sealed space. The inner sealing rib 11 c of the annular elastic body 11 seals while sliding with the writing instrument main body 3. The outer sealing rib 11a performs sealing while sliding with the exterior body 1. That is, in order to perform sealing, the inner diameter of the inner sealing rib 11c (part A in FIG. 10) is smaller than the outer diameter of the writing instrument body 3 (part B in FIG. 12), and the outer diameter of the outer sealing rib 11a (in FIG. 10). (C section) is set larger than the inner diameter (D of FIG. 11) of the exterior body 1, but if the difference in diameter between these members, that is, B-A and C-D, is large, the sealing becomes strong, Since the magnitude of the friction that becomes a load when the writing instrument body 3 moves back and forth increases, sliding becomes worse. Therefore, in order to obtain a good knock feeling, the knock load is 1 kgf or less, and the range in which sufficient sealing is obtained is that the difference in diameter between the members is preferably between 0.1 mm and 0.4 mm. Then, the diameter difference between the inner sealing rib 11c and the writing instrument body 3 is set to 0.3 mm, and the diameter difference between the outer sealing rib 11a and the outer package 1 is set to 0.2 mm.

13 and 14, the lid 4 rotates as the writing instrument body 3 advances, opens the front end opening 1a of the exterior body 1, and the pen tip 2 and the writing instrument body 3 protrude from the front end opening 1a. Show the state. For convenience of explanation, FIG. 13 is a longitudinal sectional view, and the pen tip 2 is not displayed. FIG. 14 shows the exterior body 1 and the annular elastic body 5 as longitudinal sections. Each stage (1) to (5) in FIGS. 13 and 14 shows the same moment.
As the writing instrument body 3 moves forward, the concave curved surface 3g of the writing instrument body 3 and the inner cam portion 4d of the lid 4 come into contact with each other, and the writing instrument body 3 receives the elastic force from the coil spring 8 and the annular elastic body 11 and the annular member 13. The lid 4 is forcibly rotated while resisting the force converted in the rotation direction of the lid 4 through the contact portion 13a.
Along with the rotation of the lid body 4, the annular member 13 and the annular elastic body 11 are pushed down by the rotation of the outer cam portion 4 f of the lid body 4 and move backward. At this time, the diameter of the inner wall of the outer package 1 is slightly larger from the rear than the portion in contact with the outer sealing rib 11a of the annular elastic body 11, so that the outer sealing rib of the moved annular elastic body 11 is increased. The contact between 11a and the outer package 1 is reduced, and the sliding resistance is reduced. Therefore, the load required for the annular elastic body 11 and the annular member 13 to move backward is reduced, that is, the load in the forward direction of the writing instrument main body 3 for rotating the lid body 4 can be reduced, so the knock load is reduced. It can be done.
When the writing instrument body 3 advances to the state of step (3), the outer cam portion 4f of the lid body 4 and the inclined surface 13d of the annular member 13 come into contact with each other. Since the annular member 13 receives the resilient force of the coil spring 8 from the rear and applies a forward biasing force to the lid 4, the outer cam portion 4 f of the lid 4 is pressed by the inclined surface 13 d of the annular member 13. Then, it slides on the inclined surface 13d and enters the locking groove 13e. (Step (4)). At this time, the contact between the outer cam portion 4f of the lid body 4 and the bottom surface of the locking groove 13e is aligned with the rotational axis 4c of the lid body 4 in the direction of applying the force from the annular member 13. Rotational force is not applied to the lid body 4, and the rotation of the lid body 4 is stopped to be in a locked state. It should be noted that the locking groove 13e does not have to be aligned with the rotation axis 4c of the lid 4 with respect to the direction in which the force is applied from the annular member 13 due to an error in member dimensions, assembly variation, etc. depending on the product. The outer cam portion 4f of the lid body 4 is locked to the step portion 13h. Even if the lid 4 is rotated too much, it comes into contact with the protrusion 13f of the annular member 13, and the rotation of the lid 4 is finished and locked in that state.
When the lid 4 is locked, the inner cam portion 4d of the lid 4 and the concave curved surface 3g of the writing instrument main body 3 are not in contact with each other, and further advancement of the writing instrument main body 3 causes the front end opening 1a of the exterior body 1 to move. The tips of the nib 2 and the writing instrument body 3 are projected. (Stage (5))
At the position where the pen tip 2 protrudes, the front protrusion 3a provided at the rear of the writing instrument body 3 is engaged with the gear member 7 arranged on the inner side of the tip of the clip 6, and the pen tip protruding state is maintained.

FIGS. 15 and 16 show a state in which the lid body 4 rotates as the writing instrument body 3 moves backward to close the front end opening 1 a of the exterior body 1. For convenience of explanation, FIG. 15 is a longitudinal sectional view, and FIG. 16 is a longitudinal sectional view of the exterior body 1 and the annular elastic body 5. In addition, each stage (1)-(5) of FIG. 15 and FIG. 16 has shown the same moment.
When the writing instrument main body 3 is further advanced from the protruding locking state of the nib 2, the rear projection 3b rotates the gear member 7, the locking between the front projection 2a and the gear member 7 is released, and the writing instrument main body 3 is a coil spring. Starts retreating with a resilience of 8. At the stage where the writing instrument body 3 starts to retract, the lid 4 is locked by the annular member 13 and therefore does not rotate.
When the writing instrument body 3 is retracted to the state of stage (2), the release projection 3f provided at the tip of the writing instrument body 3 comes into contact with the inner hole 13g of the annular member 13, and further the writing instrument body 3 is brought to the state of stage (3). When retreating, the writing instrument main body 3 retreats while the annular member 13 is inclined along the scraping portion 3 h provided on the opposite side of the release protrusion 3 f of the writing instrument main body 2.
The clearance between the intermediate hole portion 13g and the writing instrument body 3, the axial width of the intermediate hole portion 13g, the height and angle of the release protrusion 3f of the writing instrument body 3, and the positions of the scraping portion 3h and the release protrusion 3f of the writing instrument body 3 If the relationship is not appropriate, the annular member 13 does not tilt, and the writing instrument main body 3 and the annular member 13 are in a state of stagnation or the annular member 13 does not tilt sufficiently. As a range of good operation in which the above-mentioned trouble does not occur, the clearance between the inner hole portion 13g and the writing instrument body 3 is 0.05 mm to 0.5 mm, and the axial width of the inner hole portion 13g is 0.2 mm to 1.5 mm. The height of the release protrusion 3f of the writing tool body 3 is 0.15 mm to 0.4 mm, the angle of the release protrusion 3f on the rear side of the shaft is 155 ° to 170 °, and the rear side of the scraping portion 3h of the writing tool body 3 is The clearance between the side start portion and the shaft rear side start portion of the release protrusion 3f is set to 0.15 mm to 0.5 mm.
By tilting the annular member 13, the balance between the locking of the lid body 4 and the annular member 13 is lost, and the step portion 13 h of the annular member 13 is lowered with respect to the rotation trajectory of the outer cam portion 4 f of the lid body 4. Therefore, the pressing force in the forward direction from the rear coil spring 8 is transmitted to the outer cam portion 4f of the lid body 4 through the contact surface 13c of the annular elastic body 11 and the annular member 13, and the lid body 4 is rotated in the closing direction. The outer cam portion 4f gets over the step portion 13h, and the lid body 4 rotates in the closing direction (step (4)).
Even if the balance of the locking between the lid body 4 and the annular member 13 is not lost due to an error in member dimensions, assembly variations, etc. depending on the product, the annular member 13 is inclined and the projection 13f of the annular member 13 is covered by the lid. The outer cam portion 4f of the body 4 is pushed to forcibly push the outer cam portion 4f out of the locking groove 13e, and the lid body 4 rotates in the closing direction.
The outer cam portion 4f of the lid body 4 that has come out of the locking groove 13e of the annular member 13 is pressed by the contact surface 13c of the annular member 13, and receives a resilient force in the direction of closing the front end opening 1a of the exterior body 1. The lid 4 closes the front end opening 1a (step (5)).
As the height of the step portion 13h of the annular member 13, if it is too high, the locking cannot be released, and if it is too low, the step 13h is not locked. Therefore, the height of the step portion 13h is 0.1 mm to 1.0 mm. Is good.
The rotating shaft 4c of the lid 4 has a recess 4i that is cut by a quarter so that the projection 13f of the annular member 13 is accommodated in a state where the lid 4 closes the front end opening 1a. In addition, since the edge part of this recessed part 4i and the protrusion 13f of the annular member 13 are rubbed by rotation of the cover body 4, each corner | angular part of the edge part of the recessed part 4i and the protrusion 13f is made into a gentle curved surface, and is prevented from catching. .
Further, the release protrusion 3f of the writing instrument main body 3 is provided on the small diameter portion 3d of the writing instrument main body 3, and the small diameter portion 3d is a portion that is in air-tight sliding contact with the annular elastic body 11, so In order not to generate a parting line or the like to be formed, the core pin is first removed and molded by a method (so-called unreasonable removal) in which the core pin is bent and taken out from the mold. In order to prevent the release protrusion 3f from being crushed during the unreasonable removal, the rear protrusion angle of the release protrusion 3f is set to an angle of 155 ° or more, and the flat portion is provided at the apex portion of the release protrusion 3f. is doing.

(Example 3)
FIG. 17 shows a vertical sectional view of another example. It is shown as a figure corresponding to FIG.
The application of the rotational force to the lid 4 utilizes the elastic force of the coil spring 8 that urges the writing instrument body 3 backward as in the above example.

In this embodiment, an acrylic pen tip (pen tip diameter: 2 mm) is used as the pen tip 2, and an ink containing an organic solvent as a main solvent is used as the ink. As the nib 2, as shown in FIG. 18, which is a longitudinal sectional view of the nib side, a polyacetal plastic pen nib having a thin tube portion 2b through which ink passes can be used. At this time, the axial length of the nib 2 can be reduced by using the relay core 14 that connects the ink occlusion body 9 and the nib 2 in the small diameter portion 3 d of the writing instrument body 3. It can prevent ink drop at the bottom.
In the present embodiment, since the above-described fine nib 2 is used and an ink mainly containing an organic solvent that easily causes nib drying is used, in order to prevent the nib from drying at the product distribution stage. The small cap 15 is attached to the nib holder 2a in a press-fit state. As a material for the small cap 15, polypropylene with less gas permeation is used in order to prevent the nib 2 from drying. The small cap 15 is a thing to be removed and used when the user performs an initial appearance operation.
In FIG. 15 and subsequent figures, the figure after the small cap 15 is removed is shown.

A perspective view of the lid 4 is shown in FIG. In this embodiment, since a relatively thin nib 2 is used and oil-based ink having a high nib drying property is used, drying of the nib 2 is suppressed by using polypropylene as the material of the lid 4. ing.
However, since the material of the lid 4 is made of polypropylene, the slidability is worse than that of polyacetal. Therefore, the shape of the outer cam portion 4f of the lid 4 is changed, and the lid 4a is different from the above example. The slidability of the lid 4 was improved.
The outer cam portion 4f is formed in a protruding shape on the outer side of the side wall portion 4b of the lid 4 as in the above example. The outer cam portion 4f has a cam inclined surface 4g, and an inclined portion 4j is provided on the rotating shaft side of the cam inclined surface 4g. The lid 4 is rotated by receiving the forward biasing force of the coil spring 8 via the annular member 13. However, in order for the lid 4 to rotate, the outer cam portion 4 f of the lid 4 slides on the annular member 13 and the lid 4 is rotated. It is necessary for the body 4 to rotate. By providing the inclined portion 4j on the outer cam portion 4f, the sliding between the outer cam portion 4f of the lid body 4 and the annular member 13 is improved, and the slidability of the lid body 4 is improved.
Further, an outer cam portion 4f is formed with respect to the rotation shaft 4c of the lid body 4 at an edge portion of the lid portion 4a which is sandwiched between the side wall portions 4b of the lid body 4 and forms a space portion through which the pen tip 2 passes. The opposite edge portion 4k is located on the inner side of the surface of the virtual sphere of the lid body 4, that is, has a shape recessed in the center direction of the virtual sphere. The edge 4k of the lid 4 always passes through the front end opening 1a of the exterior body 1 when the lid 4 is opened and closed, but the front end opening 1a of the exterior body 1 is provided with an annular elastic body 5, and the lid 4 The edge 4k of the body 4 is always in contact with and slides on the annular elastic body 5. Therefore, when the edge 4k of the lid 4 is recessed in the center direction from the virtual spherical surface, the contact with the annular elastic body 5 is reduced, the sliding resistance can be reduced, and the lid When the body 4 starts the closing operation, the edge 4k of the lid 4 and the annular elastic body 5 are prevented from being caught, and the lid 4 can be satisfactorily closed.
Further, in the present embodiment, since ink using an organic solvent as a medium is used in the inside, it is desirable to make the sealed space of the pen tip 2 as small as possible. From the rear end of the inner cam portion 4d of the lid body 4 to the rotation shaft The distance to 4c is 3.6 mm, the length of the pen tip 2 obtained thereby (the length from the end of the writing instrument body 3 to the top of the pen tip 2) is 5.2 mm, and the sealed space volume is 470 mm ³ . Good visibility of the nib 2 and dry resistance of the nib 2 are compatible.

The perspective view of the front-end | tip part of the writing instrument main body 3 in which the nib 2 was in the insertion state was shown in FIG. Since this embodiment uses ink containing an organic solvent as a medium inside, it is necessary to fill the vapor generated from the nib 2 faster in the sealed space of the nib 2 and prevent the nib 2 from drying. For this reason, the minimum cross-sectional area of the air groove 3i formed by the writing instrument body 3 and the pen tip holder 2a is 1.0 mm ² with respect to the space volume of the sealed space of 470 mm ³ . As a result, the vapor filling speed in the sealed space can be increased, and the nib drying can be suppressed.

Next, the operation will be described. Since the opening operation of the lid 4 is the same as that of the second embodiment, the description thereof is omitted.
21 and 22 show a state in which the lid body 4 rotates as the writing instrument main body 3 moves backward to close the front end opening 1a of the exterior body 1. FIG. For convenience of explanation, FIG. 21 is a longitudinal sectional view, and FIG. 22 is a longitudinal sectional view of the exterior body 1 and the annular elastic body 5. Each stage (1) to (5) in FIGS. 21 and 22 shows the same moment.
When the writing instrument main body 3 is further advanced from the protruding locking state of the nib 2, the rear projection 3b rotates the gear member 7, the locking between the front projection 2a and the gear member 7 is released, and the writing instrument main body 3 is a coil spring. Starts retreating with a resilience of 8. At the stage where the writing instrument body 3 starts to retract, the lid 4 is locked by the annular member 13 and therefore does not rotate.
When the writing instrument body 3 is retracted to the state of stage (2), the release projection 3f provided at the tip of the writing instrument body 3 comes into contact with the inner hole 13g of the annular member 13, and further the writing instrument body 3 is brought to the state of stage (3). When retreating, the writing instrument main body 3 retreats while the annular member 13 is inclined along the scraping portion 3 h provided on the opposite side of the release protrusion 3 f of the writing instrument main body 2. By tilting the annular member 13, the balance between the locking of the lid body 4 and the annular member 13 is lost, and the step portion 13 h of the annular member 13 is lowered with respect to the rotation trajectory of the outer cam portion 4 f of the lid body 4. Therefore, the pressing force in the forward direction from the rear coil spring 8 is transmitted to the outer cam portion 4f of the lid body 4 through the contact surface 13c of the annular elastic body 11 and the annular member 13, and the lid body 4 is rotated in the closing direction. The outer cam portion 4f gets over the stepped portion 13h, and the lid body 4 starts to rotate in the closing direction. At the initial stage of rotation of the lid body, the edge 4k of the lid body 4 has a shape recessed in the center direction from the virtual sphere surface, so that it does not contact the annular elastic body 5 and the initial stage of rotation of the lid body 4 However, the external resistance is as small as possible. Therefore, the lid body 4 can be easily rotated in the closing direction by the force of the rear coil spring 8 when the locking of the outer cam portion 4f and the step portion 13h is released. Even if the balance of the locking between the lid body 4 and the annular member 13 is not lost due to an error in member dimensions, assembly variations, etc. depending on the product, the annular member 13 is inclined and the projection 13f of the annular member 13 is covered by the lid. The outer cam portion 4f of the body 4 is pushed to forcibly push the outer cam portion 4f out of the locking groove 13e, and the lid body 4 rotates in the closing direction. (Stage (3))
The clearance between the intermediate hole portion 13g and the writing instrument body 3, the axial width of the intermediate hole portion 13g, the height and angle of the release protrusion 3f of the writing instrument body 3, and the positions of the scraping portion 3h and the release protrusion 3f of the writing instrument body 3 If the relationship is not appropriate, the annular member 13 does not tilt, and the writing instrument main body 3 and the annular member 13 are in a state of stagnation or the annular member 13 does not tilt sufficiently. As a range of good operation in which the above-mentioned trouble does not occur, the clearance between the inner hole portion 13g and the writing instrument body 3 is 0.05 mm to 0.5 mm, and the axial width of the inner hole portion 13g is 0.2 mm to 1.5 mm. The height of the release protrusion 3f of the writing tool body 3 is 0.15 mm to 0.4 mm, the angle of the release protrusion 3f on the rear side of the shaft is 155 ° to 170 °, and the rear side of the scraping portion 3h of the writing tool body 3 is The clearance between the side start portion and the shaft rear side start portion of the release protrusion 3f is set to 0.15 mm to 0.5 mm.
The outer cam portion 4f of the lid body 4 that has come out of the locking groove 13e of the annular member 13 is pressed by the contact surface 13c of the annular member 13, and receives a resilient force in the direction of closing the front end opening 1a of the exterior body 1. The lid 4 rotates in a direction to close the front end opening 1a. By providing the inclined portion 4j on the outer cam portion 4f of the lid body 4, the contact point with the annular member 13 becomes an acute angle, and the projection 13f of the annular member 13 slides on the inclined portion 4j, so that the 1/4 cut of the rotating shaft 4c is performed. Fit into the recessed portion 4i. (Stage (4))
Therefore, the lid 4 closes the front end opening 1a without stopping in the middle of rotation (step (5)).

DESCRIPTION OF SYMBOLS 1 Exterior body 1a Front end opening part 1b Rear end opening part 1c Slit hole 1d Stopper 1e Protrusion 1f Bearing part 2 Pen tip 2a Pen tip holder 2b Narrow tube part 3 Writing instrument main body 3a Front projection 3b Rear projection 3c Shoulder part 3d Thin diameter part 3e Diameter part 3f Release protrusion 3g Concave surface 3h Cutting part 3i Air groove 4 Lid 4a Lid 4b Side wall 4c Rotating shaft 4d Inner cam part 4e Locking protrusion 4f Outer cam part 4g Cam slope 4h Stopper 4i Concave part 4j Inclined part 4k Edge 5 Annular elastic body 6 Clip 7 Gear member 8 Coil spring 9 Ink occlusion body 10 Tail plug 10a Rib 11 Annular elastic body 11a Outer sealing rib 11b Outer inclination prevention rib 11c Inner sealing rib 12 String winding spring 13 Annular member 13a Connection part 13b Side wall portion 13c Contact surface 13d Inclined surface 13e Locking groove 13f Projection 13g Middle hole 13h Step 14 Relay core 15 Small cap

Claims (3)

A writing instrument body with a pen tip at the tip is housed in the exterior body so as to be movable back and forth, and a lid body that releases and closes the front end opening of the exterior body by a rotational motion is provided at the distal end portion of the exterior body, and this lid body is exteriorized An elastic member that urges in the rotational direction to close the front end opening of the body is disposed, and an inner cam portion provided on the inner side of the lid body and an outer cam portion formed on the tip portion of the writing instrument body are brought into contact with each other, The lid body is locked by the locking mechanism in the state where the lid body is pushed open against the elastic force of the elastic body as the writing instrument moves forward, and the tip of the exterior body is maintained in the released state. The lid and the writing instrument main body are in a non-contact state, and when the writing instrument main body is retracted, the locking mechanism for the lid is released while maintaining the non-contact state between the lid and the writing instrument main body, A retractable writing instrument in which the lid closes the opening at the front end of the exterior body after the pen tip is retracted. The retractable writing instrument according to claim 1, wherein the locking mechanism is formed by fitting over the unevenness between the lid and the peripheral member. The elastic member gives a linear elastic force to the cam portion formed in the outer portion with respect to the rotation center of the lid, either directly or via an interposed member, and the rotation end position of the lid is determined. A locking portion is defined, and the locking mechanism positions the elastic member or lid in a straight line with respect to the linear elastic force provided by the elastic member. The retractable writing instrument according to claim 1, which is moved to a position to be moved.

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