JPS6329585Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is an ink cylinder of a writing instrument such as a marking pen or a ballpoint pen, and especially an ink cylinder of a writing instrument that has a holder that stores ink inside and holds a pen tip in the tip opening. Regarding.

In some writing instruments such as marking pens, the tip of the ink cylinder of the writing instrument has a diaphragm shape, and the pen tip is clamped and fixed at the tip, but in writing instruments for fine writing, the pen tip is clamped and fixed in a holder. After the pen tip is once tightly fitted inside, the fitting part at the end of the holder is tightly fitted and fixed to the fitting part at the tip of the ink cylinder.

Similarly, in the case of writing instruments such as ballpoint pens, the tip of the ink cylinder of the writing instrument is shaped like a tip, and a holder that rotatably holds the ball, which is the pen tip, is clamped and fixed at the tip, or this holder is directly or After this holder is further tightly fitted into the holder using this holder as an inner holder, the fitting portion at the end of the holder is tightly fitted and fixed to the fitting portion at the tip of the ink cylinder.

However, there is a small gap between the ink cylinder fitting part and the holder fitting part, and ink penetrates this gap due to surface tension and eventually reaches the outside of the holder, staining clothes that come into contact with the holder. This often leads to serious accidents.

To prevent this, it would be possible to completely seal it by applying an adhesive or heat welding, but this would increase the number of steps and lead to higher costs.

This invention solves the above drawbacks without increasing costs, and will be described in detail below with reference to the drawings.

1 is an ink cylinder, and Fig. 1 shows an example in which a highly stretchable metal such as aluminum is stretched and molded, but it can also be molded by blow molding or injection molding of thermoplastic resin (however, it is divided into upper and lower parts). It is also possible to mold the material by a method (it is necessary to integrate the material after molding). Reference numeral 2 represents a small diameter cylinder portion connected to the tip of the ink cylinder 1, and 3 represents an ink absorbing material such as coarse hair or synthetic fiber.

Annular grooves 4, 4' of a size such that the surface tension of the ink does not act on the inner circumferential surface of the narrow diameter cylindrical portion 2 are provided around the inner circumferential surface thereof. In this example, two annular grooves are provided in parallel, but only one annular groove may be provided. However, it is more reliable to prevent ink from flowing out if a plurality of them are provided around the circumference.

5 is a pen nib holder with a truncated conical tip 6
and a small-diameter cylindrical fitting part 7. In this embodiment, the marking pen tip 8 is clamped and fixed to the rear fitting part 7.
is tightly fitted and fixed to the fitting portion on the inner circumferential surface of the small diameter cylindrical portion 2.

Since a minute gap is created between the inner circumferential surface of the narrow diameter cylinder part 2 and the outer circumferential surface of the fitting part 7, the ink penetrates from the ink absorbing material 3 due to surface tension, but when it reaches the annular groove 4, the groove 4 becomes the fitting part. Since a relatively large space is formed between the outer circumferential surface of the ink and the outer circumferential surface of the ink, the surface tension is no longer applied and the ink stops penetrating.

In the unlikely event that gravity is applied in addition to surface tension, and the ink gradually increases in the grooves 4, surface tension acts further and the ink reaches the grooves 4', the surface tension ceases to act again and ink penetration stops again.

As described above, the ink cylinder of the present invention has no fear of ink leaking from the fitting portion.

[Brief explanation of the drawing]

FIG. 1 is a partially omitted vertical cross-sectional view of a writing instrument using the ink cylinder of this invention, and FIG. 2 is a longitudinal cross-sectional view of the main parts. 1... Ink cylinder, 2... Small diameter cylinder part, 4, 4'...
...Annular groove, 5...Nib holder.

Claims (1)

[Scope of utility model registration request] An ink cylinder whose tip is opened as a small diameter cylinder, an annular groove is provided on the inner peripheral surface of the small diameter cylinder, and a fitting part of a pen nib holder is tightly fitted and fixed, An ink barrel for a writing instrument, characterized in that the annular groove forms a space between the annular groove and the outer circumferential surface of the fitting part of the holder, the size of which does not allow the surface tension of the ink to act.