JP3198778B2 - Writing implement - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a writing instrument in which ink stored in a raw ink state in an ink storage chamber is supplied to a pen tip, and the volume of the ink storage chamber decreases as the ink is consumed. The present invention relates to a structure in which a part of a wall forming an ink storage chamber is a movable wall.

[0002]

2. Description of the Related Art One type of writing implement in which ink stored in a raw ink state in an ink storage chamber is supplied to a pen point is to allow air to enter the ink storage chamber instead of consuming ink. It has a structure. A typical example is a common fountain pen. In addition, a valve mechanism which can be opened by an appropriate knock structure such as a rear knock structure or a front knock structure between the ink storage chamber and the pen tip is often included in this type. .

Another type has a structure in which air is not positively introduced into the ink storage chamber even when ink is consumed. As an example of this, a part of the wall forming the ink chamber is a movable wall so that the volume of the ink chamber decreases as the ink is consumed as described above. Hereinafter, this type of writing implement is referred to as, for example, one in which the ink storage chamber is formed of a soft bag that is easily deformed, or one in which a so-called slide stopper or the like is disposed at the rear of the ink. Incidentally, a very familiar example of this latter is the usual oil-based inkball pen. That is, a grease-like viscous liquid for preventing ink backflow is provided at the rear of the ink contained in the ink containing cylinder,
For example, polypten is provided. This viscous liquid forms the movable wall. In recent years, molded products,
Accordingly, a study has been made on a movable wall portion which is made entirely or mainly of a solid member (for example, Japanese Patent Publication No.
-9960, JP-B-2-36398, JP-B-2-36399, JP-B5-54391, JP-A-61-179799, and JP-A-62-1.
No. 99492, JP-A-62-238799,
JP-A-3-13396, JP-A-4-332697
And Japanese Patent Application Laid-Open No. 4-326984).

[0004] In this kind of writing implement, it is necessary to pay attention to ink leakage from the pen tip. In this regard, in the case of the oil-based ink ball pen described above, ink leakage occurs due to the viscous nature of the ink itself and the strong capillary force at the tip of the ball pen (which may be said to be the presence of a valve between the ball and the tip). Although it has been overcome, when the ink is of low viscosity like a normal water-based ink or has a nib different from that of a ballpoint pen, ink leakage does not necessarily occur only at the nib portion. There are things that cannot be overcome.

[0005] For this reason, there is an ink jet printer in which a resistance structure against ink leakage is added in the ink passage to the pen tip. The idea regarding the flow of ink is that if it cannot be overcome "before (pen tip)", it will be treated "on the way". For example, Japanese Patent Publication No. 2-14200
Japanese Patent Application Laid-Open Publication No. H10-209,1991 basically has a valve structure that shuts off the ink passage by elastic contact of members, but has the advantage of not requiring a conscious knocking operation in principle. Have.

[0006] Similarly, the idea of arranging an object behind the ink, which resists the advance of the ink, also holds. For example, as can be seen in the above-mentioned publications, the movable wall provides resistance to ink advance. The device has been devised so much that it cannot be given too much resistance.

The present invention also aims to provide a means for preventing ink leakage, similarly to the above-mentioned various prior arts in such a writing instrument. The idea is that
It belongs to the arrangement in which the resistance of the ink advance is arranged "behind". However, if it is further divided, it is a kind of arrangement in which the resistance is arranged "after the movable wall portion".

[0008]

SUMMARY OF THE INVENTION The present invention is based on the idea that an air chamber having a lower pressure than the outside world is provided behind the movable wall. In other words, if an air chamber that acts as a depressurizing force (suction force) with the movable wall as a partition wall from the ink storage chamber is provided, it is possible to exert a resistance against the forward movement of the movable wall. Of course, this resistance must not be too great, so that the outside air can enter the air chamber moderately. A means for that is to provide an elastic wall portion and a capillary film forming wall portion (liquid film forming wall portion by capillary force) in a partition wall portion between the air chamber and the outside. Further, in the present invention, the ink contained in the ink containing chamber is used as the film forming liquid in the capillary film forming wall. For this purpose, the ink in the ink chamber and the ink in the capillary film forming wall are communicated by a capillary passage (a passage in which the ink is held by the capillary force). Therefore, the present invention is a writing instrument in which ink stored in a raw ink state in an ink storage chamber is supplied to a pen tip. The movable wall portion is provided with a movable wall portion, an air chamber is provided with the movable wall portion as a partition wall portion between the ink chamber, and an elastic wall portion is provided on a partition wall portion between the air chamber and the outside. In addition, the gist of the present invention is to provide a writing instrument characterized in that a capillary film forming wall portion made of ink which communicates with the ink in the ink storage chamber through the capillary passage is provided.

[0009]

The capillary film forming wall portion can be easily understood by considering, for example, a case where the liquid is held in the slit by capillary force. The liquid is usually present throughout the slit (spreading the membrane) and separates one side of the slit from the other. If the pressure on one side is greater than the pressure on the other side by more than the membrane tension, the state of the membrane is broken, and air enters from the higher pressure to the lower pressure through the slit, and When the pressure difference is reduced to such an extent that the pressure can be increased, the film is formed again to separate both sides. Of course, it is not necessary to use a slit, so that it is simply a capillary membrane forming wall. However, only the capillary film forming wall portion is insufficient in consideration of the case where the pressure in the air chamber side is higher than the outside. The elastic wall part compensates for this. The elastic wall portion is in a deformed state due to the small pressure in the air chamber, and if the pressure in the air chamber is to be increased, the amount of deformation is reduced, thereby trying to absorb the pressure increase.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. The pen tip 1 protrudes from the tip of the barrel 2. Here, pen point 1
Although the illustration is made with consideration given to a fiber converging body having a tapered tip shape, for example, a brush ear made of a brush converging body, a communicating porous elastic body such as urethane is made into a brush-like shape. For example, a so-called pen tip of a brush pen, a pen tip of a ball pen composed of a ball and a tip, and a pen tip of a small tube writing instrument composed of a small tube and a needle body may be used. In addition, although the shaft cylinder 2 is illustrated by taking into account that a synthetic resin having transparency is obtained by injection molding as necessary, it is made of a metal such as aluminum,
It may be one composed of two parts, a shaft main body and a pen tip holder. The material and component configuration are appropriate.

An appropriate writing ink 3 such as a writing liquid, a cosmetic liquid, and a correction liquid is contained in the barrel 2 in a raw ink state.
For example, 200 cps. Of course, a low-viscosity material having a viscosity of not more than about may be used. Although it is inserted directly into the barrel 2, it may have an ink cartridge structure as in a general fountain pen.

A grease-like viscous liquid 4 such as, for example, polybutene is contained in the rear part (upper part of the drawing) of the ink 3.
This is an example of the movable wall described above. That is, the viscous liquid 4 is also a part of the wall as the ink storage chamber together with the barrel 2 forming the main wall of the ink storage chamber. It is like a piston for a cylinder, and the molded product can be made entirely or mainly as described above. However, if the viscous liquid 4 is used, the filling operation can be completed. In addition, the movable wall portion may be one that provides resistance to advance from the “back” to the ink 3 (on the flow), but is generally a straight tubular shaft cylinder 2 (such as a U-shaped one). In some cases, if the inner diameter is large, the viscous liquid 4 works with its own weight together with the ink 3,
In addition, it shows that the present invention is not a problem.

An elastic film 5 is attached to the rear part of the barrel 2 so as to be spaced from the viscous liquid 4. The tail plug 6 applies a clamping force to the elastic membrane 5 together with the barrel 2. The tail plug 6 has a communication hole 7 with the outside world.
The rear part of the viscous liquid 4 (this space is an air chamber) 8 is a wall portion that hermetically partitions the outside from the outside. Here, the elastic film body 5 is, for example, a rubber balloon, and is preferably a material that can be greatly elastically deformed by a slight pressure. If the airtight compartment can be satisfied, it is not always necessary to exert the clamping force. For example, the elastic membrane 5 can be attached by bonding or the like.
In the case where the barrel 2 is composed of two parts, the barrel body and the pen tip holder, it is easy to provide a tail plug part integrally with the barrel body. You don't have to use it.

The air chamber 8 is not a completely closed chamber. Pen tip 1
When the ink 3 and the viscous liquid 4 are about to fall under the influence of gravity in the state shown in the drawing, a depressurizing force is acting on the air chamber 8. Although the internal pressure tries to decrease by the amount of the liquid 4 moving forward,
A certain decrease is absorbed by the elastic deformation of the elastic film body 5, and a further decrease is prevented by the invasion of outside air into the air chamber 8. That is, although the internal pressure of the air chamber 8 is slightly lower than the external pressure, the air chamber 8 has an outside air intake so as not to be too low. The above-mentioned capillary film forming wall portion serves as the outside air intake portion. In the drawing, two small holes are formed in the side wall of the barrel 2. The front small hole 9 and the rear small hole 10. Both small holes 9 and 10 have a size that can hold ink by capillary force, and are communicated by slits 11 that can also hold ink by capillary force. The capillary membrane forming wall in the one shown is
Is provided by providing an ink film.
If the internal pressure of the air chamber 8 is to be reduced to a certain degree or more, the ink film at the rear small hole 10 is broken, and outside air enters the air chamber 8. Here, an outer body 12 is provided to prevent the slit 11 and the like from being exposed to the outside.
3 is provided, and the space between the barrel 2 and the exterior body 12 communicates with the outside air. In addition, the front small hole 9 and the slit 11
At the rear small hole 10, a passage for communicating the ink for forming the membrane with the ink in the ink storage chamber, that is, a capillary passage in the illustrated one.

In this way, the writing can be continued smoothly without the ink 3 being no longer supplied to the pen point 1. However, for example, the elastic film body 6 does not respond to an increase in the volume in the air chamber 16 due to a rise in temperature or the like. The amount of deformation can be compensated by a small amount. Also, for example, when the pen tip 1 is turned upward, the ink 3 and the viscous liquid 4 try to recede. However, the fact that the ink 3 leaks out from the pen tip 1 and is larger than the resistance exerted by the pen tip 1 makes it possible to compensate for the loss. Not only as a special writing tool that always keeps the same direction, but also as a normal writing tool, setting the capillary force of each part or the inner diameter of the barrel 2 is basically arbitrary, so the same ink amount Even so, by adjusting the storage height of the ink 3, the ink 3 can be sufficiently put to practical use.

Although an example has been described above, various modifications can be made. For example, in the above, the slit 11 formed in the side wall of the barrel 2 is used for the capillary passage, but the capillary passage can also be formed by using a fiber bundle, a communicating porous body, or the like. It is also possible to use a separate member that connects the front small hole 9 and the rear small hole 10 of the barrel 2 and serves as, for example, a rod-shaped capillary passage body. Similarly, for example, a fiber bundle, a communicating porous body, or the like can be used for the capillary film forming wall instead of simply forming an ink film on the rear small hole 10. In this case, the outside air enters the air chamber by pushing away ink held in a place where the capillary force is relatively weak among the ink held in the fiber bundle or the like. Therefore, it is not necessary to provide a large hole, but it is not always necessary to form a capillary membrane forming wall portion with a small hole. Further, for example, if necessary, the above-described technique for “mid-way” treatment in the ink flow may be used together.

[0017]

According to the present invention, there is provided a writing instrument for supplying ink stored in a raw ink state in an ink storage chamber to a pen tip,
In a case where a movable wall is provided on a wall forming the ink storage chamber so that the volume of the ink storage chamber decreases as ink is consumed, an air chamber having the movable wall as a partition wall with the ink storage chamber is provided. The present invention is characterized in that the partition wall between the air chamber and the outside is provided with an elastic wall portion and a capillary film forming wall portion made of ink which communicates with the ink in the ink storage chamber through the capillary passage. The writing implement is provided with one means for preventing ink leakage from the pen tip, but in particular, as a movable wall, a restriction that the molded article must be used as a whole or a main body, or
With respect to the movable wall portion, there is a great advantage that it is necessary to manage with high accuracy for variations in the dimensions and physical properties of parts, and that such a limitation can be resolved and a relatively inexpensive product can be obtained.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view illustrating one embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 pen tip 2 barrel 3 ink 4 viscous liquid 5 elastic membrane 6 tail plug 7 communication hole 8 air chamber 9 front small hole 10 rear small hole 11 slit 12 exterior body 13 air hole

Continuation of the front page (56) References JP-A 3-95283 (JP, U) JP-A 51-91037 (JP, U) JP-A 51-98634 (JP, U) JP-A 49-25517 (JP) , U) Patent 66890 (JP, C2) (58) Fields investigated (Int. Cl. ⁷ , DB name) B43K 5/02 B43K 7/02 B43K 8/02

Claims (1)

(57) [Claims] 1. A writing instrument for supplying ink stored in a raw ink state in an ink storage chamber to a pen tip,
In a case where a movable wall is provided on a wall forming the ink storage chamber so that the volume of the ink storage chamber decreases as ink is consumed, an air chamber having the movable wall as a partition wall with the ink storage chamber is provided. A writing instrument, wherein a partition wall portion between the air chamber and the outside world is provided with an elastic wall portion and a capillary film forming wall portion made of ink which communicates with the ink in the ink storage chamber through a capillary passage.