JP2016041515A - Pipe type ball-point pen - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pipe type ball-point pen capable of obtaining sufficient ink fluidity upon writing and a reliable sealing property between a caulked part and a ball upon non-writing.SOLUTION: A pipe type ball-point pen includes: a ball-embracing part in which a ball 6 is embraced rotatably by a caulked part 4 formed by a ball-point pen chip 2 to press and deform a tapered tip of a metallic pipe 3 diametrically inward, and a plurality of inward protrusion parts 5 formed by the ball-point pen chip 2 to press and deform a sidewall near the tip of the pipe 3 diametrically inward. A resilient body 11 energizes the ball 6 forward, and the ball 6 is brought into close contact with an inner circumferential surface of the caulked part 4. Difference between a maximum inner diameter B of the ball-embracing part and a diameter A of the ball 6 is set to be 25 μm or larger. An annular convex surface 4a an inner diameter of which is made gradually small according to access to a front side is formed on an inner circumferential surface of the caulked part 4. Upon non-writing, the ball 6 is brought into close contact with the annular convex surface 4a of the caulked part 4 by forward energization of the resilient body 11.SELECTED DRAWING: Figure 2

Description

The present invention relates to a pipe-type ballpoint pen. More specifically, a caulking portion formed by pressing and deforming a tapered tip portion of a metal pipe radially inward and a side wall near the tip end of the pipe is formed by pressing and deforming radially inward. The present invention relates to a pipe-type ballpoint pen including a ballpoint pen tip having a ball holding portion in which a ball is rotatably held by a plurality of inward protruding portions.

Conventionally, for example, Patent Document 1 discloses a pipe-type ballpoint pen tip in which a spherical concave portion having a curvature equivalent to that of a ball is formed on the inner peripheral surface of a crimping portion.

The conventional pipe-type ballpoint pen tip is provided with an inward protruding portion and a caulking portion in order to improve ink outflow at the time of writing (for example, to easily discharge ink having relatively large colorant particles). As the amount of movement in the radial direction of the ball in the ball holding portion between is set larger, the amount of pressing deformation when forming the inward protruding portion by punching increases, and accordingly, the cross section of the inner surface of the crimping portion The shape tends to be distorted from a circular shape, and at the same time, the amount of bending inward of the caulking portion to form a spherical concave portion having the same curvature as the ball on the inner peripheral surface of the caulking portion (the amount of caulking deformation) To increase. As a result, the inner surface of the caulking portion cannot be properly brought into pressure contact with the ball during the caulking process, and it may be difficult to form a caulking portion having a reliable sealing property.

Therefore, conventionally, a pipe-type ballpoint pen that satisfies both sufficient ink outflow properties and reliable sealing properties has not yet been obtained.

JP 2006-103288 A

The present invention solves the above-mentioned conventional problems, and is a pipe-type ballpoint pen that can provide sufficient ink spillage during writing and a reliable seal between the crimped portion and the ball during non-writing. Is to provide. In the present invention, “front” refers to the ball-point pen side, and “rear” refers to the opposite side.

[1] In the first invention of the present application, a caulking portion 4 formed by pressing and deforming a tapered tip portion of a metal pipe 3 radially inward, and a side wall near the tip of the pipe 3 in the radial direction A ball-point pen tip 2 having a ball holding portion in which a ball 6 is rotatably held by a plurality of inward protruding portions 5 formed by inwardly pressing and deforming, and urging the ball 6 forward; A pipe-type ballpoint pen including a projecting body 11 for bringing the ball 6 into close contact with the inner peripheral surface of the crimping portion 4, wherein a difference between a maximum inner diameter B of the ball holding portion and a diameter A of the ball 6 is 25 μm or more, and on the inner peripheral surface of the caulking portion 4 is formed an annular convex surface portion 4a having an inner diameter that gradually decreases toward the front. The above-mentioned bolt is formed on the annular convex surface portion 4a of the caulking portion 4. It is a requirement that is closely Le 6.

In the pipe-type ballpoint pen 1 of the first invention, the difference between the maximum inner diameter B of the ball holding portion and the diameter A of the ball 6 is 25 μm or more, and the caulking portion 4 By forming the annular convex surface portion 4a having an inner diameter that gradually decreases toward the surface, the ball 6 is brought into close contact with the annular convex surface portion 4a of the crimping portion 4 by forward urging of the elastic body 11 when not writing. In addition, sufficient ink spillability at the time of writing can be obtained, and reliable sealing performance between the crimped portion 4 and the ball 6 at the time of non-writing can be obtained.

In the present invention, the ball 6 preferably has a diameter A in the range of 0.3 mm to 0.7 mm (preferably 0.3 mm to 0.5 mm). The difference between the maximum inner diameter B of the ball holding portion and the diameter A of the ball 6 is preferably 30 μm or more from the standpoint that smoother ink outflow can be obtained. In addition, the amount of movement of the ballpoint pen in the ballpoint pen holding portion in the front-rear direction is preferably in the range of 15 μm to 65 μm from the viewpoint of obtaining a smooth ink outflow property.

[2] According to the second invention of the present application, in the pipe-type ballpoint pen 1 of the first invention, the outer diameter gradually increases toward the outer peripheral surface of the caulking portion 4 radially outward of the annular convex surface portion 4a. An ink circulation gap 7 is formed between the annular convex surface portion 4a and the ball 6 in a state in which the annular concave surface portion 4b is provided and the ball 6 is brought into contact with the inward protruding portion 5, It is a requirement that a part of the ball 6 protrudes in front of an imaginary straight line P that contacts the tip of the annular concave surface portion 4b and the rear end of the annular concave surface portion 4b.

The pipe-type ballpoint pen 1 of the second invention avoids the tip of the annular concave surface portion 4b (tip of the crimping portion 4) from hitting the paper surface even when writing with the ballpoint pen body inclined with respect to the paper surface, so that smooth writing is possible. It is possible to avoid the deformation of the inner peripheral surface of the caulking portion 4 (that is, the cross-sectional shape is changed from a circular shape to a distorted shape), and a reliable sealing property between the ball 6 and the caulking portion 4 when not writing. Is maintained.

[3] The third invention is the pipe-type ballpoint pen 1 of the second invention, wherein the rear end of the annular concave surface portion 4b is located in front of the inner peripheral surface base end 4c of the caulking portion 4. Is a requirement.

In the pipe-type ballpoint pen 1 of the third invention, the rear end of the annular concave surface portion 4b is located in front of the inner peripheral surface base end 4c of the crimping portion 4, thereby further crimping the writing. It is possible to avoid the tip of the portion 4 from hitting the paper surface. If the rear end of the annular concave surface portion 4b is located behind the inner peripheral surface proximal end 4c of the caulking portion 4, the virtual straight line P that contacts the distal end of the annular concave surface portion 4b and the rear end of the annular concave surface portion 4b. However, since a part of the ball 6 does not protrude to the front side, the tip of the annular concave surface portion 4b (tip of the crimping portion 4) may come into contact with the paper surface when writing with the ballpoint pen body inclined with respect to the paper surface.

[4] In the fourth invention, in any one of the first to third inventions, an annular concave surface in a vertical direction from an imaginary straight line P in contact with a front end of the annular concave surface portion 4b and a rear end of the annular concave surface portion 4b. It is a requirement that the maximum depth D of the portion 4b is 2 μm or more.

In the pipe-type ballpoint pen 1 of the fourth invention, the maximum depth D of the annular concave surface portion 4b in the vertical direction from the virtual straight line P in contact with the tip of the annular concave surface portion 4b and the rear end of the annular concave surface portion 4b is 2 μm. By being above (preferably 4 μm or more), it is possible to form an appropriate annular convex surface portion 4 a on the inner peripheral surface of the crimped portion 4.

The pipe-type ballpoint pen of the present invention provides sufficient ink outflow at the time of writing and also provides a reliable seal between the crimped portion and the ball at the time of non-writing.

It is a longitudinal cross-sectional view which shows embodiment of this invention. It is a principal part expanded longitudinal sectional view at the time of non-writing of FIG. FIG. 3 is an enlarged vertical sectional view of a main part of FIG. 2. FIG. 3 is an enlarged sectional view taken along line XX in FIG. 2. FIG. 2 is an enlarged vertical cross-sectional view of a main part in a contact state (at the time of writing) between the ball of FIG. FIG. 6 is an enlarged vertical sectional view of a main part of FIG. 5. FIG. 2 is an enlarged vertical sectional view showing a main part of the ball-point pen tip shown in FIG. 1 before caulking. FIG. 2 is an enlarged vertical cross-sectional view of a main part showing a caulking process of the ballpoint pen tip of FIG. 1.

An embodiment of a pipe-type ballpoint pen 1 of the present invention will be described with reference to the drawings (see FIGS. 1 to 8).

A pipe-type ballpoint pen 1 according to the present embodiment includes a ballpoint pen tip 2 that has a ball 6 rotatably held at its tip, a holder 8 that holds the rear part of the ballpoint pen tip 2, the holder 8, and the ballpoint pen tip 2. And an ink containing cylinder 9 in which the holder 8 is press-fitted and fixed to the opening of the front end, an ink 9a accommodated in the ink containing cylinder 9 and a follow-up. It comprises a body 9b and a tail plug 10 having a vent hole that is press-fitted and fixed to the rear end opening of the ink containing cylinder 9.

Ink storage cylinder The inside of the ink storage cylinder 9 is filled with ink 9a and a follower 9b made of a high-viscosity fluid that is disposed at the rear end of the ink 9a and moves forward as the ink 9a is consumed. The Examples of the ink 9a include low-viscosity aqueous or oil-based inks and aqueous or oil-based gel inks having shear thinning viscosity. Examples of the follower 9b include a configuration made of only a high-viscosity fluid, or a configuration in which a solid is contained in a high-viscosity fluid.

As the colorant of the ink 9a, for example, a pigment or a dye is used. Examples of the dye include an acid dye, a direct dye, and a basic dye. Examples of the pigment include inorganic pigments, organic pigments, fluorescent pigments, pearl pigments, metallic pigments, phosphorescent pigments, white pigments such as titanium oxide, metal powder pigments, reversible thermochromic microcapsule pigments, and the like.

-Bullet body The bullet body 11 includes a front straight portion 11a and a rear coil portion 11b that are integrally connected. A bulging portion 11c is formed at the rear end portion of the coil portion 11b. The bulging portion 11c gets over the locking projection 8a on the inner peripheral surface of the holder 8 from the rear, and the bulging portion 11c is locked to the front surface of the locking projection 8a. Thereby, the projectile 11 is held in a compressed state. The resilience of the projectile 11 (ie, the force that pushes the ball 6 forward) is set to 10 to 25 grams.

The tip of the straight portion 11a is brought into contact with the rear surface of the ball 6 and presses the ball 6 forward, whereby the ball 6 is brought into close contact with the inner peripheral surface of the caulking portion 4 of the ballpoint pen tip 2 in a circumferential manner. The space between the caulking portion 4 and the inner peripheral surface is sealed. Since the ball 6 is in close contact with the inner peripheral surface of the crimping portion 4, even if the pen tip is stored in a downward state, ink leakage from the pen tip is prevented. Air contamination from the front is prevented.

Ballpoint pen tip The ballpoint pen tip 2 has a crimped portion 4 formed by pressing and deforming a tapered tip of a metal pipe 3 radially inward, and a side wall near the tip of the pipe 3 inward in the radial direction. A plurality of (specifically, four) inwardly projecting portions 5 formed by being pressed and deformed, and a ball holder that rotatably holds the ball 6 by the caulking portion 4 and the inwardly projecting portion 5. The holding part is configured. The metal pipe 3 is a cylindrical body made of stainless steel (for example, austenitic stainless steel such as SUS304, SUS321, etc.). The metal pipe 3 is preferably a cylindrical body (straight tubular cylinder) having at least a straight tip at least at the tip. For example, the metal pipe 3 has a straight cylindrical shape as a whole, or has a straight tip. There is a configuration in which the rear side has a shape in which the outer diameter and the inner diameter increase. The inward projecting portions 5 are circumferentially arranged on the inner peripheral surface of the pipe 3 at equal intervals.

An annular convex surface portion 4a is formed on the inner peripheral surface of the crimped portion 4 so that the inner diameter gradually decreases toward the front. On the outer peripheral surface of the caulking portion 4 radially outward of the annular convex surface portion 4a, an annular concave surface portion 4b having an outer diameter that gradually decreases toward the front is formed.

The annular convex surface portion 4a has a shape in which the inner diameter gradually decreases toward the front. Examples of the annular convex surface portion 4a include a configuration including an annular convex curved surface, a configuration including an annular convex curved surface and an annular inclined surface, and a configuration including a plurality of annular inclined surfaces.

The annular concave surface portion 4b has a shape in which the outer diameter gradually decreases toward the front. Examples of the annular concave surface portion 4b include a configuration including an annular concave curved surface, a configuration including an annular concave curved surface and an annular inclined surface, and a configuration including a plurality of annular inclined surfaces.

The difference between the maximum inner diameter B of the ball holding portion and the diameter A of the ball 6 is set to 25 μm or more (preferably 30 μm or more). Thereby, sufficient ink outflow property at the time of writing can be obtained.

The movable amount of the ballpoint pen in the ballpoint pen holding portion is set in the range of 15 μm to 30 μm. Thereby, sufficient ink outflow property at the time of writing can be obtained.

The ball 6 has a diameter A in the range of 0.3 mm to 0.7 mm (preferably 0.3 mm to 0.5 mm).

At the time of non-writing, the ball 6 is brought into close contact with the annular convex surface portion 4a of the caulking portion 4 in a circumferential shape by the forward urging of the elastic body 11. By forming the annular convex surface portion 4a on the inner peripheral surface of the caulking portion 4, even if the cross-sectional shape of the inner peripheral surface of the tip portion of the pipe 3 before caulking is slightly distorted from a circular shape, 11, the ball 6 easily bites into the annular convex surface portion 4a, and a reliable sealing property between the inner peripheral surface of the crimping portion 4 and the ball 6 is obtained.

When the ball 6 is brought into contact with the inward protruding portion 5 (that is, during writing), an ink flow gap 7 is formed between the annular convex surface portion 4a and the ball 6, and the annular concave surface portion 4b. The ball 6 protrudes ahead of a virtual straight line P that is in contact with the front end of the ring-shaped concave surface portion 4b and the rear end of the annular concave surface portion 4b. Thus, even when writing with the ballpoint pen body tilted with respect to the paper surface, the tip of the annular concave surface portion 4b (tip of the crimping portion 4) is prevented from hitting the paper surface, and a smooth writing feeling can be obtained and the crimping portion 4 Deformation of the inner peripheral surface (that is, from a circular shape to a distorted shape) can be avoided, and a reliable sealing performance between the ball 6 and the caulking portion 4 during non-writing is maintained.

Further, the rear end of the annular concave surface portion 4 b is positioned in front of the inner peripheral surface base end 4 c of the crimping portion 4. Specifically, as shown in FIG. 6, the rear end of the annular concave surface portion 4 b is positioned forward in the axial direction by a distance C from the inner peripheral surface base end 4 c of the caulking portion 4. Thereby, it is possible to further prevent the annular concave surface portion 4b (the tip of the crimping portion 4) from hitting the paper surface during writing.

Further, the maximum depth D of the annular concave surface portion 4b in the vertical direction from the virtual straight line P in contact with the front end of the annular concave surface portion 4b and the rear end of the annular concave surface portion 4b is set to 2 μm or more (preferably 4 μm or more). The Thereby, an appropriate annular convex surface portion 4 a can be formed on the inner peripheral surface of the crimped portion 4.

-Manufacturing method The manufacturing method of the ball-point pen tip 2 used for this Embodiment is demonstrated.
As shown in FIG. 7, the side wall in the vicinity of the tip of the metal pipe 3 having a tapered tip (specifically, a tapered tip having a diameter reduced toward the front) is inwardly deformed ( After forming a plurality of inward protruding portions 5 for ball receiving seats by punching), the ball 6 is inserted into the front side of the inward protruding portion 5.

Next, as shown in FIG. 8, the crimping portion 4 is formed by bringing the pressure contact surface of the crimping tool 12 into pressure contact with the outer peripheral surface of the tapered tip portion of the metal pipe 3. Since the crimping surface of the crimping tool 12 is convex, an annular convex surface portion 4 a is formed on the inner peripheral surface of the crimping portion 4 simultaneously with the formation of the crimping portion 4, and the crimping portion 4 An annular concave surface portion 4b is formed on the outer peripheral surface. In addition, the manufacturing method of the said ball-point pen tip 2 is an example, and is not restricted to this.

DESCRIPTION OF SYMBOLS 1 Pipe type ball-point pen 2 Ball-point pen tip 3 Pipe 4 Caulking part 4a Annular convex surface part 4b Annular concave surface part 4c Inner peripheral surface base end 5 of the caulking part Inward protruding part 6 Ball 7 Ink flow gap 8 Holder 8a Locking protrusion 9 Ink receiving cylinder 9a Ink 9b Follower 10 Tail plug 11 Bullet 11a Straight part 11b Coil part 11c Swelling part 12 Caulking tool P Virtual straight line A Diameter of ball B Maximum inner diameter C of ball holding part Rear end of annular concave part and caulking part Distance in the axial direction between the inner peripheral surface proximal end of the ring and the maximum depth of the annular concave surface portion

Claims (4)

A caulking portion formed by pressing and deforming a tapered tip portion of a metal pipe radially inward, and a plurality of inner portions formed by pressing and deforming a side wall near the tip end of the pipe radially inward A ball-point pen tip having a ball holding portion in which the ball is rotatably held by the protruding portion; and a projectile that urges the ball forward and closely contacts the inner peripheral surface of the crimping portion. A pipe-type ballpoint pen provided, wherein the difference between the maximum inner diameter of the ball holding portion and the diameter of the ball is 25 μm or more, and the inner diameter gradually decreases toward the inner peripheral surface of the crimping portion toward the front. A pipe-type ballpoint pen characterized in that the annular convex surface portion is formed and the ball is brought into close contact with the annular convex surface portion of the caulking portion by forward urging of the elastic body when not writing. On the outer circumferential surface of the caulking portion radially outward of the annular convex surface portion, an annular concave surface portion whose outer diameter gradually decreases toward the front is provided, and the ball is in contact with the inward protruding portion, An ink flow gap is formed between the annular convex surface portion and the ball, and a part of the ball protrudes in front of an imaginary straight line contacting the tip of the annular concave surface portion and the rear end of the annular concave surface portion. The pipe-type ballpoint pen according to claim 1. The pipe-type ballpoint pen according to claim 2, wherein a rear end of the annular concave surface portion is located in front of an inner peripheral surface proximal end of the caulking portion. The pipe-type ballpoint pen according to any one of claims 1 to 3, wherein a maximum depth of the annular concave surface portion in a vertical direction from a virtual straight line contacting a front end of the annular concave surface portion and a rear end of the annular concave surface portion is 2 µm or more. .

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