JPS641101Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a ballpoint pen tip for water-based ink, and more particularly to a ballpoint pen tip made of a processed metal pipe and applied to a ballpoint pen using low-viscosity water-based ink.

Conventional technology Ballpoint pen tips that have ball holding parts, ink guide grooves, etc. formed inside them by molding conventional synthetic resins have the disadvantage that the ball tends to fall off when subjected to strong writing pressure due to the plasticity of the synthetic resin. .
Further, ballpoint pen tips made by cutting and forming metal materials are made of metals such as nickel silver from the viewpoint of machinability, but they have drawbacks such as poor wear resistance and susceptibility to corrosion by water-based inks. On the other hand, stainless steel, which has excellent wear resistance and corrosion resistance, has poor machinability and is difficult to put into practical use.

In addition, in a conventional ballpoint pen tip for water-based ink, the structure of the ball seat is such that in the cross section, a center hole and a plurality of ink grooves communicating with the center hole and extending radially are formed to penetrate in the axial direction. Generally, the diameter of the hole is larger than the width of the radial groove. For this reason, the capillary force of the center hole is relatively weaker than that of the surrounding radial grooves, so when replenishing the ink consumed from the nib during writing, ink is preferentially supplied to the periphery of the ball from the center of the back of the ball, The center becomes hollow and air flows into it, causing broken or blurred handwriting, or the axial ink column in the center hole breaks due to the impact that the pen encounters during normal use. This often caused ink to run out.

Problems to be Solved by the Invention The present invention aims to provide a ballpoint pen tip for water-based ink that solves the above-mentioned drawbacks.

Means to Solve the Problem The ballpoint pen tip of the present invention has a configuration in which an ink guide core is combined with a ball holder obtained by deforming a pipe made of a metal material such as stainless steel, which has wear resistance and corrosion resistance. be.

The details of the configuration will be explained below.

The ball holder of the ballpoint pen tip of the present invention has a corresponding number of recesses formed near the tip of the metal pipe by pressing deformation in the axial direction from three or more locations on the outer surface at approximately the same position in the axial direction. The recessed portion is a chevron-shaped protrusion that protrudes toward the axis inside the pipe, and each of the peaks of the protrusion is spaced apart from each other by a capillary size in a cross section, and is aligned with the axis. A central hole is formed by surrounding the axis of a regular polygon with the protruding portions at the center, and a gap having a width approximately equal to one side of the regular polygon is formed between the protrusions and communicating with the central hole. The ball is rotatably held in the tip of the pipe with the front surface of the protruding portion acting as a ball receiving seat.

A tip of a rod-shaped ink guide core having an end surface having a diameter larger than the diameter of the center hole is inserted into the rear pipe of the ball holder with the end surface abutting the rear surface of the protrusion, and the ball and ink guide core are inserted into the rear pipe of the ball holder. A gap between the center hole and the protruding portion is maintained slightly in the axial direction as an ink reservoir and an ink passage between the end surface of the core, and
The ballpoint pen tip of the present invention is constructed.

The recesses are formed in an appropriate number of three or more depending on the diameter of the ball. Here, the capillary size is approximately 0.01
The range is from mm to 0.3 mm.

The balls used are made of materials such as cemented carbide, ruby, and stainless steel, and the ink guide cores are resin processed fiber bundles, rod-shaped synthetic resin molded bodies with axial capillary grooves formed inside, and rod-shaped. open-cell plastic porous bodies, rod-shaped bodies with axial slits, and other striated bodies.

Function In the water-based ink ballpoint pen using the tip of the present invention, ink supplied from the ink storage section inside the barrel is guided to the rear surface of the protruding part of the ball holder through the ink guide core, and the ink is guided between the center hole and the protruding part. Capillary action in the interstices fills those spaces and is supplied to the writing surface by the rotation of the ball. In this case, since the width of the gap is approximately equal to one side of the regular polygon formed by the tops of the peaks of the protrusions surrounding the center hole, the ink is uniformly distributed from the entire cross section of the ink passage leading to the back of the ball. is supplied to This prevents air from flowing into the center hole or the gap during writing, and allows continuous ink to flow out from the pen tip.

In this way, the center hole and the gap between the protrusions are essential as a means for supplying ink to the balls by keeping ink always present between the ball seats and the balls, and the amount of ink supplied to the ball seats is It is regulated by the total area in the cross section of the center hole and the gap between the protrusions. In order to ensure a sufficient amount of ink supply, it is preferable to increase the total area, but on the other hand, increasing the center hole or widening the gap between the protrusions weakens their capillary action. . In ballpoint pens that use water-based ink with low viscosity, if the capillary action of the ink passage in the pen tip is weak, the ink may flow continuously in the axial direction in the ink passage due to the introduction of air due to the rotation of the ball during writing, impact applied to the pen, etc. The pillars are divided and the ink tends to run out. An effective means for ensuring the ink holding power of the ink passage and sufficient ink supply so that ink does not run out during normal use is to make the length of the ink passage in the axial direction as short as possible. Considering this reason and the manufacturing means for forming the sloping ball seat, the protrusion in the pipe formed by the recess should have a chevron shape to satisfy both of the above conditions.

Embodiment An embodiment of the ballpoint pen tip of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a front view of the ballpoint pen tip of the present invention, FIG. 2 is a longitudinal sectional view of the same, and FIG.
4 is a cross-sectional view taken along line A-A in the figure, and FIG. 4 is a longitudinal cross-sectional view taken along line B-B in FIG. 3, with the balls and ink guide cores omitted; 3 represents a ball, a pipe, and a recess, respectively. Each of the four recesses 3 is a chevron-shaped protrusion 3' that protrudes toward the axis inside the pipe.
Each of the peaks of the protruding portion is spaced apart from each other by a capillary size in a cross section, and surrounds the axis in a regular polygonal shape to form a central hole 4, A gap 5 is formed between the protrusions, communicating with the center hole and having a width approximately equal to one side of the regular polygon. A ball 1 is rotatably held in the tip of the pipe 2 using the front surface 7 of the protrusion 3' as a ball receiving seat, and a rod-shaped ink guiding core having an end surface with a larger diameter than the center hole is provided in the rear part of the pipe. 6 connects the end surface to the rear surface 8 of the protrusion 3'.
It is inserted in contact with the Thus, between the ball and the ink guiding wick an ink reservoir and an ink passage consisting of a small central hole 4 and a gap 5 between the projections is maintained.

Effects of the invention As described above, although it is difficult to form by cutting, this invention combines a metal material such as stainless steel with excellent wear resistance and corrosion resistance with a deformation process from a pipe material and an ink guiding core. By having the above structure, it is possible to apply the present invention to a ballpoint pen tip using a low viscosity water-based ink.

In addition, as mentioned above, the center hole formed in the ball seat and the gap between the protrusions, which serve as the ink supply path to the back of the ball, are capillary-sized with approximately the same diameter and width, so this chip is applied. When writing with a water-based ink ballpoint pen, the center hole and the gap between the protrusions draw out ink from the ink guiding core through capillary action at a speed corresponding to the consumption of ink from the pen tip due to the rotation of the ball, and spread it over the entire back of the ball. It serves the function of supplying water evenly. As a result, ink may run out while writing,
Handwriting never becomes blurred. Further, since the ink supply channels to the back of the ball are all capillary sizes of approximately the same width, the ink will not run out under the impact normally encountered by writing instruments.

[Brief explanation of the drawing]

FIG. 1 is a front view of the ballpoint pen tip of the present invention, FIG. 2 is a longitudinal cross-sectional view of the ballpoint pen tip of FIG. 1, and FIG. 3 is a cross-sectional view taken along line A-A of FIG. FIG. 4 is a longitudinal sectional view taken along the line B--B in FIG. 3, with the ball and ink guiding core omitted. 1...ball, 2...pipe, 3...recess,
3'... Protrusion, 4... Center hole, 5... Gap, 6
...Ink guide core, 7... Front surface of the protrusion, 8... Rear surface of the protrusion.

Claims (1)

[Scope of utility model registration request] Near the end of the metal pipe, three or more places on the outer surface at approximately the same position in the axial direction are pressed and deformed in the centripetal direction to form a recess that serves as a ball receiving seat, and the pipe end is bent to hold the ball. In the ballpoint pen tip, the recess 3 is a chevron-shaped protrusion 3' that protrudes toward the axis inside the pipe.
Each of the peaks of the protruding portion is spaced apart from each other by a capillary size in a cross section, and surrounds the axis in a regular polygonal shape to form a central hole 4, A gap 5 having a width approximately equal to one side of the regular polygon is formed between the protrusions and communicating with the center hole, and a gap 5 having a diameter larger than the center hole is formed from the end of the pipe opposite to the ball. A ballpoint pen tip for water-based ink, in which a rod-shaped ink guide core 6 having an end surface is inserted into a pipe with the end surface abutting the rear surface 8 of the protrusion.