JP2865582B2 - Ballpoint pen - Google Patents

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 device, 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 during 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 outflow of ink (to increase the writing density), and has a large diameter of the ink storage tube to increase the amount of loaded ink. 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 danger that the ink and the head will be added directly, causing a remarkable backflow and soiling the hands and clothes. In addition, since the viscosity of the ink is low and the amount of outflow is large, if the tip side faces downward and the gap between the tip ball and the tip caulking portion occurs, the ink bleeds (DC).
The problem exists.

[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 reverse flow of ink caused by upward writing or impact of a ballpoint pen and direct current when the tip side is placed downward, and to prevent stains in the barrel of the ballpoint pen, hands, and clothes. In addition, it is possible to prevent handwriting and dry-up immediately after the impact. It is another object of the present invention to satisfy the above-mentioned problems as a ballpoint pen for fine writing with a tip ball having a diameter of φ0.3 or φ0.4.

[0004]

A ballpoint pen according to the present invention devised to achieve the above object is a ballpoint pen having a tip of a ballpoint pen at a tip of a joint and an ink storage tube at the rear. A bush is fixed to the shaft center behind the joint, a valve chamber is provided in the shaft center of the bush, and a tapered or spherical ball seat at the rear of the valve chamber has a required number of protrusions on the front peripheral wall of the valve chamber. A ridge is provided, and a ball valve capable of closely contacting the ball receiving seat elastically deforms the ridge and is loosely fitted into the valve chamber so that it cannot be pulled out, and a rear end of the bush comes in contact with a front end of the bush. A spring is urged into the tip bore,
The tip of the spring presses the back of the tip ball rotatably held at the tip end of the tip, so that the tip ball comes into close contact with the inner edge of the ball holding portion of the tip. Close to the hole is closed,
When the tip side is downward, the sealed state is released, and the ball valve comes into contact with the rear end of the ridge, so that ink flows into the chip through a guide hole, a valve chamber, a groove formed between the ridges, and the like. Inflow is possible.

[0005]

1 to 4 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. Further, a space in front of the ball receiving seat 14 is formed as a valve chamber 15, and a required number of elastic pieces 19 are formed on a peripheral portion of a shaft portion in front of the bush at a predetermined location with a slit 19b. In addition, a ridge 19 a is provided on the inner surface of the elastic piece 19. 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 19a, and the ridge 19a is elastically expanded from the front end so that the valve chamber 15
The ball valve 21 is loosely fitted therein.

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 spring 20 has an upright straight portion 20b at the front and a winding portion 20a formed at the rear. The spring 20 is inserted into the hole of the joint 3, and the straight portion 20b is inserted into the inner hole of the chip 5. I do.

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. At this time, the protrusion 16 comes into close contact with the peripheral surface of the hole. Further, when the bush 13 is fixed, the ball valve 21 is restrained by the peripheral surface of the joint 3 hole portion, so that the ball valve 21 cannot be reliably pulled out by the ridge 19a. There are various methods for fixing the bush 13 such as a method of providing a groove and a protrusion between the peripheral surface of the hole of the joint 3 and the outer peripheral portion of the bush 13 to elastically lock the bush 13, and is not limited to the embodiment. Things.

Further, the rear end of the winding portion 20a of the spring comes into contact with the tip of the bush 13, and the tip of the straight portion 20b comes into contact with the back surface of the tip ball 5a in a pressing manner. still,
The tip ball 5a is brought into close contact with the inner edge of the ball holding portion (formed by caulking or the like) of the chip 5 by the pressing.

As described above, when the tip side is downward, the ball valve 21 comes into contact with the rear end of the ridge 19a, and ink flows through the guide hole 18, the valve chamber 15, the groove between the ridges and the like. It enters the inner hole of the chip 5 and reaches the back of the tip ball 5a.

A flange 7a is provided at the rear end of the engagement 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 cylindrical portion 12 with its front end abutting on the rear end of the flange portion 7a.
8 is connected. 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. A grease-like follower 30 which is filled with an ink 28 having a shear thinning property and is movable at the rear end of the ink 28 so as to come into contact with and follow the ink surface as the ink is consumed.
Is filled. A follower rod 31 made of resin and having a specific gravity equivalent to that of the follower 30 is immersed in the follower 30. The follower rod 31 is provided as necessary (when the cross-sectional diameter of the ink storage section is large and the head of the ink is large, and when the viscosity of the ink is low and the ink head cannot be supported). 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. 5 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 the present embodiment, the ball valve 21 is loosely fitted into the valve chamber 34 by elastically expanding the ridge 33 without providing the slit 19b or the like at the tip of the bush 32. In this case, even if lubricating means is applied to the bush and the ball valve, there is a problem that the ridge 33 is slightly deformed or damaged when the bush is formed or when the ball valve is inserted. A tail plug 29 is crimped to the rear end of the barrel 1.

[0014]

First, FIG. 1 shows a state before writing with the chip 5 facing down, at which time the ball valve 21 comes into contact with the rear end of the ridge 19a and the guide hole 18 is opened. The ink 2 that has entered the valve chamber 15 from the ink storage tube 4 through the conducting hole 18
8 is guided to the back of the tip ball 5a through a groove or the like formed between the ridges. In this state,
Since the tip ball 5a is brought into close contact with the inner edge of the chip holding portion by the pressing of the spring 20, direct current of ink is prevented.
Further, since the tip ball 5a is slightly retracted by the writing pressure, a gap is generated and ink can flow out.

FIG. 2 shows a state in which the tip 5 is directed upward. At this time, the ball valve 21 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, the ink acts in the backward direction in the upward writing, so that air is trapped in the chip, and the ink does not immediately follow in the downward writing, resulting in rubbing.
Further, air entrapment is accumulated by repeating upward writing. )

The direct current and the reverse flow of the ink are applied to the spring 2.
0 is pressed by the tip ball 5a, but solid matter adheres to the tip ball 5a due to the processing variation of the tip holding portion and the gap between the tip holding portion and the tip ball 5a. In order to supplement the incomplete state of the case, it is necessary to support the large head of the ink to reliably prevent the backflow of the ink and to reduce the air entrainment (preventing the scuffing). Further, 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 7 a of the joint 3 abutting against the front end of the barrel 6. Since the ribs 8 of the die 7 bite against the step 9 of the base 2, the chip 5 is rattled against the base 2.

[0017]

The configuration and operation of the ballpoint pen according to the present invention are as described above.
In the case of fine writing, the backflow of ink can be prevented by upward writing or impact by a ball valve loosely fitted in the valve chamber, and since the tip ball is in close contact with the inner edge of the chip holding part except during writing, When placed downward, it is possible to prevent writing blur due to direct current and dry-up of the ink. Therefore, accidents that stain the inside of the barrel, hands, clothes, and the like are prevented. or,
The ink immediately follows after upward writing or impact, thereby preventing flaring. 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 longitudinal sectional view of a main part of a ballpoint pen according to a second embodiment of the present invention, showing a state where a chip is directed upward;

[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 7 Locking cylinder 7a Flange 8 Rib 9 Step 10 Chip fitting hole 10a Chip fitting hole 10b Holder fitting hole 10c Step portion 11 Holder 12 Fitting tube portion 12a Window portion 13 Bush 14 Ball receiving seat 15 Valve chamber 16 Protrusion 17 Locking portion 18 Guide hole 19 Elastic piece 19a Protrusion 19b Slit 20 Spring 20a Winding portion 20b Straight portion 21 Ball valve 22 Cap 23 Inner cap 24 Clip 25 Vent hole 26 Rib 27 Seal plug 28 Ink 29 Tail plug 30 Follower 31 Follower rod

Claims (5)

(57) [Claims] 1. A tip of a ballpoint pen at a tip of a joint,
In a ball-point pen having an ink storage tube at the rear,
A bush is fixed to the shaft center behind the joint, a valve chamber is provided in the shaft center of the bush, and a tapered or spherical ball seat at the rear of the valve chamber has a required number of protrusions on the front peripheral wall of the valve chamber. A ridge is provided, and a ball valve capable of closely contacting the ball receiving seat elastically deforms the ridge and is loosely fitted into the valve chamber so that it cannot be pulled out, and a rear end of the bush comes in contact with a front end of the bush. A spring is urged into the chip inner hole, and the tip of the spring presses the back of the tip ball rotatably held at the tip end of the tip so that the tip ball comes into close contact with the inner edge of the tip ball holding portion. When the ball valve is in the upward direction, the ball valve is in close contact with the ball receiving seat, and the guide hole is sealed. Through the valve chamber, grooves formed between the ridges, etc. Ballpoint pen, wherein the ink is configured to flow into the chip Te. 2. The ink storage tube has a low viscosity ink or a basically low viscosity ink, but has a high viscosity statically. 2. The ballpoint pen according to claim 1, wherein the ink is filled with ink having a so-called shear thinning property, and a follower is provided at a rear end of the ink so as to follow the consumption of the ink. 3. An upright straight portion is formed at the front of the spring, and a winding portion is formed at the rear. The straight portion is inserted into the inner hole of the chip, the winding portion is positioned at the rear end of the chip, and the rear end of the winding portion is formed. 2. The ball-point pen according to claim 1, wherein the ball-point pen contacts the front end of the bush. 4. The ballpoint pen according to claim 1, wherein a required number of elastic pieces are provided in front of the valve chamber of the bush, and a ridge is formed on an inner surface of the elastic piece. 5. The ballpoint pen according to claim 1, wherein a separate ink container is pressure-bonded to the rear end of the joint.