JPS6126079Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a ballpoint pen tip in which a thin synthetic resin receiving layer is formed on a metal ball seat.

In a ballpoint pen tip using water-soluble ink, forming the ball seat by caulking a part of the metal pipe on three sides, etc.
This is a conventionally known method. However, due to the direct sliding contact between the ball and the ball seat, an unpleasant squeaking sound is generated when writing, and writing lines are often not continuous because the ball does not rotate smoothly. However, if the ball seat is made of only synthetic resin such as polyacetal or polyamide, it will undergo plastic deformation that increases the sinking of the ball while receiving strong writing pressure. The gap between him and the ball was too large, resulting in a victory. The above-mentioned disadvantages may be overcome by forming a thin synthetic resin receiving layer on the metallic ball seat. However, if you insert a thin and small synthetic resin sheet from the front of the metal pipe and spread it evenly over the ball seat,
The effort required for this is extremely difficult, and it is expected that there will be large variations in accuracy. In addition, it is necessary to devise a method to prevent the sheet from rotating due to the rotation of the ball, so its practicality is extremely poor. It was all I could do.

Therefore, the purpose of the present invention is to form a thin synthetic resin receiving layer on a metal ball seat with as little effort as possible, with uniform precision, and with special To provide a ballpoint pen tip that does not require a tangling prevention means.

The present invention will be described with reference to an embodiment shown in the accompanying drawings. By constricting a part of a metal pipe 1 such as stainless steel into a pleat shape, the pleat-shaped opening 2a
A curved ball seat part 3 is formed which is continuous with the through hole 2 which is arranged radially, and a flanged protrusion 5 at the front end of the synthetic resin ink lead-out core 4 which is inserted into the through hole 2 and extends. It is fitted into and locked into a part of each pleated opening 2a by thermocompression bonding, and is also in close contact with the curved ball seat portion 3. Of course, the length of the synthetic resin ink lead-out wick 4 is arbitrary, and other simple rod-shaped ink lead-out wicks are arranged rearward in series so that they are not affected by the heat during thermocompression bonding. You can also do that. In the figure, 6 indicates a ball, and 7 indicates a tip end portion.

By the way, referring to the method of thermocompression bonding, for example, a heating pin whose tip has a curvature that matches the curvature of the ball 6 is inserted from the front of the metal pipe 1, and then inserted into the flanged protrusion 5 of the ink lead-out core 4. If pressed, the flanged protrusion 5 can be immediately deformed. Also, at this time, it is best to keep the temperature of the heating pin as low as possible and actively use pressure. Alternatively, after the ball 6 is placed in the metal pipe 1, pressure and heat may be applied from the outside via the ball 6.

The effects of the above-mentioned configuration will be described below. In the present invention, the flanged protrusion 5 for forming a thin synthetic resin receiving layer on the metal ball receiving portion 3 is a synthetic resin ink guide. Since it is formed at the front end of the core 4, when the ink lead-out core 4 is inserted from the tip of the metal pipe 1, the flanged protrusion 5 is immediately inserted, which saves time and effort regardless of the thickness of the flanged protrusion 5. be able to. Moreover, since the part of the flanged protrusion 5 that overlaps a part of each pleated opening 2a is fitted and locked by thermocompression bonding, entanglement can be prevented reliably and easily. Further, as described above, only a portion of each fold-shaped opening 2a is clogged by the flanged protrusion 5, and the remaining portion remains open (see FIG. 3), so that the ink is not obstructed from being discharged. Furthermore, since the ball is closely attached to the ball receiving seat part 3 by heat-pressing, it is possible to create a very thin resin layer, so even if the ball is used with strong writing pressure, the ball 6 will not sink excessively, and the ball 6 will be received. It is possible to form curved surfaces with uniform precision, and ink runoff over time is also improved.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of the ballpoint pen tip of the present invention, Fig. 2 is a sectional view taken along the - line in Fig. 1, and Fig. 3 is a sectional view taken along the - line in Fig. 1 and viewed in the direction of the arrow. be. DESCRIPTION OF SYMBOLS 1...Metal pipe, 2...Through hole, 2a...Fold-shaped opening, 3...Ball receiver, 4...Ink lead-out core, 5...Flame-shaped protrusion.

Claims (1)

[Scope of utility model registration request] By constricting a part of the metal pipe 1 into a pleated shape, a curved ball seat portion 3 is formed which is continuous with the through hole 2 in which the pleated openings 2a are arranged radially.
The flanged protrusion 5 at the front end of the synthetic resin ink lead-out wick 4 that is inserted into the through hole 2 and extended is fitted and locked into a part of each pleated opening 2a by thermocompression bonding, and the curved ball A ballpoint pen tip that is in close contact with the seat part 3.