JPH1095193A - Ballpoint pen - Google Patents

Abstract

(57) [Abstract] [Purpose] Low-viscosity ink or basically low-viscosity, but has high viscosity statically, and the viscosity decreases by rotation of the ball during writing, causing ink to flow out. This is a ball-point pen for fine writing using ink having a so-called shear thinning viscosity, and can prevent backflow of ink due to upward writing or impact and writing blur. In a ball-point pen having a tip of a ball-point pen at the tip of a joint and an ink storage tube at the rear, a shaft for pressing the tip and a holder to be fitted on the tip is formed at the tip of the joint, and a rear portion thereof. A valve chamber is provided at the axis of the valve chamber, a tapered or spherical ball receiving seat is provided at the rear of the valve chamber, and a required number of ridges are provided at the front peripheral wall of the valve chamber, so that the ball receiving seat can be closely contacted. When the ball valve is in close contact with the ball receiving seat and the conducting hole is sealed, and when the tip side is upward, the above-mentioned ball valve is in close contact with the ball receiving seat and the conducting hole is sealed so that backflow of ink can be prevented, and In the downward direction, the above-mentioned closed state is released, and the ball valve comes into contact with the rear end of the ridge, so that ink can flow into the chip through the guide hole, the valve chamber, the groove formed between the ridges, and the like. Becomes

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a low-viscosity ink or a low-viscosity ink which basically has a low viscosity, but has a high viscosity in a static state. The present invention relates to an improvement of a ballpoint pen using an ink which is discharged and has so-called shear thinning viscosity.

[0002]

2. Description of the Related Art The applicant of the present invention discloses, in Japanese Utility Model Publication No. 4-52067, a mechanism for preventing backflow of ink of a ballpoint pen provided with a valve chamber into which a ball is loosely fitted. In this case, a required number of protrusions are provided in a valve chamber in which a ball is loosely fitted with a synthetic resin mouth plug to prevent the ball from being pulled out, and a gap formed between the protrusions at the time of writing. And the ink flows to the chip. Further, a ballpoint pen using an ink having a shear thinning viscosity, in which the viscosity is reduced by the rotation of the tip ball during writing and the ink flows out, is known. In general, a ballpoint pen using ink having shear thinning viscosity has a large amount of ink flowing out (to increase the writing density), and has a large diameter of the ink storage tube to increase the amount of ink loaded. or,
Since the viscosity of the ink is smaller than that of the oil-based ball-point pen ink, the flow resistance to the ink storage tube is small. Therefore,
Ink leakage (ink flows backward at the rear end of the ink storage tube) easily occurs due to the ink's own weight or impact. For this purpose, a grease-like follower is provided at the rear end of the ink, which normally moves following the consumption of ink during writing, but suppresses the backflow of the ink against its own weight or impact. However, even when the follower is provided, if the ink immediately below the ball of the chip runs out when writing upward, there is a risk that a remarkable backflow occurs because the ink head is added directly and the hands and clothes are stained.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a low-viscosity ink or a low-viscosity ink which basically has a low viscosity and the viscosity is reduced by rotation of a ball during writing so that the ink flows out. Improvement of a ballpoint pen using ink
It is possible to prevent backflow of ink caused by upward writing or impact of a ballpoint pen, and to prevent contamination of the inside of the barrel of the ballpoint pen, hands, and clothes. In addition, it is possible to prevent handwriting immediately after the impact. Also, the diameter of the tip ball is φ0.3, φ0.4
It is an object of the present invention to satisfy the above problems as a ballpoint pen for fine writing.

[0004]

In order to achieve the above object, a ballpoint pen according to the present invention has a tip of a small ballpoint pen having a tip ball diameter of .phi.0.3 and .phi.0.4 at the end of a joint, and ink is accommodated in the back. In a ball-point pen having a tube, a shaft portion for crimping a chip and a holder to be fitted on the chip is formed at the end of a joint, and a valve chamber is provided on an axis behind the valve pen. A required number of protrusions are provided on the peripheral wall, and the outer periphery of a bush having a tapered or spherical ball receiving seat on the front surface and a conducting hole formed behind it is tightly fitted to the rear inner hole of the valve chamber. A ball valve is fixed to the ball receiving seat and can be closely contacted with the ball receiving seat. The ball valve is loosely fitted into the valve chamber, and an ink storage tube is fitted around the outer periphery of the fitting cylinder portion behind the joint, and the ink storage is performed. The tube contains low-viscosity ink or basically low-viscosity ink. However, the ink is statically high in viscosity and filled with ink that has a so-called shear-thinning property, in which the viscosity decreases when the tip ball rotates during writing and the ink flows out. When the tip side is upward, the ball valve is in close contact with the ball receiving seat and the guide hole is sealed, and when the tip side is downward, the sealing state is released and the rear end of the ridge is provided. The ball valve is brought into contact with the nozzle and the ink flows into the chip through a guide hole, a valve chamber, a groove formed between the ridges, and the like.

[0005]

1 to 5 show a first embodiment of the present invention. First, as shown in the figure, a locking cylinder 7 is provided in the first half of the joint 3 and a fitting cylinder 12 is provided in the second half, and the locking cylinder 7 on the front side is provided.
Is provided with a rib 8 inclined forward in the axial direction at a required position on the circumference. An inner shaft portion 10 having a chip fitting hole 10a at the center from the front end of the locking cylinder portion 7 is formed, and a holder fitting hole 10b is formed outside the inner shaft portion 10.
The chip 5 is pressed into the chip fitting hole 10a from the rear end side. In addition, the holder 1 is fitted to the chip 5.
1 is press-fitted to the inner shaft portion 10, and the holder 11 is substantially pressed into the holder fitting hole 10b. A window 12a is formed in a side surface of the fitting tube 12.

The joint 3 is made of an elastically deformable synthetic resin and is integrally formed, and has a large-diameter hole rearwardly communicating with the chip fitting hole 10a.
On the other hand, the bush 13 has a ball receiving seat 14 having a tapered or spherical shape at the axis, and a conducting hole 18 penetrating from the center of the ball receiving seat 14 to the rear end. A space in front of the ball receiving seat 14 is formed as a valve chamber 15.
A ridge 19 is provided on the inner surface. Further, a protrusion 16 is formed circumferentially on the outer peripheral portion of the bush 13, and a locking portion 17 having a circumferential shape or a ridge is formed rearward. As described above, the valve chamber 15 is formed between the ball receiving seat 14 and the ridge 19,
The ball valve 20 is loosely fitted in the valve chamber 15.

The tip 5 is a thin tube made of stainless steel or the like. The tip ball 5a rotates while the tip ball 5a is substantially in contact with a receiving seat 5b having a channel into which ink can flow by being pressed and caulked at three locations on the outer periphery. It is crimped to be freely held.

The bush 13 is inserted from the rear end of the joint 3, and the locking portion 17 is elastically engaged with the window 12a to be positioned and fixed in the hole behind the joint 3. (See FIG. 5) At this time, the projection 16 comes into close contact with the peripheral surface of the hole. Further, when the bush 13 is fixed, the ball valve 20 is restrained by the peripheral surface of the hole of the joint 3, so that the protrusion 19 prevents the ball valve 20 from being reliably pulled out. There are various methods of fixing the bush 13 such as a method of providing a groove and a protrusion between the outer peripheral surface of the hole of the joint 3 and the outer peripheral portion of the bush 13 to elastically lock the bush 13. It will be described later.

As described above, when the tip side is downward, the ball valve 20 comes into contact with the rear end of the ridge 19,
The ink enters the inner hole of the chip 5 through the guide hole 18, the valve chamber 15, the groove between the ridges and the like, and reaches the back surface of the tip ball 5a.

A flange 7a is provided at the rear end of the locking cylinder 7 of the joint 3, and a fitting cylinder 12 is provided behind the flange 7a.
Is extended. A cylindrical ink storage tube 4 is press-fitted and fixed to the outer periphery of the fitting tube portion 12 with its tip abutting on the rear end of the flange portion 7a. Is provided so as to protrude slightly from the outer periphery of the ink container 4 so that the joint 3 and the ink container 4 can be firmly joined together.

The inner diameter of the ink container 4 communicates with the guide hole 18 of the joint 3. The ink in the ink storage tube 4 has low viscosity or basically low viscosity, but has high viscosity statically, and the viscosity is reduced by rotation of the ball during writing, so that the ink can flow out. The ink 27 having the shear thinning property is filled, and the trailing end of the ink 27 is filled with a grease-like follower 29 that can move following the ink surface as the ink is consumed. A follower rod 30 made of resin having a specific gravity substantially equal to that of the follower 29 is immersed in the follower 29. The follower rod 30 is required (the diameter of the cross section of the ink container is large, and the ink head is large).
In addition, when the viscosity of the ink is low and the ink head cannot be supported, etc.). The follower rod is formed as required, such as a rod having a round or irregular cross section, a cylinder, a cup, or the like.

As described above, the refill of a ball-point pen constituted by fixing the tip 5 and the ink containing tube 4 filled with ink to the joint 3 is inserted into the shaft cylinder 1, and the joint 3 is attached to the front surface of the shaft portion 6. The rear end edge of the flange 7a is abutted, and the base 2 provided with the step 9 on the inner surface thereof is brought into contact with the peripheral surface of the rib 8 of the joint 3 in a state where the step 9 is brought into contact with the peripheral surface of the rib 8. A ballpoint pen is formed by screwing to the shaft portion 6 of the ballpoint pen.

FIG. 6 shows a second embodiment of the present invention. Since it is basically the same as the first embodiment, only the differences will be described. In this embodiment, a window portion 41a is formed in the fitting tube portion 41 of the joint 40, and the bush 4 is formed in the window portion 41a.
The small projections 42a provided on the outer periphery of the elastic member 2 are elastically engaged with each other, and the fitting window 12 may not be provided with the cut window 12b as in the previous example (FIG. 5).

FIG. 7 shows a third embodiment of the present invention. This is also basically the same as in the first embodiment.
In the present embodiment, a circumferential mountain-shaped projection 47a provided on the outer periphery of the bush 47 is pressed against the inner hole wall of the fitting cylindrical portion 46 of the joint 45 in a biting manner.

[0015]

First, FIG. 1 shows a state before writing with the tip 5 facing down. At that time, the ball valve 20 comes into contact with the rear end of the ridge 19 and the guide hole 18 is opened. The ink 27 that has entered the valve chamber 15 from the ink storage tube 4 through the conducting hole 18
Is guided to the back of the tip ball 5a through a groove or the like formed between the ridges.

FIG. 2 shows a state in which the tip 5 is directed upward. At this time, the ball valve 20 is in close contact with the ball receiving seat 14 of the valve chamber 15 and seals the guide hole 18. Even if the ink immediately below 5a runs out, the ink does not flow backward. Therefore, when the chip 5 is turned downward, the ink can immediately flow out, and the writing is prevented from being flared.
(By the way, in the structure without the ball valve, even if the ink does not immediately flow backward in the upward writing, the ink acts in the backward flow direction, so that air is trapped in the chip, and the downward writing causes the ink not to follow immediately, resulting in rubbing.)

When the refill of the ballpoint pen according to the embodiment is mounted on the barrel 1, the base 2 is screwed with the flange 7a of the joint 3 abutting against the front end of the shaft 6. Since the ribs 8 of the stopper tube 7 bite against the step 9 of the base 2, the chip 5 is rattled against the base 2.

[0018]

The configuration and operation of the ballpoint pen according to the present invention are as described above.
In the fine writing, the backflow of ink due to upward writing or impact can be prevented by a ball valve loosely fitted in the valve chamber, and an accident that stains the inside of the shaft cylinder, hands, clothes, and the like is prevented. or,
Since ink immediately follows upward writing or impact, writing is prevented. In addition, the ballpoint pen according to the embodiment has an effect that the writing feel is good because the tip and the base are loosened through the joint.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a main part of a ballpoint pen according to a first embodiment of the present invention, showing a state where a chip is directed downward.

FIG. 2 is a longitudinal sectional view of a main part of the ballpoint pen according to the first embodiment, showing a state in which a chip is directed upward;

FIG. 3 is a longitudinal sectional view showing the entirety of the ballpoint pen according to the first embodiment, showing the first half thereof.

FIG. 4 is a longitudinal sectional view showing the entirety of the ballpoint pen according to the first embodiment, showing the latter half thereof.

FIG. 5 is a plan view showing a fixed state of the joint and the bush in the first embodiment.

FIG. 6 is a longitudinal sectional view of a main part of a ballpoint pen according to a second embodiment of the present invention, showing a state in which a chip is directed downward.

FIG. 7 is a vertical sectional view of a main part of a ballpoint pen according to a third embodiment of the present invention, showing a state in which a chip is directed downward.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Shaft cylinder 2 Base 3 Joint 4 Ink storage tube 5 Tip 5a Tip ball 5b Receiving seat 6 Shaft part 7 Locking cylinder part 7a Flange part 8 Rib 9 Step part 10 Inner shaft part 10a Chip fitting hole 10b Holder fitting hole 10c Step portion 11 Holder 12 Fitting tube portion 12a Window portion 12b Cut window 12c Projection portion 12d Inclined surface 12e Step portion 13 Bush 14 Ball receiving seat 15 Valve chamber 16 Projection portion 17 Locking portion 18 Guide hole 19 Projection 20 Ball valve 21 Cap 22 Inner cap 23 Clip 24 Vent 25 Rib 26 Seal plug 27 Ink 28 Tail plug 29 Follower 30 Follower rod 40 Joint 41 Fitting cylinder 41a Window 42 Bush 42a Projection 45 Joint 46 Fitting cylinder 47 Bush 47a Projection Department

Claims (2)

[Claims] 1. A tip ball diameter of φ0.
3. A tip of a ball-point pen having a diameter of 0.4 mm and a ball-point pen having an ink storage tube at the rear is formed with a shaft portion for pressing the chip at the end of a joint, and a valve is provided at the rear axis. The chamber is provided with a required number of projections on the front peripheral wall of the valve chamber, and a tapered or spherical ball receiving seat on the front surface and a bushing having a guide hole formed on the rear side of the valve chamber are formed around the valve chamber. A ball valve that is tightly fixed to the rear inner hole and that can closely contact the ball receiving seat at that time is loosely fitted into the valve chamber, and an ink storage tube is provided on the outer periphery of the fitting cylindrical portion behind the joint. When the ink is inserted, low-viscosity ink or low-viscosity ink, which is basically low-viscosity but has high viscosity statically, is reduced in viscosity by rotation of the tip ball during writing, and ink flows out. Filled with so-called shear thinning ink,
A follower is provided at the rear end of the ink to follow the consumption of the ink.When the tip side is upward, the ball valve is in close contact with the ball receiving seat and the guide hole is sealed. And the ball valve is in contact with the rear end of the ridge so that the ink flows into the chip through a guide hole, a valve chamber, a groove formed between the ridges, and the like. Characteristic ballpoint pen. 2. The ballpoint pen according to claim 1, wherein a shaft portion for pressing the chip and a holder fitted on the chip is formed at the end of the joint.