JP4647368B2 - Ballpoint pen tip - Google Patents

Description

The present invention relates to a ballpoint pen tip. More specifically, the present invention relates to a so-called pipe-type ballpoint pen tip portion in which a ball is rotatably held at a tip portion of a metal plate pipe.

Conventionally, in Patent Document 1, for the purpose of suppressing wobbling or bending of a pipe during writing, a ball is rotatably held at the tip of a metal pipe, and the pipe is fixed to the tip of a holder. A tip of a ballpoint pen is disclosed in which a support cylinder fixed to the outer periphery is fixed to the holder.

The conventional ball-point pen tip portion suppresses the wobbling and bending of the pipe during writing, but the pipe tip portion protrudes to the outside to such an extent that the needle shape can be recognized. Therefore, if the tip of the pipe becomes smaller as the outer diameter of the ball becomes smaller, the tip of the pipe becomes slightly due to strong writing pressure during writing, and there is a possibility that some users cannot obtain a stable writing feeling. In addition, when an excessive force such as a drop impact is applied, the tip of the pipe may be bent.

Further, the tip of the conventional ballpoint pen has a support tube made of metal, and usually the outer surface of the support tube is not colored at all. For this reason, the tip of the conventional ballpoint pen cannot be immediately discriminated just by visually recognizing it from the outside. In addition, it has a plain appearance with poor color.

JP-A-8-118876

The present invention solves the above-mentioned conventional problems, and any user can obtain a stable writing feeling, the tip of the pipe does not bend even if an excessive force is applied, and the ink It is an object of the present invention to provide a ballpoint pen tip that can immediately determine the color and obtain a colorful appearance. In the present invention, “front” refers to the pen tip side, while “rear” refers to the opposite side.

In the present invention, the ball receiving seat 21 is formed by pressing and deforming the side wall near the tip of the metal pipe 2 inward, and the tip edge 22 is formed by pressing and deforming the tip of the pipe 2 inward. The ball 3 is rotatably held by the ball receiving seat 21 and the tip end edge portion 22, and the pipe 2 is press-fitted and fixed in the mounting hole 41 of the tip portion of the holder 4 made of synthetic resin. The tip of the pipe 2 is a tip of a ballpoint pen that protrudes forward, and the front outer surface of the holder 4 is formed in a conical shape with a diameter decreasing toward the front, and the thickness of the tip of the holder 4 is increased. When T is set to 0.03 mm (millimeters) to 0.3 mm (millimeters) and the diameter of the ball 3 is D, the length L at which the tip of the pipe 2 projects forward from the tip of the holder 4 The Set 0.5 × D~2.8 × D, the pipe 2 is provided with a tapered surface 23 at the rear of the leading edge 22, is brought close to the tip of the holder 4 and the tapered surface 23, during writing, It is a requirement that the tapered surface 23 of the pipe 2 and the tip of the holder 4 can simultaneously contact the writing surface (Claim 1).

The ballpoint pen tip 1 (Claim 1) has no wobbling because the thickness T of the tip of the holder 4 is set to 0.03 mm to 0.3 mm (preferably 0.05 mm to 0.25 mm). A stable writing feeling can be obtained and the ball 3 can be properly brought into contact with the writing surface. If the wall thickness T at the tip of the holder 4 is smaller than 0.03 mm (preferably 0.05 mm), the pipe 2 cannot be sufficiently held, and a user with a high writing pressure cannot write the pipe 2 when writing. There is a risk of the tip end wobbling. On the other hand, when the thickness T of the tip of the holder 4 is larger than 0.3 mm (preferably 0.25 mm), at the time of writing, the ball pen tip 1 is slightly tilted from the vertical state with respect to the writing surface. There is a possibility that the tip of the holder 4 comes into contact with the writing surface and prevents proper contact between the ball 3 and the writing surface.

The ballpoint pen tip 1 (Claim 1) has a length L from which the tip of the pipe 2 protrudes forward from the tip of the holder 4 to 0.5 × D to 2.8 × D (preferably 0.5 × D). D to 2.5 × D), a stable writing feeling without wobbling can be obtained, the ball 3 can be properly brought into contact with the writing surface, and even if an excessive force is applied, the pipe 2 There is no risk that the tip of the bend will bend. If the projecting length L of the pipe 2 tip is smaller than 0.5 × D, the writing of the holder 4 can be achieved by simply tilting the ball-point pen tip 1 from the vertical state with respect to the writing surface during writing. The tip may contact the writing surface and prevent proper contact between the ball 3 and the writing surface. On the other hand, when the protruding length L of the tip of the pipe 2 is larger than 2.8 × D (preferably 2.5 × D), the pipe 2 cannot be sufficiently held, and writing pressure is reduced during writing. For a large user, the tip of the pipe 2 may wobble, and further, when an excessive force such as a drop impact is applied, the tip of the pipe 2 may be bent.

In the ballpoint pen tip 1 (Claim 1), the front outer surface of the holder 4 is formed in a conical surface shape whose diameter decreases toward the front, so that the tip of the holder 4 can be appropriately thinned and wobbled. The ball 3 can be brought into proper contact with the surface to be written and at the same time a stable writing feeling can be obtained. If the front outer surface of the holder 4 is a right cylindrical shape, a user with a large writing pressure may wobble the tip of the pipe 2.

In the ballpoint pen tip 1 (Claim 1), the angle α of the conical front outer surface of the holder 4 is preferably in the range of 25 degrees to 110 degrees (preferably 25 degrees to 60 degrees). Thereby, the tip end portion of the holder 4 can be set to be appropriately thin, and a stable writing feeling without wobbling can be obtained and the ball 3 can be properly brought into contact with the writing surface. Further, the front outer surface of the holder 4 having a conical surface shape may be constituted by a plurality of conical surfaces. In the ballpoint pen tip 1 (Claim 1), the maximum outer diameter of the conical front outer surface of the holder 4 is preferably 2 mm or more. Thereby, the front part of the holder 4 has sufficient strength without the wobbling of the pipe 2.

Prior Symbol ballpoint pen tip 1 (claim 1), the tip of the holder 4 becomes positioned in the vicinity of the radially outward or recessed portion 24 of the recessed portion 24 of the ball seat of the pipe 2 the outer surface ( Claim 2) is preferred.

By the ballpoint pen tip 1 (Claim 2), the protruding length L of the tip of the pipe 2 can be set appropriately, and as a result, a stable writing feeling without wobbling can be obtained and the ball on the writing surface can be obtained. 3 can be properly brought into contact with each other, and a tip end portion of the ballpoint pen that does not bend the end portion of the pipe 2 even when an excessive force is applied can be reliably obtained.

In the ballpoint pen tip 1 (Claim 2), the tip of the holder 4 is positioned in the vicinity of the ball receiving recess 24 on the outer surface of the pipe 2. For example, the tip of the holder 4 is more than the recess 24. A configuration in which the recess 24 is completely covered by the front end portion of the holder 4 that is positioned slightly forward or a configuration in which the front end of the holder 4 is positioned slightly rearward of the recess portion 24 can be given. It is preferable to set so that the tip of the holder 4 is located within a range of 1 mm from the edge of the portion 24.

The ballpoint pen tip 1 (claim 1), at the time of writing, a metallic conical surface of the pipe 2 and the tip of the synthetic resin holder 4 is, simultaneously contact the writing surface, whereby the conventional pipes not be obtained by the formula ballpoint pen, good writing feeling can be obtained.

Also, the present invention, the distal end near the side wall of the metal pipe 2 to form a ball seat 21 by pressing deformed inward, the leading edge 22 by pressing deforming the tip of the pipe 2 to the inside The ball 3 is rotatably held by the ball receiving seat 21 and the tip edge portion 22, and the pipe 2 is press-fitted and fixed in the mounting hole 41 at the tip portion of the holder 4 made of synthetic resin. 4 is a ballpoint pen tip portion in which a support cylinder 5 is fixed to the outer surface of the pipe 2 and the outer surface of the pipe 2 projecting forward from the tip of the holder 4, and the tip of the pipe 2 is projected forward from the tip of the support cylinder 5. The front outer surface of the support tube 5 is formed in a conical surface shape whose diameter decreases toward the front, and the wall thickness T at the tip of the support tube 5 is set to 0.03 mm to 0.3 mm. When the diameter of 3 is D, The length L tip of lifting cylinder 5 wherein the pipe end 2 protrudes forward, is set to 0.5 × D~2.8 × D, when the support cylinder 5 is made of synthetic resin with the The pipe 2 is provided with a tapered surface 23 at the rear of the leading edge 22, the tapered surface 23 and the tip of the support cylinder 5 are brought close to each other, and when writing, the taper surface 23 of the pipe 2 and the tip of the support cylinder 5 are It is a requirement that the writing surface can be simultaneously contacted (Claim 3) .

The ballpoint pen tip 1 (Claim 3 ) has a wobbling because the thickness T of the tip of the support tube 5 is set to 0.03 mm to 0.3 mm (preferably 0.05 mm to 0.25 mm). A stable writing feeling can be obtained, and the ball 3 can be properly brought into contact with the writing surface. If the wall thickness T at the tip of the support cylinder 5 is smaller than 0.03 mm (preferably 0.05 mm), the pipe 2 cannot be sufficiently held, and a user with a high writing pressure can write the pipe 2 during writing. There is a risk that the tip of the head will wobble. On the other hand, when the wall thickness T at the tip of the support cylinder 5 is larger than 0.3 mm (preferably 0.25 mm), at the time of writing, the ball pen tip 1 is slightly tilted from the vertical state with respect to the writing surface. The tip of the support cylinder 5 may come into contact with the writing surface, which may hinder proper contact between the ball 3 and the writing surface.

The ball-point pen tip 1 (Claim 3 ) has a length L from which the tip of the pipe 2 protrudes forward from the tip of the support tube 5 to 0.5 × D to 2.8 × D (preferably 0.8. By setting to 5 × D to 2.5 × D), a stable writing feeling without wobbling can be obtained and the ball 3 can be properly brought into contact with the writing surface, and even if excessive force is applied. There is no possibility that the tip of the pipe 2 bends. If the protruding length L of the tip end of the pipe 2 is smaller than 0.5 × D, the support cylinder 5 can be obtained by slightly tilting the tip end portion 1 of the ball-point pen from the vertical state during writing. There is a possibility that the tip of the contact with the writing surface prevents proper contact between the ball 3 and the writing surface. On the other hand, when the protruding length L of the tip of the pipe 2 is larger than 2.8 × D (preferably 2.5 × D), the pipe 2 cannot be sufficiently held, and writing pressure is reduced during writing. For a large user, the tip of the pipe 2 may wobble, and if an excessive force such as a drop impact is applied, the tip of the pipe 2 may be bent.

The front end portion 1 of the ballpoint pen (Claim 3 ) can be set to have a thin tip at the front end portion of the support tube 5 by forming the front outer surface of the support tube 5 into a conical surface shape whose diameter decreases toward the front. In addition, a stable writing feeling without wobbling can be obtained, and the ball 3 can be properly brought into contact with the writing surface. If the front outer surface of the support cylinder 5 is a right cylinder, the tip of the pipe 2 may wobble for a user with high writing pressure.

In the ballpoint pen tip 1 (Claim 3 ), the angle α of the conical front outer surface of the support tube 5 is preferably in the range of 25 degrees to 110 degrees (preferably 25 degrees to 60 degrees). . Thereby, the tip end portion of the support cylinder 5 can be set to be appropriately thin, and a stable writing feeling without wobbling can be obtained and the ball 3 can be properly brought into contact with the writing surface. Moreover, you may comprise the conical front outer surface of the said support cylinder 5 by several conical surfaces. In the ballpoint pen tip 1 (Claim 3 ), the maximum outer diameter of the conical front outer surface of the support tube 5 is preferably 2 mm or more. Thereby, the front part of the support cylinder 5 has sufficient strength without the wobbling of the pipe 2.

Prior Symbol ballpoint pen tip 1 (claim 3), the tip of the support cylinder 5 becomes positioned in the vicinity of the radially outward or recessed portion 24 of the recessed portion 24 of the ball seat of the pipe 2 the outer surface (Claim 4 ) is preferable.

By the ballpoint pen tip 1 (Claim 4 ), the protruding length L of the tip of the pipe 2 can be set appropriately, and as a result, a stable writing feeling without wobbling can be obtained and the ball on the writing surface. 3 can be properly brought into contact with each other, and a tip end portion of the ballpoint pen that does not bend the end portion of the pipe 2 even when an excessive force is applied can be reliably obtained.

In the ballpoint pen tip 1 (Claim 4 ), the tip of the support cylinder 5 is located in the vicinity of the ball receiving recess 24 on the outer surface of the pipe 2, for example, the tip of the support cylinder 5 is a recess. A configuration in which the recess 24 is completely covered by the tip of the support cylinder 5 or a configuration in which the tip of the support cylinder 5 is positioned slightly behind the recess 24 is described. It is preferable to set so that the tip of the support cylinder 5 is located within a range of 1 mm or less from the edge of the recess 24.

In the ballpoint pen tip 1 (Claim 3 ), during writing, the conical surface of the metal pipe 2 and the tip of the synthetic resin support cylinder 5 are simultaneously in contact with the surface to be written. Good writing quality that cannot be obtained with a ballpoint pen.

Prior Symbol ballpoint pen tip 1 (claim 3), the fixing portions 53 and 54 of the holder 4 and the support tube 5, it is disposed behind (claim 5) is preferred over the mounting hole 41 .

The ball-point pen tip 1 (Claim 5 ) can further prevent wobbling during writing and can provide a stable writing feeling. If the fixing portions 53 and 54 between the support cylinder 5 and the holder 4 are arranged only radially outward of the mounting hole 41, the pipe 2 may wobble together with the holder 4 due to a large writing pressure during writing. The fixing portions 53 and 54 between the support cylinder 5 and the holder 4 may be provided at least at one location behind the mounting hole 41, and radially outward of the mounting hole 41 in front of the fixing portions 53 and 54. to, but it may also be provided another anchor portion 52 of the support tube 5 and the holder 4.

Prior Symbol ballpoint pen tip 1 (claim 1 to 5), the holder 4 is to be colored in the color of the ink to be discharged from a pipe 2 leading end (claim 6) are preferred.

The ball-point pen tip 1 (Claim 6 ) can immediately distinguish the ink color, obtain a colorful appearance, and make the ink stain at the tip of the holder 4 inconspicuous. In particular, in the case of the configuration in which the tip of the holder 4 is located radially outward of the ball receiving recess 24 on the outer surface of the pipe 2 or in the vicinity of the recess 24 (Claim 2), the pen made of an elastic material Due to the close contact between the tip seal member and the tip of the pipe 2, a phenomenon that the ink discharged from the tip of the pipe 2 adheres to the outer surface of the tip of the holder 4 (hereinafter referred to as ink smear) may occur, and the appearance of the tip of the holder 4 may be impaired. is there. However, since the holder 4 is colored in the color of the ink discharged from the tip of the pipe 2 (Claim 6 ), the ink stain at the tip of the holder 4 can be made inconspicuous, and the appearance of the tip of the holder 4 is impaired. There is no.

Prior Symbol ballpoint pen tip 1 (claims 3 to 6), the supporting cylinder 5, with a synthetic resin, it is colored in the color of the ink to be discharged from the pipe 2 leading end (claim 7) is preferable .

The ball-point pen tip 1 (Claim 7 ) can immediately determine the ink color, obtain a colorful appearance, and make the ink stain at the tip of the support cylinder inconspicuous. In particular, in the case of a configuration in which the tip of the support cylinder 5 is located radially outward of the ball seat recess 24 on the outer surface of the pipe 2 or in the vicinity of the recess 24 (Claim 4 ), the elastic material is used. Due to the close contact between the pen tip seal member and the tip of the pipe 2, a phenomenon (hereinafter, referred to as ink smear) occurs that the ink discharged from the tip of the pipe 2 adheres to the outer surface of the tip of the support cylinder 5, and the appearance of the tip of the support cylinder 5 There is a risk of damage. However, since the support cylinder 5 is colored with the color of the ink discharged from the tip of the pipe 2 (Claim 7 ), the ink stain at the tip of the support cylinder 5 can be made inconspicuous, and the appearance of the tip of the support cylinder 5 can be seen. Will not be damaged.

According to the ball-point pen tip of claim 1, any user can obtain a stable writing feeling, and the tip of the pipe is not bent even if an excessive force is applied. According to the tip of the ballpoint pen of the first aspect, a good writing quality that cannot be obtained with a conventional pipe-type ballpoint pen is obtained.

According to the tip of the ballpoint pen of the second aspect, the protruding length L of the tip of the pipe can be set appropriately.

According to the ballpoint pen tip of claim 3 , any user can obtain a stable writing feeling, and the tip of the pipe is not bent even if an excessive force is applied. According to the tip of the ballpoint pen of the third aspect, a good writing quality that cannot be obtained with a conventional pipe-type ballpoint pen can be obtained.

According to the tip of the ballpoint pen of claim 4 , the protruding length L of the tip of the pipe can be set appropriately.

According to the tip of the ballpoint pen of the fifth aspect , the wobble at the time of writing can be further prevented, and a stable writing feeling can be obtained.

According to the tip of the ballpoint pen of the sixth aspect , the ink color can be immediately discriminated and a colorful appearance can be obtained, and the ink stain at the tip of the holder can be made inconspicuous.

According to the tip of the ballpoint pen of claim 7 , the ink color can be immediately discriminated and a colorful appearance can be obtained, and the ink stain at the tip of the support cylinder can be made inconspicuous.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First Embodiment)
It shows a first embodiment of the present invention ballpoint pen tip 1 in Figure 1.
The pipe 2 is made of a metal (for example, austenitic stainless steel such as SUS304, SUS305, or SUS321) that is a straight cylinder.

On the outer surface of the side wall near the front end of the pipe 2, a plurality of (specifically, three) recesses 24 are formed at equal intervals in the circumferential shape due to inward pressing deformation. A ball receiving seat 21 made of a plurality of (specifically, three) inward projections is formed on the inner surface of the side wall near the tip of the pipe 2. A tip edge portion 22 is formed at the tip of the pipe 2 by being annularly pressed and deformed inward. The ball 3 is rotatably held by the ball receiving seat 21 and the tip edge portion 22.

Further, a tapered surface 23 is continuously provided behind the front end edge 22 of the outer surface of the pipe 2. The tapered surface 23 is formed in front of the recess 24 and behind the tip edge 22.

The holder 4 is obtained by injection molding of a synthetic resin (for example, polyacetal, polypropylene, etc.). The holder 4 is molded from a synthetic resin colored in the same color or substantially the same color as the ink discharged from the tip of the pipe 2 (ie, the pen tip). A mounting hole 41 having an inner diameter slightly smaller than the outer diameter of the pipe 2 is formed in the distal end portion of the holder 4 in the axial direction. A locking wall 42 is formed at the bottom of the mounting hole 41.

The front outer surface of the holder 4 is formed in a conical shape. The angle α of the conical front outer surface of the holder 4 is set to 40 degrees. The maximum outer diameter of the conical front outer surface of the holder 4 is set to 2.0 mm.

The pipe 2 is press-fitted into the mounting hole 41 of the holder 4, the rear end of the pipe 2 is brought into contact with the locking wall portion 42, and the pipe 2 is press-fitted and fixed to the mounting hole 41 of the holder 4.

The wall thickness T at the tip of the holder 4 is set to 0.05 mm. In addition, a length L at which the tip of the pipe 2 projects forward from the tip of the holder 4 is set to 0.2 mm. In the present embodiment, since the diameter D of the ball 3 is 0.25 mm, the protruding length L is set to 1.25 × D. The tip of the holder 4 is located radially outward of the recess 24 on the side wall near the tip of the pipe 2.

A chamfered portion 43 is formed on the outer surface of the tip of the holder 4. The chamfered portion 43 is formed in a conical shape, and its angle β is set to 80 degrees. The tip of the holder 4 is close to the rear of the tapered surface 23 of the pipe 2, and the chamfered portion 43 is formed on an extension line along the surface of the tapered surface 23. Thereby, at the time of writing, the taper surface 23 and the chamfered portion 43 can simultaneously contact the writing surface. The angle β of the chamfered portion 43 is set to be the same as that of the tapered surface 23.

(Second Embodiment)
It shows a second embodiment of the present invention ballpoint pen tip 1 in FIG.
The pipe 2 is made of a metal (for example, austenitic stainless steel such as SUS304, SUS305, or SUS321) that is a straight cylinder.

On the outer surface of the side wall near the front end of the pipe 2, a plurality of (specifically, three) recesses 24 are formed at equal intervals in the circumferential shape due to inward pressing deformation. A ball receiving seat 21 made of a plurality of (specifically, three) inward projections is formed on the inner surface of the side wall near the tip of the pipe 2. A tip edge portion 22 is formed at the tip of the pipe 2 by being annularly pressed and deformed inward. The ball 3 is rotatably held by the ball receiving seat 21 and the tip edge portion 22.

Further, a tapered surface 23 is continuously provided behind the front end edge 22 of the outer surface of the pipe 2. The tapered surface 23 is formed in front of the recess 24 and behind the tip edge 22.

The holder 4 is obtained by injection molding of a synthetic resin (for example, polyacetal, polypropylene, etc.). The holder 4 is molded from a synthetic resin colored in the same color or substantially the same color as the ink discharged from the tip of the pipe 2 (ie, the pen tip). The tip of the holder 4 is tapered, and an attachment hole 41 having an inner diameter slightly smaller than the outer diameter of the pipe 2 is formed in the axial direction. A locking wall 42 is formed at the bottom of the mounting hole 41.

The pipe 2 is press-fitted into the mounting hole 41 of the holder 4, the rear end of the pipe 2 is brought into contact with the locking wall portion 42, and the pipe 2 is press-fitted and fixed to the mounting hole 41 of the holder 4.

The support cylinder 5 is obtained by injection molding of a synthetic resin (for example, polyacetal, polypropylene, etc.). The support cylinder 5 is formed of a synthetic resin colored in the same color or substantially the same color as the ink discharged from the tip of the pipe 2 (that is, the pen tip).

The front outer surface of the support cylinder 5 is formed in a conical surface shape. The angle α of the front outer surface of the conical surface of the support cylinder 5 is set to 55 degrees. The maximum outer diameter of the conical front outer surface is set to 2.1 mm. The rear outer surface of the support cylinder 5 is formed in a right cylindrical shape.

A support hole 51 having an inner diameter slightly smaller than the outer diameter of the pipe 2 is provided at the tip of the support cylinder 5 in the axial direction. The inner diameter of the support hole 51 is set substantially equal to the inner diameter of the mounting hole 41. Further, a fixing portion 54 with the outer surface of the holder 4 is formed on the inner wall of the rear end opening of the support tube 5.

The outer surface of the tip of the pipe 2 protruding forward from the tip of the holder 4 is press-fitted and fixed in the support hole 51 of the support tube 5, and the holder 4 behind the mounting hole 41 is fixed in the fixing portion 54 of the support tube 5. The outer surface is press-fitted and fixed.

The wall thickness T at the tip of the support cylinder 5 is set to 0.12 mm. Further, a length L at which the tip of the pipe 2 projects forward from the tip of the support cylinder 5 is set to 0.72 mm. In the present embodiment, since the diameter D of the ball 3 is 1.0 mm, the protruding length L is set to 0.72 × D. The tip of the support cylinder 5 is located radially outward of the recess 24 in the side wall near the tip of the pipe 2.

A chamfered portion 55 is formed on the outer end surface of the support cylinder 5. The chamfered portion 55 is formed in a conical shape, and its angle β is set to 85 degrees. The tip of the support cylinder 5 is close to the rear of the tapered surface 23 of the pipe 2, and the chamfered portion 55 is formed on an extension line along the surface of the tapered surface 23. Thereby, at the time of writing, the taper surface 23 and the chamfered portion 55 can simultaneously contact the writing surface. The angle β of the chamfered portion 55 is set to be the same as that of the tapered surface 23.

It is a longitudinal cross-sectional view which shows the 1st Embodiment of this invention. It is a longitudinal cross-sectional view which shows the 2nd Embodiment of this invention.

DESCRIPTION OF SYMBOLS 1 Ball-point pen front-end | tip 2 Pipe 21 Ball receiving seat 22 Front-end edge part 23 Tapered surface 24 Indentation part 3 Ball | bowl 4 Holder 41 Mounting hole 42 Locking wall part 43 Chamfering part 4A 1st holder 4B 2nd holder 5 Support cylinder 51 Support Hole 52 Small-diameter adhering portion 53 Large-diameter adhering portion 54 Adhering portion 55 Chamfered portion T Thickness of the tip of the holder or the thickness of the tip of the support tube D Diameter of the ball L Length of the tip of the pipe protruding forward Distance from the rear edge of the holder to the tip of the holder or the tip of the support cylinder α Angle of the conical front outer surface of the holder or angle of the conical front outer surface of the support cylinder β Angle of the chamfer

Claims (7)

A ball receiving seat is formed by pressing and deforming the side wall near the tip of the metal pipe inward, and a tip edge is formed by pressing and deforming the tip of the pipe inward, and the ball receiving seat and the tip The ball pen is rotatably held by the edge, the pipe is press-fitted and fixed in the mounting hole of the synthetic resin holder tip, and the tip of the pipe protrudes forward from the holder tip. The front outer surface of the holder is formed in a conical surface shape whose diameter decreases toward the front, and the thickness T of the tip of the holder is set to 0.03 mm to 0.3 mm, and the diameter of the ball Is set to 0.5 × D to 2.8 × D, and the pipe tapers to the rear of the tip edge. A surface. A tip of a ballpoint pen , wherein the par surface and the tip of the holder are brought close to each other so that the taper surface of the pipe and the tip of the holder can simultaneously contact the writing surface during writing . The tip of the ballpoint pen according to claim 1, wherein the tip of the holder is located radially outward of the recess for the ball seat on the outer surface of the pipe or in the vicinity of the recess. A ball receiving seat is formed by pressing and deforming the side wall near the tip of the metal pipe inward, and a tip edge is formed by pressing and deforming the tip of the pipe inward, and the ball receiving seat and the tip A ball is rotatably held by an edge, and the pipe is press-fitted and fixed to a mounting hole of a synthetic resin holder tip, and supported by the holder outer surface and an outer surface of the pipe protruding forward from the holder tip. A ballpoint pen tip having a tube fixed and a tip of the pipe projecting forward from the tip of the support tube, wherein the front outer surface of the support tube is formed in a conical shape with a diameter reduced toward the front. The length at which the tip of the pipe protrudes forward from the tip of the support cylinder when the thickness T of the tip of the support cylinder is set to 0.03 mm to 0.3 mm and the diameter of the ball is D L is 0.5 D to 2.8 × D, the support cylinder is made of synthetic resin, the pipe has a tapered surface behind the front edge, and the tapered surface and the front end of the support cylinder are brought close to each other. The tip of the ball-point pen , wherein the tapered surface of the pipe and the tip of the support cylinder can be simultaneously contacted with the writing surface during writing . 4. A ballpoint pen tip according to claim 3, wherein the tip of the support cylinder is located radially outward of the ball receiving recess on the outer surface of the pipe or in the vicinity of the recess . The ball-point pen front-end | tip part of Claim 3 or 4 which has arrange | positioned the adhering part of the said support cylinder and the said holder behind the said attachment hole . The ball-point pen tip according to claim 1, wherein the holder is colored with the color of ink discharged from the tip of the pipe . The ballpoint pen tip according to any one of claims 3 to 6, wherein the support cylinder is made of a synthetic resin and is colored with the color of ink discharged from the pipe tip .

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