JPS6313036Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention has a thin tubular pen nib protruding from the tip of the barrel, and an ink guiding core that protrudes slightly from the pen nib and is loosely inserted into the pen nib so that it can come out and go out. This invention relates to a capillary type writing instrument.

In general, the following are the main inconveniences found in this type of thin tube type writing instrument. In other words, if the ink inside the pen nib evaporates and dries, smooth ink extraction cannot be expected, so the pen nib is sealed off from the outside world by a cap. The point is that it is not possible to write immediately after removing the ink, but the ink cannot be drawn out properly unless it is shaken several times. It is a common experience to shake the ink too vigorously and cause the ink to drip off, staining the paper surface. It is also conventionally known that a weight is attached to the rear of the ink guiding core so that the ink guiding core reliably moves back and forth within the pen tip when the pen is shaken.

The inventor of this invention has been engaged in research to improve the above-mentioned drawbacks for many years, and has recently developed a new method by skillfully utilizing the decompression phenomenon that occurs when removing a tightly fitted cap. I wondered if there was a way to solve this problem, and as a result of intensive study based on this perspective, I finally came to the completion of this invention.

That is, in the present invention, a thin tube-shaped pen nib 2 is provided protrudingly at the tip of a shaft tube 1, and an ink guiding core 3 made of synthetic resin is slightly protruded from the pen nib 2 inside the pen nib 2 so that it can be retracted and retracted. The ink guide core 3 is fitted and provided.
In a thin tube-shaped writing instrument whose rear end is in contact with an elastic porous body 4 provided in contact with an ink storage body 5, the ink guide core 3 is a single linear molded product, and The space leading to the opening at the tip of the thin tubular nib 2 at the front is closed, and the negative pressure when the cap is removed acts on the opening at the tip of the tubular nib 2, causing the ink guiding core 3 and the ink to move forward. It is a capillary type writing instrument that can be attracted to.

The present invention will be explained below with reference to embodiments shown in the drawings.

In the figure, 1 is a barrel, 2 is a capillary pen nib consisting of a ceramic capillary tube 2a and a stainless steel capillary tube 2b, 3 is an ink guiding core inserted loosely into the capillary pen nib 2, and 4 is an ink guide body. An elastic porous foam body is in contact with the rear end of the guide core 3, 5 is an ink storage body, and 6 and 7 are holders.

By the way, Utility Model Application No. 52-1999, which is related to the invention of the present applicant.
Publication No. 136736 discloses an ink guide core 3 made of a synthetic resin, including a point in which ink guide grooves are continuously formed on its surface, and an elastic porous foam with which the rear end of the core 3 comes into contact. 4, a lead holder is fixed to the rear end of the ink guiding core, and the lead holder comes into contact with the inner surface of the barrel in a normal state, and The above arrangement did not allow the core to move forward.

The present invention is the same as that of the above-mentioned publication in that the ink guide core 3 made of synthetic resin is used.
It differs in that it consists of a single linear molded product. That is, in the present invention, a tightly fitted cap (not shown) is used.
In order for the ink guide core 3 to be pulled up within the tubular nib 2 by the depressurization phenomenon when the ink guide core 3 is removed, there must be no protrusion of any kind that would prevent the ink guide core 3 from being pulled up. In addition, it must be made of synthetic resin from the viewpoint of lightness so that it can be pulled up by the above-mentioned decompression phenomenon. By the way, the length is 7mm and the diameter is 0.285.
The weight of the polyacetal ink guide core 3 of mm is
It is light at 0.3mg, but if it were made of SUS304, it would be 7mm long and 0.2mm in diameter and heavy at 1.6mg, which is too heavy and inappropriate for achieving the purpose of this project.

The ink guide core 3, which is a single linear molded product made of synthetic resin, is held by the surface tension of the ink interposed between it and the capillary pen tip 2, even if the pen tip 2 is turned downward. Not only will it not fall due to its own weight, will not fall even if you shake it a little, but it will not slip out and fly out due to the impact force when you accidentally drop the writing instrument.

The inner diameter of the thin tubular nib 2 is, for example, 0.3 mm, since this type of writing instrument is used for writing thin lines.
Further, the ratio of the outer diameter of the ink guide core 3 to the inner diameter of the capillary pen nib 2 is 85 to 97%, which can be said to be a suitable range based on the results of many experiments.

By the way, in the device described in the above-mentioned publication, a method was adopted in which the ink-containing elastic porous body 4 is pressed with a lead holder at the rear end of the ink guide core to squeeze out the ink (when not in use, the lead holder is (The ink guiding core is in contact with the inclined part of the inner surface of the front part of the shaft cylinder, thereby preventing the ink guiding core from moving forward). Therefore, even if negative pressure acts on the tip opening of the capillary pen tip due to the depressurization phenomenon that occurs when the cap (not shown) is removed, the effect of attracting the ink guide core and ink forward cannot be expected. In the end, I had no choice but to resort to the above-mentioned method. In contrast, in the present invention, as shown in the drawing, the space leading to the tip opening of the thin tubular nib 2 in front of the elastic porous body 4 is closed. As a result, negative pressure is applied to the opening at the tip of the capillary pen tip 2 when the cap is removed, making it possible to attract the ink guiding core 3 and the ink accompanying it.

As mentioned above, the present invention provides an ink guiding core 3.
Since it is light and straight, even the depressurization phenomenon that occurs when removing the cap is sucked in, and the length of the protrusion from the tip of the pen tip 2 is much larger than normal.
To make it possible to easily grasp a protruding part of an ink guide core 3 which cannot be grasped in normal conditions. This makes it easier to further pull out the gripped protrusion, and when the ink guide core 3 is pulled out, the ink in the gap is brought along and wetted the inner wall surface of the tip of the dry capillary nib 2, so that subsequent ink can be applied. This ensures reliable derivation and eliminates the problem of poor ink flow at the beginning of use, without causing ink splatter or the like.

Furthermore, even if the ink guide core 3 made of synthetic resin becomes worn out due to long-term use and you want to replace it with a new one, it can be easily grasped due to the above-mentioned pressure reduction phenomenon, so it can be easily pulled out and replaced.
Replacement is extremely easy, as it is sufficient to simply insert a new pen from the tip of the nib 2.

[Brief explanation of drawings]

The figure is a sectional view showing the main parts of the present invention. 1... Barrel, 2... Tubular pen tip, 3... Ink guide core.

Claims (1)

[Scope of utility model registration request] A thin tube-shaped pen nib 2 is provided protrudingly at the tip of the barrel cylinder 1, and an ink guide core 3 made of synthetic resin is provided inside the pen nib 2 so as to slightly protrude from the pen nib 2 and is loosely fitted so as to be retractable. In a thin tube-shaped writing instrument in which the rear end of the ink guiding core 3 is brought into contact with an elastic porous body 4 provided in contact with the ink absorbing body 5, the ink guiding core 3 is a single linear molded item. The space leading to the opening at the tip of the capillary nib 2 in front of the elastic porous body 4 is closed, and the negative pressure when the cap is removed acts on the opening at the tip of the tubular pen nib 2 to guide the ink. A thin tube type writing instrument capable of drawing body 3 and ink forward.