JPH02306Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to the tip of a ballpoint pen that uses ink that is ejected by capillary force, and is aimed at achieving good ink ejection properties.

In conventional ballpoint pens, using a coil spring to provide sliding force to the ball is
For example, as disclosed in Japanese Utility Model Publication No. 52-10977, coil springs have poor ink retention properties and cannot be practically used except for raw ink type writing instruments that use pen cores (so-called bellows).

The present invention has been made in view of the above-mentioned points, and will be explained below based on the attached drawings.In Fig. 1 showing an embodiment of the present invention, reference numeral 1 indicates a pipe-shaped chip made of a hard material such as stainless steel. The diameter of the center hole 1a of the pipe-shaped chip 1 is reduced, and a small end portion 1b is filled with resin such as polyacetal or polyamide, cemented carbide, ruby, etc.
A ball 2 made of glass, ceramic, etc. is held so that its tip protrudes. Further, reference numeral 3 is a chip holder to which the pipe-shaped chip is attached, and its center hole 3
A is a rod-shaped body 4 made of ceramic, metal such as stainless steel, synthetic resin such as polyacetal, polyamide, acrylic resin, etc., and has appropriate ink flow passages inside and outside; urethane, SBR (styrene, butadiene rubber), NBR
Porous elastic liquid-containing material 5 made of materials such as (nitrile-butadiene rubber); fiber bundles, sintered bodies of synthetic resins, metals, or their oxides, monofilament self-fused products of synthetic resins, etc. Ink guiding member 6 made of something that looks like dirt
are inserted sequentially.

Here, the center hole 1a of the pipe-like tip 1 has a diameter at least at its tip so as not to prevent the ball 2 from moving backward until its tip becomes flush with the tip of the pipe-like tip 1. The diameter of the center hole 3a of the tip holder 3 is larger than that of the ball 2, and the rod-shaped body 4 is loosely inserted so that sliding inside the pipe-shaped tip 1 is not hindered. However, the ink guide member 6 is formed by press-fitting, adhesion, fusing, or other means so that the elastic liquid-containing member 5 does not move backward as a reaction force when the elastic liquid-containing member 5 urges the ball 2 forward via the rod-shaped body 4. It is fixed to the chip 3 by any means such as position fixing via a separate body.

In the figure, the rear end 4a of the rod-like body 4 is a bulge, but this is mainly intended to prevent the rod-like body 4 from sinking into the elastic liquid-containing 5.
Further, reference numeral 7 indicates the tip of the barrel to which the tip holder 3 is attached, but this is also outside the scope of the present invention, as it may be integrated with the tip holder 3. The description will be omitted.

Now, when using the ballpoint pen nib of the present invention as a ballpoint pen, regardless of the structure of the ink chamber such as a raw ink type or a medium line absorber type, the ink is guided to the elastic liquid-containing liquid 5 by the ink guiding member 6. The ink is temporarily retained by the elastic liquid-containing material 5. On the other hand, the ball 2, which slides when it comes into contact with a writing surface such as a paper surface, can transfer force from the writing surface to the rod 4 even when writing diagonally (when the rod 4 is not perpendicular to the writing surface). , the elastic liquid-containing material 5 is contracted or restored via the rod-shaped body 4. As a result, the ink held in the elastic liquid-containing member 5 is discharged when the elastic liquid-containing member 5 contracts, and the ink is discharged from the gap between the rod-shaped body 4 and the center hole 1a of the pipe-shaped chip 1, and in some cases, the ink is The ink passes through the ink flow path formed in the ink flow path, and finally moves to the writing surface.
When the elastic liquid-containing material 5 is restored, new ink is supplied to the elastic liquid-containing material 5 from the ink guiding member 6.

Here, the capillary force in the ink flow path formed by the rod-shaped body 4 and the center hole 1a of the pipe-shaped chip 1 or the ink flow path formed in the rod-shaped body 4 is such that the elastic liquid-containing 5 does not contract. Although it is desirable that the ink retention force be stronger than that of First, by applying extreme capillary force to the ink flow path formed by the rod-shaped body 4 and the central hole 1a of the pipe-shaped chip 1, the ink dischargeability is improved. The situation where there is a shortage of these items can be completely avoided.

In addition, in the present invention, the elastic force of the elastic liquid-containing 5 is not inherently limited in any way as long as the elastic liquid-containing 5 can change its volume due to pressure during writing, but the elastic force of the elastic liquid-containing 5 is not limited in any way, but The larger the distance, the larger the change in the volume of the elastic liquid-containing liquid 5, which can suppress ball flying (a phenomenon in which the ball 2 comes off the tip of the pipe-shaped tip 1), and also prevent the rod-shaped body 4 from moving due to friction with the ball 2. There is less wear (of course,
Compared to the case where the ball 2 is not present and the rod-like body 4 protrudes directly from the tip of the pipe and is subject to wear from the writing surface, the wear on the rod-like body 4 is greater when the ball 2 is present for the same elastic force. There are few. ), and since it can be used not only for general writing but also for vertical writing, line drawing, and drafting, it is preferable that the ball 2 be as small as possible. 10g at a time
Hereinafter, it should be noted that it is sufficient to set the weight to be 50 g or less even when the ball 2 is displaced backward until it becomes flush with the pipe-shaped tip.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view of a main part showing an embodiment of the present invention. 1... Pipe-shaped tip, 1b... Tip small part,
2... Ball, 3... Chip holder, 3a...
central hole, 4... rod-shaped body, 5... elastic liquid-containing material, 6...
...Ink guide member.

Claims (1)

[Scope of utility model registration request] A synthetic resin rod-like body whose tip abuts against the rear side of the ball is inserted into the center hole of a tip holder equipped with a pipe-like tip that holds a ball at its tip end, and the ball is moved forward through the rod-like body. An elastic liquid-containing material for urging and an ink guiding member for connecting the elastic liquid-containing material to the ink are sequentially inserted, and at least the tip of the ball is displaced backward until its tip is flush with the tip of the pipe-shaped tip. A ballpoint pen nib portion formed by forming the diameter of the center hole of the pipe-shaped tip at least at the tip portion to be larger than the diameter of the ball so as not to interfere with the ball.