JPH07172094A - Chip for ball-point pen - Google Patents

Abstract

PURPOSE:To prevent ink from leaking and unify line width and density of calligraphy by elastically supporting a hard ball mounted in a ball hole with an elastic body and providing a stopper for preventing the hard ball from retracting in the ball hole greater than a certain distance. CONSTITUTION:On a bottom face 31 of a ball hole 3, a ball 6A consisting of a hard ball 62 which has a diameter a little smaller than that of the ball hole 3 and is coated with an elastic material layer 61 is laid. After a hard ball 7 has butted against it, a tip of a cylindrical part 1 is caulked in the central direction so as to adhere the hard ball 7 and a ball hole opening inner peripheral edge 32 to each other. Although the elastic material layer 61 of the ball 6A is flattened a little by writing pressure, as its inside consists of the hard ball 62, the shape of the layer is not deformed anymore after only a fixed distance is changed, so that the distance between the hard ball 7 and the ball hole inner peripheral edge 32 does not become larger than a certain distance. That is, the ball 6A also serves as a stopper.

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ballpoint pen tip. To be more specific, the inner surface of the hard ball and the inner edge of the ball hole opening can be brought into close contact with each other to seal the inner surface. In addition, even if a large writing pressure is applied to the hard ball during writing, it will not retreat for a certain distance or more, so a certain line width and density The present invention relates to a ballpoint pen tip for obtaining handwriting.

2. Description of the Related Art In a conventional ballpoint pen using a tip for a ballpoint pen, in order to prevent ink from leaking or blowing out, a cap provided with a rubber member which adheres to a hard ball at the tip of the tip is inserted into the ballpoint pen, or hot-melt adhesive is applied. An outer surface seal structure has been used in which the tip of the chip is covered with a polymer composition such as an agent. The cap provided with the rubber member inside has a complicated structure and is costly,
The method of coating the tip with the polymer composition is such that the ink leaks when the ballpoint pen reaches the user's hand and starts writing.
There was a problem that the blowout could not be prevented. In order to solve the above-mentioned problems, the applicant has developed a ball-point pen tip capable of sealing an inner surface by elastically supporting a hard ball mounted in a ball hole with an elastic body and sticking the hard ball to the inner peripheral edge of the ball hole opening. A patent application was filed on April 8, 1993.

The invention of the above patent application has no ink leakage or ink ejection, and even if it is used in an ink pressure type ball-point pen, the ink is a gel ink or a low viscosity ink. Even if it is, we provide a ballpoint pen tip that can seal the inner surface with high tightness without ink leakage, but when writing with strong writing pressure, the elastic body is pressed by the hard ball and contracts and deforms, and the hard ball and ball hole opening There is a problem that the gap with the inner peripheral edge becomes large, the amount of outflow of ink becomes large, the line width of the handwriting becomes large, or the density of the handwriting becomes large, and the line width and the density of the handwriting become uneven.

In order to solve the above-mentioned problems, according to the present invention, a hard ball mounted in a ball hole is elastically supported by an elastic body, and the hard ball is brought into close contact with the inner peripheral edge of the ball hole opening portion. A stopper is provided to prevent the hard ball from retracting beyond a certain distance. In the invention of claim 2, the elastic body and the stopper are also made of a hard ball coated with an elastic material layer, and in the invention of claim 3, the elastic body is a spherical body having a diameter smaller than that of the hard ball, and the stopper is the inner circumference of the ball hole. The rib is provided so as to project in the vertical direction.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS.
Explained by. In the figure, A is a barrel, B is a ballpoint pen tip, C is a tail plug, and barrel A is a metal or synthetic resin barrel with a ballpoint tip B at its tip and a tailplug C at its end. Each is closely fitted and contains ink for a ballpoint pen inside the barrel. The ballpoint pen tip B is made by cutting a metal such as stainless steel or injection-molding an engineering resin such as polyacetal resin. A recess 4 is formed at the end, and an ink guide hole 5 is provided between the ball hole 3 and the recess 4. The ink guide hole 5 includes a central hole 51 having a circular cross section and a plurality of radial grooves 52 extending radially from the central hole 51. On the bottom surface 31 of the ball hole 3, a ball 6A composed of a hard ball 62 having a diameter slightly smaller than that of the ball hole 3 and covered with an elastic material layer 61 is placed,
After the hard ball 7 is brought into contact with it, the tip of the tubular portion 1 is caulked in the central direction, and the hard ball 7 and the inner peripheral edge 3 of the ball hole opening 3
Stick 2 together. It is desirable to form a recess 33 in the bottom surface 31 of the ball hole 3 in order to prevent the ball 6 from swinging. The ball-point pen tip B assembled in this manner is press-fitted through the tip opening of the barrel A, and the collar 2 is pressed against the tip of the barrel A. Then, the barrel A with the tip B mounted thereon is inverted, ink is injected, and the tail plug C is press-fitted into the end of the barrel A (upper in the inverted state). In this embodiment, an example in which the elastic body has a spherical shape is shown, but the same effect can be expected even if the elastic body has an appropriate shape such as a cylindrical body. Next, a second embodiment of the present invention will be described with reference to FIG.
And FIG. 4 demonstrates. The difference from the first embodiment is that the ball 6B made of an elastic material has a slightly smaller diameter,
The periphery of B is held by ribs 34 protruding from the peripheral wall of the ball hole 3. The ribs prevent the balls 6B from swinging and also prevent the ink from flowing due to a large diameter. The upper end of the rib 34 is a receiving portion 35 for locking the hard ball 7.
I am trying. The hard ball 7 can retreat by the distance d between the hard ball 7 and the receiving portion 35. The head of the ballpoint pen tip B has a shell-like shape, and the collar portion 2 has a step portion 21.

EFFECT OF THE INVENTION In the ballpoint pen tip of the present invention, since the elastic body elastically supports the hard ball and the hard ball is brought into close contact with the inner peripheral edge of the upper portion of the ball hole, even when used in an ink pressure type ballpoint pen, Even if the ink is not only gel-like ink but also low-viscosity water-based ink or oil-based ink, the hard ball and the inner peripheral edge of the upper part of the ball hole surely adhere,
Since the inner surface is sealed, even if the ball-point pen is impacted by dropping or shaking, there is no ink leakage or blowout even in an environment with low atmospheric pressure such as in high mountains, and the finger is dirty and the writing surface is dirty. There is no accident. Since the inner surface of the ball has a great sealing effect, there is no need for parts or processes to seal the outer surface, and there is no risk of water or solvent in the ink volatilizing and fading, making writing impossible. When a large writing pressure is applied to the hard ball 7, the hard ball 7 retracts and the writing pressure is transmitted to the elastic body. (1) In the case of the first embodiment, the elastic material layer 61 of the ball 6A is It deforms to a flat shape due to the writing pressure, but since it is a hard ball 62 inside it, it will no longer deform if it is deformed by a certain distance, so the distance between the hard ball 7 and the ball hole inner peripheral edge 32 is greater than a certain amount. I won't. That is, the ball 6A also functions as a stopper. (2) In the case of the second embodiment, when the hard ball 7 retreats by the distance d, it comes into contact with the receiving portion 35 of the rib 34 and does not retreat anymore. Therefore, the distance between the hard ball 7 and the ball hole inner peripheral line 32 is equal to or more than a certain value. Does not grow to Therefore, even if a large writing pressure is applied to the hard ball during writing, the outflow amount of the ink will not be excessive and the line width of the handwriting will not be large or the density will not be large. Therefore, it is convenient to use in a so-called capless ballpoint pen.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a ballpoint pen equipped with a tip for a ballpoint pen according to a first embodiment.

FIG. 2 is a cross-sectional view taken along line XX of FIG.

FIG. 3 is a vertical cross-sectional view of a ballpoint pen tip according to a second embodiment.

4 is a horizontal cross-sectional view taken along line YY of FIG.

[Explanation of symbols]

 A shaft cylinder B tip for ballpoint pen C tail plug 1 cylinder part 2 flange part 21 step part 3 ball hole 31 bottom surface 32 opening inner peripheral edge 33 recessed part 34 rib 35 receiving part 4 recessed part 5 ink guide hole 51 center hole 52 radial groove 6A elastic material Hard ball with layer overlaid 6B Sphere made of elastic material 61 Elastic material layer 62 Hard ball 7 Hard ball

Claims (3)

[Claims] 1. A hard ball 7 mounted in a ball hole 3 is elastically supported by an elastic body, and the hard ball 7 is fixed to the inner peripheral edge 3 of the ball hole opening.
A tip for a ball-point pen, which is provided with a stopper which is closely attached to the ball hole 2 and prevents the hard ball 7 from retreating for a predetermined distance or more in the ball hole 3. 2. The tip for a ball-point pen according to claim 1, wherein the elastic body and the stopper also serve as the hard ball 6A having the elastic material layer coated thereon. 3. The tip for a ball-point pen according to claim 1, wherein the elastic body is a spherical body 6B having a diameter smaller than that of the hard ball 7, and the stopper is a rib protruding vertically on the inner circumference of the ball hole 3.