JPH0852978A - Ball-point pen - Google Patents

Abstract

PURPOSE:To smoothly perform a handwriting having uniform density even when writing with low angle by a method wherein each of angle relationships of two fixing sections formed on a reduced diameter section in a tapered face of a ball-point pen tip, a diameter and a projection height of a ball and a distance relationship thereof with an opening secion of the tip are specified. CONSTITUTION:A ball-point pen tip A is so constituted that a reduced diameter section 2 is formed on a tip of a tapered face 1 and an ink passage 3 of an inner section thereof is opened to a ball holding chamber 7. A ball 8 is held in the ball holding chamber 7 and the ball 8 is projected from a tip opening section 10 of the reduced diameter section 2. In this case, equations of gamma+10 deg.<=beta<=gamma +40 deg. and beta10 deg.<=alpha<=beta+40 deg. are satisfied with respect to the reduced diameter while an angle of a first fixing section 2a in the tip side is designated as (alpha), an angle of a succeeding second fixing section 2b as (beta) and an angle of the tapered face 1 as (gamma). On the other hand, equations of 0.25D<=h<=0.35D and 0.007mm <=t<= 0.30mm are satisfied while a diameter of the ball 8 is designated as (D), a projection height as (h) and a distance between the ball 8 and tip opening section 10 as (t).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bob which is a part of an ink passage, in which a tapered portion is formed by caulking inward a leading edge portion of a taper surface which is reduced in diameter toward the leading end. The present invention relates to a ball pen tip in which a ball as a writing member is held in the ball holding portion while partially protruding from the opening.

[0002]

2. Description of the Related Art Ball pens have hitherto been designed so that they can be written mainly at a writing angle in the range of 90 ° to 50 °. However, when writing Arabic characters or English letters, sometimes they are written at a writing angle lower than usual, and there has been a demand for a ball-point pen capable of writing with clear handwriting even at a low writing angle.

[0003]

In order to write at a low writing angle, it is necessary that the tip edge portion of the ball-point pen tip is not scratched by a writing object such as paper. Therefore, even when writing at a low writing angle, a ball other than the ball is used.
It suffices that the tip of the rupen tip does not come into contact with the writing surface. In order to prevent the tip of the ball-pen tip from coming into contact with the writing surface, the caulking angle of the reduced diameter part that prevents the ball from jumping out should be set to a small angle or the tip of the ball-tip tip should be made thin. It is possible.
However, in order to obtain the necessary amount of diameter reduction to hold the ball by thinning the thickness of the tip part or reducing the caulking angle of the tip end part, when processing with a large caulking angle It has to be processed with a large amount of deformation compared to. This adversely affects the inner surface of the reduced diameter portion corresponding to the caulking portion of the ink passage, and the tip shape of the fore edge tends to be non-uniform, which hinders the uniform supply of ink to the writing surface. When the handwriting is shaded due to obstacles such as even rotation of the tool, and the tip shape of the forehead is uneven, a portion that extends beyond the tip side is formed more than necessary. Therefore, there is a problem in that it easily comes into contact with the writing surface at a low writing angle.

[0004]

According to the present invention, a reduced diameter portion is formed by caulking inwardly a leading edge portion of a taper surface that is reduced in diameter toward the leading end, and is a part of an ink passage. BO
In a ball pen tip in which a ball as a writing member is held in the ball holding portion while partially protruding from the opening, the reduced diameter portion has a first crimping portion and a second crimping portion having different crimping angles. The first crimping portion on the front edge side has a crimping angle of α, a second crimping angle of β, a taper surface reduction angle of γ, and the diameter of the ball is D Assuming that the height of the ball protruding from the opening is h, and the distance between the outer shape of the tip fore edge portion and the outer shape of the ball in the opening is t, the following (Equation 5) to (Equation 5) to (Equation 5) A gist of a ballpoint pen tip satisfying the expression (8).

[0005]

[Formula 5] 0.25D ≦ h ≦ 0.35D

[0006]

[Formula 6] 0.007 mm ≤ t ≤ 0.030 mm

[0007]

[Formula 7] γ + 10 ° ≦ β ≦ γ + 40 °

[0008]

[Formula 8] β + 10 ° ≦ α ≦ β + 40 ° is a gist.

[0009]

In order to prevent the edge of the ball-point pen tip from coming into contact with the surface to be written even when writing at a low writing angle, the ball protrusion height (h) and the outer shape of the tip fore edge portion in the opening are provided. It suffices to adjust the distance (t) and the caulking angle between the ball and the outer shape of the ball. The length of t such that the tip edge portion of at least the opening of the ball-pen tip does not contact the writing surface is determined by the writing angle (θ), the diameter (D) of the ball, and the ball protrusion height (h). ) Changes. The distance (t) between the outer shape of the tip edge portion and the outer shape of the ball in the opening is defined by the writing angle (θ) and the ball.
The formula (9) below is expressed by the diameter (D) of the ball and the height (h) of the ball. The writing angle (θ) referred to here is the minimum desired writing angle among the angles formed by the longitudinal direction of the writing instrument and the writing surface.

[0010]

[Formula 9]

However, in order to prevent the ball from slipping off by forming the reduced diameter portion by crimping the fore end portion of the ball pen tip, ink is supplied to the inner wall of the ball holding portion. It has the meaning of forming a control part. The ink supply control portion adjusts the pressing force of the caulking process to bring the inner wall of the ball holding portion into contact with the ball,
A part of the inner wall of the ball holding part is provided around a part which is smooth and has a uniform clearance with the ball. This portion serves to uniformly and easily apply the ink to the surface of the ball, and to uniformly supply the ink on the ball to the writing surface (hereinafter, this ball holding portion will be described later). A smooth portion surrounding the inner wall and having a uniform clearance with the ball is called an ink control section). That is, by surrounding the ink control unit, it is possible to obtain a handwriting with a uniform density that is not affected by the writing direction and the writing angle as much as possible. As a result of intensive studies, the inventors of the present invention have an effect of being able to obtain a handwriting with a uniform density that is not affected by the writing direction and the writing angle of the ink control section as much as possible, and form the shape of the tip portion of the ball pen tip uniformly. That is, it was found that the caulking angle of the tip fore edge of the ball-point pen tip is greatly affected, and even when writing at a low writing angle, it is possible to obtain a beautiful handwriting with uniform light and shade without getting caught on the writing surface. I got a rupen tip.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An example will be described below with reference to the drawings. As shown in FIG. 1, which is a cross-sectional view of a main part of the ball-point pen tip A of the present invention, the ball-point pen tip A has a taper surface 1 whose diameter decreases in the tip direction (upward direction in the drawing). By crimping the tip of the taper surface 1 inward, the reduced diameter portion 2
Has been formed. The ink passage 3 is formed as a communication hole in the ball pen tip A.
Has a plurality of inward projections 4 having ball receiving seats 4a.
The central hole 5 and the ink groove 6 having a reduced diameter are formed by
Further, a center hole 5 and an ink groove 6 are opened in the ball holding chamber 7 formed by the inward protruding portion 4. Ball 8
Is held in the ball holding chamber 7 while being prevented from popping out by the diameter-reduced portion 2, and has its tip portion projected from the tip opening 9 of the diameter-reduced portion 2. Ball 8 from this tip opening 9
The protruding distance h is the height of the ball.

The reduced diameter portion 2 has two kinds of caulking portions having different caulking angles. The first caulking portion 2a on the tip side and the second caulking portion 2b continuous with the first caulking portion 2a. When the taper angle of the taper surface 1 (angle of reduction of the taper surface) is γ, the caulking angle of the first caulking portion 2a is α, and the caulking angle of the second caulking portion 2b is β, γ +
10 ° ≦ β ≦ γ + 40 °, β + 10 ° ≦ α ≦ β + 40 °
It is designed to be. Substantially 0 ° ≦ γ, α <1
Since it is 80 °, 20 ° ≦ α <180 °, 10 °
≦ β <140 °, 0 ° ≦ γ <100 °. The ball-pen tip A shown has α = about 80 °, β = about 50 °, γ
= About 30 °, h = about 0.200 mm, D = about 0.7 m
m, t = about 0.020 mm is shown.

The ink control portion 10, which corresponds to the reduced diameter portion 2 of the ball holding chamber 7, is a portion which is pressed around the ball 8 and is circumferentially provided at the time of caulking, and is smooth and has a ball shape. It has a uniform clearance with the cable. The smoothness of the ink control unit 10 facilitates the movement of the ink and also makes it easy to ride the ink on the ball. In addition, the fact that the ink control unit 10 has a uniform clearance with the ball 8 means that the amount of ink discharged onto the writing surface on the ball is uniform, which means that the density of the handwriting is different. It also provides good uniformity of handwriting width.

Here, the caulking angle and the taper diameter reducing angles α, β, γ, and the outer shape and the shape of the tip fore end portion in the opening portion,
The ball pen tips with the distance t from the contour of the ball set to various values were created, and the ball pen tips created were caught on the writing surface at a writing angle of 40 ° (Test 1) and the density of the handwriting. (Test 2) was tested. As for the test samples in which the value of t was variously set, samples of α = 80 °, β = 50 °, γ = 30 ° were prepared, and the test 1 and the test 2 were performed. The results are shown in (Table 1) to (Table 17). The ball-pen tip used in the test had a taper surface with a diameter reduction angle of 30 °.
5 ° is used, and the caulking angle that cannot be processed is indicated by −.

As a method of manufacturing the ball-pen tip used in the test, first, the taper surface 1 of the ball-pen tip A,
The ball holding chamber 7 and the ink passage 3 are formed by cutting or the like. The ink passage 3 is formed with the central hole 5 and the ink groove 6 so as to leave the inward protruding portion 4, and then the box
The ball 8 is inserted into the holding chamber 7. In order to hold the ball 8, the caulking process for forming the reduced diameter portion 2 at the tip of the ball pen tip A is performed.

[Test 1] (Hooking test on writing surface at a writing angle of 40 °) A writing test was conducted under the following test conditions to examine the catching between the ball-pen tip and the paper surface. Evaluation ◯: No contact between the ball-pen tip and the paper surface. Δ: There was contact between the ball-pen tip and the paper surface, and generation of frictional noise was recognized, but writing was possible. X: The ball pen tip scratched the surface of the paper, and a uniform writing line was not obtained.

[Test 2] (Test of degree of shading of handwriting) A writing test was conducted under the test conditions shown below, and the number of shading of the handwriting was counted.

Test conditions Writing angle: 40 ° Vertical writing load: 200 g Writing distance: 100 m Tester used: Spiral writing tester (Seiki KOGYO)
LAB) Test paper: NS55 recording paper (Kuryo Scientific Machinery Co., Ltd.) Writing instrument: BK100 (oil-based ballpoint pen, Pentel Co., Ltd.) Tip material: Ferrite stainless steel Tip size: Ball diameter 0.7mm, ball height 0.2
00 mm

[0020]

[Table 1]

[0021]

[Table 2]

[0022]

[Table 3]

[0023]

[Table 4]

[0024]

[Table 5]

[0025]

[Table 6]

[0026]

[Table 7]

[0027]

[Table 8]

[0028]

[Table 9]

[0029]

[Table 10]

[0030]

[Table 11]

[0031]

[Table 12]

[0032]

[Table 13]

[0033]

[Table 14]

[0034]

[Table 15]

[0035]

[Table 16]

[0036]

[Table 17]

[0037]

The ball-point pen tip of the present invention is capable of obtaining beautiful handwriting with uniform shading even when writing at a low writing angle without being caught by the writing surface.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part showing an example of the present invention.

[Explanation of symbols]

 A ball pen tip 1 taper surface 2 reduced diameter portion 2a first crimped portion 2b second crimped portion 3 ink passage 4 inward protruding portion 4a ball receiving seat portion 5 center hole 6 ink groove 7 ball embracing Chamber 8 Ball 9 Tip opening 10 Ink control section t Distance between tip outer shape and ball outer shape D Ball diameter h Ball protrusion height α First caulking angle β The crimping angle of the 2nd crimping part is γ The taper surface reducing angle

Claims (1)

[Claims] 1. A ball holding portion which is a part of an ink passage, wherein a reduced diameter portion is formed by caulking inward a leading edge portion of a taper surface which is reduced in diameter toward a leading end, In a ball-point pen tip that holds a ball as a writing member while partially projecting from the opening, the reduced diameter portion includes a first caulking portion and a second caulking portion having different caulking angles, and a tip end. The caulking angle of the first caulking portion on the edge side is α, the second
The crimping angle is β, the taper surface reducing angle is γ, and
The diameter of the ball was D, the protruding height of the ball protruding from the opening was h, and the distance between the outer shape of the tip end portion of the opening and the outer shape of the ball was t. In this case, the following features (Equation 1) to (Equation 4) are satisfied:
Rupen tip. [Formula 1] 0.25D ≦ h ≦ 0.35D [Formula 2] 0.007 mm ≦ t ≦ 0.030 mm [Formula 3] γ + 10 ° ≦ β ≦ γ + 40 ° [Formula 4] β + 10 ° ≦ α ≦ β + 40 °