JPH0811483A - Writing instrument - Google Patents

Abstract

PURPOSE:To prevent the generation of foams forming a possible cause for ink leakage by forming an additional opening of a writing instrument on an end face on the opposite side of an ink interface of a cover provided with a storage section for storing high viscosity fluid inside and forming an opening allowing the cover to communicate with the inner wall of an ink tank in a writing instrument. CONSTITUTION:An end face of an ink tank for storing ink 2 in the free state inside on the opposite side of a penpoint is used as an air feed opening, and a high viscosity fluid 3 (example: silicone grease) moving together with the interface of ink following the ink consumption as a backflow prevention body and also a cover 4 are formed on the interface of ink 2. The cover 4 is provided with a storage section 4a for storing high viscosity fluid 3, and an opening 8 communicating with between the inner wall of the ink tank and the cover 4 is formed on the storage section 4a. The opening 8 communicates with an opening 4b formed on the end face on the opposite side of ink interface of the cover 4. As a result, the generation of foams forming a possible cause of ink leakage can be controlled as much as possible.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses an end face of an ink tank, which contains ink in a free state inside, on the side opposite to the pen tip, as an air supply port for ink consumption, and as a backflow preventer at the ink interface. A writing instrument comprising a lid and a high-viscosity fluid that moves along with the interface of the ink as the ink is consumed, wherein the lid has a storage section for storing the high-viscosity fluid therein and The present invention relates to a writing instrument in which an opening communicating with an inner wall of an ink tank and a lid is formed in the portion.

[0002]

2. Description of the Related Art A so-called raw ink type writing instrument which stores ink in the ink tank in a free state as described above can hold a relatively large volume of ink in the writing instrument, while the ink in the ink tank is in a free state. Because of this, tight control of ink leakage is required. Most of writing instruments that use ink cannot be written because the interior of the writing instrument becomes negative pressure unless the volume of the writing instrument using ink as handwriting and the air inside the writing instrument is replenished. By forming the air circulation hole that communicates with the ink tank, it is possible to suppress negative pressure in the ink tank, but forming the hole that communicates with the ink tank is itself disadvantageous for ink leakage.

[0003] A raw ink type writing instrument in which ink is replenished with air in an ink tank without forming an air circulation hole in a portion where ink substantially exists In some tanks, a high-viscosity fluid and a lid that moves according to the decrease in volume of the ink are arranged at the interface of the ink in the tank. However, such a structure has a problem that the high-viscosity fluid adheres to the wall surface of the ink tank as the lid moves, and the high-viscosity fluid existing around the lid decreases. JP-A-62-238799 discloses that a high-viscosity fluid is present in an amount larger than the decreasing amount.
In No. 3, a storage chamber for high-viscosity fluid (silicon oil) is provided in the lid (slide stopper), and the high-viscosity fluid stored through a hole formed in the side wall is supplied between the lid and the inner wall of the ink tank. A writing instrument made of is disclosed.

FIG. 6 shows an enlarged sectional view of a main part of a conventional writing instrument, which will be described. An ink 2, a high-viscosity fluid 3 and a lid 4 are arranged inside the ink tank 1. The inside of the lid 4 is a storage chamber 401 that stores the high-viscosity fluid 3 and has an opening on the atmosphere side. And the hole 4 formed in the side wall
The high-viscosity fluid 3 from the inside is covered with the lid 4 and the ink tank 1.
It is supplied between the inner wall 1a and the inner wall 1a.

[0005]

The lid 4 has a hole 402.
Due to the holes, there is an obstacle wall 403 against the escape of bubbles when the storage chamber 401 is filled with the high-viscosity fluid 3. If bubbles are formed in the holes 402, the liquid-tightness of the high-viscosity fluid is lowered, which causes a problem of ink leakage.

[0006]

That is, according to the present invention, the end face of the ink tank, which accommodates ink in a free state inside, on the side opposite to the pen tip is used as an air supply port accompanying the consumption of ink, and flows back to the interface of the ink. A writing tool that includes a lid and a high-viscosity fluid that moves together with the interface of the ink as the ink is consumed, as the preventive body, wherein the lid has a storage portion that accommodates the high-viscosity fluid therein. Along with this, in a writing instrument in which an opening communicating with the inner wall of the ink tank and the lid is formed in this storage, the opening also opens on the end surface of the lid opposite to the ink interface. Writing instruments that are characterized by

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An example will be described below with reference to the drawings.
FIG. 1 is a cross-sectional view of a main part showing an example of the writing instrument A of the present invention. The inside of the barrel 5 serves as the ink tank 1, and the pen tip 6 is attached to the tip of the small diameter portion. A tail plug 7 having an air circulation hole 7a at the end of the barrel 5 opposite to the pen tip 6
Is attached in a press-fitted state. The ink 2 is accommodated in the ink tank 1 in a free state in which it is not held by an ink occlusion body such as a fiber bundle.

As shown in FIG. 2, which is an enlarged view of the main part of FIG. 1, a high-viscosity fluid 3 and a lid 4 are arranged as an ink backflow preventive composition at the interface portion of the ink 2. The lid 4 maintains the interface shape of the high-viscosity fluid 3 and suppresses ink leakage as much as possible. As the high-viscosity fluid 3, one having a relatively high viscosity, a high surface tension and a low specific gravity with respect to the ink 2 is preferable, and depending on the type of the ink, as an example, a gelled product of silicone grease, silicone oil, petrolatum or polybutene. And so on.

The high-viscosity fluid 3 exists in the gap 8 provided between the inner wall of the ink tank 1 and the lid 4. As a result, it is possible to suppress the movement resistance of the lid body 4 that moves as the ink 2 decreases, and to suppress the ink leakage as much as possible. Further, the lid 4 has a storage chamber 4a that stores the high-viscosity fluid 3 therein. Accommodation room 4a
Is, as shown in FIG. 3 which is a cross-sectional view taken along line I-I of FIG.
It has an opening 4b that opens to the atmosphere side (the side opposite to the ink interface) and the gap 8, and supplies the high viscosity fluid 3 inside to the gap 8.

When the high-viscosity fluid 3 is filled in the storage chamber 4a, the opening 4b also opens to the atmosphere side. Therefore, the air existing in the storage chamber 4a before the opening high-viscosity fluid 3 is filled is the high-viscosity fluid. It is possible to prevent the bubbles from being pushed out smoothly from the accommodation chamber 4a as the fuel cell 3 is filled and remaining in the accommodation chamber 4a and the gap 8 as much as possible. Further, the opening 4b is
Since it is designed to gradually expand toward the opening portion on the atmosphere side, it is more difficult for bubbles to remain. Furthermore,
Since the opening 4b does not have an undercut portion on the mold during molding, it can be relatively easily molded without difficulty. Here, it is preferable that the cover 4 has a smaller apparent specific gravity than the ink 2 and the high-viscosity fluid 3, and injection molded products of various synthetic resins can be adopted, but the ink permeability (reduction)
Considering the dimensional stability, cost, and ease of molding, polypropylene and polyethylene are preferable.

4 and 5 show another example of the lid 4. In the structure shown in FIG. 4, the lid 4 is provided on the first side of the ink interface.
This is an example in which the lid portion 4c, the second lid portion 4d on the atmosphere side, and the connecting portion e between the both are formed, and the first lid portion 4c and the second lid portion 4 are included.
A storage chamber 4a for the high-viscosity fluid 4 is provided between the space and d. FIG.
5, which is a cross-sectional view taken along the line II-II of FIG. 5, the accommodation chamber 4a is formed with an opening 4a 'that opens to the atmosphere side as a slit in the second lid. In the present example, since the portion between the first lid 4c and the second lid 4d is used as the storage chamber 4a for the high-viscosity fluid 3, the storage chamber 4a apparently has a gap over the entire circumference. Since it is opened to the portion 8, it is more advantageous from the viewpoint of supplying the high-viscosity fluid. So, for example,
Even if dust or the like has entered the storage chamber 4a, the supply of the high-viscosity fluid 3 to the gap portion 8 is not hindered.

Besides the above, various modifications can be made without departing from the gist of the present invention. As an example, in FIG. 1, the pen tip 6 shows a fiber bundle formed of an acrylic fiber, a polyester fiber, or the like in an appropriate shape.
In addition to this, a synthetic resin rod (so-called plastic pen) having an ink passage inside, a small tube type nib with a hard pipe and a needle, and a polypropylene or polyethylene called a sintered core are burned. The one using a solidified sintered body, the one using a ball rotatably held may be used. Considering that the ink supply mechanism from the ink tank 1 to the pen tip 6 has a raw ink structure, a so-called valve slide system in which the ink tank and the pen tip are divided by a valve made of an elastic body, Examples thereof include those using a temporary ink reservoir member having a comb-like cross section between the pen tip and the ink tank, those using various valve mechanisms, and the like. Of course, the end of the pen tip 6 may be directly connected to the inside of the ink tank 1 as long as unnecessary leakage of ink can be sufficiently prevented. Further, as in the example of FIG. 1, the inner surface of the shaft cylinder 5 is not used as it is as an ink tank, but an ink tank may be provided as a separate member, and the ink tank may be replaced after consumption of ink. A possible cartridge type may be used.

[0013]

According to the writing instrument of the present invention, the end face of the ink tank, which accommodates ink in a free state inside, opposite to the pen tip, is used as an air supply port accompanying the consumption of ink, and as a backflow preventer at the interface of the ink. A writing instrument comprising a lid and a high-viscosity fluid that moves along with the interface of the ink as the ink is consumed, wherein the lid has a storage section for storing the high-viscosity fluid therein and In the writing instrument, which has an opening communicating with the inner wall of the ink tank and the lid, the opening has an opening on the end surface of the lid opposite to the ink interface. A relatively large amount of high-viscosity fluid can be present to prevent ink leakage, and the high-viscosity fluid adheres to the walls of the ink tank as the lid and high-viscosity fluid move as ink is consumed. Exists around the lid Even if the viscous fluid is reduced, it is possible to secure a sufficient amount of high-viscosity fluid to suppress ink leakage, which leads to ink leakage in the area where high-viscosity fluid exists even when filling with high-viscosity fluid. It suppresses the generation of bubbles as much as possible.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part showing an example.

FIG. 2 is an enlarged view of a main part of FIG.

FIG. 3 is a sectional view taken along line I-I of FIG.

FIG. 4 is a cross-sectional view of main parts showing another example.

5 is a sectional view taken along line II-II of FIG.

FIG. 6 is a sectional view of a main part showing a conventional example.

[Explanation of symbols]

 A Writing instrument 1 Ink tank 1a Inner wall 2 Ink 3 High viscosity fluid 4 Lid 401 401 Storage chamber 402 Hole 403 Obstacle wall 4a Storage chamber 4b Opening 4c First lid 4d Second lid 4e Connecting portion 4a 'Opening 5 Axis cylinder 6 Pen tip 7 Tail plug 7a Air circulation hole 8 Gap

Claims (1)

[Claims] 1. An end face of an ink tank, which accommodates ink in a free state inside, on the side opposite to the pen tip is used as an air supply port for ink consumption, and as a backflow preventer at the interface of ink, with ink consumption. A writing instrument comprising a lid and a high-viscosity fluid that moves together with the interface of ink, wherein the lid has a storage section for storing the high-viscosity fluid therein, and the storage section has an ink tank of A writing implement having an opening communicating with an inner wall and a lid, wherein the opening is also formed on an end surface of the lid opposite to the ink interface.