JP2016221786A - Ball point pen - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ball point pen which can obtain stable contact condition between an intermediate ball and a front end part of a rod part, and surely urge a writing ball forward through the intermediate ball.SOLUTION: In a ball point pen, an intermediate ball 5 is intervened between a writing ball 4 and a spring 6. The spring 6 includes a straight rod part 61; a coil part 62 which is formed at a rear end part of the rod part 61 by being wound multiple times; and a cup-shaped part 63 which is integrally formed at a front end part of the rod 61 by being wound multiple times. An intermediate ball 5 is arranged in an ink circulation hole 33 at the center of a ball receiving seat 32. A rear face of the intermediate ball 5 is embraced by an inner surface of the cup-shaped part 63. A front face of the intermediate ball 5 contacts with a rear face of the writing ball 4.SELECTED DRAWING: Figure 3

Description

The present invention relates to a ballpoint pen.

Conventionally, in this type of ball-point pen, for example, Patent Document 1 discloses a ball-point pen that has a tip of a ball-point pen at the tip of the joint and an ink-holding tube at the back, and the ink-holding tube is filled with low-viscosity ink. In this case, a pipe-shaped tip having a receiving seat formed by a plurality of inward projections is provided at the tip of the joint, and a tip ball is rotatably held at the tip of the tip while contacting the back of the receiving seat. In addition, a contact ball that can be inserted through a hole formed in the center portion of the receiving seat is disposed in contact with the back surface of the tip ball, and further, a rod shaft on the front side of the spring is disposed on the back surface of the contact ball. The front end of the head abuts and the front end of the rod shaft presses the back surface of the tip ball via the abutting ball, so that the tip ball is brought into close contact with the inner edge of the chip ball holding portion to prevent the outflow of ink. Was Ballpoint pen characterized the door is disclosed.

JP 2006-198770 A

In the ballpoint pen of Patent Document 1, the contact state between the contact ball (corresponding to the intermediate ball of the present application) and the front end of the rod shaft portion (corresponding to the rod portion of the present application) tends to be unstable, and the rear surface of the contact ball It is difficult to reliably contact the center portion of the rod and the front end portion of the rod shaft portion. Therefore, the ballpoint pen of the above-mentioned patent document 1 may not be able to obtain a reliable close contact state between the inner edge of the ball holding portion at the time of non-writing and the tip ball (corresponding to the writing ball of the present application), or the tip ball at the time of writing. There is a risk that smooth rotation cannot be obtained.

The present invention solves the above-mentioned conventional problems, a stable contact state between the intermediate ball and the front end of the rod portion is obtained, and the writing ball can be positively biased forward via the intermediate ball, It is an object of the present invention to provide a ballpoint pen that can provide a reliable sealing property between the front end edge portion and the writing ball during non-writing and can smoothly rotate the writing ball during writing.

In the present invention, “front” refers to the chip body side, and “rear” refers to the opposite side.

1st invention of this application provides the front-end edge part 31 in the front end of the chip | tip body 3 inward, the ball | bowl receiving seat 32 is provided in the front-end vicinity inner surface of the chip | tip body 3 behind the said front-end edge part 31, and the said front end edge The writing ball 4 is rotatably held between the portion 31 and the ball seat 32, and the writing ball 4 is urged forward and the writing ball 4 is pushed forward to the front edge. A ballpoint pen in which a spring 6 is provided in close contact with the inner surface of the portion 31 and an intermediate ball 5 is interposed between the writing ball 4 and the spring 6, wherein the spring 6 includes a straight rod portion 61 and the rod A coil portion 62 integrally formed by a plurality of windings at a rear end portion of the portion 61; and a cup-shaped portion 63 integrally formed by a plurality of windings at a front end portion of the rod portion 61; Pedestal 32 An ink circulation hole 33 penetrating in the axial direction is provided in the center, the intermediate ball 5 is disposed in the ink circulation hole 33, and the rear surface of the intermediate ball 5 is held by the inner surface of the cup-shaped portion 63, It is a requirement that the front surface of the intermediate ball 5 is brought into contact with the rear surface of the writing ball 4.

In the ballpoint pen 1 of the first invention, the spring 6 includes a straight rod portion 61, a coil portion 62 integrally formed by a plurality of windings on the rear end portion of the rod portion 61, and the rod portion. A cup-shaped portion 63 integrally formed by a plurality of windings at a front end portion of 61, and an ink circulation hole 33 penetrating in the axial direction is provided at the center of the ball receiving seat 32. The intermediate ball 5 is disposed on the inner surface of the cup-shaped portion 63, the rear surface of the intermediate ball 5 is held by the inner surface of the cup-shaped portion 63, and the front surface of the intermediate ball 5 and the rear surface of the writing ball 4 are brought into contact with each other. A stable contact state between the intermediate ball 5 and the front end portion of the rod portion 61 can be obtained, and the center portion of the writing ball 4 can be positively biased forward via the intermediate ball 5, and as a result, the front end edge at the time of non-writing Part 31 and writing ball 4 With actual sealing is obtained, smooth rotation of the writing ball 4 at the time of writing can be obtained.

The second invention of the present application is that, in the ballpoint pen 1 of the first invention, the cup-shaped portion 63 is required to have a shape in which the outer diameter is gradually increased toward the front.

In the ballpoint pen 1 according to the second aspect of the invention, the cup-shaped portion 63 has a shape in which the outer diameter gradually decreases toward the rear, so that the cup-shaped portion 63 holds the rear surface of the intermediate ball 5 over a wide range. The intermediate ball 5 can be prevented from falling off the cup-shaped portion 63 at the time of writing or dropping impact, and a more stable contact state between the intermediate ball 5 and the front end of the rod portion 61 can be obtained.

The ballpoint pen 1 of the third invention of the present application is characterized in that, in the ballpoint pen of the first or second invention, the front end portion of the cup-shaped portion 63 is provided with a tightly wound portion.

The ball-point pen 1 according to the third aspect of the present invention can further hold the rear surface of the intermediate ball 5 over a wide range by the cup-shaped portion 63 by providing a tightly wound portion at the front end of the cup-shaped portion 63. The intermediate ball 5 can be prevented from falling off the cup-shaped portion 63 at the time of writing or dropping impact, and a stable contact state between the intermediate ball 5 and the front end portion of the rod portion 61 can be obtained.

According to the ballpoint pen of the present invention, a reliable sealing property between the front edge and the writing ball at the time of non-writing can be obtained, and smooth rotation of the writing ball at the time of writing can be obtained.

It is a longitudinal cross-sectional view of embodiment of this invention. It is a principal part expanded longitudinal cross-sectional view of FIG. FIG. 3 is an enlarged vertical sectional view of a main part of FIG. 2. FIG. 3 is a front view of the spring of FIG. 2.

1 to 4 show an embodiment of the present invention.

Ballpoint pen 1 of the present embodiment includes a ballpoint pen tip 2 that rotatably holds a writing ball 4 at a front end, a holder 8 in which a rear portion of the ballpoint pen tip 2 is press-fitted and fixed to a front portion 81, and The ink storage cylinder 7 in which the rear portion 83 of the holder 8 is press-fitted and fixed to the front end opening thereof, the spring 6 accommodated in the chip body 3 and in the holder 8, and the spring 6 and the writing ball 4. It consists of an intermediate ball 5 interposed therebetween and a tail plug 9 that is press-fitted and fixed to the rear end opening of the ink containing cylinder 7. The tail plug 9 has a vent hole that allows the inside of the ink containing cylinder 7 to communicate with the outside air.

Ballpoint pen tip The ballpoint pen tip 2 comprises a tip body 3 and a writing ball 4. The chip body 3 is made of a cylindrical metal cylinder. The metal cylinder is obtained, for example, from austenitic stainless steel such as SUS304, SUS305, or SUS321. A plurality of (for example, four) inner protrusions are formed at equal intervals in the circumferential direction on the inner surface in the vicinity of the front end of the chip body 3 due to inward deformation. A ball receiving seat 32 is formed by the inward projection. Further, an inward front end edge 31 is formed at the front end of the chip body 3 by being pressed and deformed inwardly in a circumferential shape. A writing ball 4 is rotatably held between the front surface of the ball receiving seat 32 and the rear surface of the front end edge 31. Between the inward protrusions, there is formed an ink circulation hole 33 extending radially outward from the center and penetrating in the axial direction. That is, the ink circulation hole 33 is formed in the ball receiving seat 32. The ball receiving seat 32 may be formed on the inner surface of the metal chip body 3 by cutting, in addition to a configuration including a plurality of inward projections by inward deformation.

The writing ball 4 has a diameter in the range of 0.3 mm to 0.7 mm (preferably 0.3 mm to 0.5 mm).

Holder The holder 8 is a cylindrical body obtained by injection molding of synthetic resin (for example, polypropylene). The holder 8 includes a tapered front portion 81 to which the ballpoint pen tip 2 is attached, a collar portion 82 that contacts the front end surface of the ink containing cylinder 7, and a rear portion 83 that is press-fitted into the front end opening of the ink containing cylinder 7. Become. On the inner surface of the holder 8, a locking wall portion 8 a made up of an annular protrusion or a plurality of protrusions arranged in a circumferential manner is integrally formed.

Ink storage cylinder The ink storage cylinder 7 is a cylindrical body that is obtained by extrusion molding of a synthetic resin (for example, polypropylene) and is open at both ends. The ink container 7 is filled with an ink 71 and a follower 72 made of a highly viscous fluid that moves forward as the ink 71 is consumed. Examples of the ink 71 include low-viscosity aqueous or oil-based inks and aqueous or oil-based gel inks having shear thinning viscosity. Examples of the follower 72 include a configuration made of only a high-viscosity fluid, or a configuration in which a solid is contained in a high-viscosity fluid.

The spring 6 includes a straight rod portion 61, a coil portion 62 integrally formed by a plurality of spiral turns on the rear end portion of the rod portion 61, and a front end portion of the rod portion 61. And a cup-shaped portion 63 integrally formed by a plurality of spiral windings. Further, a bulging portion 64 having an outer diameter larger than the outer diameter of the coil portion 62 is integrally formed at the rear end portion of the coil portion 62. In the spring 6, the rod portion 61, the coil portion 62, the cup-shaped portion 63, and the bulging portion 64 are integrally connected by a single metal wire (for example, a stainless steel wire). The The rear end of the bulging portion 64 of the spring 6 is locked to the locking wall portion 8a. The spring 6 is disposed behind the writing ball 4, biases the writing ball 4 forward via the intermediate ball 5, and brings the writing ball 4 into close contact with the inner surface of the front end edge portion 31.

-Cup-shaped part The said cup-shaped part 63 has an outer shape which is diameter-expanded gradually as an outer diameter goes ahead. The cup-shaped part 63 is provided with a tightly wound part where adjacent wire rods closely contact each other at least at the front end part. The tightly wound portion is provided at the front end portion of the cup-shaped portion 63 or at the whole.

The front end portion of the cup-shaped portion 63 is located inward in the radial direction of each inward projection constituting the ball seat 32 (inward in the radial direction of the rear surface of the inward projection). Thereby, the clearance gap between the rear surface of each said internal protrusion and the front end part outer surface of the cup-shaped part 63 can be made small, and the intermediate | middle ball | bowl 5 becomes cup shape at the time of writing (at the time of rotation of the writing ball 4) and a drop impact. It is possible to further avoid dropping from the inside of the portion 63.

Intermediate ball The intermediate ball 5 is disposed in the center of the ink circulation hole 33. The rear surface of the intermediate ball 5 is held by the inner surface of the cup-shaped portion 63. The front surface of the intermediate ball 5 and the rear surface of the writing ball 4 are brought into contact with each other, and the writing ball 4 is urged forward by the spring 6 through the intermediate ball 5.

The intermediate ball 5 has an outer diameter smaller than the writing ball 4. The intermediate ball 5 is set to be smaller than the inner diameter of the center of the ink circulation hole 33 (the diameter of the virtual inscribed circle at the top of the inward protrusion).

The material of the intermediate ball 5 and the writing ball 4 is not particularly limited, but generally, a material made of metal or ceramics is used, and a material having high hardness is preferably selected. As the material of the intermediate ball 5 and the writing ball 4, for example, ceramics such as tungsten carbide, zirconium oxide, aluminum oxide, silicon oxide, silicon carbide, and metals such as stainless steel are used. Moreover, you may use the cemented carbide alloy which consists of ceramics and a metallic binder. As such a cemented carbide, one made of tungsten carbide and a metallic binder such as cobalt or nickel is known. The intermediate ball 5 may be either the same material as the writing ball 4 or a different material.

In the ballpoint pen 1 of the present embodiment, the spring 6 has a straight rod portion 61, a coil portion 62 integrally formed by a plurality of windings on the rear end portion of the rod portion 61, and the rod portion 61. And a cup-shaped part 63 integrally formed by a plurality of windings at the front end of the ink receiving hole, and an ink circulation hole 33 penetrating in the axial direction is provided at the center of the ball receiving seat 32. The intermediate ball 5 is disposed, the rear surface of the intermediate ball 5 is held by the inner surface of the cup-shaped portion 63, and the front surface of the intermediate ball 5 and the rear surface of the writing ball 4 are brought into contact with each other. A stable contact state between the ball 5 and the front end portion of the rod portion 61 can be obtained, and the center portion of the writing ball 4 can be positively biased forward through the intermediate ball 5. As a result, the front end edge portion 31 when not writing is obtained. And writing ball 4 sure With sealing properties are obtained, smooth rotation of the writing ball 4 at the time of writing can be obtained. By obtaining a reliable sealing property between the front edge 31 and the writing ball 4, it is possible to reliably prevent air contamination from the nib in the pen tip upward state and ink leakage in the pen nib downward state when not writing. .

In the ballpoint pen 1 of the present embodiment, the cup-shaped portion 63 has a shape in which the outer diameter gradually decreases toward the rear, so that the cup-shaped portion 63 holds the rear surface of the intermediate ball 5 over a wide range. It is possible to prevent the intermediate ball 5 from falling off the cup-shaped portion 63 during writing or a drop impact, and a more stable contact state between the intermediate ball 5 and the front end of the rod portion 61 can be obtained.

The ball-point pen 1 according to the present embodiment can hold the rear surface of the intermediate ball 5 over a wide range by the cup-shaped portion 63 by providing a tightly wound portion at the front end of the cup-shaped portion 63. The intermediate ball 5 can be prevented from falling off the cup-shaped portion 63 at the time of writing or dropping impact, and a stable contact state between the intermediate ball 5 and the front end portion of the rod portion 61 can be obtained.

1 Ballpoint pen 2 Ballpoint pen tip
3 Chip body 31 Front edge 32 Ball seat (inward projection)
33 Ink flow hole 4 Writing ball 5 Intermediate ball 6 Spring 61 Rod part 62 Coil part 63 Cup-like part 64 Swelling part 7 Ink receiving cylinder 71 Ink 72 Follower 8 Holder 8a Locking wall part 81 Front part 82 Kite part 83 Rear part 9 Tail plug

Claims (3)

A front end edge is provided inwardly at the front end of the chip body, a ball receiving seat is provided on the inner surface near the front end of the chip body behind the front end edge, and a writing ball is placed between the front end edge and the ball receiving seat. A spring that is rotatably held, is provided behind the writing ball to urge the writing ball forward and to bring the writing ball into close contact with the inner surface of the front edge, and between the writing ball and the spring. A ballpoint pen with an intermediate ball
The spring is formed integrally with a straight rod portion, a coil portion integrally formed by a plurality of windings at a rear end portion of the rod portion, and a plurality of windings at a front end portion of the rod portion. A cup-shaped part, an ink circulation hole penetrating in the axial direction is provided in the center of the ball receiving seat, the intermediate ball is disposed in the ink circulation hole, and an inner surface of the cup-shaped part A ballpoint pen characterized by holding a rear surface and bringing the front surface of the intermediate ball into contact with the rear surface of the writing ball. The ball-point pen according to claim 1, wherein the cup-shaped portion has a shape that gradually increases in diameter as the outer diameter increases toward the front. The ballpoint pen according to claim 1, wherein a close-contact winding portion is provided at a front end portion of the cup-shaped portion.

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