JPH0737681U - Ballpoint pen tip - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent the pipe from bending and wobbling during writing. [Structure] A ball 3 is rotatably held by the tip of a metal pipe 2. The pipe 2 is press-fitted and fixed to the tip of the synthetic resin holder 7. The metal base 4 is fixed to the holder 7. The base 4 covers the outer peripheral surface of the pipe 2.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a ballpoint pen tip. More specifically, the present invention relates to a ball-point pen tip portion in which a ball is rotatably held at the tip of a metal pipe, and the pipe is press-fitted and fixed to the tip of a synthetic resin holder.

[0002]

[Prior art]

 In a conventional ballpoint pen of this type, for example, Japanese Utility Model Publication No. 63-10310 discloses a structure in which a metal pipe chip having a ball rotatably held at its tip is fixed to a front part of a chip holder made of resin or the like. Has been done.

[0003]

[Problems to be solved by the device]

 Normally, a ballpoint pen is used in a tilted state, not perpendicular to the writing surface, when writing by hand, so a large bending stress is applied to the pen tip by the writing pressure. Therefore, in the conventional pipe type ball-point pen described above, the pipe may be bent due to a large writing pressure during writing.

Further, when the holder is made of synthetic resin, the fixing force between the holder and the pipe tends to loosen due to aging and the like, and the pipe largely wobbles during writing, which gives an unstable writing feeling.

The present invention solves the above-mentioned conventional problems, and the pipe bends due to a large writing pressure during writing, or the pipe wobbles greatly during writing, giving an unstable writing feeling. There is no ballpoint pen tip to provide.

[0006]

[Means for Solving the Problems]

 The present invention is a ball-point pen tip portion 1 in which a ball 3 is rotatably held at the tip of a metal pipe 2 and the pipe 2 is press-fitted and fixed to the tip of a synthetic resin holder 7. It is required that the mouthpiece 4 is fixed to the holder 7 and that the mouthpiece 4 covers the outer peripheral surface of the pipe 2 behind the ball 3 holding portion.

In the above structure, a mounting hole 61 is provided in the rear portion of the mouthpiece 4, a guide hole 51 is provided in the front portion of the mouthpiece 4, and the outer periphery of the tip end portion of the holder 7 is fitted into the mounting hole 61 and the guide hole is formed. It is effective to allow the pipe 2 to pass through 51. In addition, in addition to this, the base 4 is press-fitted into the inner wall of the center hole of the tip of the holder 7, the outer peripheral surface of the pipe 2 is fitted or closely contacted with the base 4, or an ink guide member is arranged in the pipe 2. A configuration or the like to be installed is also possible.

The position where the mouthpiece 4 covers the outer peripheral surface of the pipe 2 is most effective near the ball 3 holding portion, but may be near the holder 7 as long as the pipe 2 has bending strength. .

[0009]

[Action]

 Since the metal cap 4 covers the outer peripheral surface of the pipe 2 behind the ball 3 holding portion, when a bending stress is applied to the pipe 2 during writing, the base 4 supports the outer peripheral surface of the pipe 2. As a result, the bending of the pipe 2 due to a large writing pressure during writing and the large wobble of the pipe 2 during writing can be prevented.

By the structure in which the outer periphery of the tip of the holder 7 is fitted into the mounting hole 61 at the rear of the base 4, the fixed state of the pipe 2 and the tip of the holder 7 is strengthened, and the bending of the pipe 2 is further enhanced. The wobble of the pipe 2 is suppressed. Further, in the structure in which the pipe 2 is loosely inserted into the guide hole 51 in the front portion of the mouthpiece 4, the guide hole 51 supports the outer peripheral surface of the pipe 2 at the time of writing, and of course, the pipe 2 and the mouthpiece 4 are assembled at the time of assembly. Since they are not fitted to each other, the pipe 2 and the base 4 can be smoothly attached to the holder 7, and the center deviation between the guide hole 51 and the pipe 2 is absorbed.

[0011]

Embodiments of the present invention will be described with reference to the drawings.

1 to 3 show a first embodiment of the present invention. A center hole 71 is formed through the tip of the holder 7 made of polyacetal resin, and the metal pipe 2 is press-fitted into the center hole 71. On the other hand, four axial protrusions 72 are formed on the outer periphery of the tip of the holder 7, and the metal cap 4 is fitted onto the protrusions 72.

The pipe 2 (outer diameter 0.5 mm, inner diameter 0.3 mm) is made of stainless steel, and the ball 3 (outer diameter 0.3 mm) is rotatably held by crimping the tip.

The base 4 is made of brass, has a nickel-plated layer on the surface thereof, and has a pipe-shaped small-diameter portion 5 having a guide hole 51 formed therein, and a large-diameter portion having a mounting hole 61. The part 6 is integrally configured. The inner diameter of the guide hole 51 is formed to be slightly smaller than the outer diameter of the pipe 2, and the play between the guide hole 51 and the outer periphery of the pipe 2 is set within a range of about 0.01 mm to 0.1 mm. . Further, a spiral groove 62 is formed by tapping on the inner peripheral surface of the mounting hole 61, and when the tip of the holder 7 is press-fitted into the mounting hole 61, the groove 62 is located on the outer periphery of the tip of the holder 7. The projection 72 is bite-fitted and fitted. This enables the holder 7 and the base 4 to be firmly fixed to each other without coming off easily.

FIG. 4 shows a second embodiment. The base 4 is formed by cutting with brass, and is integrally configured by a tapered small diameter portion 5 having a guide hole 51 and a large diameter portion 6 having a mounting hole 61, and a nickel plating layer is provided on the surface. . The mounting hole 61 is fitted to the outer periphery of the tip of the holder 7. Similar to the first embodiment, the fitting structure is a bite fitting between the spiral groove 62 on the inner peripheral surface of the mounting hole 61 and the four axial ridges 72 on the outer periphery of the tip of the holder 7. . On the other hand, the guide hole 51 is located near the tip of the holder 7 and exposes the pipe 2 behind the ball 3 holding portion relatively long. In this embodiment, the pipe 2 having an outer diameter of 0.7 mm and an inner diameter of 0.5 mm is adopted and has a bending strength higher than that of the first embodiment. A sufficient bending prevention effect can be obtained. The other configurations and operations are the same as those in the first embodiment.

FIG. 5 shows a third embodiment. The metal base 4 is pipe-shaped, and the pipe 2 (holding the ball 3 at the tip) is loosely inserted into the inner hole 41, and the rear end is press-fitted and fixed to the center hole 71 at the tip of the holder 7. There is. The operation effect and other configurations are the same as those in the first embodiment.

[0017]

[Effect of device]

 Since the tip of the ballpoint pen of the present invention has the above-described structure, the pipe is not bent due to a large writing pressure during writing, and the pipe does not wobble greatly during writing, which gives an unstable writing feeling.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a first embodiment of the present invention.

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

FIG. 3 is a vertical sectional view of the die of FIG.

FIG. 4 is a vertical sectional view of a second embodiment.

FIG. 5 is a vertical sectional view of a third embodiment.

[Explanation of symbols]

 1 Ballpoint Pen Tip 2 Pipe 3 Ball 4 Base 5 Small Diameter 51 Guide Hole 6 Large Diameter 61 Mounting Hole 62 Groove 7 Holder 71 Center Hole 72 Projection

Claims (2)

[Scope of utility model registration request] 1. A ball 3 is rotatably held by a tip of a metal pipe 2, and the pipe 2 is made of a synthetic resin holder 7.
At the tip of the ballpoint pen that is press-fitted and fixed to the tip of
A tip of a ballpoint pen, characterized in that a metal base 4 is fixed to a holder 7, and the base 4 covers the outer peripheral surface of the pipe 2 behind the ball 3 holding part. 2. A mounting hole 61 is provided at a rear portion of the base 4 and a guide hole 51 is provided at a front portion of the base 4, and the mounting hole 61 is provided.
The outer periphery of the tip of the holder 7 is fitted to the guide hole 5
2. The ball-point pen tip portion according to claim 1, wherein the pipe 2 is allowed to penetrate through the pipe 1.