JPS6142854Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a pipe-type ballpoint pen body that is difficult to ink.

Pipe-type ballpoint pen bodies, that is, ballpoint pen bodies that use pipe as the tip material, generally have a straight pipe center hole, so if the ball is held rotatably at the tip end, it will not roll or fall. The drawback is that the ink drop caused by this process is severe.

Therefore, normally, an ink guide rod is inserted into the center hole of the pipe so that its tip is in contact with or adjacent to the rear of the ball, that is, the back surface of the ball, in order to suppress the above-mentioned defects.

These ink guide rods include those that have irregular capillary tubes, such as fiber bundles, and those that are manufactured by extrusion molding of synthetic resin monofilaments so that they self-fuse (hereinafter referred to as monofilament self-fusing rods). It is broadly divided into those with regular capillary tubes by design, such as those with regular capillary tubes.

However, irregular capillary tubes tend to cause variations in ink flowability from product to product, and regular capillary tubes make it difficult to maintain the relationship between the ink discharge amount and the problem of ink dripping within a suitable range. As mentioned above, each had their own problems.

Based on the above, the present invention is designed to utilize the respective strengths of the irregularity of fiber bundles and the regularity of conventional monofila self-bonding materials as ink passages in the ink guiding rod. DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

In FIG. 1, reference numeral 1 is a chip made of a hard material such as metal or ceramic, which rotatably holds a ball 4 at a portion formed by a tip end portion 2 and two or more press-deformed portions 3, 3'. I have it. Further, an ink guide rod 5 made of a monofilament self-fused material of synthetic resin such as polyacetal, polyamide, or acrylic resin is inserted into the center hole of the chip 1 so that its tip abuts against the pressing deformation parts 3 and 3'. has been done.

The ink guide rod 5 has a pre-designed ink passage (not particularly shown) on its outer periphery and/or inside, and furthermore, as shown in a partial cross section in FIG. , at least a portion of the tip 6 has an irregular ink passage 7 formed by the originally fused portion being unfused. The irregular ink passages 7 may be independent of the pre-designed ink passages, but preferably have a continuous section.

The formation of irregular ink passages 7 can be achieved, for example, by deforming the tip 6 of the ink guide rod 5 by mechanical pressure, forcing the fused portion, which is a relatively weak bond, to separate, or by forcing the ink guide rod 5 to separate. This can be easily done by etching the tip 6 of the guide rod 5 with a chemical.

Here, as the mechanical pressure, it is of course possible to use various processes, but for example, the force during molding of the pressing deformation parts 3, 3' of the chip 1 can also be used. That is, the ink guide rod 5 is inserted (press-fitted, loosely inserted, etc.) into the center hole of the chip 1 to a certain position in advance, and then the tip 1 is appropriately inserted so that the tip 6 of the ink guide rod 5 is deformed. The shape is pressed and deformed. At this time, the tip of the ink guide rod 5 may be brought into contact with the ball 4 that has been inserted in advance, for example, so that the tip of the ink guide rod 5 becomes at least a part of the ball receiver. You can leave it there.

Of course, if the chip 1 is made of ceramic or the like and cannot be deformed by pressing, or if the deforming parts 3 and 3' are not required (for example, when the ball receiver is formed only with the tip of the ink guiding rod 5). In this case, it is sufficient to break off the fusion before inserting the ink guide rod 5 into the center hole of the tip 1 (in this case, the inner diameter of the rear end of the tip 1 may be enlarged to facilitate insertion). ), positioning after insertion is also optional,
It is also possible that the tip of the ink guide rod 5 enters into the gap between the pressing deformation parts 3 and 3'.

In addition, it is possible to set in advance a certain amount of parts to be fused, and for this purpose, it is necessary to avoid the close-packed structure shown in Figure 2 by extruding the base of each monofilament. The shape and arrangement including the size of each hole of the machine nozzle may be set as appropriate.

In FIG. 2, the part (multiple parts are shown) marked with reference numeral 8 is the gap left when the monofilament is fused, but the gap 8 can be used as a substantial ink passage carrier. This is optional, as will be understood from the above.

The ratio of the irregular ink passages 7 formed by melting the ink to the total length of the ink guiding rod 5 and the melting ratio at the tip of the ink guiding rod 5 are determined depending on the desired ink flowability or the ink flow rate. Although it cannot be determined definitively depending on the length of the guide rod 5 itself, we would like to add that the length should be approximately 1/5 to 4/5 of the total length, or 0.5 mm or more, and the length should be fused. The elimination rate is determined by dividing the tip of the ink guide rod 5 into two or more parts, or by dividing the total width of the irregular ink passage in the cross section of the tip of the ink guide rod 5 into the diameter of the tip of the ink guide rod 5 (although it may not be circular). (approximately) or more. Of course, this is just a guide; for example,
A portion of the irregular ink passage 7 may be formed over the entire length of the ink guide rod 5. However, it is not preferable to completely divide the ink guiding rod 5 into a plurality of independent ink guiding rods, as this may cause problems such as difficulty in fixing each rod.

In any case, the capillary force itself becomes irregular due to the formation of irregular ink passages 7 by dissolving the fusion in at least the tip 6 of the ink guiding rod 5 made of monofila self-fused material. For example, the ink guide rod 5 originally only had an ink passage due to the irregular shape of the outer surface of the monofilament itself, and the gap between the inner wall of the tip 1 and the outer wall of the ink guide rod 5 was essentially formed as the original ink passage. Even in such a case, a strong capillary force acts on the tip 6 of the ink guide rod 5 itself, which contributes to suppressing ink dripping and makes it possible to obtain good handwriting. Moreover, the ink guiding rod 5 itself is "1".
Therefore, the capillary force in the irregular ink passage 7 is extremely strong, unlike when a plurality of ink guide rods are simply used and the gaps between them are used as ink passages. .

The present invention can also be applied, for example, to the case where a spirally extruded monofilament self-bonding material is used as an ink guiding rod.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view of a main part showing an embodiment of the present invention, and FIG. 2 is an enlarged cross-sectional view of a portion of an ink guiding rod. 1... Chip, 5... Ink guide rod, 6... Tip, 7... Irregular ink passage.

Claims (1)

[Scope of utility model registration request] A pipe-shaped tip, a ball rotatably held at the tip end portion of the tip, and a synthetic resin monofilament inserted into the center hole of the tip so that its tip is positioned behind the ball. A pipe-type ballpoint pen body comprising an ink guiding rod made of a self-fusing material, characterized in that the ink guiding rod has an irregular ink passage due to at least a portion of the ink guiding rod being dissolved at least at its tip. body.