JP2017185774A - Ball point pen - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that a conventional ball point pen cannot change the amount of ink discharge with writing pressure, providing only monotonous handwriting.SOLUTION: In a ball point pen according to the present invention, during writing at weak writing pressure, a first resilient member 61 is deformed due to compression in a state in which a pressing member 5 abuts on a first regulation wall part 44a and a ball 3 abuts on a ball receiving seat 51a of the pressing member 5. During writing at strong writing pressure, the first resilient member 61 and a second resilient member 62 are deformed due to compression and the pressing member 5 abuts on a second regulation wall part 44b. This enables an ink discharge quantity to be changed with writing pressure so as to obtain various kinds of handwriting.SELECTED DRAWING: Figure 2

Description

The present invention relates to a ballpoint pen.

Conventionally, in this type of ballpoint pen, for example, Patent Document 1 discloses a ballpoint pen in which a tip having a transfer ball rotatably held at the front end is fitted to the front end of a tube provided with an ink storage portion. The rear surface of the transfer ball is pressed by a ball seat elastically biased forward with the axis of the chip in the front-rear direction, and the transfer ball is placed around the entire inner surface of the ball holding portion at the front end of the chip. A ballpoint pen is disclosed which is characterized by being in close contact.

Japanese Patent Laid-Open No. 2003-25786

In the ballpoint pen of Patent Document 1, the transfer ball is pressed onto the paper surface, the rear surface of the transfer ball contacts the concave spherical surface of the ball seat, and the rear end surface of the ball seat is the inward stepped portion of the chip. The transfer ball is retracted and stopped until it comes into contact with the front surface, and ink can be ejected. Therefore, even if the pressure is further increased, the ball and the ball seat do not retreat, so the ink discharge amount cannot be changed by the pressure, and only monotonous handwriting that is difficult to express stop, splash, and harshness is obtained. I can't.

The present invention is intended to solve the above-described conventional problems, and it is an object of the present invention to provide a ballpoint pen capable of changing the ink discharge amount by writing pressure and obtaining various handwriting. In the present invention, “front” refers to the ball-point pen side, and “rear” refers to the opposite side.

The first invention of the present application is an inward front end edge portion formed at a front end of a metal cylinder,
A pressing member that is accommodated in a cylinder body behind the front end edge portion so as to be movable in the front-rear direction and has a ball receiving seat formed at the front end;
A first restriction wall portion formed in the cylindrical body and restricting forward movement of the pressing member;
A second restricting wall portion formed in the cylindrical body and restricting rearward movement of the pressing member;
A ball held rotatably between the front edge and the ball receiving seat of the pressing member;
A first resilient member for biasing the ball forward;
A second resilient member that biases forward the pressing member having a stronger resilient force than the first resilient member;
With
In the non-writing state, the first elastic member urges the ball forward, and the ball is in close contact with the inner surface of the front end edge portion, and when the writing is performed with a low writing pressure, the pressing member The first elastic member is compressed and deformed in contact with the first regulating wall, and the ball is in contact with the ball receiving seat of the pressing member, and writing is performed with a strong writing pressure. In this case, the first and second projectiles are compressed and deformed, and the pressing member is in contact with the second restriction wall.

In the ballpoint pen of the first invention, the first elastic member urges the ball forward in a non-writing state, and the ball is in close contact with the inner surface of the front edge, so that writing is performed with low writing pressure. When the pressing member is in contact with the first restriction wall, the first elastic member is compressed and deformed, and the ball is in contact with the ball receiving seat of the pressing member. When writing with a strong writing pressure, the first and second projectiles are compressed and deformed, and the pressing member is brought into contact with the second regulating wall, so that the ink discharge amount is reduced by the writing pressure. Can be changed, and various handwriting can be obtained. The “weak writing pressure” is a writing pressure smaller than the “strong writing pressure”. The “writing pressure” in the present invention refers to a force that presses the paper surface during writing.

The second invention of the present application requires that the first and second resilient members are made of a spring or an elastomer.

In the ballpoint pen 1 of the second invention, since the first and second resilient members are made of springs or elastomers, the ink ejection amount can be changed more stably by the writing pressure. A handwriting can be obtained.

3rd invention of this application makes it a requirement that it has a through-hole which can insert the said 1st bullet body in the axial center of the said press member.

Although the ballpoint pen 1 of the third invention has a pressing member having a ball receiving seat by having a through-hole through which the first projectile can be inserted in the axial center portion of the pressing member. In addition, smooth ink circulation to the ball can be obtained.

The fourth invention of the present application is:
The metal cylinder is a small cylindrical part having a right cylindrical shape in which a ball is held at the front end;
A tapered cylindrical portion integrally connected to the rear of the small-diameter cylindrical portion and having a diameter increasing toward the rear;
A straight-cylindrical large-diameter cylindrical portion integrally connected to the rear of the tapered cylindrical portion;
With
The first restricting wall for restricting the forward movement of the pressing member is formed by the inner surface of the tapered tubular portion;
It is a requirement that the second restriction wall portion that restricts the backward movement of the pressing member is formed on the inner surface of the large-diameter cylindrical portion.

In the ballpoint pen 1 according to the fourth aspect of the invention, the metal cylinder has a straight cylindrical small-diameter cylinder part in which a ball is held at the front end, and is integrally connected to the rear side of the small-diameter cylinder part and heads backward. In addition, a smoother ink flow property to the ball can be obtained by having a tapered cylindrical portion whose diameter increases in accordance with the above and a straight cylindrical large-diameter cylindrical portion integrally connected to the rear of the tapered cylindrical portion. It is done.

5th invention of this application makes it a requirement that the whole shape of the said metal cylinder is a right cylinder shape.

In the ballpoint pen 1 according to the fifth aspect of the present invention, the overall shape of the metal cylinder is a straight cylinder, so that the ink discharge amount can be stably changed by the writing pressure while suppressing the manufacturing cost. It is possible to obtain various handwriting.

The sixth invention of the present application is:
A rear end of the first projectile is locked to an inner wall of a holder that holds the cylindrical body;
It is a requirement that the rear end of the second projectile is locked to the inner wall of the cylindrical body or the inner wall of the holder that holds the cylindrical body.

In the ballpoint pen 1 of the sixth invention, a rear end of the first projectile is locked to an inner wall of a holder that holds the cylindrical body,
The rear end of the second projectile is locked to the inner wall of the cylinder or the inner wall of the holder that holds the cylinder, so that two different types of projectiles can be easily mounted in the ballpoint pen. Can do.

The seventh invention of the present application is
A rear end of the first projectile is held or locked to the pressing member;
It is a requirement that the rear end of the second projectile is locked to the inner wall of the cylindrical body or the inner wall of the holder that holds the cylindrical body.

In the ballpoint pen 1 of the seventh invention, the rear end of the first projectile is locked to the pressing member,
Since the rear end of the second elastic body is locked to the inner wall of the cylindrical body or the inner wall of the holder that holds the cylindrical body, even if the pressing member does not have a through hole, two different types of The projectile can be easily mounted in the ballpoint pen.

According to the ballpoint pen of the present invention, the ink discharge amount can be changed by the writing pressure, and various handwriting can be obtained.

It is a principal part longitudinal cross-sectional view of Embodiment 1 of this invention. It is a principal part expanded longitudinal sectional view which shows the non-writing state of FIG. It is a principal part expanded longitudinal cross-sectional view which shows the writing state at the time of weak writing pressure of FIG. FIG. 2 is an enlarged vertical sectional view of a main part showing a writing state at the time of strong writing pressure in FIG. 1. It is a principal part longitudinal cross-sectional view of Embodiment 2 of this invention. FIG. 6 is an enlarged vertical sectional view showing a main part of the non-writing state of FIG. 5. FIG. 6 is an enlarged vertical sectional view of a main part showing a writing state at the time of weak writing pressure in FIG. 5. FIG. 6 is an enlarged vertical sectional view of a main part showing a writing state at the time of strong writing pressure in FIG. 5. It is a principal part longitudinal cross-sectional view of Embodiment 3 of this invention. FIG. 10 is an enlarged vertical sectional view showing a main part of the non-writing state of FIG. 9. FIG. 10 is an enlarged vertical sectional view of a main part showing a writing state at the time of weak writing pressure in FIG. 9. FIG. 10 is an enlarged vertical sectional view of a main part showing a writing state at the time of strong writing pressure in FIG. 9. It is sectional drawing (AA cross section of FIG. 6) which shows the ink distribution groove | channel of a press member.

[Embodiment 1]
1 to 4 show a first embodiment of the present invention.

Ballpoint pen The ballpoint pen 1 according to the present embodiment includes a ballpoint pen tip 2 that rotatably holds a ball 3 at a front end portion, a holder 7 in which a rear portion of the ballpoint pen tip 2 is press-fitted and fixed to the front portion, and the holder 7 An ink containing cylinder 8 whose rear portion is press-fitted and fixed to the front end opening, a pressing member 5 accommodated and disposed inside the ball-point pen tip 2, a first elastic member 61 and a second elastic member 62; Is provided.

Ballpoint Pen Tip The ballpoint pen tip 2 includes a metal cylinder 4, the ball 3, the pressing member 5, the first resilient member 61, and the second resilient member 62. The cylindrical body 4 includes a straight cylindrical small-diameter cylindrical portion 41, a tapered cylindrical portion 42 that is connected to the rear of the small-diameter cylindrical portion 41 and increases in diameter toward the rear, and is connected to the rear of the tapered cylindrical portion 42. It consists of a straight cylindrical large-diameter cylindrical portion 43 provided. The said cylinder 4 is obtained by austenitic stainless steel, such as SUS304, SUS305, SUS321, for example. Further, an inward front end edge portion 41a is formed at the front end of the cylindrical body 4 by being pressed and deformed inwardly in a circumferential shape. In addition, the said cylinder does not need to contain the taper cylinder part 42, and a straight shape may be sufficient as the whole cylinder.

Restriction wall portion A first restriction wall portion 44 a and a second restriction wall portion 44 b are formed on the inner surface of the cylindrical body 4, and the first restriction wall portion 44 a is formed by the inner surface of the tapered tube portion 42. . The second restriction wall portion 44b is formed by an inward protrusion (for example, an annular inward protrusion or a plurality of inward protrusions distributed in a circumferential shape). The inward protrusions are integrally formed by inward pressing deformation. The first restriction wall portion 44a is formed behind the front end edge portion 41a, and is formed in front of the second restriction wall portion 44b.

Locking wall portion A locking wall portion 45 is formed on the inner wall of the rear end of the ball-point pen tip 2. The locking wall portion 45 is formed by an inward protrusion (for example, an annular inward protrusion or a plurality of inward protrusions arranged in a circumferential manner). The inward protrusions are integrally formed by inward pressing deformation. The inward projection may be formed by a separate part.

Holder The holder 7 is a cylindrical body obtained by injection molding of synthetic resin (for example, polypropylene). The holder 7 includes a tapered front portion to which the ballpoint pen tip 2 is attached, a flange portion that comes into contact with the front end surface of the ink containing cylinder 8, and a rear portion that is press-fitted into the front end opening of the ink containing cylinder 8.

Ink storage cylinder The ink storage cylinder 8 is a cylindrical member which is obtained by extrusion molding or injection molding of synthetic resin (for example, polypropylene) and has both ends opened. The ink container 8 is filled with a follower made of ink and a high-viscosity fluid that moves forward as the ink is consumed.

The pressing member 5 includes a rod-shaped (right columnar) first small-diameter portion 51 having a ball receiving seat 51 a formed at the front end thereof, and a rear side of the small-diameter portion 51, and the small-diameter portion 51. The large-diameter portion 52 has a large outer diameter.

The pressing member 5 is obtained by cutting, pressing, or metal powder injection molding of metal (for example, austenitic stainless steel such as SUS304, SUS305, SUS321, or martensitic stainless steel such as SUS420, SUS440A, SUS440C). It is done. The martensitic stainless steel can be hardened by heat treatment, whereby the wear resistance of the ball receiving seat 51a by the balls 3 can be dramatically improved. The pressing member 5 can also be obtained by injection molding or cutting of a synthetic resin (for example, polyacetal, polyamide, ABS, glass fiber blended PET, ultrahigh molecular weight polyethylene, polytetrafluoroethylene). As a result, a soft and smooth writing feeling can be obtained when writing.

The pressing member 5 (the large-diameter portion 52 of the pressing member 5) is accommodated between the first restricting wall portion 44a and the second restricting wall portion 44b so as to be movable in the front-rear direction. The front end of the large-diameter portion 52 is in contact with the first restriction wall portion 44a and forward movement is restricted, and the rear end of the large-diameter portion 52 is in contact with the second restriction wall portion 44b and rearward Movement is restricted.

Small Diameter Part The first small diameter part 51 is accommodated in the small diameter cylindrical part 41 of the cylindrical body 4. The ball receiving seat 51a at the front end of the first small diameter portion 51 is formed by a concave surface (a concave surface having the same curvature as the curvature of the ball 3 or a conical concave surface) or a flat surface on the front end surface of the first small diameter portion 51. . The ball 3 is rotatably held between the front surface of the ball receiving seat 51a and the rear surface of the front end edge portion 41a. The outer diameter of the first small diameter portion 51 is set smaller than the inner diameter of the small diameter cylindrical portion 41 and the inner diameter of the tapered cylindrical portion 42 of the cylindrical body 4. Thereby, an ink flow gap can be formed between the outer surface of the first small diameter portion 51 and the inner surface of the small diameter cylindrical portion 41 and the inner surface of the tapered cylindrical portion 42 of the cylindrical body 4. In particular, the ball receiving seat 51a at the front end of the first small-diameter portion 51 can be formed of a concave surface to prevent the ball from shaking in the radial direction.

-Large diameter part The said large diameter part 52 is accommodated in the inside of the large diameter cylinder part 43 of the cylinder 4 so that sliding is possible. In the outer peripheral surface of the large-diameter portion 52, one or a plurality of ink circulation grooves 52a extending in the front-rear direction are provided. Since the large-diameter portion 52 is slidably accommodated in the inner surface of the large-diameter cylindrical portion 43, the outer surface of the large-diameter portion 52 is guided by the inner surface of the large-diameter cylindrical portion 43. Shaking in the radial direction is suppressed, and stable writing becomes possible. Further, the ink distribution groove 52a enables stable ink distribution.

Elastic member The first elastic member 61 and the second elastic member 62 are compression coil springs or elastomers in which a metal wire (for example, a stainless steel wire) is spirally wound (coiled). It becomes more. Regarding the elastic force of the first elastic member 61 and the second elastic member 62,
First elastic member 61 <second elastic member 62
The relationship is established. That is, the elastic force of the first elastic member 61 is set smaller than the elastic force of the second elastic member 62.

The front end portion of the first resilient member 61 is inserted through the through hole 54 and biases the rear end of the ball 3. Thereby, in a non-writing state, the inner surface of the front end edge portion 41a and the ball 3 are brought into close contact with each other, and ink leakage from the pen tip is prevented.

The rear end portion of the first elastic member 61 is locked by the elastic body locking portion 71 of the holder 7.

The front end of the second resilient member 62 is in contact with the rear end of the large-diameter portion 52 of the pressing member 5, and the rear end of the second resilient member 62 is the rear end (large diameter of the ballpoint pen tip 2). It abuts on the locking wall portion 45 at the rear end of the cylindrical portion 43. By the second elastic member 62, the pressing member 5 is always urged forward when not writing. However, when the rear end of the second elastic member 62 can be locked by the holder 7, the locking wall portion 45 may not be provided.

At the time of weak writing pressure, when the first elastic member 61 is in a compressive deformation state and the second elastic member 62 is written with a writing pressure in a state where it is not compressively deformed (this is referred to as writing state A). In addition, the close contact between the inner surface of the front edge 41a and the ball 3 is released, and the first elastic member 61 is compressed as the ball 3 moves backward, so that the ball 3 hits the ball receiving seat 51a. Be touched. Thereby, a constant clearance in which the ball 3 is movable is maintained, and the ball 3 is stably brought into contact with the ball receiving seat 51a while maintaining a constant ink discharge amount, thereby enabling smooth writing.

A large diameter front end wall (first abutting wall portion) 52b when writing is performed with a writing pressure that compresses and deforms both the first elastic member 61 and the second elastic member 62 at the time of strong writing pressure; The contact with the first restriction wall is released, the ball is retracted while being in contact with the ball receiving seat 51a, and the rear end 52c of the large diameter portion is in contact with the second restriction wall 44b. Is done. Accordingly, a constant clearance larger than that in the writing state A in which the ball 3 is movable is maintained, and the ball 3 is stably brought into contact with the ball receiving seat 51a while maintaining a larger ink discharge amount than in the writing state A. Smooth writing becomes possible. That is, the ink discharge amount can be changed by the writing pressure, and various handwriting can be obtained.

[Embodiment 2]
5 to 8 show a second embodiment of the present invention.

Ballpoint pen The ballpoint pen 1 according to the present embodiment includes a ballpoint pen tip 2 that rotatably holds a ball 3 at a front end portion, a holder 7 in which a rear portion of the ballpoint pen tip 2 is press-fitted and fixed to the front portion, and the holder 7 An ink containing cylinder 8 whose rear portion is press-fitted and fixed to the front end opening, a pressing member 5 accommodated and disposed inside the ball-point pen tip 2, a first elastic member 61 and a second elastic member 62; Is provided.

Ballpoint Pen Tip The ballpoint pen tip 2 includes a metal cylinder 4, the ball 3, the pressing member 5, the first resilient member 61, and the second resilient member 62. The said cylinder 4 is obtained by austenitic stainless steel, such as SUS304, SUS305, SUS321, for example. Further, an inward front end edge portion 46 is formed at the front end of the cylindrical body 4 by being pressed and deformed inwardly in a circumferential shape. In addition, the said cylinder is a right cylinder shape (straight shape) as a whole.

Restriction wall portion A first restriction wall portion 47 and a second restriction wall portion 48 are formed on the inner surface of the cylindrical body 4. The first restricting wall portion 47 and the second restricting wall portion 48 are formed by inward protrusions (for example, annular inward protrusions or a plurality of inward protrusions arranged in a circumferential manner). The inward protrusions are integrally formed by inward pressing deformation. The first restriction wall portion 47 is formed behind the front end edge portion 46 and in front of the second restriction wall portion 48.

Locking wall portion A locking wall portion 45 is formed on the inner wall of the rear end of the ball-point pen tip 2. The locking wall portion 45 is formed by an inward protrusion (for example, an annular inward protrusion or a plurality of inward protrusions arranged in a circumferential manner). The inward protrusions are integrally formed by inward pressing deformation. The inward projection may be formed by a separate part.

Holder The holder 7 is a cylindrical body obtained by injection molding of synthetic resin (for example, polypropylene). The holder 7 includes a tapered front portion to which the ballpoint pen tip 2 is attached, a flange portion that comes into contact with the front end surface of the ink containing cylinder 8, and a rear portion that is press-fitted into the front end opening of the ink containing cylinder 8.

Ink storage cylinder The ink storage cylinder 8 is a cylindrical member which is obtained by extrusion molding or injection molding of synthetic resin (for example, polypropylene) and has both ends opened. The ink container 8 is filled with a follower made of ink and a high-viscosity fluid that moves forward as the ink is consumed.

The pressing member 5 includes a rod-shaped (right columnar) first small-diameter portion 51 having a ball receiving seat 51 a formed at the front end thereof, and a rear side of the small-diameter portion 51, and the small-diameter portion 51. The large-diameter portion 52 has a large outer diameter.

The pressing member 5 is obtained by cutting, pressing, or metal powder injection molding of metal (for example, austenitic stainless steel such as SUS304, SUS305, SUS321, or martensitic stainless steel such as SUS420, SUS440A, SUS440C). It is done. The martensitic stainless steel can be hardened by heat treatment, whereby the wear resistance of the ball receiving seat 51a by the balls 3 can be dramatically improved. The pressing member 5 can also be obtained by injection molding or cutting of a synthetic resin (for example, polyacetal, polyamide, ABS, glass fiber blended PET, ultrahigh molecular weight polyethylene, polytetrafluoroethylene). As a result, a soft and smooth writing feeling can be obtained when writing.

The pressing member 5 (the large-diameter portion 52 of the pressing member 5) is accommodated between the first restricting wall portion 47 and the second restricting wall portion 48 so as to be movable in the front-rear direction. The front end of the large-diameter portion 52 is in contact with the first restriction wall portion 47 to restrict forward movement, the rear end of the large-diameter portion 52 is in contact with the second restriction wall portion 48, and the rear Movement is restricted.

-Small diameter portion The ball receiving seat 51a at the front end of the first small diameter portion 51 has a concave surface (a concave surface having the same curvature as the curvature of the ball 3 or a conical concave surface) or a flat surface on the front end surface of the first small diameter portion 51. It is formed. The ball 3 is rotatably held between the front surface of the ball receiving seat 51a and the rear surface of the front edge portion 46. The outer diameter of the first small diameter portion 51 is set smaller than the minimum diameter of the first restriction wall portion 47. Thereby, an ink circulation gap can be formed between the outer surface of the first small diameter portion 51 and the minimum diameter of the first restriction wall portion 47. In particular, the ball receiving seat 51a at the front end of the first small-diameter portion 51 can be formed of a concave surface to prevent the ball from shaking in the radial direction.

Large-diameter portion The large-diameter portion 52 is accommodated in the cylinder 4 so as to be slidable in the front-rear direction between the first restriction wall 47 and the second restriction wall 48. One or a plurality of ink flow grooves 52 a extending in the front-rear direction are provided through the outer peripheral surface of the first small-diameter portion 51 and the outer peripheral surface of the large-diameter portion 52. The large-diameter portion 52 is accommodated in the cylindrical body 4 and between the first restriction wall portion 47 and the second restriction wall portion 48 so as to be slidable in the front-rear direction. Since the outer surface of the portion 52 is guided by the inner surface of the cylindrical body 4, shakiness in the radial direction of the small diameter portion 51 is suppressed, and stable writing is possible. Further, the ink distribution groove 52a enables stable ink distribution.

Elastic member The first elastic member 61 and the second elastic member 62 are compression coil springs or elastomers in which a metal wire (for example, a stainless steel wire) is spirally wound (coiled). It becomes more. Regarding the elastic force of the first elastic member 61 and the second elastic member 62,
First elastic member 61 <second elastic member 62
The relationship is established. That is, the elastic force of the first elastic member 61 is set smaller than the elastic force of the second elastic member 62.

The front end portion of the first resilient member 61 is inserted through the through hole 54 and biases the rear end of the ball 3. Thereby, in a non-writing state, the inner surface of the front end edge portion 41a and the ball 3 are brought into close contact with each other, and ink leakage from the pen tip is prevented.

The rear end portion of the first elastic member 61 is locked by the elastic body locking portion 71 of the holder 7.

The front end of the second resilient member 62 is brought into contact with the rear end of the large-diameter portion 52 of the pressing member 5, and the rear end of the second resilient member 62 is engaged with the rear end of the ballpoint pen tip 2. It abuts against the wall 45. By the second elastic member 62, the pressing member 5 is always urged forward when not writing. However, when the rear end of the second elastic member 62 can be locked by the holder 7, the locking wall portion 45 may not be provided.

At the time of weak writing pressure, when the first elastic member 61 is in a compressive deformation state and the second elastic member 62 is written with a writing pressure in a state where it is not compressively deformed (this is referred to as writing state A). In addition, the close contact between the inner surface of the front edge 46 and the ball 3 is released, and the first elastic member 61 is compressed as the ball 3 moves backward, so that the ball 3 hits the ball receiving seat 51a. Be touched. Thereby, a constant clearance in which the ball 3 is movable is maintained, and the ball 3 is stably brought into contact with the ball receiving seat 51a while maintaining a constant ink discharge amount, thereby enabling smooth writing.

A large diameter front end wall (first abutting wall portion) 52b when writing is performed with a writing pressure that compresses and deforms both the first elastic member 61 and the second elastic member 62 at the time of strong writing pressure; The contact with the first restriction wall 47 is released, the ball is retracted while being in contact with the ball receiving seat 51a, and the rear end 52c of the large-diameter portion abuts against the second restriction wall 48. Be touched. Accordingly, a constant clearance larger than that in the writing state A in which the ball 3 is movable is maintained, and the ball 3 is stably brought into contact with the ball receiving seat 51a while maintaining a larger ink discharge amount than in the writing state A. Smooth writing becomes possible. That is, the ink discharge amount can be changed by the writing pressure, and various handwriting can be obtained.

[Embodiment 3]
9 to 12 show a third embodiment of the present invention.

Ballpoint pen The ballpoint pen 1 according to the present embodiment includes a ballpoint pen tip 2 that rotatably holds a ball 3 at a front end portion, a holder 7 in which a rear portion of the ballpoint pen tip 2 is press-fitted and fixed to the front portion, and the holder 7 An ink containing cylinder 8 whose rear portion is press-fitted and fixed to the front end opening, a pressing member 5 accommodated and disposed inside the ball-point pen tip 2, a first elastic member 61 and a second elastic member 62; Is provided.

Ballpoint Pen Tip The ballpoint pen tip 2 includes a metal cylinder 4, the ball 3, the pressing member 5, the first resilient member 61, and the second resilient member 62. The cylindrical body 4 includes a straight cylindrical small-diameter cylindrical portion 41, a tapered cylindrical portion 42 that is connected to the rear of the small-diameter cylindrical portion 41 and increases in diameter toward the rear, and is connected to the rear of the tapered cylindrical portion 42. It consists of a straight cylindrical large-diameter cylindrical portion 43 provided. The said cylinder 4 is obtained by austenitic stainless steel, such as SUS304, SUS305, SUS321, for example. Further, an inward front end edge portion 46 is formed at the front end of the cylindrical body 4 by being pressed and deformed inwardly in a circumferential shape. In addition, the said cylinder does not need to contain the taper cylinder part 42, and a straight shape may be sufficient as the whole cylinder.

Restriction wall portion A first restriction wall portion 47 and a second restriction wall portion 48 are formed on the inner surface of the cylindrical body 4, and the first restriction wall portion 47 is formed by the inner surface of the tapered cylinder portion 42. . The second restriction wall portion 48 is formed by an inward protrusion (for example, an annular inward protrusion or a plurality of inward protrusions distributed in a circumferential shape). The inward protrusions are integrally formed by inward pressing deformation. The first restriction wall portion 47 is formed behind the front end edge portion 46 and in front of the second restriction wall portion 48.

Locking wall portion A locking wall portion 45 is formed on the inner wall of the rear end of the ball-point pen tip 2. The locking wall portion 45 is formed by an inward protrusion (for example, an annular inward protrusion or a plurality of inward protrusions arranged in a circumferential manner). The inward protrusions are integrally formed by inward pressing deformation. The inward projection may be formed by a separate part.

Holder The holder 7 is a cylindrical body obtained by injection molding of synthetic resin (for example, polypropylene). The holder 7 includes a tapered front portion to which the ballpoint pen tip 2 is attached, a flange portion that comes into contact with the front end surface of the ink containing cylinder 8, and a rear portion that is press-fitted into the front end opening of the ink containing cylinder 8.

Ink storage cylinder The ink storage cylinder 8 is a cylindrical member which is obtained by extrusion molding or injection molding of synthetic resin (for example, polypropylene) and has both ends opened. The ink container 8 is filled with a follower made of ink and a high-viscosity fluid that moves forward as the ink is consumed.

The pressing member 5 includes a rod-shaped (right columnar) first small-diameter portion 51 having a ball receiving seat 51 a formed at the front end thereof, and a rear side of the small-diameter portion 51, and the small-diameter portion 51. The large-diameter portion 52 has a large outer diameter.

The pressing member 5 is obtained by cutting, pressing, or metal powder injection molding of a metal (for example, austenitic stainless steel such as SUS304, SUS305, SUS321, or martensitic stainless steel such as SUS420, SUS440A, SUS440C). It is done. The martensitic stainless steel can be hardened by heat treatment, whereby the wear resistance of the ball receiving seat 51a by the balls 3 can be dramatically improved. The pressing member 5 can also be obtained by injection molding or cutting of a synthetic resin (for example, polyacetal, polyamide, ABS, glass fiber blended PET, ultrahigh molecular weight polyethylene, polytetrafluoroethylene). As a result, a soft and smooth writing feeling can be obtained when writing.

The pressing member 5 (the large-diameter portion 52 of the pressing member 5) is accommodated between the first restricting wall portion 47 and the second restricting wall portion 48 so as to be movable in the front-rear direction. The front end of the large-diameter portion 52 is in contact with the first restriction wall portion 47 to restrict forward movement, the rear end of the large-diameter portion 52 is in contact with the second restriction wall portion 48, and the rear Movement is restricted.

Small Diameter Part The first small diameter part 51 is accommodated in the small diameter cylindrical part 41 of the cylindrical body 4. The ball receiving seat 51a at the front end of the first small diameter portion 51 is formed by a concave surface (a concave surface having the same curvature as the curvature of the ball 3 or a conical concave surface) or a flat surface on the front end surface of the first small diameter portion 51. . The ball 3 is rotatably held between the front surface of the ball receiving seat 51a and the rear surface of the front edge portion 46. The outer diameter of the first small diameter portion 51 is set smaller than the inner diameter of the small diameter cylindrical portion 41 and the inner diameter of the tapered cylindrical portion 42 of the cylindrical body 4. Thereby, an ink flow gap can be formed between the outer surface of the first small diameter portion 51 and the inner surface of the small diameter cylindrical portion 41 and the inner surface of the tapered cylindrical portion 42 of the cylindrical body 4. In particular, the ball receiving seat 51a at the front end of the first small-diameter portion 51 can be formed of a concave surface to prevent the ball from shaking in the radial direction.

-Large diameter part The said large diameter part 52 is accommodated in the inside of the large diameter cylinder part 43 of the cylinder 4 so that sliding is possible. In the outer peripheral surface of the large-diameter portion 52, one or a plurality of ink circulation grooves 52a extending in the front-rear direction are provided. Since the large-diameter portion 52 is slidably accommodated in the inner surface of the large-diameter cylindrical portion 43, the outer surface of the large-diameter portion 52 is guided by the inner surface of the large-diameter cylindrical portion 43. Shaking in the radial direction is suppressed, and stable writing becomes possible. Further, the ink distribution groove 52a enables stable ink distribution.

Elastic member The first elastic member 61 and the second elastic member 62 are compression coil springs or elastomers in which a metal wire (for example, a stainless steel wire) is spirally wound (coiled). It becomes more. Regarding the elastic force of the first elastic member 61 and the second elastic member 62,
First elastic member 61 <second elastic member 62
The relationship is established. That is, the elastic force of the first elastic member 61 is set smaller than the elastic force of the second elastic member 62.

The front end portion of the first resilient member 61 biases the rear end of the ball 3. Thereby, in a non-writing state, the inner surface of the front end edge portion 41a and the ball 3 are brought into close contact with each other, and ink leakage from the pen tip is prevented.

The rear end portion of the first elastic member 61 is held or locked by the pressing member 5.

The front end of the second resilient member 62 is in contact with the rear end of the large-diameter portion 52 of the pressing member 5, and the rear end of the second resilient member 62 is the rear end (large diameter of the ballpoint pen tip 2). It abuts on the locking wall portion 45 at the rear end of the cylindrical portion 43. By the second elastic member 62, the pressing member 5 is always urged forward when not writing. However, when the rear end of the second elastic member 62 can be locked by the holder 7, the locking wall portion 45 may not be provided.

At the time of weak writing pressure, when the first elastic member 61 is in a compressive deformation state and the second elastic member 62 is written with a writing pressure in a state where it is not compressively deformed (this is referred to as writing state A). In addition, the close contact between the inner surface of the front edge 46 and the ball 3 is released, and the first elastic member 61 is compressed as the ball 3 moves backward, so that the ball 3 hits the ball receiving seat 51a. Be touched. Thereby, a constant clearance in which the ball 3 is movable is maintained, and the ball 3 is stably brought into contact with the ball receiving seat 51a while maintaining a constant ink discharge amount, thereby enabling smooth writing.

A large diameter front end wall (first abutting wall portion) 52b when writing is performed with a writing pressure that compresses and deforms both the first elastic member 61 and the second elastic member 62 at the time of strong writing pressure; The contact with the first restriction wall 47 is released, the ball is retracted while being in contact with the ball receiving seat 51a, and the rear end 52c of the large-diameter portion abuts against the second restriction wall 48. Be touched. Accordingly, a constant clearance larger than that in the writing state A in which the ball 3 is movable is maintained, and the ball 3 is stably brought into contact with the ball receiving seat 51a while maintaining a larger ink discharge amount than in the writing state A. Smooth writing becomes possible. That is, the ink discharge amount can be changed by the writing pressure, and various handwriting can be obtained.

DESCRIPTION OF SYMBOLS 1 Ball-point pen 2 Ball-point pen tip 3 Ball 4 Cylinder body 41 Small diameter cylinder part 41a Front end edge part 42 Tapered cylinder part 43 Large diameter cylinder part 44a First restriction wall part 44b Second restriction wall part 45 Locking wall part 46 Front end edge part 47 1st regulation wall part 48 2nd regulation wall part 5 Pressing member
51 First small-diameter portion 51a Ball receiving seat 52 Large-diameter portion 52a Ink flow groove 52b Large-diameter portion front end wall (first contact wall portion)
52c Large-diameter portion rear end wall (second contact wall portion)
53 Second small diameter portion 54 Through hole 61 First elastic member 62 Second elastic member 7 Holder 71 Elastic body locking portion 8 Ink receiving cylinder

Claims (7)

An inward front end edge formed at the front end of the metal cylinder,
A pressing member that is accommodated in a cylinder body behind the front end edge portion so as to be movable in the front-rear direction and has a ball receiving seat formed at the front end;
A first restriction wall portion formed in the cylindrical body and restricting forward movement of the pressing member;
A second restricting wall portion formed in the cylindrical body and restricting rearward movement of the pressing member;
A ball held rotatably between the front edge and the ball receiving seat of the pressing member;
A first resilient member for biasing the ball forward;
A second resilient member that biases forward the pressing member having a stronger resilient force than the first resilient member;
With
In the non-writing state, the first resilient member urges the ball forward, and the ball is in close contact with the inner surface of the front edge portion,
When writing with a weak writing pressure, the first elastic member is compressed and deformed in a state where the pressing member is in contact with the first regulating wall, and the ball hits the ball receiving seat of the pressing member. Is touched,
The ballpoint pen, wherein the first and second projectiles are compressed and deformed when the writing is performed with a strong writing pressure, and the pressing member is brought into contact with the second regulating wall. The ballpoint pen according to claim 1, wherein the first and second elastic members are made of a spring or an elastomer. 3. The ballpoint pen according to claim 1, further comprising a through-hole through which the first projectile can be inserted in an axial center of the pressing member. The metal cylinder is a small cylindrical part having a right cylindrical shape in which a ball is held at the front end;
A tapered cylindrical portion integrally connected to the rear of the small-diameter cylindrical portion and having a diameter increasing toward the rear;
A straight-cylindrical large-diameter cylindrical portion integrally connected to the rear of the tapered cylindrical portion;
With
The first restricting wall for restricting the forward movement of the pressing member is formed by the inner surface of the tapered tubular portion;
4. The ballpoint pen according to claim 1, wherein the second restriction wall portion that restricts rearward movement of the pressing member is formed on an inner surface of the large-diameter cylindrical portion. 5. The ballpoint pen according to any one of claims 1 to 3, wherein the entire shape of the metal cylinder is a right cylinder. A rear end of the first projectile is locked to an inner wall of a holder that holds the cylindrical body;
The ballpoint pen according to any one of claims 1 to 5, wherein a rear end of the second elastic body is locked to an inner wall of the cylindrical body or an inner wall of a holder that holds the cylindrical body. A rear end of the first projectile is held or locked to the pressing member;
The ballpoint pen according to any one of claims 1 to 5, wherein a rear end of the second elastic body is locked to an inner wall of the cylindrical body or an inner wall of a holder that holds the cylindrical body.

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