JPH08244394A - Knock type ballpoint pen - Google Patents

Abstract

PURPOSE: To prevent the contamination of a hand, clothes or barrel inside and skipping of writing by preventing the direct and reverse flows of ink. CONSTITUTION: A refill 1 has a tip 12 of a ballpoint pen at the head of a joint 2 and an ink container 17 at the rear, and an erected rod shaft 16a formed at the end of the bore 11 of the tip and a spring 16. The end of the rod shaft pushes the rear end of the head ball, the head ball is brought into close contact with the inner edge of the ball holding part of the tip end to prevent the flow- out of ink. The contact state of the ball with the inner edge of the holding part is released by writing pressure by a mechanism for preventing the direct and reverse flow of the ink so that the ink can flow out as the ball rotates. The ink of low viscosity is filled in an ink containing tube, and a follower which follows up the ink as the ink is consumed is provided at the rear end of the ink.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art The same applicant discloses in JP-B-4-52067 a mechanism for preventing backflow of ink in a ballpoint pen provided with a valve chamber in which a ball is loosely fitted. This is a synthetic resin mouth plastic with a required number of ridges that prevent balls from being pulled out in the valve chamber where the balls are loosely fitted, and when writing, the gap formed between the ridges. The ink is made to flow through the chip to communicate with the chip. In addition, the ink of the oil-based ball-point pens known in the related art has a high viscosity, and the amount of ink flowing out by the rotation of the tip ball during writing is small. Further, there are problems such as bloating, unevenness of writing lines, low density, and high writing pressure.
Further, as an improvement of the conventional oil-based ball-point pen, the ink has a relatively low viscosity, but a water-based ball-point pen ink having a so-called shear thinning viscosity, in which the viscosity is lowered by the rotation of the tip ball and the ink smoothly flows out. Are known. However, this has a drawback that the ink is easily dried, and therefore 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 ink outflow is still large and the diameter of the ink containing tube is increased to increase the loading amount of ink in order to extend the writing life. . The same applies to the water-based ink, but since the viscosity of the ink is smaller than that of the ink of the conventional oil-based ballpoint pen, the flow resistance to the ink containing tube is small. Therefore, ink leakage (ink flows back to the rear end of the ink containing tube) is likely to occur due to its own weight and impact. Therefore, a grease-like follower is provided at the trailing end of the ink, which normally moves following the consumption of the ink during writing, but suppresses backflow of the ink against its own weight and impact. However, even if the follower is provided, if the ink immediately below the tip ball runs out when writing upward, there is a risk of conspicuous backflow due to the addition of the ink head 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 will bleed (DC) when a gap is formed between the tip ball and the tip holding portion when the tip side is faced down. Further, there is a problem that writing blurring occurs because the ink immediately below the tip ball tends to flow backward after writing upward and after impact such as knocking and dropping. Further, if the writing tip is inserted into a chest pocket or the like while protruding, there is a risk that the clothes will be soiled.

[0003]

DISCLOSURE OF THE INVENTION An object of the present invention is to provide a knock type ballpoint pen which is equipped with a ballpoint pen refill using low viscosity ink and which allows a writing tip to be retracted from a shaft tip opening. It is intended to prevent direct current of ink, knock, drop impact, and backflow of ink against upward writing to prevent contamination of the shaft, hands, clothes, and the like. or,
Upward writing, preventing writing blurring caused by ink exhaustion due to air entrapment immediately below the tip ball when shock is applied, and writing blurring caused by incomplete drying between the tip ball and the inner edge of the chip holding part Can be prevented.
Further, it is provided with a safety mechanism in which the writing tip is automatically retracted into the barrel even if the writing tip is inserted into a chest pocket or the like while protruding.

[0004]

DISCLOSURE OF THE INVENTION The knock type ballpoint pen of the present invention devised in order to achieve the above object is a rotary operation of a shaft cylinder, a knock operation well known in a Kahn type knock mechanism, and a clip at the time of knocking. The writing instrument shaft such as a knock mechanism with a safety mechanism that locks it at the tip to make the writing tip part projecting and unlocks when the clip is inserted into the chest pocket, and the writing tip part goes into the shaft. A ballpoint pen refill is mounted on a barrel, and the ballpoint refill is axially moved relative to the barrel to allow the writing tip to be retracted from the tip of the shaft, and the mounted ballpoint refill is the tip of the joint. The tip of the ball-point pen and the ink storage tube at the rear are provided, and the shaft center of the joint and the inner hole of the tip are provided with a mechanism for preventing direct current and backflow of ink. Is filled with low-viscosity ballpoint pen ink, and a follower that follows the ink as the ink is consumed is placed at the rear end of the ink. The ink does not flow backwards, and it is possible to prevent stains on the hands, barrel, and clothes and blurring of writing.

[0005]

1 to 3 show a first embodiment of a refill for a ballpoint pen mounted on a knock type ballpoint pen of the present invention. First, FIGS. 1 and 2 show a refill 1 of a ballpoint pen of the present invention. The joint 2 has a front shaft portion 3 formed in front of a collar-shaped step portion 4 and a rear shaft portion 4 formed in the rear thereof, and the tip 12 of the front shaft portion 3 holds an end ball 12a in an inner hole 11. The shaft portion 13 of is fixed. The inner hole portion 11 is formed by chip fitting holes 11a and 11b from the front, and a convex locking portion 14 is formed on the outer peripheral portion of the shaft portion 13 of the chip 12 if necessary so as to bite into the chip fitting hole 11b. Locked in a shape.

The tip 12 is crimped so that the tip ball 12a is rotatably held in a state where the tip ball 12a is substantially in contact with a seat having a channel 12b into which ink can flow. In addition, the spring 1 is attached to the inner hole of the tip 12.
6 is inserted, the rear end of the shaft portion 13 of the tip is appropriately crimped, and the rear end of the spring 16 is provided so as not to be pulled out.

Further, an upright rod shaft portion 16a is formed ahead of the spring 16, and the tip of the rod shaft portion 16a abuts the rear end of the tip ball 12a in a pressing manner. The tip ball 12a is brought into close contact with the inner edge of the ball holding portion (formed by caulking or the like) of the chip 12 by its pressing.

Further, a valve chamber 6 which is appropriately eccentric with the axial center of the tip 12 is provided behind the inner hole 11, and a tapered or spherical ball receiver is provided in the rear portion of the valve chamber 6 so as to communicate with the guide hole 9. Zodiac 7
Are formed. A groove 8 into which ink can flow is formed on one side of the inner wall of the valve chamber 6. Further, a ball valve 10 is loosely fitted in the valve chamber 6, and with the tip 12 facing downward, the ball valve 10 abuts against the rear end of the shaft portion 13 of the tip in a biased state, and the groove portion 8 is formed. The ink that has flowed in from the guide hole 9 through the like is flowed into the inner hole portion of the chip.

A rear shaft portion 5 is provided behind the step portion 4 of the joint 2.
Has been extended. On the outer periphery of the rear shaft portion 5, a cylindrical ink storage tube 17 is press-fitted and fixed by abutting its tip to the rear end of the step portion 4, and the inner diameter portion of the ink storage tube 17 is conducted to the guide hole 9 of the joint 2. There is. Further, the ink containing tube 17 is filled with ink 18 which is an oil-based ballpoint pen having excellent drying resistance, and the rear end of the ink 18 is in the form of a grease that can be moved by contacting the ink surface as the ink is consumed. The follower 19 is filled. For example, a transparent PP resin molded product or the like is used for the ink containing tube 17.

On the other hand, FIGS. 4 to 6 show an example of a knock type ballpoint pen. Basically, fairness 4-5398
Since it is the same as the knock-type writing instrument of Japanese Patent Publication No. 7, the following description will be made only on the main points and differences.

The shaft cylinder 20 is integrally formed with a clip 21 having a slit 30 on a side surface opposite to the clip 21 and a mounting leg portion 22 having grooves 23 connected to both sides of the slit 30 and communicating with the slit 30. A ball portion 24 is provided at the tip of the clip 21, and the ball portion 24 is provided with a hook-shaped locking step portion 25 and a side wall 26. Clip 21
Is a locking projection 33 and a locking step 25 of a knock body 31 described later.
Is elastically displaceable in the lateral direction by a distance capable of releasing the engagement with. The slit 3 is formed on the side surface of the shaft cylinder 20.
A window hole 27 is provided separately from 0. The shaft cylinder 20 is formed of a transparent resin molded product containing the above-mentioned integrated polyester resin.

Further, the knock body 31 has a locking projection 3 on its side surface.
3, a stopper piece 32 is provided on the coaxial line, and an engaging protrusion 34 in an elastically displaceable state is provided on an axis different from the engaging protrusion 33.

The refill 1 of the ball-point pen is inserted into the inner hole of the barrel 20 while the rear end of the coil spring 35 is in contact with the step 4, and the tip of the coil spring 35 is aligned with the inner step 28 of the barrel. The knock body 31 is mounted in a state of being abutted and accommodating the rear portion of the refill 1 of the ballpoint pen from the rear end of the barrel 20. The locking projection 33 and the stopper piece 32 of the knock body 31 pass through the groove 23, the locking projection 33 penetrates into the slit 30, and the stopper piece 32 is attached to the mounting leg 22.
Located in the inner groove 23. At that time, the locking projection 34 penetrates the rear end portion of the window hole 27 of the shaft cylinder to prevent the knock body 31 from being pulled backward.

FIG. 7 shows a second embodiment of the refill of the ball-point pen, and only differences from the first embodiment will be described below. First, the joint 40 is integrally formed of elastically deformable synthetic resin, and communicates with the tip fitting hole 49, and the valve chamber 41 is provided at the rear side. Also, valve chamber 4
1 has a tapered or spherical ball seat 42 at the rear end.
Is provided on the front peripheral wall of the valve chamber 41.
Is provided.

A ball receiving seat 42 is provided behind the valve chamber 41.
A ball guide 46 is formed in the valve chamber 41 by elastically deforming the protrusion 43 so that the ball valve 46 is loosely fitted in the valve chamber 41 so as not to be extracted. An ink guide groove is formed between the protrusions with which the ball valve 46 abuts. Further, the rear end of the spring 48 contacts the step portion 45 at the front end of the protrusion 43, and the rod shaft portion 48
The front end of a presses the rear end of the front ball 47a.

As described above, when the tip side is facing downward, the ball valve 46 comes into contact with the rear end of the ridge 43,
Ink passes through the guide hole 44, the valve chamber 41, the ink guide groove between the ridges, and the inner hole portion of the tip 47, and the tip ball 47a is formed.
It is possible to flow to the rear end.

FIG. 8 shows the third part of the ballpoint pen refill.
Is shown. Since it is basically the same as the first embodiment, only the differences will be described below. The front end of the spring 55 fitted into the tip 47 forms a seat, and the pushing body 54 having the rod shaft portion 54a is disposed in the front portion thereof, and the tip of the rod shaft portion 54a is the rear end of the tip ball 47a. Abutting against.

Further, FIG. 9 shows the fourth part of the refill of the ballpoint pen.
Is shown. Since it is basically the same as the first embodiment, only the differences will be described below. An upright rod shaft portion 48 a is formed at the front end of the spring 48. or,
It may be provided with a tapered winding portion along the tapered inner hole in front of the tip 47. Furthermore, since the inner hole of the chip is usually formed by a stepped hole, when it is formed in a spring having a stepwise winding portion that is reduced in diameter along the stepped hole. There is also.
Further, the front end of the winding part may be brought into contact with the tip ball. (Not shown) In the refill of the ball-point pen of the above-described embodiment, the joint and the ink containing tube are formed as separate members, but it is also possible to form both of them as an integral resin molded product.

[0019]

First, in the first embodiment of the refill of the ballpoint pen, FIG. 1 shows the state in which the tip 12 is directed upward, and at that time, the ball valve 10 is in the ball receiving seat 7 of the valve chamber 6.
Since the guiding hole 9 is sealed at the position, even if the ink is written upward and the ink immediately below the tip ball 12a of the chip runs out,
The head is not caught by the ink and does not flow back. Therefore,
The ink can immediately flow out when the tip 12 is turned downward, and blurring can be prevented in writing. (By the way, in the structure without the ball valve, the ink works backward in the upward writing, so that air is trapped in the tip, and the ink does not follow immediately in the downward writing and blurring occurs.)

As shown in FIG. 2, in the writing state with the tip 12 facing downward, the ball valve 10 abuts on one side of the rear end of the crimp portion 15 of the tip in a biased state, and the other side is inside the tip 12. A groove 8 into which ink can flow is formed, and the ink 18 that has entered the valve chamber 6 from the ink containing pipe 17 through the guide hole 9 is guided to the rear end of the tip ball 12a of the chip 12 through the groove 8.

In this state, the direct current of the ink is prevented because the tip ball 12a is brought into close contact with the inner edge of the chip holding portion by pressing the rod shaft portion 16a. Further, since the tip ball 12a slightly retracts due to the writing pressure, a gap is created to allow the ink to flow out, and the writing causes a large amount of the ink to flow out due to the rotation of the tip ball 12a, which makes it possible to write with high density without fluffing. Become.

Directly below the tip ball 12a is a channel 12b (tip ball receiving seat having ink inflow grooves penetrating toward the chip inner hole at a plurality of locations), and a rod shaft portion is provided in the center hole of the channel 12b. 16a penetrates. The ink in the chip is the ink inflow groove, the central hole, and the rod shaft portion 16a.
It is guided to just below the tip ball 12a through a gap between and.

Next, in the second embodiment of the refill of the ballpoint pen, FIG. 7 shows a state in which the tip 47 is directed upward, at which time the ball valve 46 comes into close contact with the ball receiving seat 42 of the valve chamber 41. Since the guide hole 44 is sealed by the upward writing, the ink does not flow back even if the ink immediately below the tip ball 47a is used up. With the tip 47 facing down,
The ball valve 46 comes into contact with the rear end of the protrusion 43, and the guide hole 44 is opened. The ink that has entered the valve chamber 41 from the ink containing tube 4 through the guide hole 44 passes through the ink guide groove formed between the ridges and is guided to the rear end of the tip ball 47a. Other functions are the same as those in the first embodiment.

In the first embodiment, unlike the second embodiment, there is no ridge that abuts the ball valve so that it cannot be pulled out.
The mold precision and molding conditions for molding are easy. (By the way, the ridge is undercut when the mold is released, so it is difficult to obtain dimensional accuracy.) In addition, it is easy to insert the ball valve into the valve chamber (the ridge uses elastic deformation to form the ball valve. There is a problem of damaging the ridge because it is inserted.) It is advantageous for machine assembly. However, in the first embodiment, since the spring 16 cannot be pulled out, it is necessary to crimp the rear end of the tip 12, which is disadvantageous to the second embodiment due to the labor of processing.

Since the third and fourth embodiments of the refill of the ballpoint pen are basically the same as the first embodiment, only the essential points will be described. First, in the third embodiment, as shown in FIG. 8, by providing a separate pushing body 54 at the front end of the spring 55, the swingability of the rod shaft portion 54a is good, and the friction of the portion contacting the tip ball 47a is achieved. Since the resistance can be selected (material, shape), the writing feel is good. Further, the fourth embodiment is advantageous in cost because the rod shaft portion 48a is provided integrally with the winding portion of the spring 48 as shown in FIG. Further, by providing a winding portion that reduces in diameter in a taper shape or a step shape along the inner hole portion of the tip 47, stability of the shaft center of the rod shaft portion is good, deviation of ink induction and contact resistance with the tip ball are improved. Stabilize.

Further, since the tip ball 47a is always in close contact with the inner edge of the tip holding portion, the tip portion is dried to prevent writing blurring. Also, air entrapment may be accumulated by repeated upward writing, which is inferior to that in the first and second embodiments, but upward writing and impact may be applied due to the combined action of the tip ball 47a and an appropriate composition of ink and follower. However, the entrainment of air is appropriately prevented, and it is possible to prevent backflow of ink and blurring of writing in practical use.

Further, FIG. 4 shows a state in which the refill 1 of the ballpoint pen is housed in the barrel 20, and when the rear end of the knock body 31 is knocked forward to advance, the locking projection 33 causes the locking step portion of the clip. 25 to engage the tip 12 as shown in FIG.
The tip of the shaft is projected from the shaft tip port 29. From this state, when the distal end portion of the clip 21 is elastically displaced laterally on the side where the side wall 26 is present, the locking projection 33 is disengaged from the locking step portion 25 and the state of FIG. 3 is restored again. Further, when the clip 21 is inserted into a chest pocket or the like in the state of FIG. 5, the locking step portion 25 is pushed up, so that the engagement with the locking protrusion 33 is released, and the tip 12 is inserted from the shaft tip opening 29 into the shaft cylinder. Immerse yourself. Therefore,
If you accidentally insert the tip into the pocket with the tip protruding, you do not have to worry about soiling your clothes. Further, when replacing the refill 1 of the ballpoint pen with a new one, if the locking projection 34 of the knock body 31 is pushed inward, the engagement between the locking projection 34 and the window hole 27 of the shaft cylinder is released, and the knock body is released. It is possible to take out the refill 1 of the ballpoint pen together with 31.

[0028]

The structure and operation of the knock type ball-point pen of the present invention are as described above, and by using the low-viscosity ball-point pen ink, there is no fluff, dark lines, no unevenness, and no cap is required. It is possible to provide a knock-type ballpoint pen that does. Further, since the ink is a low-viscosity ink, direct current of the ink, upward writing, knocking, and backflow of the ink due to impact are prevented, so that an accident that stains the inside of the barrel, hands, clothes, etc. is prevented. Also, blurring of writing can be prevented. or,
Since the tip ball comes into close contact with the inner edge of the tip holding portion except when writing, there is an effect of preventing writing blurring due to drying over time. Further, if the clip is inserted into a chest pocket or the like while the writing tip is projected, the writing tip automatically immerses in the barrel, so there is no risk of soiling clothes.

[Brief description of drawings]

FIG. 1 is mounted on a knock type ballpoint pen of the present invention,
FIG. 3 is a vertical cross-sectional view showing the entire refill of the ball-point pen of the first embodiment, showing a state in which the tip faces upward.

FIG. 2 is an enlarged cross-sectional view of an essential part of the refill of the ball-point pen of the first embodiment, showing a state in which the tip is facing downward.

FIG. 3 is an enlarged transverse sectional view of a valve chamber portion in the first embodiment.

FIG. 4 is a partially non-sectional longitudinal sectional view showing an example of a knock type ballpoint pen having a ballpoint pen refill mounted therein, showing a state in which a writing tip portion is immersed.

5 is a vertical cross-sectional view of a part of a cross section corresponding to FIG. 4, showing a state in which a writing tip is projected.

FIG. 6 is a top view corresponding to FIG.

FIG. 7 is an enlarged cross-sectional view of a main part of the refill of the ball-point pen of the second embodiment, showing a state in which the tip is facing upward.

FIG. 8 is an enlarged cross-sectional view of an essential part of the refill of the ball-point pen of the third embodiment, showing a state in which the tip is facing upward.

FIG. 9 is an enlarged cross-sectional view of a main part of the refill of the ball-point pen of the fourth embodiment, showing a state in which the tip is facing upward.

[Explanation of symbols]

 1 Ballpoint pen refill 2 Joint 3 Front shaft part 4 Step part 5 Rear shaft part 6 Valve chamber 7 Ball receiving seat 8 Groove part 9 Guide hole 10 Ball valve 11 Inner hole part 11a Tip fitting hole 11b Tip fitting hole 12 Tip 12a Tip Ball 12b Channel 13 Shaft portion 14 Locking portion 15 Caulking portion 16 Spring 16a Rod shaft portion 17 Ink storage tube 18 Ink 19 Follower 20 Shaft cylinder 21 Clip 22 Mounting leg portion 23 Groove 24 Ball portion 25 Locking step portion 26 Side wall 27 Window Hole 28 Inner surface step 29 Shaft tip opening 30 Slit 31 Knock body 32 Stopper piece 33 Locking protrusion 34 Locking protrusion 35 Coil spring 40 Joint 41 Valve chamber 42 Ball seat 43 Protrusion 44 Guide hole 45 Step 46 Ball valve 47 Tip 47a Tip ball 48 Spring 48a Rod shaft 49 Tip fit Attachment hole 50 Joint 51 Tip fitting hole 52 Step portion 53 Guide hole 54 Pushing body 54a Rod shaft portion 55 Spring

Claims (4)

[Claims] 1. A knock type ball-point pen in which a ball-point pen refill is mounted, and a writing point can be projected from and retracted from a shaft tip opening by axially shifting the ball-point re-feel relative to a barrel, The tip of the joint is equipped with the tip of the ballpoint pen and the ink storage tube at the rear, and the upright rod shaft is formed in front of the spring in the inner hole of the tip, and the tip of the rod shaft is the rear end of the tip ball. The tip ball comes into close contact with the inner edge of the ball holding section at the tip of the tip to prevent the ink from flowing out, and the writing pressure releases the close contact between the tip ball and the inner edge of the ball holding section of the tip. A mechanism is provided to prevent direct current and backflow of the ink so that the ink can flow out with the rotation of the ink, the ink containing tube is filled with low viscosity ink, and the ink is consumed at the rear end of the ink. A knock-type ball-point pen characterized in that a follower that follows the ink is arranged. 2. A spring and a pusher body having a rod shaft portion at the front end of the spring are inserted into a chip inner hole portion so as to be axially movable, and the tip of the rod shaft portion presses the rear end of the tip ball to make the tip ball. Is closely contacted with the inner edge of the ball holding portion at the tip of the tip to prevent ink from flowing out, and the writing pressure releases the close contact between the tip ball and the inner edge of the ball holding portion of the tip, causing the ink to flow out as the tip ball rotates. The knock-type ball-point pen according to claim 1, wherein a refill of the ball-point pen configured so as to be possible is mounted. 3. A ball valve provided in the rear of the valve chamber, the valve chamber communicating with the rear end of the tip in the axial center of the joint, and the tapered or spherical ball seat in the rear of the valve chamber. Is loosely fitted, and the spring is inserted into the inner hole of the chip so that the spring cannot be pulled out from the rear end of the chip.When the chip side is facing upward, the ball valve is in close contact with the ball receiving seat and the guide hole is sealed. It is equipped with a ballpoint pen refill configured to prevent backflow of ink and to release the above-mentioned sealed state when the tip side is downward and to allow ink to flow into the tip through the guide hole and the valve chamber. The knock-type ballpoint pen according to claim 1, wherein 4. A safety mechanism is provided that locks the tip of the clip at the time of knocking so that the writing tip is in a protruding state, and when the clip is inserted into a chest pocket, the locking is released and the writing tip is retracted into the shaft. The knock-type ballpoint pen according to any one of claims 1 to 3, wherein the ballpoint pen is a knock-type ballpoint pen.