JPH09131994A - Capless writing instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a convenient writing instrument in which leakage, dry up and counterflow of ink can be prevented surely by sealing the gap between a writing ball and the holding part on the periphery thereof and which can be employed suitably in the ball point pen for neutral ink while taking account of the reset action in containing the writing instrument. SOLUTION: A writing instrument 3 having a writing part 3a at the forward end is contained in a body and a guide tube 5 for inserting the forward end part of writing instrument 3 is provided at the forward end part in the body. A sealing cover 7 is provided, while being urged in the opening direction, in the vicinity of forward end of the guide tube 5 and a slide ring 9 is provided while being urged rearward by means of a tension spring 10. A thread member 11 for stretching the sealing cover 7 is stretched between the slide ring 9 and sealing cover 7 so that the sealing cover 7 comes into tight contact with the writing part 3a at the forward end resiliently thus sustaining sealed state. At the time of advancing/retracting operation of writing instrument 3, the guide tube 5 advances slightly to release the sealed state and the thread member 11 slacks to open the sealing cover 7. Furthermore, a stopper 16 to be engaged with the retracting slide ring 9 is provided on the outer circumference of writing instrument 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cap which can securely hold a writing portion at the tip of a writing object in a sealed state with a simple structure when the writing object is stored. It is related to a writing instrument.

[0002]

2. Description of the Related Art A so-called neutral ink ball-point pen having a viscosity lower than that of oil-based ink and higher in viscosity than water-based ink does not cause dripping of ink. In recent years, they have been particularly favored and used because they do not fade.

This neutral ink ballpoint pen has a cap for sealing and protecting the writing portion at the tip. As shown in Japanese Utility Model Publication No. 61-39592 and Japanese Utility Model Application Laid-Open No. 1-139593, for example, a thick or spherical sealing material made of an elastic material such as rubber is provided on the cap. By making the tip writing portion elastically contact the seal material, the gap between the writing ball of the tip writing portion and the surrounding holding portion is closed, thereby leaking and drying the ink. And the backflow is prevented.

[0004] However, the cap-type writing instrument has to be removed every time when writing is used, and the attaching and detaching operation is troublesome, and the removed cap may be lost. Furthermore, with a sealed cap, when the cap is put on the writing instrument body, the internal pressure of the cap increases, and air passes through the slight gap between the writing ball and the surrounding holding part and air enters the writing body. Because it may be mixed,
As in the case of the above-mentioned proposed cap, it is necessary to provide air circulation means in the cap itself.

Accordingly, even in the case of the ballpoint pen made of neutral ink, the tip writing portion can be made to protrude and disappear by knocking operation without the cap, and further, a capless writing implement having a mechanism for preventing ink leakage, drying and backflow. It is desired that

In recent years, there is a capless writing implement in which a tip writing portion is projected by a one-touch operation such as knocking so that a writing state can be provided, and a mechanism for preventing drying of ink of a writing body is provided.

Various proposals have been made for a capless writing instrument having this drying prevention mechanism. For example, Japanese Patent Publication No. 4-14880, Japanese Patent Publication No. 5-68360 and Japanese Utility Model Application Laid-Open No. 2-112492 disclose such a technique. As can be seen, an openable and closable seal lid is provided at the end of a seal cylinder (cylinder) arranged in the main body, and the writing body is advanced through a thread-like member stretched and connected between the seal lid and the writing body. There has been proposed a device in which a sealing lid can be opened and closed by a retreating action.

[0008] The mechanism proposed above, when the tip writing portion of the writing body is housed in the seal cylinder, the sealing lid portion at the tip and the circumferential projections and the like that are in close contact with the outer periphery of the writing body behind the air hole. The seal is sealed at two places before and after the seal portion, and the inside of the seal cylinder is shut off from the outside to maintain the seal state. Thereby, in a writing instrument such as a batting-based aqueous ink ballpoint pen or a batting-type marker having an air hole near the tip writing portion, the tip writing portion is kept in a completely sealed state with the air hole, and the ink is discharged. Prevent drying.

However, in the case of the above-mentioned proposed drying prevention mechanism, the sealing structure is complicated because it has two sealing portions, and the gap between the ball of the tip writing portion and the surrounding holding portion is closed. In particular, in the case of a ballpoint pen made of neutral ink, it cannot be said that the ballpoint pen is in a sealed state, and has little effect on leakage, drying and backflow of ink.

That is, in the case of a ballpoint pen of neutral ink, the rear end of the writing body is not completely sealed, but is filled with a gel-like fluid sealant having a specific gravity different from that of the ink and having viscosity and fluidity. The backflow is prevented and the amount of ink is allowed to be reduced, so that even if the rear end of the writing body is open, it can be used without any problem, and the air hole near the tip writing portion can be eliminated. Therefore, the effect of preventing leakage, drying, and backflow of ink cannot be expected simply by housing the tip writing portion in the seal cylinder as described above.

Therefore, up to now, there has been no practical application of a capless type pen made of neutral ink which can be written by knocking operation.

Therefore, the present invention can be suitably used for a ballpoint pen made of neutral ink, and can be used as a capless writing implement capable of securely holding a tip writing portion in which a writing ball is partly held in a sealed state, particularly a capless writing implement. The gap between the ball of the tip writing portion and the surrounding holding portion can be reliably held in a sealed state by the direct contact of the seal lid which moves back and forth with the forward and backward movements and opens and closes, so that the ink is removed. It is an object of the present invention to provide a capless writing implement capable of reliably preventing leakage, drying and backflow, and performing a knocking operation for advancing and retreating a writing body without any problem.

Further, in the case of such a capless writing instrument, depending on the strength of the tension spring for keeping the sealing lid closed and the retraction spring of the writing body, the seal is required before the writing body retreats into the main body. Since there is a concern that the lid may be closed, the present invention provides a capless writing instrument that takes this point into consideration.

[0014]

A capless writing instrument of the present invention which solves the above-mentioned problems is a tip writing portion in which a writing ball is held in a main body having a hole into which a tip portion of a writing body appears and disappears. And a forward and backward mechanism for accommodating the cursive body having the above, and for advancing the cursive body against the urging force of the retracting spring to hold the cursive body in the writing state and retracting the cursive body to the retracted state. Is provided with a guide cylinder through which the front part of the cursive body can penetrate so as to be movable forward and backward so as to regulate forward movement above a certain level, and at least the inner surface near the tip of the guide cylinder. Is provided with a seal lid made of an elastic body and urged in the opening direction, and a slide ring urged rearward by a tension spring is slightly faster than the writing body when the writing body is advanced by the forward / backward mechanism. Push A slidable thread-like member that pulls the seal lid when the writing body is accommodated is stretched between the slide ring and the seal lid, and the seal lid is attached to the tip writing portion of the writing body. On the other hand, it is provided so as to elastically adhere to maintain the sealed state so as to fill the gap between the writing ball and the ball holding portion around it, and the guide tube together with the slide ring is slightly It is provided so that the thread-like member is loosened as the slide ring advances and the seal lid is opened after the seal lid is released from the sealed state of the tip writing portion by moving forward.

According to the first aspect of the present invention, in the capless writing instrument having the above structure, an engaging portion with which the retracting slide ring can be engaged is provided between the outer periphery of the writing body and the rear surface of the slide ring in the stored state. It is characterized in that it is provided so as to have a slight interval, and that the slide ring retracts the cursive body to the position immediately before the storage position when the retracting operation is performed.

According to a second aspect of the present invention, in the capless writing instrument having the above structure, the repulsive force of the retracting spring is set to the same level as or slightly stronger than that of the tensioning spring, and, apart from these springs, smaller than these. A separating spring for urging the guide cylinder in the forward direction by elastic force is provided.

According to a third aspect of the invention, in the capless writing instrument of each of the above-mentioned inventions, the thread-shaped member stretched between the slide ring and the seal lid is composed of one thread-shaped member.
A central portion of the thread member is hung around a slide ring, and both ends are connected to opposing positions of a seal lid.

[0018]

According to the capless writing instrument of the present invention, when the tip writing portion of the writing body is housed in the main body, the seal lid made of the elastic body is pulled by the slide ring together with the guide tube through the thread member. , The writing body is held in a closed state that intersects with the main body axis, and the writing body has a tip writing portion that fills the gap between the writing ball and the surrounding holding portion with respect to the inner surface of the seal lid. The seal lid is elastically deformed and adheres elastically. As a result, the gap between the writing ball of the tip writing portion and the periphery of the ball is maintained in a completely sealed state, and leakage, drying, and backflow of the ink from the tip writing portion can be prevented.

Next, when the writing body is moved forward by the forward / backward movement mechanism in order to bring it into a writing state, the slide ring is pushed slightly earlier than the writing body to move forward during the forward movement operation. The tension of the pulling thread member is loosened by a slight forward movement of the pulling thread, and the guide tube that is biased in the forward direction together with the slide ring moves forward slightly and the sealing state of the tip writing portion by the seal lid is released. Become. After that, the cursive writing begins to move forward with the slide ring, the thread-like member is further loosened, the seal lid urged in the opening direction opens, and after the sealing lid is opened, only the cursive writing further advances to the tip. The writing portion protrudes from the hole at the tip of the main body and is held in a writable state.

When the writing body is stored by the advancing / retracting mechanism, the writing body is retracted by the elastic force of the retracting spring and the slide ring is retracted by the urging force of the pulling spring, and the stored state is restored.

In particular, in the case of the first aspect of the invention, since the engaging portion with which the retracting slide ring can be engaged is provided on the outer periphery of the writing body, the writing body is provided with the elastic force of the retracting spring. Not only that, it is pushed by the retracting action of the slide ring to positively retract to the vicinity of the storage position, and the slide ring disengages from the locking part near the storage position, and only the retracting spring allows the storage position to be adjusted. Return to.

When the slide ring and the cursive body are retracted, the seal lid is held open while the thread member for pulling is in a loose state, and the thread member is tensioned due to the retraction of the slide ring. Along with this, the seal lid is pulled to be in the closed state, but at this time, since the writing body is already in a considerably retracted position, the seal lid can be closed without any problem. Moreover, after the closed state, the guide tube moves in the backward direction so that the inner side surface of the seal lid is elastically deformed with respect to the tip writing portion of the writing body where it reaches the storage position so that the tip writing portion is filled. Elastically adheres to. This makes it possible to completely seal the gap between the ball at the tip writing portion and the surrounding holding portion.

In the case of the second aspect of the invention, since the repulsive force of the retracting spring is set to the same level as or slightly higher than that of the tension spring, the cursive body retreats at substantially the same time as or slightly earlier than the slide ring. However, when the thread member is tensioned by pulling the seal lid by retracting the slide ring and the seal lid is pulled to the closed state, the cursive body is already in a considerably retracted position, and the seal lid can be closed without any problem.

Moreover, since the elastic force of the separating spring for urging the guide cylinder in the forward direction is smaller than that of the tensioning spring, after the closing state as described above, the guide cylinder is moved by the tensioning spring. The thread-like member is pulled by the slide ring that retracts due to the biasing force, and moves in the retracting direction against the biasing force of the detaching spring, and the inner side surface of the seal lid is the tip end writing part on the tip writing part of the writing body at the storage position. The parts are elastically adhered so as to fill the part, and are kept in a predetermined contact state.

Further, according to the third aspect of the present invention, since the thread member for pulling is composed of one thread member, the pulling force acting on both end portions connected to the seal lid becomes equal, and the seal state is maintained. Can be held satisfactorily.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1A is a sectional view of a writing instrument (ballpoint pen) showing a first embodiment of the present invention.
(B) is a side cross-sectional view of the position of FIG. (A) rotated by 90 degrees, and both show a sealed state in which the writing body is stored in the main body.

In the figure, reference numeral 1 is a front shaft, and 2 is a rear shaft having a cam wall 2a provided at a rear portion thereof, and these two are screwed together to form an integrated writing instrument main body. At the tip of tip shaft 1,
It has a hole in which the tip of the cursive body appears. Reference numeral 3 is a writing body of a neutral ball-point pen housed in the main body, and holds a writing ball at a tapered tip portion so as to be able to roll in a partially protruding state (about 30 to 40% of the ball diameter). It has a tip writing portion 3a. The writing body 3 is filled with a neutral ink, and a fluid sealant is filled near the rear end of the writing body 3 to prevent backflow of the ink.

Reference numeral 4 denotes a locking ring provided by means of press fitting or the like so as not to come into contact with the stepped portion in the front shaft 1 and to move further forward.

Reference numeral 5 is a guide cylinder which is arranged inside the front shaft 1 and through which the writing body 3 can penetrate. The guide cylinder 5 is inserted through the locking ring 4 so as to be movable in the front-rear direction, and the guide cylinder 5 is provided. A stepped portion 5a having a hook-shaped cross section at the rear end is locked to the locking ring 4 so as to restrict forward movement beyond a certain level. In a normal storage state, the tip of the writing body 3 is held in the guide cylinder 5. In the case of the figure, the guide cylinder 5 is integrally formed with an auxiliary cylinder 6 having a slightly larger diameter for accommodating a retracting spring for a writing body, which will be described later, via the step portion 5a.

A seal lid 7 having two ears 7a and 7b at positions opposite to each other on the peripheral portion is connected to the edge portion near the tip of the guide cylinder 5 through a hinge portion 8 and is connected to the axis of the front shaft 1. It is biased in the opening direction so as to open and close between a closed state that is substantially orthogonal to it and a position that rises outward from a position that is substantially parallel to the axis.

At least the inner surface of the seal lid 7 is made of an elastic material such as a rubber material or a synthetic resin material having elasticity.
As shown in an enlarged view in FIG. 2, when the tip writing portion 3a of the writing body 3 abuts, the tip writing portion 3a is elastically deformed to an extent to fill a gap between the writing ball of the tip writing portion 3a and the holding portion around the writing ball. It is provided so that it can closely contact.

That is, the diameter of the writing ball of the ballpoint pen is usually 0.3 to 0.5 mm, and the protruding dimension thereof is 0.1.
It is about 0.2 mm. Therefore, the tip writing portion 3a abutting on the seal lid 7 is deeper than the projection size of the ball,
For example, if the elastic body has an elasticity that covers 0.4 mm or more, the gap between the ball and the surrounding holding portion can be filled.

Therefore, the seal lid 7 of the illustrated embodiment
As shown in an enlarged view in FIG. 2, the tip of the writing body 3 is written inside a frame dish portion 7c formed in a dish shape having a central opening by a metal material such as stainless steel, a synthetic resin material, or another rigid material. An elastic body 7d such as silicone rubber having elasticity which can be deformed by the contact of the portion 3a is provided so as not to be easily detached by an attaching means or a fitting means.

In addition, the seal lid 7 itself is made of an elastic material so that the inner surface is bulged spherically or has a thick plate shape, or the inner surface of the plate-shaped seal lid 7 made of a rigid material. As described above, it is possible to carry out various constitutions such as attaching an elastic body such as rubber to the elastic body so that the tip writing portion 3a can be elastically deformed.

Reference numeral 9 denotes a slide ring which is slidably arranged in the front shaft 1 in the axial direction and through which the rear portion of the writing body 3 penetrates. A tension spring 10 is interposed between the slide ring 9 and the locking ring 4,
As a result, the slide ring 9 is constantly biased rearward.

The slide ring 9 and the seal lid 7 described above
A slack thread-like member 11 that stretches the seal lid 7 when the cursive writing is stored is stretched between them.
When the normal cursive body 3 is stored, the spring 1
The seal lid 7 is pulled rearward through the filamentous member 11 with a biasing force of 0 and held in a closed state in which the seal lid 7 is in contact with the tip of the guide cylinder 5. The thread-like member 11 is made of a material that hardly expands and contracts due to temperature and humidity and is resistant to friction and tension, for example, a monofilament yarn of a synthetic resin, and is made of a thin and moderately slack material.

In the case of the drawing, one thread-shaped member is used as a stretching means for the thread-shaped member 11, and the central portion of this thread-shaped member is located on the outer peripheral portion of the small diameter portion on the rear surface side with respect to the slide ring 9 as shown in FIG. Both ends of the thread-like member are wound around, and threading holes 12 and 1 are provided at opposite positions of the slide ring 9.
2 extends forward in parallel with the body axis, and further passes through guide grooves 13, 13 provided on the outer periphery of the locking ring 4, and both ends are connected to two ears 7 a, 7 b of the sealing lid 7.

As a means for connecting both ends of the thread member 11 to the seal lid 7, as shown in FIG. 3, cut holes are formed in the ears 7a, 7b, and a ball-shaped stopper 11a,
The thread-like member 11 having 11b is joined by being locked through the cut hole. Of course, the other end of the filamentous member 11 may be joined to the ears 7a and 7b. Alternatively, two thread-like members may be used, and both ends may be connected to the ears 7a and 7b of the seal lid 7 and the slide ring 9 by the same means as described above, and may be stretched. As described above, it is preferable to use one thread-like member in order to equalize the acting tensile force and to absorb the variation in the length of the two thread-like members.

Reference numeral 14 denotes a retracting spring for the writing body 3, which is housed in the auxiliary cylinder 6 in the case of the drawing and has a step 3b at the rear end of the small diameter portion and a step 5a at the rear end of the guide cylinder 5. And is provided so as to always urge the writing body 3 backward. The retraction spring 14 also functions as a separation spring for urging the guide cylinder 5 in the forward direction.

The rear end portion of the writing body 3 penetrates the stopper ring 15 fitted to the rear shaft 2 and extends rearward. An engagement portion 16 such as a crimp or a press-fit projection is provided on the outer periphery of the writing body 3. The engagement portion 16 contacts the stopper ring 15 so that further retreat is restricted. Has become. Thereby, the storage position of the cursive writing 3 is set.

Further, the retreat restricting locking portion 16 also serves as a locking portion with which the slide ring 9 is engaged when retreating. Therefore, when the writing body 3 is retreated, the sliding ring 9 also serves as the writing body 3. Can be set back. When the writing member 3 shown in FIG. 1 is stored, the locking portion 16 is provided at a position having a slight distance S1 from the rear surface of the slide ring 9 so as to reduce the shock at the time of the retreat operation. Desirable above.

As the engaging portion with which the slide ring 9 engages, an engaging portion such as a protrusion or step different from the engaging portion 16 for restricting the retreat is provided on the outer periphery of the writing body 3. It is also possible to set it.

The retracting spring 14 has a smaller elastic force than the pulling spring 10. Therefore, when the writing body 3 is in the storage position, the pulling spring 10 urges the filamentous member. 11, the seal lid 7 is held in a closed state in which the seal lid 7 is in contact with the guide cylinder 5, and as shown in FIG. 1, the guide cylinder 5 resists the elastic force of the retracting spring 14 which also functions as a separation. By pulling, the tip writing portion 3a is elastically pushed into the inner surface of the seal lid 7 and held in a close contact state. At this time, a slight space S2 is maintained between the step 5a at the rear end of the guide cylinder 5 and the locking ring 4.

Therefore, with respect to the above-mentioned interval S2, the seal lid 7 is kept in a closed state by abutting on the guide tube 5 when the step portion 5a is in abutting engagement with the engaging ring 4. It is set so as to be in slight contact with the tip writing portion 3a of the writing body 3 in the storage position or to be slightly detached (state in FIG. 5).

Numeral 17 is a pushing member disposed rearward of the stopper ring 15 in the rear shaft 2 so as to be movable in the axial direction. The pushing member 17 is provided at one position of a cylindrical portion 17a into which the rear portion of the writing body 3 is slidably fitted, and at a plurality of positions such as a position facing each other as shown in the drawing. The rod 17c is provided so as to extend forward through the stopper ring 15 so as to push the slide ring 9.

When the tip of the rod 17c is substantially in contact with the slide ring 12 and the cursive body 3 is in a normal storage state (state of FIG. 1), the pushing member 17 has a cylindrical portion 1.
Between the bottom flange portion 17b of 7a and the rear end of the cursive body 3, a space S2 'approximately corresponding to the space S2 between the stepped portion 5a of the guide cylinder 5 and the locking ring 4 is provided. It is provided so as to come into contact with the rear end of the writing body 3 to be pushed by the forward movement of the pushing member 17.

Therefore, the pushing member 17 first pushes the slide ring 9 slightly by the rod 17c by the forward movement of the forward / backward mechanism, and then pushes the writing body 3 by the bottom of the tubular portion 17a. 18 is a cylindrical portion 17a
Is an air flow hole formed at the bottom of the airbag.

Further, in this embodiment, as a forward / backward moving mechanism, the rotary cam 19 that abuts and engages with the flange portion 17b and the pushing member 17 are provided in the rear shaft 2 on the rear side of the pushing member 17. A bottomed tubular pusher 2 that fits into the tubular portion 17a
0 is stored. The pusher 20 has a cam surface for rotating the rotating cam 19 on the front surface of the front end large diameter portion 20a,
A rear portion 20b protruding from the rear end of the main body is a knock bar. As a result, a well-known rotary cam mechanism is formed, and the writing body 3 is locked forward by the knocking operation by the pusher 20, and the writing body 3 is moved by the spring 14 by the next knocking operation.
It returns to the original storage state with the resilience of. This point is the same as the operation of the conventionally known rotary cam mechanism, and the detailed illustration and description thereof will be omitted.

A slight gap is provided between the rear end of the large-diameter portion 20a of the pusher 20 and the inner flange of the rear end of the rear shaft 2 to absorb a slight elongation of the thread member 11. This is because

The operation state of the writing instrument of this embodiment will be described. In the normal storage state of the writing body 3 of FIG. 1, since the elastic force of the tension spring 10 is larger than that of the retreat spring 14, the slide ring 9 is moved. Is in the rearmost position, the thread-like member 11 pulls the seal lid 7 and holds it in the closed state, and the guide cylinder 5 is displaced rearward against the urging force of the spring 14, so that the seal lid 7 writes at the tip. Part 3a
The gap between the ball of the tip writing portion 3a and the surrounding holding portion is kept in a sealed state.

When the pushing tool 20 is knocked to move the pushing member 17 forward for writing, the slide ring 9 is pushed by the pushing member 17 to move forward. This movement loosens the tension of the thread member 11, and at the same time, the guide cylinder 5 moves forward to the position where the step portion 5a is locked by the locking ring 4 by the urging force of the spring 14, prior to the movement of the writing body 3. , The seal lid 7 as shown in FIG.
Touches the tip writing portion 3a lightly or slightly separates.

Then, as the pushing member 17 moves forward, the bottom of the cylindrical portion 17a comes into contact with the rear end of the writing body 3 to move the writing body 3 and the slide ring 9 together. As a result, when the thread-like member 11 is loosened and the seal lid 7 is urged in the opening direction, the urging force is applied to the seal lid 7, and even when the seal lid 7 is not urged, the seal lid 7 is pushed by the tip writing portion 3 a of the writing body 3. At this time, the tip writing portion 3a does not rub the inner surface of the seal lid 7 strongly. After the seal lid 7 is completely opened, the writing body 3 is further advanced while the thread-like member 11 is slack, and the tip writing portion 3a is moved to the front shaft 1 as shown in FIG.
Protruding from the hole at the tip of, and is held in a writable state.

When the cursive body 3 is stored, the pusher 2
When the knocking operation is performed on “0”, the cursive writing 3 moves the retreat spring 1
4 and the slide ring 9 is retracted by the urging force of the tension spring 10, however, at this time, even if the slide ring 9 retreats quickly, the slide ring 9 is provided on the outer periphery of the writing body 3. The writing body 3 is also pushed by the retreating action of the slide ring 9 by being engaged with the locking portion 16, and is positively retracted to near the storage position. Moreover, when the storage ring is near the storage position, the slide ring 9 is disengaged from the locking portion 16 and returns to the predetermined storage position only by the retraction spring 14, so that a strong impact does not act on the writing body 3.

When the slide ring 9 is retracted, the seal lid 7 is pulled to a closed state as the thread member 11 is tensioned. At this time, the cursive body 3 is retracted as described above. Is already in a very retracted position, the seal lid 7 can be closed without problems. In addition, after being in the closed state, the guide cylinder 5 moves in the retreating direction, the seal lid 7 abuts on the tip writing section 3a of the writing body 3, and the elastic body 7d fills the tip writing section 3a while being elastically deformed. Elastically adhere to each other. As a result, the tip writing portion is kept in a sealed state.

In this first embodiment, the cursive body 3
Although a rotary cam mechanism is used as the forward / backward moving mechanism, other knocking or rotary forward / backward moving mechanisms can be used.

Next, a second embodiment of the present invention will be described with reference to FIGS.
Description will be made based on 0.

FIG. 7 (a) is a sectional view of the writing instrument, and FIG. 7 (b) is a side sectional view of the state of FIG. 7 (a) rotated by 90 degrees, both of which are seals in which the writing body 3 is housed in the main body. It shows the state. Components common to the first embodiment are denoted by the same reference numerals.

In this embodiment, the guide tube 5 is
A lid forming member 22 in which a seal lid 7 is continuously provided is fixed to a front end portion of a cylindrical body 21 which is inserted through the locking ring 4 so as to be movable back and forth and through which a front portion of the writing body 3 is inserted. A separation spring 24 is provided between the stepped portion 23 and the locking ring 4 for urging the guide cylinder 5 in the forward direction. On the outer periphery of the cylinder body 21 on the rear side of the locking ring 4, there is provided a projection 25 that engages with the locking ring 4, so that the forward movement of the guide cylinder 5 by a certain amount or more can be restricted. The step 23 may be provided by integrally forming the lid forming member 22 with the cylindrical body 21.

Further, in the seal lid 7, as in the first embodiment, the elastic body 7d is attached to the inside of the frame dish portion 7c made of a rigid material, but the elastic body 7d is attached to the tip writing portion 3a of the writing body 3. It can be implemented in various forms that can elastically abut and achieve a sealing action. A thread-like member 11 as tension means is stretched between the seal lid 7 and a slide ring 9 slidably disposed in the front shaft 1 in the axial direction by the same means as in the previous embodiment. Further, a spring 10 for urging the slide ring 9 backward is interposed between the slide ring 9 and the locking ring 4 so that the seal lid 7 can be pulled. This point is the same as in the first embodiment.

The retracting spring 14 for urging the writing body 3 backward is interposed between the locking portion 16 such as a crimp provided on the outer periphery of the writing body 3 and the locking ring 4, and The stopper ring 15 in which the locking portion 16 is fitted to the rear shaft 2
, The further retreat of the cursive 3 is regulated.

Particularly in this embodiment, the resilience of the retreat spring 14 is set to the same level as or slightly stronger than the tension spring 10 for urging the slide ring 9 backward.

Further, the separation spring 24 is set to have an elastic force smaller than that of the both springs 10 and 14. As a result, when the cursive 3 is in the normal storage position,
The urging force of the tension spring 10 causes the seal lid 7 to come into contact with the guide cylinder 5 via the thread-like member 11 so as to be kept in a closed state, and the guide cylinder 5 is pulled apart as shown in FIG. The projection 25 of the guide cylinder 5 is positioned apart from the locking ring 4 by being pulled against the elastic force of the engagement 24. Also, at this time, the interval S2 between the locking ring 4 and the convex portion 25 is such that the seal lid 7 is kept in the closed state and in the storage position when the convex portion 25 is in contact with the locking ring 4. The writing body 3 is set so as to be in light contact with the tip writing portion 3a or slightly separated therefrom.

Therefore, also in this embodiment, when the writing body 3 is normally stored, as shown in FIG. 7, the convex portion 25 of the guide cylinder 5 is held at a position apart from the locking ring 4. The elastic body 7d of the seal lid 7 is elastically deformed into a conical shape and elastically adheres so as to wrap the tip writing portion 3a, so that the gap between the writing ball and the surrounding holding portion can be completely sealed. Become.

The forward / backward mechanism and the pushing member of the writing body 3 can be basically implemented in the same manner as in the case of the first embodiment, so a detailed illustration will be omitted, but the forward / backward mechanism is omitted. The rod 17c of the pushing member penetrating the stopper ring 15 is provided so as to push the slide ring 9 in the forward direction and advance the cursive body 3 by the forward operation by the.

Also in this embodiment, when the writing body 3 is normally stored, the slide ring 9 is at the rearmost position, and the seal lid 7 is pulled through the thread member 11 to be held in the closed state. And detaching spring 24
Since the resilient force is smaller than the tension spring 10, the guide cover 5 is displaced rearward against the urging force of the separation spring 24, and the seal cover 7 is attached to the tip writing portion 3a. The gap between the ball of the tip writing portion 3a and the surrounding holding portion is kept in a sealed state by elastic deformation.

When the advancing / retreating mechanism is operated to move forward for writing, the slide ring 9 is first pushed by the rod 17c of the pushing member to move forward, and this movement loosens the tension of the thread member 11 at the same time. , Guide tube 5
Move away from the writing body 3 to the position where the projection 25 is locked to the locking ring 4 by the urging force of the spring 24, and the seal lid 7 is moved to the tip writing section 3 as shown in FIG.
Lightly touches a or slightly separates. Thereafter, the writing member 3 and the slide ring 9 advance together by the advancement of the pressing member 17, and the thread-like member 11 is loosened, and when the seal lid 7 is urged in the opening direction, by the urging force, Cursive 3 moves forward even when not energized
Of the thread-like member 11
The writing body 3 is further advanced while slack, and the tip writing portion 3a protrudes from the hole at the tip of the front shaft 1 as shown in FIG.

When the cursive body 3 is stored, the cursive body 3 is moved backward by the operation of the forward / backward movement mechanism.
And the slide ring 9 is retracted by the urging force of the tension spring 10.

At this time, since the repulsive force of the retracting spring 14 is set to the same level as or slightly stronger than that of the tensioning spring 10, the cursive body 3 retracts substantially simultaneously with the slide ring 9 or slightly earlier. When the thread member 11 is tensioned by pulling the seal lid 7 by retracting the slide ring 9 and the seal lid 7 is pulled to the closed state, the writing body 3 is already in a considerably retracted position, and the seal lid 7 can be closed without any problem. Further, after the closed state, the guide cylinder 5 moves to the tension spring 1
0 is pulled by the slide ring 9 which retreats by the urging force of 0, moves in the retreating direction against the urging force of the separation spring 24, and the inner surface of the seal lid 7 is the writing body 3 in the storage position.
Is elastically adhered to the tip writing portion 3a, and is maintained in a predetermined close contact state.

In each of the above embodiments, a shock absorbing means may be provided to absorb the shock when the cursive body moves backward.

[0071]

As described above, according to the capless writing instrument of the present invention, the cap is not required to be attached and detached, so that it is easy to use. Since the gap between the peripheral holding portion and the surrounding portion can be reliably maintained in a sealed state by the direct contact of the seal lid, it is possible to reliably prevent the leakage, drying, and backflow of the ink. Further, when the writing body is advanced, the sealing state of the tip writing portion by the seal lid is first released, and then the seal lid is opened and the tip writing portion advances, so that the elastic body of the seal lid is not damaged by the tip writing portion.

Moreover, since there is no sealing part except the gap between the ball of the tip writing part and the ball holding part around it, when the tip writing part is sealed with the elastic seal lid, Unlike the cap type, the internal pressure of the cap is not increased, and therefore air is not likely to enter the writing body. Further, since there is no seal portion close to the outer periphery of the cursive body, there is no resistance to the forward and backward movement of the cursive body, so that a spring for returning the cursive body does not require a very strong elastic force.

Particularly, when the cursive body is stored, the method according to claim 1
According to the invention of claim 2, the slide ring also positively retracts the cursive body at the same time.
In the case of the invention of the present invention, since the resilience of the retraction spring is equal to or stronger than that of the tension spring that urges the slide ring backward, there is no delay in the return action of the cursive writing, so that the sealing Does not hinder the closing action of the lid.

Therefore, the present invention can be particularly suitably applied to a ballpoint pen of neutral ink in which the trailing end of the writing body is opened and the fluid end is filled with a fluid sealant, and the structure is simple and easy to assemble. Therefore, it can be manufactured at low cost.

[Brief description of the drawings]

FIGS. 1A and 1B are a cross-sectional view and a side cross-sectional view of a writing instrument according to a first embodiment of the present invention in a state in which a writing body is stored.

FIG. 2 is an enlarged cross-sectional view of a seal lid portion of the previous figure (b).

FIG. 3 is a partially enlarged perspective view of a state where a seal lid is slightly opened.

FIG. 4 is a front view from the rear side of a slide ring portion.

FIG. 5 is a cross-sectional view showing a state in which a seal of a tip writing portion by a seal lid is released.

FIG. 6 is a side sectional view of a writing state in which a tip writing portion of a writing body is protruded.

FIGS. 7A and 7B are a cross-sectional view and a cross-sectional view of a part of a writing instrument according to a second embodiment of the present invention in a state in which a writing body is stored.

FIG. 8 is an enlarged cross-sectional view of the front part of FIG.

FIG. 9 is a cross-sectional view showing a state in which a seal at a tip writing portion by a seal lid is released.

FIG. 10 is a side sectional view of a part of a writing state in which a tip writing portion of a writing body is protruded.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Front axis 2 ... Rear axis 3 ... Writing body 3a ... Tip writing part 4 ... Locking ring 5 ... Guide cylinder 5a ... Step part 7 ... Seal lid 7a, 7b ... Ear 7c ... ... frame plate 7d ... elastic body 8 ... hinge 9 ... ... slide ring 10 ... tension spring 11 ... thread-like member 14 ... retraction spring 15 ... stopper ring 17 ... pushing member 17a ... Cylinder 17b Flange 17c Rod 19 Rotating cam 20 Pusher 24 Release spring 25 Projection

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[Procedure amendment]

[Submission date] February 12, 1997

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction contents]

[Document Name] Statement

[Title of Invention] Capless writing instrument

[Claims]

2. A writing body having a tip writing portion that holds a writing ball is housed in a main body having a hole at the tip of which the tip portion of the writing body appears and retracts, and the writing body is used as a retracting spring. A forward / backward mechanism for advancing against the biasing force to hold in a writing state and retracting to a retracted state is provided, and the front part of the main body can be penetrated by the front part of the writing body.
De is provided so as to restrict the movable and constant over the forward longitudinal biased in the forward direction, at least the inner surface is luciferyl Lumpur cover such a resilient body is provided in the vicinity of the tip of the guide, further slide ring biased rearwardly by spring tension is, the during forward operation of the cursive by forward and backward mechanism provided to be pushed rather cursive O Rihaya, the slide ring and said seal cover Between them, a slack thread-like member that stretches the seal lid when the cursive body is stored is stretched, and the seal lid closes the gap between the writing ball and the surrounding ball holding part with respect to the tip writing part of the cursive body. It is provided so as to be tightly closed so as to be filled, and maintains a sealed state.
After de has canceled the sealing state of the tip writing portion by the sealing lid slightly moved forward, loosened thread members become accompanied the advancement of the slide ring is provided so as sealing lid is opened, further On the outer periphery of the writing body, a locking portion with which a retreating slide ring can be provided is provided so as to have a slight gap between the writing ring and the rear surface of the slide ring in the retracted state, and the slide ring holds the writing body at the time of retreat operation. A capless writing instrument configured to be retracted to just before a storage position.

3. A writing body having a tip writing portion holding a writing ball is housed in a main body having a hole at the tip of which the tip portion of the writing body appears and retracts, and the writing body is provided with a retracting spring. A forward / backward mechanism for advancing against the biasing force to hold in a writing state and retracting to a retracted state is provided, and the front part of the main body can be penetrated by the front part of the writing body.
De is provided so as to restrict the movable and constant over the forward longitudinal biased in the forward direction, at least the inner surface is luciferyl Lumpur cover such a resilient body is provided in the vicinity of the tip of the guide, further slide ring biased rearwardly by spring tension is, the during forward operation of the cursive by forward and backward mechanism provided to be pushed rather cursive O Rihaya, the slide ring and said seal cover Between them, a slack thread-like member that stretches the seal lid when the cursive body is stored is stretched, and the seal lid closes the gap between the writing ball and the surrounding ball holding part with respect to the tip writing part of the cursive body. It is provided so as to be tightly closed so as to be filled, and maintains a sealed state.
After the slide ring is slightly advanced and the sealing state of the tip writing portion by the seal lid is released, the thread-like member is loosened as the slide ring advances, and the seal lid is opened. the elastic force of the retraction spring is pulling for the spring and set the same level or slightly stronger, further Apart from these spring, pull-off spring is provided to bias the guide in the forward direction with a small elastic force than these Capless writing implement characterized by the following.

4. A thread-shaped member stretched between a slide ring and a seal lid is composed of one thread-shaped member, the central portion of the thread-shaped member is wound around a slide ring, and both ends thereof are seal lids. The capless writing instrument according to claim 2 or 3 , wherein the capless writing instrument is connected to opposite positions.

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cap which can securely hold a writing portion at the tip of a writing object in a sealed state with a simple structure when the writing object is stored. It is related to a writing instrument.

[0002]

2. Description of the Related Art A so-called neutral ink ball-point pen having a viscosity lower than that of oil-based ink and higher in viscosity than water-based ink does not cause dripping of ink. In recent years, they have been particularly favored and used because they do not fade.

This neutral ink ballpoint pen has a cap for sealing and protecting the writing portion at the tip. As shown in Japanese Utility Model Publication No. 61-39592 and Japanese Utility Model Application Laid-Open No. 1-139593, for example, a thick or spherical sealing material made of an elastic material such as rubber is provided on the cap. By making the tip writing portion elastically contact the seal material, the gap between the writing ball of the tip writing portion and the surrounding holding portion is closed, thereby leaking and drying the ink. And the backflow is prevented.

[0004] However, the cap-type writing instrument has to be removed every time when writing is used, and the attaching and detaching operation is troublesome, and the removed cap may be lost. Furthermore, with a sealed cap, when the cap is put on the writing instrument body, the internal pressure of the cap increases, and air passes through the slight gap between the writing ball and the surrounding holding part and air enters the writing body. Because it may be mixed,
As in the case of the above-mentioned proposed cap, it is necessary to provide air circulation means in the cap itself.

Accordingly, even in the case of the ballpoint pen made of neutral ink, the tip writing portion can be made to protrude and disappear by knocking operation without the cap, and further, a capless writing implement having a mechanism for preventing ink leakage, drying and backflow. It is desired that

In recent years, there is a capless writing implement in which a tip writing portion is projected by a one-touch operation such as knocking so that a writing state can be provided, and a mechanism for preventing drying of ink of a writing body is provided.

Various proposals have been made for a capless writing instrument having this drying prevention mechanism. For example, Japanese Patent Publication No. 4-14880, Japanese Patent Publication No. 5-68360 and Japanese Utility Model Application Laid-Open No. 2-112492 disclose such a technique. As can be seen, an openable and closable seal lid is provided at the end of a seal cylinder (cylinder) arranged in the main body, and the writing body is advanced through a thread-like member stretched and connected between the seal lid and the writing body. There has been proposed a device in which a sealing lid can be opened and closed by a retreating action.

[0008] The mechanism proposed above, when the tip writing portion of the writing body is housed in the seal cylinder, the sealing lid portion at the tip and the circumferential projections and the like that are in close contact with the outer periphery of the writing body behind the air hole. The seal is sealed at two places before and after the seal portion, and the inside of the seal cylinder is shut off from the outside to maintain the seal state. Thereby, in a writing instrument such as a batting-based aqueous ink ballpoint pen or a batting-type marker having an air hole near the tip writing portion, the tip writing portion is kept in a completely sealed state with the air hole, and the ink is discharged. Prevent drying.

However, in the case of the above-mentioned proposed drying prevention mechanism, the sealing structure is complicated because it has two sealing portions, and the gap between the ball of the tip writing portion and the surrounding holding portion is closed. In particular, in the case of a ballpoint pen made of neutral ink, it cannot be said that the ballpoint pen is in a sealed state, and has little effect on leakage, drying and backflow of ink.

That is, in the case of a ballpoint pen made of neutral ink, the back end of the writing body is not completely sealed, but is filled with a viscous and fluid gel-like fluid sealing material to prevent the ink from flowing backward and to prevent the ink from flowing backward. Thus, even if the rear end of the writing body is open, it can be used without any problem, and the air hole near the front writing part can be made unnecessary. Therefore, the effect of preventing leakage, drying, and backflow of ink cannot be expected simply by housing the tip writing portion in the seal cylinder as described above.

Therefore, up to now, there has been no practical application of a capless type pen made of neutral ink which can be written by knocking operation.

Therefore, the present invention can be suitably used for a ballpoint pen made of neutral ink, and can be used as a capless writing implement capable of securely holding a tip writing portion in which a writing ball is partly held in a sealed state, particularly a capless writing implement. The gap between the ball of the tip writing portion and the surrounding holding portion can be reliably held in a sealed state by the direct contact of the seal lid which moves back and forth with the forward and backward movements and opens and closes, so that the ink is removed. It is an object of the present invention to provide a capless writing implement capable of reliably preventing leakage, drying and backflow, and performing a knocking operation for advancing and retreating a writing body without any problem.

Further, in the case of such a capless writing instrument, depending on the strength of the tension spring for keeping the sealing lid closed and the retraction spring of the writing body, the seal is required before the writing body retreats into the main body. Since there is a concern that the lid may be closed, the present invention provides a capless writing instrument that takes this point into consideration.

[0014]

According to the present invention, there is provided a capless writing instrument for solving the above-mentioned problems. A cursive body having a tip writing portion holding a ball for use is accommodated, and the cursive body is moved forward against the urging force of a retreating spring, held in a writing state, retracted to a retracted state, and retracted. A mechanism is provided, and a guide through which the front part of the cursive writing penetrates is provided at the front part of the main body so as to be movable forward and backward and regulates a predetermined or more forward movement. An openable and closable seal lid having a side surface made of an elastic body is provided, and a thread-like member further connected to the seal lid, wherein the seal lid is pulled when the writing body is stored by the advance / retreat mechanism,
The writing tip and the surrounding ball holding part are brought into close contact with the tip writing part so as to fill the gap between the writing ball and the ball holding part, and the sealing state is maintained. A thread-like member is provided.When the writing body is moved forward, the guide slightly moves by the time the writing body starts to advance, and the sealing state of the sealing lid is released. The member is loosened to be in an open state, and is provided so that the thread-like member is tensioned after the cursive body retreats to just before the storage position at the time of storing operation of the cursive body, the seal lid is closed, and the seal state is maintained. It is characterized by having.

According to the second aspect of the present invention, in the capless writing instrument, the slide ring urged rearward by the tension spring is pressed earlier than the writing body when the writing body is advanced by the advance / retreat mechanism. Is provided between the slide ring and the seal lid, a slack thread-like member that stretches the seal lid when the writing body is stored, and the seal lid is in close contact with the tip writing portion of the writing body. In addition to being provided so as to maintain a sealed state, when the writing body is advanced, the guide is slightly advanced together with the slide ring to release the sealed state of the tip writing portion by the seal lid, and then the slide ring is advanced. Along with this, the thread-like member is loosened and the seal lid is opened, and a retreating slide ring engages the outer periphery of the writing body. The locking portion to be obtained is provided so as to have a slight space between the rear surface of the slide ring in the storage state, and the slide ring is configured to retreat the writing body to just before the storage position during the retreat operation. Features.

According to a third aspect of the present invention, in the capless writing instrument having the above-described configuration, the resilience of the retraction spring is set to be substantially the same as or slightly higher than that of the tension spring, and apart from these springs, the resilience is smaller than these. A separation spring is provided for urging the guide in the forward direction by a resilient force.

According to a fourth aspect of the present invention, in the capless writing instrument of the above respective inventions, the thread member stretched between the slide ring and the seal lid is made of one thread member.
A central portion of the thread member is hung around a slide ring, and both ends are connected to opposing positions of a seal lid.

[0018]

According to the capless writing instrument of the present invention, in a state where the tip writing portion of the writing body is stored in the main body, the seal lid made of the elastic body is pulled by the thread-like member together with the guide, and intersects with the main body axis. The writing body elastically deforms the seal lid so that the tip writing portion fills the gap between the writing ball and the surrounding holding portion with respect to the inner surface of the seal lid. And elastically adhere. As a result, the gap between the writing ball of the tip writing portion and the periphery of the ball is maintained in a completely sealed state, and leakage, drying, and backflow of the ink from the tip writing portion can be prevented.

Next, when the writing body is moved forward by the forward / backward movement mechanism in order to enter the writing state, the guide moves slightly forward by the time the writing body starts to move forward, and the sealing state of the tip writing portion by the seal cover is obtained. Is released, the thread-like member is loosened and the seal lid urged in the opening direction is opened, and after the seal lid is opened, only the writing body further advances, and the tip writing portion is moved from the hole at the tip of the main body. It protrudes and is kept in a writable state.

When the cursive body is stored by the forward / backward movement mechanism, the cursive body returns to a predetermined storage position by the resilience of the retraction spring, and the thread-like member is tensioned. Until is retracted to the position immediately before the storage position, the thread-like member is in a loose state and the seal lid is held open, and then the thread-like member is tensioned, the seal lid is closed, and the guide is further retracted. Then, the seal lid completely seals the tip writing portion.

In the case of the capless writing instrument according to the second aspect of the present invention, when the writing body is stored, the seal lid made of an elastic body is pulled by a slide ring together with a guide via a thread-like member and held in a closed state. As a result, the writing body is maintained in a state in which the gap between the writing ball of the tip writing portion and the periphery of the ball is completely sealed by the seal lid as described above.

Next, when the writing body is moved forward by the forward / backward movement mechanism in order to enter the writing state, the slide ring is pushed slightly faster than the writing body and moves forward at the time of this forward operation, and the slide ring is moved forward. With the slight advance, the tension of the tension thread member is loosened, and the guide urged in the forward direction together with the slide ring moves slightly forward, so that the sealing state of the tip writing portion by the seal lid is released. . After that, the cursive writing begins to move forward with the slide ring, the thread-like member is further loosened, the seal lid urged in the opening direction opens, and after the sealing lid is opened, only the cursive writing further advances to the tip. The writing portion protrudes from the hole at the tip of the main body and is held in a writable state.

When the cursive body is stored by the forward / backward movement mechanism, the cursive body retreats by the resilience of the retraction spring and the slide ring retreats by the urging force of the tension spring, and returns to the above-mentioned stored state. In the case of the second aspect of the present invention, the writing member is provided with an engaging portion on the outer periphery of the writing body, with which the retreating slide ring can be engaged. The ring is also pushed by the retreating action of the ring and is positively retracted to the vicinity of the storage position. Further, the slide ring is disengaged from the locking portion near the storage position and returns to the predetermined storage position only by the retraction spring.

Further, when the slide ring and the writing material are retracted, the seal lid is held open while the tension thread member is in a loose state, and the thread member is strained by the slide ring retracting. Along with this, the seal lid is pulled to be in the closed state, but at this time, since the writing body is already in a considerably retracted position, the seal lid can be closed without any problem. Moreover, after the closed state, the guide moves in the retreating direction so that the inner side surface of the seal lid is elastically deformed and fills the tip writing portion of the writing body which has reached the storage position. Adhere elastically. This makes it possible to completely seal the gap between the ball at the tip writing portion and the surrounding holding portion.

In the case of the third aspect of the present invention, the elasticity of the retraction spring is set to be substantially the same as or slightly stronger than that of the tension spring, so that the writing body retreats substantially simultaneously with the slide ring or slightly earlier. However, when the thread-like member is tensioned due to the retreat of the slide ring and the seal lid is pulled to be in the closed state, the writing body is already at a considerably retracted position, and the seal lid can be closed without any problem.

Further, since the resilience of the separation spring for urging the guide in the forward direction is smaller than that of the tension spring, after the closing state as described above, the guide is
The thread member is pulled by the slide ring that is retracted by the urging force of the tension spring, moves in the retreating direction against the urging force of the separation spring, and the inner surface of the seal lid is the writing point at the tip of the writing body in the storage position. , So as to fill the writing portion at the front end, and is kept in a predetermined close contact state.

Further, according to the fourth aspect of the present invention, since the tension thread-like member is formed of one thread-like member, the tensile forces acting on both ends connected to the seal lid become uniform, and the sealing state is obtained. Can be favorably maintained.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1A is a sectional view of a writing instrument (ballpoint pen) according to the first embodiment of the present invention.
(B) is a side cross-sectional view of the position of FIG. (A) rotated by 90 degrees, and both show a sealed state in which the writing body is stored in the main body.

In the drawing, reference numeral 1 denotes a front shaft, and 2 denotes a rear shaft provided with a cam wall 2a at a rear portion thereof, which are screwed together to form a main body of a writing instrument. At the tip of tip shaft 1,
It has a hole in which the tip of the cursive body appears. Reference numeral 3 denotes a writing body of a ballpoint pen made of neutral ink accommodated in the main body. The writing ball can be rolled in a tapered tip portion with a writing ball partially protruding (about 30 to 40% of the ball diameter). It has a tip writing section 3a held by the user. The writing body 3 is filled with neutral ink, and near the rear end thereof is filled with a fluid sealing material for preventing backflow of the ink (not shown).

Reference numeral 4 denotes a locking ring provided so as to abut against the step in the front shaft 1 by means such as press-fitting so as not to move forward.

Reference numeral 5 denotes a cylindrical guide (hereinafter referred to as a guide cylinder) which is disposed inside the front shaft 1 and through which the writing body 3 can penetrate, and is movable in the front-rear direction with respect to the locking ring 4. The stepped portion 5a having a hook-shaped cross section at the rear end of the guide cylinder 5 is locked to the locking ring 4 so as to restrict forward movement by a certain amount or more. In a normal storage state, the tip of the writing body 3 is held in the guide cylinder 5. In the case shown in the figure, a slightly larger auxiliary cylinder 6 for accommodating a retreat spring 14 of a writing body to be described later is formed integrally with the guide cylinder 5 via the step 5a.

A seal lid 7 having two ears 7a and 7b is connected to an edge near the tip of the guide cylinder 5 at opposite positions of the peripheral edge via a hinge portion 8 so as to be connected to the axis of the front shaft 1. On the other hand, it is provided so as to be urged in the opening direction so as to open and close between a closed state substantially perpendicular to the axis and a position rising outward from a position substantially parallel to the axis.

At least the inner surface of the seal lid 7 is formed of an elastic material such as a rubber material or an elastic synthetic resin material.
As shown in an enlarged view in FIG. 2, when the tip writing portion 3a of the writing body 3 abuts, the tip writing portion 3a is elastically deformed to an extent to fill a gap between the writing ball of the tip writing portion 3a and the holding portion around the writing ball. It is provided so that it can closely contact.

That is, the writing ball of a ballpoint pen usually has a diameter of 0.3 to 0.5 mm, and its projection dimension is 0.1 mm.
It is about 0.2 mm. Therefore, the tip writing portion 3a abutting on the seal lid 7 is deeper than the projection size of the ball,
For example, if the elastic body has an elasticity that covers 0.4 mm or more, the gap between the ball and the surrounding holding portion can be filled.

For this reason, the sealing lid 7 of the illustrated embodiment is
As shown in an enlarged view in FIG. 2, the tip of the writing body 3 is written inside a frame dish portion 7c formed in a dish shape having a central opening by a metal material such as stainless steel, a synthetic resin material, or another rigid material. An elastic body 7d such as silicone rubber having elasticity which can be deformed by the contact of the portion 3a is provided so as not to be easily detached by an attaching means or a fitting means.

In addition, the seal lid 7 itself is formed of an elastic body, and the inner surface is formed into a shape in which the inner surface is bulged in a spherical shape or a thick plate shape, or the inner surface of the plate-shaped seal lid 7 made of a rigid material is used. For example, it is possible to implement various configurations that can be elastically deformed to the extent that the tip writing portion 3a can be sealed as described above, such as by sticking an elastic body such as rubber to the base member.

Reference numeral 9 denotes a slide ring which is disposed inside the front shaft 1 so as to be slidable in the axial direction and through which a rear portion of the writing body 3 penetrates. A tension spring 10 is interposed between the slide ring 9 and the locking ring 4,
As a result, the slide ring 9 is constantly biased rearward.

The slide ring 9 and the seal lid 7
A slack thread-like member 11 that stretches the seal lid 7 when the cursive writing is stored is stretched between them.
When the normal cursive body 3 is stored, the spring 1
The seal lid 7 is pulled rearward through the filamentous member 11 with a biasing force of 0 and held in a closed state in which the seal lid 7 is in contact with the tip of the guide cylinder 5. The thread-like member 11 is made of a material that hardly expands and contracts due to temperature and humidity and is resistant to friction and tension, for example, a monofilament yarn of a synthetic resin, and is made of a thin and moderately slack material.

In the case shown in the figure, a single thread-like member is used as a means for extending the thread-like member 11, and the center of the thread-like member is located on the outer peripheral portion of the rear-side small diameter portion with respect to the slide ring 9 as shown in FIG. The thread-like member is wound around the thread-like member, and both end portions of the thread-like member are located at opposing positions of the slide ring 9.
2 extends forward in parallel with the body axis, and further passes through guide grooves 13, 13 provided on the outer periphery of the locking ring 4, and both ends are connected to two ears 7 a, 7 b of the sealing lid 7.

As shown in FIG. 3, cutout holes are formed in the ears 7a and 7b as means for connecting both ends of the thread-like member 11 to the seal lid 7, and ball-like stoppers 11a and
The thread-like member 11 having 11b is joined by being locked through the cut hole. Of course, the other end of the filamentous member 11 may be joined to the ears 7a and 7b. Alternatively, two thread-like members may be used, and both ends may be connected to the ears 7a and 7b of the seal lid 7 and the slide ring 9 by the same means as described above, and may be stretched. As described above, it is preferable to use one thread-like member in order to equalize the acting tensile force and to absorb the variation in the length of the two thread-like members.

Numeral 14 denotes a spring for retreating the writing body 3, which is accommodated in the auxiliary cylinder 6 in the case shown in the figure, and has a step 3b at the rear end of the small diameter part of the writing body 3 and a step 5a at the rear end of the guide cylinder 5. And is provided so as to always urge the cursive body 3 backward. The retraction spring 14 also functions as a separation spring for urging the guide cylinder 5 in the forward direction.

The rear end portion of the writing body 3 extends rearward through a stopper ring 15 fitted on the rear shaft 2. An engagement portion 16 such as a crimp or a press-fit projection is provided on the outer periphery of the writing body 3. The engagement portion 16 contacts the stopper ring 15 so that further retreat is restricted. Has become. Thereby, the storage position of the cursive writing 3 is set.

The locking portion 16 for regulating the retraction also serves as a locking portion with which the slide ring 9 is engaged when the writing member 3 is retracted. Can be retracted. When the writing member 3 shown in FIG. 1 is stored, the locking portion 16 is provided at a position having a slight distance S1 from the rear surface of the slide ring 9 so as to reduce the shock at the time of the retreat operation. Desirable above.

As a locking portion with which the slide ring 9 is engaged, a locking portion such as a projection or a step portion is provided on the outer periphery of the writing body 3 other than the locking portion 16 for restricting retraction. It is also possible to put.

The retraction spring 14 has a smaller resilient force than the tension spring 10, and therefore, when the writing body 3 is in the retracted position, the thread-like member is urged by the tension spring 10. 11 is held in a closed state in which the seal lid 7 is in contact with the guide cylinder 5 while the guide lid 5 is in contact with the guide cylinder 5 and resists the elastic force of the retreating spring 14 which also serves as separation as shown in FIG. The tip writing portion 3 a is elastically pushed into the inner surface of the seal lid 7 and is kept in close contact therewith. At this time, a slight space S2 is maintained between the step 5a at the rear end of the guide cylinder 5 and the locking ring 4.

For the above-mentioned interval S2, while the stepped portion 5a is in abutment and engagement with the engagement ring 4, the seal lid 7 abuts on the guide cylinder 5 and is kept closed. Is set so that the tip writing portion 3a of the writing body 3 at the storage position is lightly contacted or slightly separated (the state of FIG. 5).

Reference numeral 17 denotes a pushing member which is disposed rearward of the stopper ring 15 in the rear shaft 2 so as to be movable in the axial direction. The pushing member 17 is provided at one position of a cylindrical portion 17a into which the rear portion of the writing body 3 is slidably fitted, and at a plurality of positions such as a position facing each other as shown in the drawing. The rod 17c is provided so as to extend forward through the stopper ring 15 so as to push the slide ring 9.

The pushing member 17 has the tip of the rod 17 c substantially in contact with the slide ring 9, and
Is in the normal storage state (the state of FIG. 1),
a is provided between the bottom of "a" and the rear end of the writing body 3 so as to have an interval S2 'substantially corresponding to the interval S2 between the step 5a of the guide cylinder 5 and the locking ring 4. , Pushing member 17
Is provided so as to abut against and push the rear end of the cursive body 3 by the forward action of.

Therefore, the pushing member 17 pushes the slide ring 9 slightly by the rod 17c and then pushes the writing body 3 by the bottom of the cylindrical portion 17a by the forward action of the forward and backward mechanism. 18 is a cylindrical portion 17a
Is an air flow hole formed at the bottom of the airbag.

In this embodiment, as a forward / backward movement mechanism, a rotating cam 19 which comes into contact with the flange portion 17b in the rear shaft 2 on the rear side of the pushing member 17; A bottomed cylindrical pusher 2 fitted to the cylindrical portion 17a
0 is stored. The pusher 20 has a cam surface for rotating the rotating cam 19 on the front surface of the front end large diameter portion 20a,
A rear portion 20b protruding from the rear end of the main body is a knock bar. As a result, a well-known rotary cam mechanism is formed, and the writing body 3 is locked forward by the knocking operation by the pusher 20, and the writing body 3 is moved by the spring 14 by the next knocking operation.
It returns to the original storage state with the resilience of. This point is the same as the operation of the conventionally known rotary cam mechanism, and the detailed illustration and description thereof will be omitted.

The reason why a slight gap is provided between the rear end of the large diameter portion 20a of the pusher 20 and the inner flange of the rear end of the rear shaft 2 is to absorb the slight elongation of the thread member 11. To do that.

The operating state of the writing instrument of this embodiment will be described. In the normal storage state of the writing body 3 in FIG. 1, the elasticity of the tension spring 10 is larger than that of the retraction spring 14, so that the slide ring 9 is not used. Is in the rearmost position, the thread-like member 11 pulls the seal lid 7 to hold it in the closed state, and displaces the guide cylinder 5 backward against the urging force of the spring 14 so that the seal lid 7 is Part 3a
The gap between the ball of the tip writing portion 3a and the surrounding holding portion is kept in a sealed state.

When the pushing member 20 is knocked to advance the pushing member 17 to make the writing state, the slide ring 9 is first pushed by the pushing member 17 to move forward. This movement loosens the tension of the thread member 11, and at the same time, the guide cylinder 5 moves forward to the position where the step portion 5a is locked by the locking ring 4 by the urging force of the spring 14, prior to the movement of the writing body 3. , The seal lid 7 as shown in FIG.
Touches the tip writing portion 3a lightly or slightly separates.

Thereafter, as the pushing member 17 advances, the bottom of the cylindrical portion 17a comes into contact with the rear end of the writing body 3 to advance the writing body 3 and the slide ring 9 together. As a result, when the thread-like member 11 is loosened and the seal lid 7 is urged in the opening direction, the urging force is applied to the seal lid 7, and even when the seal lid 7 is not urged, the seal lid 7 is pushed by the tip writing portion 3 a of the writing body 3. At this time, the tip writing portion 3a does not rub the inner surface of the seal lid 7 strongly. After the seal lid 7 is completely opened, the writing body 3 is further advanced while the thread-like member 11 is slack, and the tip writing portion 3a is moved to the front shaft 1 as shown in FIG.
Protruding from the hole at the tip of, and is held in a writable state.

When the cursive body 3 is stored, the pressing tool 2
When the knocking operation is performed on “0”, the cursive writing 3 moves the retreat spring 1
4 and the slide ring 9 is retracted by the urging force of the tension spring 10, however, at this time, even if the slide ring 9 retreats quickly, the slide ring 9 is provided on the outer periphery of the writing body 3. The writing body 3 is also pushed by the retreating action of the slide ring 9 by being engaged with the locking portion 16, and is positively retracted to near the storage position. Moreover, when the storage ring is near the storage position, the slide ring 9 is disengaged from the locking portion 16 and returns to the predetermined storage position only by the retraction spring 14, so that a strong impact does not act on the writing body 3. Therefore, the ink is not faded due to the ink or the backward movement of the fluid sealing material due to the impact, and writing is impossible (so-called ink drop) does not occur.

Further, the retraction of the slide ring 9 causes the sealing lid 7 to be pulled and closed as the thread-like member 11 is tensioned. At this time, the writing body 3 which is retracted as described above. Since is already in a considerably retracted position, the seal lid 7 can be closed without any problem. In addition, after being in the closed state, the guide cylinder 5 moves in the retreating direction, the seal lid 7 abuts on the tip writing section 3a of the writing body 3, and the elastic body 7d fills the tip writing section 3a while being elastically deformed. Elastically adhere to each other. As a result, the tip writing portion is kept in a sealed state.

In the first embodiment, the cursive 3
Although a rotary cam mechanism is used as the forward / backward moving mechanism, other knocking or rotary forward / backward moving mechanisms can be used.

Next, a second embodiment of the present invention will be described with reference to FIGS.
Description will be made based on 0.

FIG. 7A is a cross-sectional view of a writing instrument, and FIG. 7B is a side cross-sectional view of the state shown in FIG. The state is shown. Components common to the first embodiment are denoted by the same reference numerals.

In this embodiment, the guide cylinder 5 is
A lid forming member 22 having a sealing lid 7 connected thereto is fixed to a front end of a cylindrical body 21 which is inserted through the locking ring 4 so as to be movable back and forth and which can penetrate the front part of the writing body 3. 22
And a separation spring 24 for urging the guide cylinder 5 in the forward direction is disposed between the step portion 23 and the locking ring 4. On the outer periphery of the cylinder body 21 on the rear side of the locking ring 4, there is provided a projection 25 that engages with the locking ring 4, so that the forward movement of the guide cylinder 5 by a certain amount or more can be restricted. The step 23 may be provided by integrally forming the lid forming member 22 with the cylindrical body 21.

As in the first embodiment, the seal lid 7 has an elastic body 7d attached inside a frame dish 7c made of a rigid material. Various embodiments are possible in which the sealing action can be achieved by elastic contact. A thread-like member 11 as tension means is stretched between the seal lid 7 and a slide ring 9 slidably disposed in the front shaft 1 in the axial direction by the same means as in the previous embodiment. Further, a spring 10 for urging the slide ring 9 backward is interposed between the slide ring 9 and the locking ring 4 so that the seal lid 7 can be pulled. This point is the same as in the first embodiment.

A retraction spring 14 for urging the writing body 3 rearward is interposed between a locking portion 16 such as a crimp provided on the outer periphery of the writing body 3 and the locking ring 4. Stopper ring 15 in which locking portion 16 is fitted to rear shaft 2
, The further retreat of the cursive 3 is regulated.

In particular, in the case of this embodiment, the resilience of the retraction spring 14 is set to be substantially the same as or slightly stronger than the tension spring 10 for urging the slide ring 9 backward.

The separation spring 24 is set to have a smaller resilience than the springs 10, 14. As a result, when the cursive 3 is in the normal storage position,
The urging force of the tension spring 10 causes the seal lid 7 to come into contact with the guide cylinder 5 via the thread-like member 11 so as to be kept in a closed state, and the guide cylinder 5 is pulled apart as shown in FIG. The projection 25 of the guide cylinder 5 is positioned apart from the locking ring 4 by being pulled against the elastic force of the engagement 24. Also, at this time, the interval S2 between the locking ring 4 and the convex portion 25 is such that the seal lid 7 is kept in the closed state and in the storage position when the convex portion 25 is in contact with the locking ring 4. The writing body 3 is set so as to be in light contact with the tip writing portion 3a or slightly separated therefrom.

Therefore, also in this embodiment, in the normal storage state of the writing body 3, as shown in FIG. 7, the projection 25 of the guide cylinder 5 is held at a position away from the locking ring 4. The elastic body 7d of the seal lid 7 is elastically deformed into a conical shape and elastically adheres so as to enclose the tip writing portion 3a, so that the gap between the writing ball and the surrounding holding portion can be completely sealed. Become.

The forward / backward movement mechanism and the pushing member of the writing body 3 can be basically carried out in the same manner as in the first embodiment. The rod 17c of the pushing member penetrating the stopper ring 15 is provided so as to push the slide ring 9 in the forward direction and to advance the writing body 3 by the forward operation by.

Also in this embodiment, when the writing body 3 is normally stored, the slide ring 9 is at the rearmost position, and the seal lid 7 is pulled through the thread member 11 to be held in the closed state. And detaching spring 24
Since the resilient force is smaller than the tension spring 10, the guide cover 5 is displaced rearward against the urging force of the separation spring 24, and the seal cover 7 is attached to the tip writing portion 3a. The gap between the ball of the tip writing portion 3a and the surrounding holding portion is kept in a sealed state by elastic deformation.

When the advancing / retracting mechanism is operated to make a writing state, first, the slide ring 9 is pushed forward by the rod 17c of the pushing member so that the tension of the thread-like member 11 is loosened by this movement. , Guide cylinder 5
Move away from the writing body 3 to the position where the projection 25 is locked to the locking ring 4 by the urging force of the spring 24, and the seal lid 7 is moved to the tip writing section 3 as shown in FIG.
Lightly touches a or slightly separates. Thereafter, the writing member 3 and the slide ring 9 advance together by the advancement of the pressing member 17, and the thread-like member 11 is loosened, and when the seal lid 7 is urged in the opening direction, by the urging force, Cursive 3 moves forward even when not energized
Of the thread-like member 11
The writing body 3 is further advanced while slack, and the tip writing portion 3a protrudes from the hole at the tip of the front shaft 1 as shown in FIG.

When the writing body 3 is stored, the writing body 3 is moved by the operation of the forward / backward movement mechanism to move the writing body 3 back.
And the slide ring 9 is retracted by the urging force of the tension spring 10.

At this time, since the elasticity of the retraction spring 14 is set to be approximately the same as or slightly stronger than that of the tension spring 10, the writing body 3 retreats almost simultaneously with the slide ring 9 or slightly earlier. When the thread-like member 11 is tensioned due to the retreat of the slide ring 9 and the seal lid 7 is pulled to be in a closed state, the writing body 3 is already at a considerably retracted position, and the seal lid 7 can be closed without any problem. Further, after the closed state, the guide cylinder 5 moves to the tension spring 1
0 is pulled by the slide ring 9 which retreats by the urging force of 0, moves in the retreating direction against the urging force of the separation spring 24, and the inner surface of the seal lid 7 is the writing body 3 in the storage position.
Is elastically adhered to the tip writing portion 3a, and is maintained in a predetermined close contact state.

In each of the above-described embodiments, a shock absorbing means may be provided to absorb a shock when the writing body retreats.

[0073]

As described above, according to the capless writing instrument of the present invention, the cap is not required to be attached and detached, so that it is easy to use. Since the gap between the peripheral holding portion and the surrounding portion can be reliably maintained in a sealed state by the direct contact of the seal lid, it is possible to reliably prevent the leakage, drying, and backflow of the ink. Further, when the writing body is advanced, the sealing state of the tip writing portion by the seal lid is first released, and then the seal lid is opened and the tip writing portion advances, so that the elastic body of the seal lid is not damaged by the tip writing portion.

Further, since there is no hermetically sealed portion except for sealing the gap between the ball of the tip writing portion and the surrounding ball holding portion, when the tip writing portion is sealed with an elastic sealing lid, Unlike the cap type, the internal pressure of the cap is not increased, and therefore, there is no danger that air will enter the writing body. Further, since there is no seal portion close to the outer periphery of the cursive body, there is no resistance to the forward and backward movement of the cursive body, so that a spring for returning the cursive body does not require a very strong elastic force.

When the writing body is retracted and returns to the storage position, the impact is small, so that the ink and the fluid sealing material are prevented from retreating, and no ink fading or writing failure occurs.

In particular, at the time of storing operation of cursive writing,
In the case of the invention according to the third aspect, the slide ring simultaneously performs the action of positively retreating the cursive writing.
In the case of the invention of the present invention, since the resilience of the retraction spring is equal to or stronger than that of the tension spring that urges the slide ring backward, there is no delay in the return action of the cursive writing, so that the sealing Does not hinder the closing action of the lid.

Therefore, the present invention can be particularly preferably used for a ballpoint pen of neutral ink in which the trailing end of the writing body is opened and the end of the ink is filled with a flowable sealing material, and the structure is simple and easy to assemble. Therefore, it can be manufactured at low cost.

[Brief description of the drawings]

FIGS. 1A and 1B are a cross-sectional view and a side cross-sectional view of a writing instrument according to a first embodiment of the present invention in a state in which a writing body is stored.

FIG. 2 is an enlarged cross-sectional view of a seal lid portion of the previous figure (b).

FIG. 3 is a partially enlarged perspective view of a state where a seal lid is slightly opened.

FIG. 4 is a front view from the rear side of a slide ring portion.

FIG. 5 is a cross-sectional view showing a state in which a seal of a tip writing portion by a seal lid is released.

FIG. 6 is a side sectional view of a writing state in which a tip writing portion of a writing body is protruded.

FIGS. 7A and 7B are a cross-sectional view and a cross-sectional view of a part of a writing instrument according to a second embodiment of the present invention in a state in which a writing body is stored.

FIG. 8 is an enlarged cross-sectional view of the front part of FIG.

FIG. 9 is a cross-sectional view showing a state in which a seal at a tip writing portion by a seal lid is released.

FIG. 10 is a side sectional view of a part of a writing state in which a tip writing portion of a writing body is protruded.

[Explanation of symbols] 1 ... front shaft 2 ... rear shaft 3 ... cursive body 3a ... tip writing part 4 ... locking ring 5 ... guide tube 5a ... step 7 ... seal lid 7a, 7b ...... Ear 7c ...... Frame dish 7d ...... Elastic body 8 ...... Hinge part 9 ...... Slide ring 10 ...... Tension spring 11 ...... Filament member 14 ...... Retraction spring 15 ...... Stopper ring 17 ...... Press Moving member 17a ...... Cylinder part 17b ...... Flange part 17c ...... Rod 19 ...... Rotating cam 20 ...... Pusher 24 ...... Pulling spring 25 ...... Convex part

Claims (3)

[Claims] 1. A writing body having a tip writing portion holding a writing ball is housed in a main body having a hole at the tip of which the tip portion of the writing body appears and retracts, and the writing body is provided with a retracting spring. It is equipped with a forward / backward mechanism for advancing against the biasing force, holding it in the writing state and retracting it to the stored state, and a guide cylinder through which the front part of the writing body can penetrate in the front part in the main body. Is provided so as to be movable back and forth and regulate forward movement above a certain level, and a seal lid is provided near the tip of this guide cylinder, at least the inner side surface of which is made of an elastic body and is biased in the opening direction, Further, a slide ring biased rearward by a tension spring is provided so as to be pushed slightly earlier than the writing body when the writing body is advanced by the forward and backward movement mechanism.
Between the slide ring and the seal lid, a slackable thread-like member that stretches the seal lid when the writing body is stored is stretched, and the seal lid is attached to the tip writing portion of the writing body and the writing ball and its surroundings. It is provided so as to elastically adhere to maintain the sealed state so as to fill the gap with the ball holding part of the body, and at the time of the forward operation of the writing body, the guide tube moves slightly forward together with the slide ring to move the seal lid. After releasing the sealing state of the tip writing part by the, the thread member is loosened as the slide ring advances, and the seal lid is opened, and the slide ring retracts further on the outer periphery of the writing body. Is provided so as to have a slight gap between the sliding ring and the rear surface of the slide ring in the housed state, and the slide ring directly moves the cursive body to the housed position when the retracting operation is performed. A capless writing instrument characterized by being configured to be retracted to the front. 2. A writing body having a tip writing portion that holds a writing ball is housed in a main body having a hole at the tip of which the tip portion of the writing body appears and disappears, and the writing body is provided with a retracting spring. It is equipped with a forward / backward mechanism for advancing against the biasing force and holding it in the writing state and retracting it to the stored state, and in the front part of the main body, there is a guide tube through which the front part of the writing body can penetrate. Is provided so as to be movable back and forth and regulate forward movement above a certain level, and a seal lid is provided near the tip of this guide cylinder, at least the inner surface of which is made of an elastic body and is biased in the opening direction, Further, a slide ring biased rearward by a tension spring is provided so as to be pushed slightly earlier than the writing body when the writing body is moved forward by the forward / backward movement mechanism.
Between the slide ring and the seal lid, a slackable thread-like member that stretches the seal lid when the writing body is stored is stretched, and the seal lid is attached to the tip writing portion of the writing body and the writing ball and its surroundings. It is provided so as to elastically adhere to hold the sealed state so as to fill the gap with the ball holding part of the, and at the time of the forward movement operation of the writing body, the guide tube moves slightly forward together with the slide ring to move the seal lid. After releasing the sealed state of the tip writing part by the, the thread-like member is loosened as the slide ring moves forward, and the seal lid is opened, and the elastic force of the retracting spring is for pulling. It is set to the same level as or slightly stronger than the springs. A capless writing instrument that features 3. A thread-shaped member stretched between a slide ring and a seal lid is composed of one thread-shaped member, the central portion of the thread-shaped member is wound around a slide ring, and both ends thereof are seal lids. The capless writing instrument according to claim 1 or 2, wherein the capless writing instrument is connected to each other at opposite positions.