JPH10217667A - Ballpoint pen - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a direct flow and a reverse flow of ink, blur after upward writing or impact and to prevent the direct flow of the ink even if a tip ball is dropped in a ballpoint pen using aqueous ink or low viscosity oily ink having shear-rate thinning. SOLUTION: In the ballpoint pen, a tapered receiving set 13 is provided at a tip 5 rear end disposed concentrically with a joint 3, and a collar 16 having a tapered part is provided substantially at a center. An ink guide groove 15 at a predetermined position of an outer periphery of a barrel extended forward and a small-diameter part 18 at its end are provided. A dowel 14 integrally having the barrel extended rearward is provided, and the dowel is brought at its tip of the part 18 into contact with a rear end of a tip ball 5a, urged by a spring 23 to bring the ball into contact with an inner edge of an enclosing part of the tip end. In this state, a gap for feeding ink is formed between a receiving seat of the joint and the tapered part of the dowel. At the time of dropping the ball, the tapered part is brought into close contact with the seat of the joint to prevent the direct flow of the ink.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aqueous ink having a so-called shear-thinning viscosity, which has a high viscosity in a static state, and the viscosity is reduced by the rotation of a ball during writing so that the ink flows out. The present invention relates to an improvement of a ballpoint pen using an oil-based ink having a high viscosity.

[0002]

2. Description of the Related Art A ballpoint pen using an aqueous ink having a shear-thinning property, in which the viscosity is reduced by rotation of a tip ball at the time of writing and the ink flows out, is known. In general, ballpoint pens that use water-based inks having low shear viscosity or low-viscosity oil-based inks have a large amount of outflow of ink (to increase the writing density) by increasing the diameter of the ink storage tube and increasing the amount of loaded ink. I have. Further, since the viscosity of the ink is smaller than that of a normal oil-based ballpoint pen, the flow resistance to the ink container is small. Therefore, ink leaks due to the ink's own weight or impact (ink flows backward to the rear end of the ink storage tube)
Tends to occur. 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. In addition, since the viscosity of the ink is low and the amount of outflow is large, there is a problem in that the ink bleeds (direct current) when a gap is formed between the tip ball and the tip caulking portion when the tip side is directed downward.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a ballpoint pen using a water-based ink having a 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 is discharged. It is possible to prevent the backflow of ink caused by upward writing or impact of a ballpoint pen and the direct current when the tip side is placed downward, preventing contamination of the inside of the barrel, the hand, and the clothes where the ballpoint pen is mounted as a refill. Make it possible. 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 of a joint and an ink storage tube at a rear side.
A ballpoint pen filled with a water-based ink or a low-viscosity oil-based ink having a so-called shear thinning property. In this, a tapered receiving seat is provided at the tip end of the joint axis, and a flange having a tapered portion that can be in close contact with the receiving seat is provided at substantially the center,
A coma having an ink guide groove and a small-diameter portion at the tip at an outer periphery required portion of the shaft portion extending forward and a shaft portion integrally extending rearward is provided. The tip of the diameter portion contacts the rear end of the tip ball, and the tip ball is urged by a spring so as to be in close contact with the inner edge of the holding portion at the tip of the tip. A gap through which ink can flow is formed between the tapered portion.

A ball pen according to a second aspect of the present invention is the ball pen according to the first aspect, wherein a top is inserted from the rear end of the joint, and the rear end of the flange and the inner step of the joint. And a spring is biased between them.

A ballpoint pen according to a third aspect of the present invention is the ballpoint pen according to the first aspect, wherein a bush having a valve chamber at the rear end of the joint shaft is fixed, and a valve is provided at the rear end of the valve chamber. The body receiving seat is provided with a required number of ridges on the front peripheral wall of the valve chamber, and the valve body that can be brought into close contact with the valve body receiving seat elastically deforms the ridge and cannot be pulled out into the valve chamber and is loosely fitted. The spring is biased between the front end of the bush and the rear end of the collar of the top.

[0007]

1 and 2 show a first embodiment of the present invention. First, 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. The front locking cylinder 7 is provided with a rib 8 inclined forward in the axial direction at a required position on the circumference. ing.
Further, a chip fitting hole 10 is formed in the locking cylinder portion 7 from the front end, and the chip 5 is pressed into the chip fitting hole 10 from the rear end side.

The joint 3 is made of an elastically deformable synthetic resin and is integrally formed. The joint 3 communicates with the chip fitting hole 10 and is located at the rear end of the shaft 11 of the chip 5 at the rear. 13 are provided. A slit portion 21 is formed at a required position on the rear end side of the fitting tube portion 12 so that the rear end portion can be appropriately expanded by elastic deformation. In addition, a tapered surface 24 is provided at the rear end of the fitting cylinder portion 12, and an inner step portion 22 is formed at the rear end of an inner hole communicating with the receiving seat 13.

The top 14 has a flange 16 provided with a tapered portion 17 at the approximate center thereof so as to be able to come into close contact with the receiving seat 13. It has a small diameter portion 18 and is formed integrally with a shaft portion 20 extending rearward. The tip 5 is swaged so that the tip ball 5a is rotatably held with the tip ball 5a substantially in contact with a seat having a channel 5b into which ink can flow.

The top 14 is provided with the fitting cylinder 12 of the joint 3.
The spring 23 is urged between the step 19 at the rear end of the flange 16 and the inner step 22 of the joint 3 while the rear end is elastically expanded. The shaft portion in front of the top 14 is fitted into the inner hole of the chip 5 to secure a gap between the tapered portion 17 and the receiving seat 13 through which ink can flow. The tip of the tip 18 abuts the rear end of the tip ball 5a, and the tip ball 5a comes into close contact with the inner edge of the holding portion at the tip of the tip 5.

A flange 26 is provided at the rear end of the locking cylinder 7 of the joint 3, and the fitting cylinder 12 extends behind the flange 26. 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 26. A water-based ink or a low-viscosity shear-thinning ink, which has a high viscosity statically in the ink storage tube 4 and whose viscosity is reduced by rotation of the tip ball 5a during writing so that the ink can flow out. The ink 25 is filled with a grease-like follower that can move following the ink surface by contact with the ink surface as the ink is consumed. (Not shown)

As described above, a ballpoint 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 as a refill, and the joint 3 is attached to the front surface of the shaft portion 6. The rear end edge of the flange 26 is abutted against the base 2 with the step 9 provided on the inner surface thereof, and the step 9 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. It is screwed to the shaft 6.

FIG. 3 shows a second embodiment of the present invention. In this embodiment, a small-diameter rod shaft portion 31 that presses the tip ball 5a is separately attached to the tip of the top 30. This is nothing but design convenience. The other configuration is the same as that of the first embodiment, and the description is omitted.

FIG. 4 shows a third embodiment of the present invention. Only differences from the first embodiment will be described below. In this embodiment, a separate bush 45 having a valve chamber 47 at the rear end of the joint 40 axis is fixed by press fitting or the like, and a tapered or spherical valve body receiving seat 46 is provided at the rear end of the valve chamber 47. , 4 of valve room
7 A required number of protrusions 49 are provided on the front peripheral wall, and a spherical valve body 50 which can be in close contact with the valve body receiving seat 46 is elastically deformed by the protrusions and is loosely fitted into the valve chamber without being pulled out. , Bush 4
A spring 44 is urged between the front end of the frame 5 and the rear end of the flange 43 of the top 41. In addition, a guide hole 48 penetrating from the center of the valve body receiving seat 46 to the rear end is provided.

The bush 45 is fixed by the joint 4
There are various methods, such as a method of providing a groove and a protrusion between the peripheral surface of the rear end hole of the 0 and the outer peripheral part of the bush 45 and elastically locking, and are not limited to the embodiment. Also, if a required number of elastic pieces are formed on required portions of the shaft peripheral surface in front of the bush to form a required number of elastic pieces, and protrusions are provided on the inner surface of the elastic pieces, the insertion of the valve body into the valve chamber is facilitated, After the bush is fixed to the joint, the outer peripheral portion is restrained and the valve body cannot be pulled out.

[0016]

First, FIG. 1 shows a state before writing with the chip 5 facing down, and at this time, the top 14 has a small diameter portion 18 at the tip.
Is in contact with the rear end of the tip ball 5a, and a gap is formed between the tapered portion 17 of the flange portion 16 and the receiving seat 13. In this state, the small diameter portion 18
As a result, the tip ball 5a is pressed in close contact with the inner edge of the holding portion, thereby preventing direct current.

In the writing state, the tip ball 5a is slightly retracted by the writing pressure, so that a gap is formed and the ink flows out. Further, the writing lowers the viscosity by the rotation of the tip ball 5a and the ink flows out, so that writing with no dents and high density can be performed.

When the ballpoint pen of the embodiment is mounted on the barrel 1 as a refill, the base 2 is screwed with the flange 26 of the joint 3 abutting against the front end of the shaft 6. Since the ribs 8 of the locking cylinder 7 abut the step 9 of the base 2 in a biting manner, play is stopped between the chip 5 and the base 2.

In the case of the third embodiment, the small diameter portion 41
The first means in which the tip ball 5a is pressed closely to the inner edge of the ball holding portion of the chip in a, and the second means in which the valve body 50 seals the guide hole 48 are used in combination. Even when the means is incomplete, the backflow of the ink can be reliably prevented. In addition, backflow of ink due to repetition of upward writing and blurring of writing due to the backflow are prevented.

In the event that the tip ball 5a falls off due to the influence of excessive writing or a drop impact, as shown in FIG. The tip protrudes, and the above-described tapered portion 17 of the top 14 comes into close contact with the receiving seat 13 of the joint 3 so that direct current of ink can be prevented.

[0021]

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 ball holding portion of the chip except during writing, direct current or backflow of ink is prevented, and Accidents that stain the inside of the cylinder, hands, clothes, etc. are prevented. In addition, handwriting due to drying is 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 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 a ballpoint pen in a state where a tip ball has dropped off.

FIG. 3 is a vertical 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. 4 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 Cap 3 Joint 4 Ink storage tube 5 Tip 5a Tip ball 5b Channel 5c Center hole 6 Shaft part 7 Locking cylinder part 8 Rib 9 Step part 10 Chip fitting hole 11 Shaft part 12 Fitting cylinder part 13 Receiving seat 14 frame 15 ink guide groove 16 flange portion 17 taper portion 18 small diameter portion 19 step portion 20 shaft portion 21 slit portion 22 inner step portion 23 spring 24 taper surface 25 ink 26 flange portion 30 frame 31 rod shaft portion 40 joint 41 frame 41a Small diameter portion 42 Step portion 43 Flange portion 44 Spring 45 Bush 46 Valve body receiving seat 47 Valve chamber 48 Guide hole 49 Ridge 50 Valve body

Claims (3)

[Claims] 1. A tip of a ballpoint pen at a tip of a joint,
The rear end is filled with a water-based ink or a low-viscosity oil-based ink having a so-called shear thinning viscosity, which has a statically high viscosity and the viscosity decreases when the tip ball rotates during writing, and the ink flows out. In a ball-point pen having an ink storage tube fixed thereto, a tapered receiving seat is provided at the rear end of the tip at the joint axis, and a tapered portion is provided at substantially the center so as to be able to come into close contact with the receiving seat. A collar having a flange portion, having an ink guiding groove and a small-diameter portion at the tip at a required location on the outer periphery of the shaft portion extending forward, and a piece having a shaft portion extending rearward are provided integrally,
In addition, the top of the top of the small diameter portion contacts the rear end of the tip ball, and the top ball is urged by a spring so that the tip ball comes into close contact with the inner edge of the holding portion at the tip of the tip. A ballpoint pen having a gap formed between the receiving seat of the joint and the tapered portion of the top, through which ink can flow. 2. The ballpoint pen according to claim 1, wherein a top is inserted from a rear end of the joint, and a spring is biased between a rear end of the flange and an inner step of the joint. 3. A bush having a valve chamber is fixed to the rear end of the joint shaft, a valve body receiving seat is provided at the rear end of the valve chamber, and a required number of ridges are provided on a front peripheral wall of the valve chamber. The valve element that can be brought into close contact with the valve element receiving seat elastically deforms the ridge and cannot be pulled out into the valve chamber and is loosely fitted. A spring is provided between the front end of the bush and the rear end of the collar of the top. The ballpoint pen according to claim 1, wherein the ballpoint pen is energized.