JPH11301164A - Ballpoint pen - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ballpoint pen for a ball face character with an ink direct flow and ink reverse flow prevention of a low cost using a low viscosity ink. SOLUTION: In the ballpoint pen 1 comprising a tip 3 of the pen made of a resin at a front end and an ink containing tube 2 at a rear part, a ball receiving seat 7 brought into contact with a back surface of a tip ball 14 at the time of applying a writing pressure and a spring set for pressing the back surface of the ball 14 to bring the ball 14 into close contact with an inner edge of a ball embracing part, an overall circumferential neck part 5 is formed rear of a tip barrel 4 press bonded to the tube 2 so that its inner surface is formed as a guide hole 11 with a tapered part 8 on a longitudinal inner surface. Its front tapered part 8 is formed as the seat 7, and a rib 9 of a predetermined position is formed on its forward inner surface to form a valve chamber between the seat 7 and the rib 9. A ball valve 12 is elastically deformed at the part 5 in an enlarging direction by pressing a rear tapered part 8 from a rear end of the barrel 4 so that the valve 12 is movably engaged with the chamber. At the time of upward directing the tip 3, the valve 12 is brought into close contact with the seat 7 to liquidtightly block the hole 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ballpoint pen filled with a low-viscosity ink.

[0002]

2. Description of the Related Art The ink of a conventionally known oil-based ballpoint pen has a high viscosity, and a small amount of ink flows out by rotation of a tip ball during writing. In addition, there are problems such as unevenness, unevenness of writing lines, low density, and high writing pressure. In addition, as an improvement of the conventional oil-based ballpoint pen, a relatively low-viscosity ink is used. Are known. However, since this ink has a drawback that the ink easily dries, a cap for sealing the writing tip is required. Therefore, a low-viscosity oil-based ink with excellent drying resistance is conceivable. However, the amount of the ink flowing out is also large, and in order to increase the writing life, the diameter of the ink storage tube is increased to increase the amount of ink loaded. . The same applies to the water-based ink. However, since the viscosity of the ink is smaller than that of the conventional oil-based ballpoint 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 weight and impact of the ink. For this purpose, a grease-like follower is provided at the rear end of the ink, which normally moves following the consumption of the ink during writing, but suppresses the backflow of the ink against its own weight or impact.

[0003] However, even when the follower is provided, when writing upward, if the ink on the back surface of the tip ball runs out, a significant backflow occurs because the ink head is added directly. In addition, direct current (ink bleeding) of the ink is also easy. If the ink causes backflow or direct current, there is a risk of soiling clothes and the like. In addition, there is a problem that handwriting is caused by dropping or knocking impact. Therefore, as a preventive measure, an ink follower (follower) is provided at the rear end of the ink, and a spring for pressing the back surface of the tip ball so that the tip ball comes into close contact with the inner surface of the ball holding portion of the tip is provided. A method has been adopted in which a valve mechanism is provided between the rear end and the front of the ink storage unit to prevent direct current or backflow of ink.

FIGS. 6 to 8 show a conventional ballpoint pen, which has been disclosed by the same applicant. In this ball-point pen, a tip of a ball-point pen is fixed to the tip of an ink container filled with ink, and a valve member is disposed in the ink container tube so as to face the rear end of the chip. A ball receiving seat is formed at the rear end of the valve chamber in communication with the guide hole, and a resilient piece that is elastically displaceable is formed in front of the valve chamber with a slit at a required portion. A protrusion is formed on the inner surface of the elastic piece, and the ball valve is loosely fitted into the valve chamber between the ball receiving seat and the protrusion. The valve member has a conical or spherical ball receiving seat that comes into close contact with the ball valve when the ball valve comes into contact with the ball valve. The ball valve is easily inserted into the valve chamber by easily moving over the ball chamber, and is disposed in the ink storage tube, and the ball valve is loosely fitted into the valve chamber in a state where the outer periphery of the front portion is restricted.

[0005]

The ballpoint pen of the present invention using a low-viscosity ink is a ballpoint pen for a bold character having a relatively large tip ball diameter, and a conventional one is a metal tip. It is intended to solve the problem of high cost due to the structure having a joint between the tip and the ink storage tube, or the structure of the above-mentioned conventional example or the injection molded product integrally having the joint portion. is there.

[0006]

The present invention has the following arrangement to solve the above-mentioned problems. A ball-point pen according to the first aspect of the present invention is a ball-point pen having a tip of a resin ball-point pen at the tip and an ink storage tube at the back, wherein the ball-point pen comes into contact with the back surface of the tip ball when writing pressure is applied. A spring seat that presses the back surface of the tip ball so that the seat and the tip ball are in close contact with the inner edge of the ball holding portion is provided at a required position, and furthermore, the entire circumference is provided around the rear outer periphery of the tip shaft portion that is pressed against the ink storage tube. A tapered portion is formed on the front and rear inner surfaces with its inner surface as a guide hole, and the front tapered portion is used as a ball receiving seat, and further, a required rib is formed on its front inner surface to form a ball receiving seat. A ball chamber is formed between the rib and the valve chamber, and the ball valve presses a taper portion at the rear from the rear end of the tip shaft portion to elastically deform the crooked portion in the expanding direction, so that the ball valve moves into the valve chamber. When fitted , The chip is configured to guide holes in close contact with the ball valve ball seat when upward is closed in liquid-tight manner.

According to a second aspect of the present invention, there is provided a ball-point pen according to the first aspect, wherein the ink storage tube has a low-viscosity ink such as an aqueous or low-viscosity oil-based ink having a so-called shear thinning property. And a grease-like follower is provided at the rear end of the ink to follow the ink as the ink is consumed.

[0008]

1 to 5 show an embodiment of a ball-point pen according to the present invention. The ball-point pen is provided with a tip 3 of a resin ball-point pen at the tip and an ink container 2 at the rear. 4 and 5
As shown in FIG. 7, the tip 3 is caulked so that the tip ball 14 is rotatably held with the tip ball 14 substantially in contact with the receiving seat 15a having the channel portion 15 into which ink can flow. (Ball holding part 15c)

More specifically, the channel portion 15 has a receiving seat 15a and a tip ball 14 which come into contact with the back of the tip ball 14 with the tip 3 when pen pressure is applied.
Spring seats 15b for pressing the back surface of the tip ball 14 in close contact with the inner edge of the tip ball 5c are arranged alternately in a radial pattern, and the chip 3 is disposed between the provided seat 15a and the spring seat 15b.
An ink inflow groove 15e is formed to supply ink from the rear end to the tip ball 14. The close contact of the tip ball 14 with the inner surface of the ball holding portion 15c is extremely important for drying the writing tip and preventing direct current of ink. By the way, as a method for pressing the back surface of the tip ball, a spring is provided in the inner hole of the chip and the tip ball is pressed by the tip, and a frame having a rod shaft portion for pressing the back surface of the tip ball on the front surface of the spring. Intervening.
According to the embodiment of the present invention, such members are omitted, so that the cost is superior.

[0010] Further, an entire circumferential concave portion 5 is formed on the outer peripheral portion of the shaft portion 4 of the chip that is pressed against the ink containing tube 2, and a rear end portion 6 is further formed behind the concave portion. The shaft portion 4 is pressed against the ink containing tube 2, and the outer peripheral portion of the rear end portion 6 is set slightly smaller than the inner peripheral size of the ink containing tube 2.

Further, a tapered portion is formed on the front and rear inner surfaces of the inner surface of the concave portion 5 as a guide hole 11, and a rib 9 at a required position is formed on a front inner surface of the front tapered portion as a ball receiving seat 7. A valve chamber 10 is formed between the ball receiving seat 7 and the rib 9. Note that the cylindrical portion forming the concave portion 5 and the front and rear tapered portions are set to a thickness (thin wall) that is easily elastically deformed. Further, since the outer peripheral dimension of the rear end 6 is set slightly smaller than the inner peripheral dimension of the ink container 2, the ball valve 12 is moved from the rear end of the rear end 6 of the tip 3 to the tapered section 8 behind. , The front and rear tapered portions are easily bent and deformed while the rear end portion 6 slides.
Are loosely fitted in the valve chamber, and when the tip 3 is facing upward, the ball valve 12 comes into close contact with the ball receiving seat 7 and the guide hole 11
Can be closed in a liquid-tight manner. Although the ball valve is shown as a sphere in the embodiment, a rod-shaped body may be used as an equivalent means.

The ink storage tube 2 is filled with a low-viscosity ink 16 such as a water-soluble or low-viscosity oil-based ink having a so-called shear thinning property, and follows the ink at the rear end of the ink as the ink is consumed. A grease-like follower 17 is provided. If necessary, a resin follower rod having substantially the same specific gravity as the follower is immersed in the follower 16. (Not shown) The ink storage tube 2 is an extruded tube made of polypropylene resin or a metal tube.

[0013]

In the ballpoint pen, the tip ball 14 is brought into close contact with the inner edge of the ball holding portion 15c of the chip by the pressing of the spring seat 15b, so that direct current of ink is prevented. In addition, since the tip ball 14 slightly retreats due to the writing pressure, a gap is generated and ink can flow out, and the ink smoothly flows by rotation of the tip ball 14 by writing.

FIGS. 1 and 2 show a state in which the tip 3 is directed upward. At this time, the ball valve 12 is located in the ball receiving seat 7 of the valve chamber 10 and seals the guide hole 11, so that the upward writing is performed. Even if the ink on the back surface of the tip ball 14 of the chip runs out, the ink does not clog the head and does not flow backward. Therefore, when the tip 3 in FIG. 3 is turned downward, the ink can immediately flow out, and the writing is prevented from being flared. (By the way, in the structure without a ball valve, the ink acts in the reverse flow direction by writing upward, so air is trapped in the chip,
The ink does not immediately follow with downward writing, resulting in rubbing. When the tip 3 is turned downward, the ball valve 12 comes into contact with the rib 9, and ink flows through the gap between the ribs.

When the ball valve 12 is inserted, the ball valve 12 presses the rear tapered portion 8 from the rear end of the rear end 6 of the chip 3 so that the rear end 6 slides back and forth. Is easily bent and deformed, so that the ball valve 12 is easily loosely fitted into the valve chamber 10 without damaging the ball receiving seat 7.

[0016]

The configuration and operation of the ballpoint pen of the present invention are as described above. The mechanical part that can prevent direct current of ink and the mechanical part that can prevent backflow by forming the tip from resin are chip-molded. Sometimes easy to form, and
By forming the valve chamber as described above, the ball valve can be easily fitted into the valve chamber without damaging the ball receiving seat. Can be provided.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing the entirety of a ballpoint pen according to an embodiment of the present invention, showing a state in which a chip is upward.

FIG. 2 is an enlarged sectional view of a forward part of FIG. 1;

FIG. 3 is an enlarged cross-sectional view of a tip portion of the ballpoint pen according to the embodiment, showing a state in which a chip is directed downward.

FIG. 4 is an enlarged sectional view of a main part of the tip of the chip.

FIG. 5 is a cross-sectional view slightly before a channel portion of the chip.

FIG. 6 is a longitudinal sectional view showing the entire ballpoint pen of the conventional example, and shows a state in which a chip is directed upward.

FIG. 7 is an enlarged cross-sectional view of a forward part of FIG. 6;

FIG. 8 is an enlarged cross-sectional view of a tip portion of a conventional ballpoint pen, and shows a state where a tip is directed downward.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ball-point pen 2 Ink storage tube 3 Tip 4 Shaft part 5 Crack part 6 Rear end part 7 Ball receiving seat 8 Taper part 9 Rib 10 Valve room 11 Guide hole 12 Ball valve 13 Inner hole part 14 Tip ball 15 Channel part 15a Receiving seat 15b Spring seat 15c Ball holding portion 15d Center hole 15e Ink inflow groove 16 Ink 17 Follower 20 Ballpoint pen 21 Tip 22 Inner hole portion 23 Shaft portion 24 Receiving seat 25 Tip ball 26 Valve member 27 Valve chamber 28 Guide hole 29 Elastic piece 30 Slit Part 31 Ridge 32 Ball seat 33 Ball valve

Claims (2)

[Claims] 1. A ball-point pen having a tip of a resin ball-point pen at the tip and an ink-storing tube at the rear, wherein a receiving seat and the tip-ball which come into contact when writing pressure is applied to the back of the tip-ball are held by the ball. A spring seat that presses the back surface of the tip ball so as to be in close contact with the inner edge of the holding portion is provided at a required position, and furthermore, a full-peripheral concave portion is formed on the rear outer peripheral portion of the tip shaft portion that is pressed against the ink storage tube. A tapered portion is formed on the front and rear inner surfaces with the inner surface as a guide hole, a required taper is formed on the front inner surface with the front tapered portion as a ball seat, and the space between the ball seat and the rib is a valve chamber. And
When the ball valve presses the rear tapered portion from the rear end of the tip shaft portion to elastically deform the knurled portion in the expanding direction, the ball valve is loosely fitted in the valve chamber, and when the tip is upward, the ball is A ball-point pen characterized in that the valve is in close contact with the ball receiving seat and the guide hole is closed in a liquid-tight manner. 2. An ink container is filled with a low-viscosity ink such as an aqueous or low-viscosity oil-based ink having a so-called shear thinning property. 2. The ballpoint pen according to claim 1, wherein a follower is provided.