JP5372446B2 - Ballpoint pen tip - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a ball-point pen tip wherein the writing ball is located in the immediate proximity to the inner surface of the tip end when not in use, and a pressing force is given to the approximate center of the writing ball. <P>SOLUTION: The ball-point pen tip, including a valve operating mechanism wherein the rod shank of the coil spring presses forward the ball and locate it in the immediate proximity to the inner wall of the tip end, has a first ink flow hole and a second ink flow hole whose inner diameter is smaller than that of the first ink flow, characteristically forming a build-up part on the joint part between the rear end of the ink flow groove and the first ink flow hole, which extends toward the axial center of the ball-point pen tip in a build-up manner. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention has an ink circulation hole and a radially extending ink circulation groove in the chip body, and a ball is inserted into the bottom wall of the ball holding chamber, and the tip of the chip is caulked inward. A valve mechanism is provided in which a part of the ball protrudes from the tip end edge of the tip and is rotatably held, the ball is pressed forward by the rod shaft portion of the coil spring, and the ball is in close contact with the inner wall of the tip end portion. Related to the ballpoint pen tip.

  A coil spring is arranged at the rear end of the ball, and the ball is brought into close contact with the inner wall surface of the tip of the tip by the elastic force of the coil spring and is applied to the ball and the inner wall of the tip of the tip by writing pressure at the time of writing. A ballpoint pen tip having a valve mechanism for forming a gap is well known, and Japanese Patent Application Laid-Open No. 2000-158869 “Ballpoint Pen Tip” describes that even if the rod shaft portion of the coil spring moves, the rod shaft portion does not move the ink. A structure that does not close the groove is disclosed.

Japanese Patent Laid-Open No. 2000-108574 “Ball Pen Tip” forms an ink circulation hole having a tip end portion and a rear end portion having different diameters, so that the rod shaft portion of the coil spring regulates the movement of the ball pen tip. The structure which makes a rod axis | shaft part contact | abut easily is disclosed.
"JP 2000-158869 A" "JP 2000-108574 A"

  However, in Patent Document 1, the coil spring has a very small wire diameter of φ0.1 mm to φ0.3 mm, and it is very difficult to form a plurality of through grooves in the rod shaft portion. In addition, forming a through-groove smaller than the outer diameter of the rod shaft portion at the rear end of the center hole increases the number of manufacturing steps, which increases the manufacturing cost.

  Further, in Patent Document 2, there is a problem that when the rod shaft portion is bent and inserted into the ink circulation hole having a large diameter at the tip portion, a pressing force cannot be applied to the approximate center of the ball.

  In view of the above problems, the present invention provides a ball-point pen tip that can apply a pressing force to substantially the center of a ball in a ball-point pen tip in which the ball is in close contact with the inner wall surface of the tip of the tip when not in use.

In order to achieve the above object, the present invention has an ink circulation hole and a radially extending ink circulation groove in the chip body, the ball is inserted into the bottom wall of the ball holding chamber, and the tip end of the chip is disposed. By caulking inward, a part of the ball protrudes from the tip end edge of the tip and is rotatably held, the ball is pressed forward by the rod shaft portion of the coil spring, and the ball is pressed against the inner wall of the tip end portion. In the ballpoint pen tip comprising a close valve mechanism, the ink circulation hole is connected to the first ink circulation hole and the second ink circulation hole having an inner diameter smaller than the first ink circulation hole, At the joint between the rear end portion of the ink circulation groove and the first ink circulation hole, a built-up portion extending in a thicker shape on the axial center side of the ballpoint pen tip is formed, and at the rear end portion of the second ink circulation hole, Axis side of ballpoint pen tip To form a second padding portion extending padding shape, wherein the length extending in the axial center side of the padding portion is longer than the length extending in the axial center side of the second padding unit And

Furthermore, a rear ink circulation groove that does not reach the ink circulation hole is provided at a rear end portion of the second ink circulation hole, and a joint portion between the rear end portion of the rear ink circulation groove and the second ink circulation hole is provided. The second build-up part is formed .

  Furthermore, said 2nd build-up part is located in the clearance gap between said build-up parts in the circumferential direction, The ball-point pen tip of Claim 3 characterized by the above-mentioned.

  The present invention can provide a ballpoint pen tip capable of applying a pressing force to substantially the center of the ball in the ballpoint pen tip in which the ball is in close contact with the inner wall surface of the tip end portion when not in use.

Example 1
Hereinafter, examples of the present invention will be described with reference to the drawings, but the ball-point pen tip of the present invention is not limited to the examples. In the drawings, the same members and parts are denoted by the same reference numerals.

  The ballpoint pen tip 1 shown in FIG. 1 to FIG. 3 has ink circulation holes 4 and 5 and a radially extending ink circulation groove 8 in the chip body 2 and is provided on the bottom wall 6 of the ball holding chamber 3 for writing. A ball 10 is placed on a ball seat 7 having substantially the same shape as the ball, and the tip end 2a is caulked inward so that a part of the ball 10 is rotatably held so as to protrude from the tip end 2a. Yes.

  The ink circulation hole is formed by connecting a first ink circulation hole 4 and a second ink circulation hole 5 having an inner diameter smaller than the inner diameter of the first ink circulation hole 4 at the rear thereof. A built-up portion 4 a extending in a built-up shape is formed at the joint portion of the ink circulation hole 4. In addition, a second build-up portion 5 a extending in the form of a build-up is formed at the rear end portion of the second ink circulation hole 5 on the axis J side of the ball-point pen tip.

  A coil spring having a rod shaft portion 11 is disposed behind the ball 10, and when not in use, the ball 10 is brought into close contact with the inner wall surface of the tip end portion 2a by the pressing force of the coil spring, and at the time of writing. A gap mechanism is formed between the ball 10 and the inner wall of the tip end portion 2a by the writing pressure to form a valve mechanism that allows ink to flow out to the paper surface or the like.

  The ball diameter is 0.7 mm, the wire shaft diameter 11 of the coil spring is 0.15 mm, the first ink circulation hole diameter is 0.45 mm, and the second ink circulation hole diameter is 0.35 mm. there were.

  In addition, the flow of the ink for the ball-point pen from the ink storage cylinder (not shown) to the ball 10 is as follows. First, the rear hole 9, the second ink circulation hole 5, the ink circulation hole 4, and the coil spring 11 from the ink accommodation cylinder. The ball 10 is reached through the gap.

  Even if the rod shaft portion 11 of the coil spring is bent and inserted from the second ink circulation hole 5 into the ink circulation hole 4, the movement of the rod shaft portion 11 in the axis J direction of the ball-point pen tip is restricted by the built-up portion 4 a. A pressing force can be applied to the center.

Although the method of forming the built-up portion 4a is not particularly limited, by the arc forming the junction of the ink passage grooves 8 and the ink flow hole 4, meat parts that occurs during the formation of the ink flow channels 8 Since the build-up portion 4a can be formed simultaneously with the formation of the ink circulation groove 8, the use of the build-up portion 4a is preferable because the manufacturing process is not increased. Similarly, the second build-up portion 5a is also preferably formed with the rear ink circulation groove 5b from the direction of the rear hole 9, and simultaneously with the formation of the rear ink circulation groove 5b, the second build-up portion a. .

Further, by forming a built-up portion 4 a at the joint between the rear end portion of the ink flow groove 8 and the ink flow hole 4, the rod shaft portion 11 of the coil spring is formed by the built-up portion 4 a, and the axis J of the ball-point pen tip. since the movement restriction in the direction is preferable because it is possible to make it difficult to close the ink flow channel 8.

  Further, by forming a second build-up portion 5a extending in the form of a build-up on the axis J side of the ball-point pen tip at the rear end portion of the second ink flow hole 5, the inner diameter of the second ink flow hole 5 is reduced. Since the movement of the bar shaft portion 11 of the coil spring can be restricted without excessively, the effect of easily ensuring the ink flow rate is produced.

Further, since the rod shaft portion 11 of the coil spring is restricted in movement at two different positions in the axial direction of the second built-up portion 5a and the built-up portion 4a of the second ink circulation hole 5 , depending on when writing, etc. The rod shaft portion can be made difficult to move.

  In addition, the second build-up portion 5a is formed so as to be positioned in the gap between the build-up portions 4a in the circumferential direction, so that the rod shaft portion 11 of the coil spring is at a different position in the axial direction and the circumferential direction. It is preferable because the movement is restricted.

  The ball-point pen tip of the present invention can be widely used as a ball-point pen without being limited to the type of ink, such as ink imparted with water, oiliness, and shear thinning.

FIG. 3 is a longitudinal sectional view in which a part of the ball-point pen tip in Example 1 is omitted. It is the figure which abbreviate | omitted the coil spring in Example 1. FIG. FIG. 3 is a diagram illustrating a state where first and second ink circulation holes in Example 1 are formed.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ball-point pen tip 2 Tip body 3 Ball holding chamber 4 First ink circulation hole 4a Overlaying part 5 Second ink circulation hole 5a Second overlaying part 6 Bottom wall 7 Ball seat 8 Ink circulation groove 9 Rear hole 10 Ball 11 Bar shaft

Claims (3)

The chip body has an ink circulation hole and a radially extending ink circulation groove, a ball is inserted into the bottom wall of the ball holding chamber, and the tip of the chip is caulked inward so that a part of the ball A ballpoint pen tip comprising a valve mechanism that protrudes from the tip end edge of the tip and rotatably holds the ball, presses the ball forward by a rod shaft portion of a coil spring, and closes the ball to the inner wall of the tip end portion. The ink circulation hole is connected to the first ink circulation hole and the second ink circulation hole having an inner diameter smaller than that of the first ink circulation hole, and the rear end portion of the ink circulation groove and the first ink circulation hole In the ink circulation hole joint, a build-up portion extending in the form of a build-up is formed on the axial center side of the ball-point pen tip, and on the rear end portion of the second ink flow hole, the build-up form is formed on the axial center side of the ball-point pen tip. Shapes the extended second fill While, ball-point pen tip length extending in the axial center side of the padding part, characterized in longer than the length extending in the axial center side of the second padding unit. A rear ink circulation groove that does not reach the ink circulation hole is provided at a rear end portion of the second ink circulation hole, and the second meat is formed at a junction between the rear end portion of the rear ink circulation groove and the second ink circulation hole. The ball-point pen tip according to claim 1, wherein a raised portion is formed . 3. The ballpoint pen tip according to claim 1, wherein the second build-up portion is located in a gap between the build-up portions in a circumferential direction.

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