JPH10272880A - Ballpoint pen - Google Patents

Abstract

(57) [Summary] (Corrected) [PROBLEMS] To provide a ballpoint pen using low-viscosity ink, which can prevent direct current and backflow of ink, upward writing, and writing blur after impact. SOLUTION: A receiving ball 3 having a slightly larger diameter than a tip ball 2 is disposed in a substantially abutting state on a receiving seat surface at a rear end of a tip tip inner hole, and a tip ball in abutting state with a front end of the receiving ball. Is disposed, the tip ball is reduced in diameter at the tip end portion, rotatably held by the tip ball holding portion 1c, and when the receiving ball comes into contact with the front surface of the receiving ball on the inner surface of the chip. A step is formed to allow close contact, and a spring 4 is inserted into an inner hole behind the receiving seat surface 1d of the chip, and the tip of the rod shaft portion 4a presses the back of the receiving ball, and the receiving ball is pressed. By pressing the back surface of the tip ball rotatably held by the tip end of the tip, the tip ball comes into close contact with the inner edge of the ball holding portion of the chip, and ink is prevented from flowing out.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art In general, a ballpoint pen using a water-based ink having a so-called shear-thinning viscosity or a low-viscosity oil-based ink, in which the viscosity is reduced by rotation of a tip ball during writing and the ink flows out, is known. . A ballpoint pen using such an ink has a large amount of ink flowing out (in order to increase the writing density), so that the diameter of the ink storage tube is increased to increase the amount of ink loaded. Further, since the viscosity of the ink is much smaller than that of the oil-based ball-point pen, the flow resistance to the ink container 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. However, even when the follower is provided, if the ink on the back surface of the tip 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. Further, since the viscosity of the ink is low and the amount of outflow is large, there is a problem that the ink is bleeding (direct current) when a gap is formed between the tip ball and the tip holding portion when the tip side is directed downward. Further, since the holding portion at the tip end of the tip holding the tip ball is formed in a small and thin shape, there is an accident that the tip ball falls off due to deformation or wear due to excessive writing or drop impact. In that case,
There is a risk that the ink will flow direct current and stain the surroundings.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a low-viscosity ink (an aqueous ink having a shear-thinning property or a low-viscosity ink in which the viscosity is reduced by rotation of the tip ball during writing and the ink flows out). An improvement of a ballpoint pen that uses oil-based ink, etc., which prevents reverse flow of ink caused by upward writing or impact of the ballpoint pen and direct current when the tip side is placed downward, and can be used inside the ball-point pen barrel, hand, and clothing. Can be prevented from being stained. It also prevents writing screeching caused by running out of ink due to air entrainment on the back side of the tip ball when upward writing and impact is applied, and drying caused by incomplete sealing between the tip ball and the inner edge of the tip holding portion. Enables prevention of handwriting. In addition, even when an accident occurs in which the tip ball comes off due to deformation or wear due to excessive writing or a drop impact, ink direct current can be prevented.

[0004]

According to a first aspect of the present invention, there is provided a ball-point pen having a tip of a ball-point pen at an end thereof, and an ink storage tube at a rear portion, and the ink storage tube is filled with low-viscosity ink. In the ball-point pen, a receiving ball having a diameter slightly larger than that of the tip ball is disposed substantially in contact with the receiving seat surface at the rear end of the inner hole of the tip, and the tip of the tip is placed in contact with the front end of the receiving ball. When the ball is disposed, the tip ball is reduced in diameter at the tip end portion and rotatably held by the ball holding portion at the tip, and when the receiving ball comes into contact with the front surface of the receiving ball on the inner surface of the chip. A step is formed to allow close contact, a spring is inserted into an inner hole behind the receiving seat surface of the chip, and the tip of the rod shaft portion presses the back surface of the receiving ball, and the receiving ball is moved toward the tip of the tip. Rotatably held by the part By pressing the back surface of the end ball, the tip ball is brought into close contact with the inner edge of the ball holding portion of the chip to prevent the ink from flowing out, and at this time, a gap through which ink can flow between the step portion and the front surface of the receiving ball. Is formed.

According to a second aspect of the present invention, in the ballpoint pen according to the first aspect, the rear end of the winding portion of the spring is locked by a locking step provided at the rear end of the tip. It is provided so that it cannot be removed.

A ballpoint pen according to a third aspect of the present invention is the ballpoint pen according to the first aspect, wherein a tip of the ballpoint pen is provided at a tip of a joint and an ink storage tube is provided at a rear side. A valve chamber in which a valve element is loosely fitted is provided at the rear of the tip at the shaft center of the joint, and a guide hole communicating the valve chamber and the ink storage tube is provided, and a tapered or spherical shape is provided at the rear of the valve chamber. When the tip side is upward, the valve body is in close contact with the valve body receiving seat at the rear of the valve chamber, the guide hole is sealed, and backflow of ink is prevented. Become composed.

[0007]

1 to 3 show an embodiment of the present invention. First, as shown in the figure, a rear shaft portion 10 to be fixed to an inner writing portion side of an ink container 16 filled with ink 17 inside a tube made of a polypropylene resin and an inner hole to which the tip 1 is press-fitted and fixed. 8 is provided with a tapered or spherical valve body receiving seat 12 having a guide hole 14 substantially at the center of the inside thereof, and a valve formed by the axial rear end of the chip and the valve body receiving seat 12. A structure in which a ball-shaped valve element 15 loosely fitted in the chamber 11 communicates from the ink storage tube 16 to the tip ball 2 serving as a writing portion during normal writing (in general, the valve chamber is positioned with respect to the axis of the chip). The ball-shaped valve element is eccentrically provided so as to face downward, and the ball-shaped valve element eccentrically contacts the rear end of the chip, so that the ink can flow into the chip through the groove 13 and the like. Then the valve body 15 is the joint 7 A ball-point pen having a structure in which backflow of ink is prevented by being in close contact with the valve body receiving seat 12. The ball-point pen is a so-called ball-point pen which is usually used by being inserted into a shaft cylinder (not shown) serving as a writing shaft. It shows a refill form.

In this ball-point pen, the ink 17 has a statically high viscosity, and the viscosity of the ink decreases due to the rotation of the tip ball 2 during writing, and the ink 17 has a shear thinning viscosity so that the ink flows out smoothly. A water-based ink (hereinafter referred to as a medium viscosity ink) or a low-viscosity oil-based ink is filled.
Follower rod 19 for improving the aging stability and drop resistance
Is provided.

FIG. 2 shows the tip 1 which is the writing tip of the ballpoint pen of the present invention and the inside thereof. The tip ball 2 is placed substantially in contact with the receiving seat surface 1d at the rear end of the tip end bore.
The receiving ball 3 having a slightly larger diameter is provided, and the tip ball 2 is provided in contact with the front end of the receiving ball 3, and the tip ball 2 is reduced in diameter at the tip of the tip (reduced). Diameter portion 1f) A tapered shape which is rotatably held by a ball holding portion 1c at the tip formed by caulking or the like and which can be brought into close contact with the front surface of the receiving ball 3 on the inner surface of the chip. Is formed. A spring 4 is inserted into an inner hole behind the receiving seat surface 1d of the chip 1 so that the tip of the rod shaft portion 4a presses the back of the receiving ball 3 and the receiving ball 3 rotates to the tip end of the chip. Press the back of the tip ball 2 arbitrarily held,
The tip ball 2 is brought into close contact with the inner edge of the ball holding portion 1c of the chip to prevent the ink from flowing out.
A gap through which the ink can flow is formed between the receiving ball 3 and the front surface of the receiving ball 3.

The spring 4 has a tip 1 at its rear end.
After being inserted into the chip 1 with a diameter slightly smaller than the inner diameter of the rear end side, the rear end face of the chip 1 is plastically deformed while pressing the rear end side of the spring against the chip 1 to form the locking step 1b. In addition, since the winding portion 5 of the spring 4 does not come into contact with the inner hole surface of the chip 1 and the movement of the spring action is not alienated, the center of the chip 1 having the minimum diameter is set to facilitate insertion and detection of the orientation during assembly. Since the straight rod portion 4a penetrating the hole 1e and pressing the receiving ball 3 is extended as much as possible from the center of the chip 1, the tip 1 usually has an inner diameter smaller at the center portion than at the rear end portion. The spring 4 has a small-diameter portion 5a at the distal end of the winding portion 5 in consideration of, for example, the need to make the approximate center of the spring 4 smaller in diameter than the rear end side or to make the entire outer diameter of the spring sufficiently small. To
A large diameter portion 5b is provided at the rear end of the winding portion 5. or,
The portion between the small diameter portion 5a and the large diameter portion 5b is a portion having spring properties of the spring 4, and the portion is formed in a tapered shape or a stepped shape.

By the way, the above-mentioned joint 6 and ink storage tube 16 can be formed as an integral resin molded product.
Further, the joint 6 and the ink storage tube 16 can be directly used as a shaft of a writing instrument. Further, the valve element 15 of the above-described embodiment is used.
Is shown in a ball shape, but the valve body is formed in a shaft shape and both end surfaces are formed in a tapered or spherical shape, and a groove for ink guide may be formed on a side surface if necessary. .

[0012]

FIG. 1 shows a state before writing with the chip 1 facing down. At that time, the valve body 15 comes into contact with the rear end of the chip 1 and the guide hole 14 is opened. The ink 17 that has entered the valve chamber 11 from the ink storage tube 16 through the guide hole 14 is guided to the back of the tip ball 2. In this state, the tip ball 2 is brought into close contact with the inner edge of the ball holding portion 1c of the chip through the receiving ball 3 by the pressing of the rod shaft portion 4a of the spring 4, so that the direct current of the ink is prevented. In addition, the tip ball 2 is slightly retracted by the writing pressure, so that a gap is generated so that ink can flow out. By writing, the viscosity of the tip ball 2 decreases due to the rotation of the tip ball 2 and the ink flows out. Becomes possible. In this embodiment, since there is a free space between the valve body 15 and the rear end of the chip 1, there is no hindrance to ink circulation.

A receiving seat surface 1d is provided on the back of the receiving ball 3.
There is a (reception seat of a tip ball having a plurality of ink inflow grooves penetrating toward the chip inner hole), and the tip of the rod portion 4a passes through the center hole 1e of the reception seat surface 1d. Chip 1
The ink inside is the ink inflow groove and center hole 1e and the rod shaft 4a.
Through the peripheral surface of the receiving ball 3 to the rear surface of the tip ball 2.

When the chip 1 is turned upward, the valve body 15 is in close contact with the valve body receiving seat 12 of the valve chamber 11 and the guide hole 14
Is sealed, so that ink does not flow backward even when the ink on the back surface of the tip ball 2 is exhausted by upward writing. Therefore, when the chip 1 is turned downward, the ink can immediately flow out, and writing is prevented from being rubbed. (By the way, in the structure without the valve element, the ink acts in the backward direction in the upward writing, so that air is trapped in the chip, and the ink does not follow immediately in the downward writing, and the ink is rubbed. Entanglement is accumulated.)

Further, since the tip ball 2 is always in close contact with the inner edge of the tip holding portion, the tip portion is dried to prevent handwriting. Further, even if upward writing or impact is applied by the cooperative action of the tip ball 2 and the valve element 15, air entrainment is prevented, so that writing is prevented.

In the event that the tip ball 2 falls off due to the influence of excessive writing or a drop impact, as shown in FIG. 3, the tip 1 is pushed by the rod shaft portion 4a of the spring. The front surface of the receiving ball 3 comes into close contact with the step portion 1g, so that the direct current of the ink can be prevented.

[0017]

The configuration and operation of the ballpoint pen according to the present invention are as described above. Since the tip ball is in close contact with the inner edge of the chip holding portion except when writing, the direct current or backflow of ink is prevented and the inside of the shaft cylinder is prevented. Accidents that stain hands, clothes, etc. are prevented. or,
Writing scratches due to drying are also prevented. In addition, by providing a valve element that fits loosely in the valve chamber, a state of incomplete close contact between the tip ball and the tip holding portion and a state of severe ink backflow due to upward writing or impact are guaranteed. In addition, even if an accident occurs in which the tip ball falls off due to the influence of unreasonable writing or a drop impact, direct current of the ink can be prevented.

[Brief description of the drawings]

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

FIG. 2 is a longitudinal sectional view of a chip.

FIG. 3 is a cross-sectional view of a main part showing a state in which a tip ball has fallen from a tip of a tip.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Chip 1a Shaft part 1b Locking step part 1c Ball holding part 1d Receiving seat surface 1e Center hole 1f Reduced diameter part 1g Step part 2 Tip ball 3 Receiving ball 4 Spring 4a Rod shaft part 5 Winding part 5a Small diameter part 5b Large diameter Part 6 Joint 7 Front shaft part 8 Inner hole 9 Flange part 10 Rear shaft part 11 Valve room 12 Valve body receiving seat 13 Groove 14 Guide hole 15 Valve body 16 Ink storage tube 17 Ink 18 Follower 19 Follower rod

Claims (3)

[Claims] 1. A ball-point pen having a tip of a ball-point pen at an end thereof and an ink storage tube at a rear end thereof, wherein the ink storage tube is filled with low-viscosity ink. A receiving ball having a slightly larger diameter than the tip ball is disposed substantially in contact with the surface, and a tip ball is disposed in contact with the front end of the receiving ball, and the tip ball is compressed at the tip end of the chip. A step portion is formed to be rotatably held by the ball holding portion at the tip and rotatably held at the front end of the receiving ball on the inner surface of the chip. A spring is inserted into the inner hole at the back of the seat, and the tip of the rod shaft presses the back of the receiving ball, and the receiving ball presses the back of the tip ball rotatably held at the tip of the chip. The tip ball is the tip ball Ballpoint tightly to the inner edge of the lifting unit outflow of ink is prevented, to that time, characterized by comprising been configured ink allows flow gap is formed between the front of the ball receiving said stepped portion. 2. The ballpoint pen according to claim 1, wherein a rear end of the winding portion of the spring is locked by a locking step provided at a rear end of the chip so as to be unable to be pulled out. 3. A tip of a ballpoint pen at the end of the joint,
A ballpoint pen having an ink storage tube at the rear,
A valve chamber in which a valve element is loosely fitted is provided at the rear of the tip at the shaft center of the joint, and a guide hole communicating the valve chamber and the ink storage tube is provided, and a tapered or spherical shape is provided at the rear of the valve chamber. When the tip side is upward, the valve body is in close contact with the valve body receiving seat at the rear of the valve chamber, the guide hole is sealed, and backflow of ink is prevented. The ballpoint pen according to claim 1, wherein the ballpoint pen is used.