JP2681763B2 - Writing implement - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art Heretofore, there has been known a so-called water-based ballpoint pen in which ink is incorporated in a so-called oil-based ballpoint pen using high-viscosity ink and a fibrous batting, and the ink is guided to a ballpoint pen tip via an ink guide core. ing. Each of them has some drawbacks, but one of the shortcomings is that oil-based ballpoint pens have a disadvantage in that the ink has a high viscosity, and thus the ink has a low writing density and a low writing density. Further, the water-based ball-point pen has disadvantages in that the use of the batting containing the ink increases the cost of members and increases the cost, and that the consumption of the ink is unknown. In addition, in order to improve the respective drawbacks under such circumstances, statically high viscosity ink, which has a shear thinning property in which the viscosity is reduced by the rotation of the ball during writing and the ink is discharged, The ballpoint pen used is known. However, a ball-point pen that uses ink with shear thinning properties has the property that the ink easily evaporates and the writing tip easily dries, and the ink outflow rate is large (to increase the writing density). The diameter is thickened to increase the amount of ink loaded. Further, since the viscosity of the ink is smaller than that of the ink of the oil-based ball-point pen, the flow resistance to the ink storage tube is small. Therefore, there is a problem in that ink leakage (ink flows back to the rear end of the ink containing tube) easily occurs due to the weight of the ink, an impact, and the like, and the tip ball easily pops out due to a drop impact. For this reason, usually, the rear end of the ink prevents evaporation of the ink and moves following the consumption of the ink at the time of writing, but it is a grease-like shape that suppresses the backflow of the ink against its own weight and impact. A follower is provided. Further, in order to further enhance the safety, a cup-shaped float is immersed in a follower, which is disclosed in Japanese Utility Model Publication No. 49-30035. Further, the follower plays the role as described above and also plays the role of notifying the depletion state of the ink. Of course, it is possible to color the follower, but if the colorant is compatible, there will be no sticking to the ink edge, and if the follower flows into the tip, the writing performance will be deteriorated. A ballpoint pen using a ball valve is known as a means for preventing the backflow of ink. As an example of a ball valve, a full-scale sho 57-1935
Hold the ball at the tip as disclosed in Japanese Patent No. 78,
A spring member is housed in a chip cylinder in which an ink passage hole is formed in the ball seat to communicate with the ball, and the linear portion of the spring member is inserted into the ink passage hole so that the back surface of the ball is resilient. There is known a tip portion of a water-based ballpoint pen in which the side circumference of the ball is brought into close contact with the inner wall of the tip portion by pressing in the tip direction. This is intended to eliminate the defect (ink shortage due to ink backflow) in which ink drops back axially rearward when left standing upward or when dropped. Also, as a second example of a ball valve, the same applicant discloses in Japanese Utility Model Publication No. 4-52067 a mechanism for preventing backflow of a ballpoint pen provided with a valve chamber in which a ball (ball valve) is loosely fitted. This is a synthetic resin mouth plastic with a required number of protrusions that prevent the ball valve from being pulled out in the valve chamber where the ball valve is loosely fitted, and is formed between the protrusions when writing. The ink is made to flow through the gap so as to flow to the chip, and the defect that ink flows backward is eliminated. Further, although the above-mentioned mouth plastics are obtained by injection molding, it is difficult to obtain dimensional accuracy because the protrusions are undercut at the time of mold release, and it is necessary to devise to prevent damage to the protrusions by inserting the ball valve. It is troublesome. Also, during manufacturing, centrifugal treatment is performed to remove air bubbles that have become trapped after ink filling, but at that time there is the inconvenience that the ball valve is elastically entangled in the protrusion due to centrifugal force and the ball valve is fixed. To do. In addition, since a normal ballpoint pen has a backlash between the tip end of the mouthpiece and the tip, there is a problem that the tip swings during writing and the writing feeling is bad. Further, when not in use, the tip ball is pressed against a non-liquid absorbing and non-continuous bubble sealing seal provided on the cap. Normally, the tip of the chip is tightly fitted to the tip of the shaft and a resin cap is fitted. However, if there is no ventilation means in the cap, the internal pressure of the cap increases when the cap is fitted, and a part of the air It flows into the ink through a slight gap between the ball and the chip holding it. The inflowing air remains as bubbles in the ink because there is no escape area due to the follower, and there is a drawback that the smooth outflow of ink during writing is hindered. Therefore, ventilation means is provided between the tip of the writing brush and the cap to prevent it, but this has a negative effect on the evaporation of the ink.

[0003]

DISCLOSURE OF THE INVENTION The present invention is the result of repeated improvements based on the knowledge of the above-mentioned prior art. The object is to show statically high viscosity, and In a ball-point pen that uses a water-based ink that has shear thinning properties, in which the viscosity decreases due to rotation and the ink flows out, the backflow of the ink and follower due to upward writing or drop impact is reliably prevented, and the cap It is possible to prevent the inflow of air bubbles into the ink by suppressing the increase of the internal pressure at the time of mounting, and to prevent the evaporation of ink by a follower that suppresses the evaporation of ink and a simple means that the tip of the chip does not directly ventilate the outside air. Further, even if an infant accidentally swallows the cap and gets stuck in the throat, air communication is possible and a danger such as suffocation can be avoided. In addition, at the time of manufacture, after the ballpoint pen is filled with ink and follower, centrifugation is suspended in order to remove the entrapped air bubbles, but the tips of the bundled ballpoint pens contact the contact surface inside the centrifuge container. The purpose is to make sure that only defoaming can be performed by devising so that all of the above will hit, and to clearly inform the depleted state of the ink without deteriorating the writing performance. Further, in the refill type in which the lead can be replaced, it is possible to prevent the backlash from occurring in the mouthpiece during writing.

[0004]

A ballpoint pen of the present invention devised to achieve the above object is a ballpoint pen having a ball valve for preventing backflow of ink.
The ink containing cylinder connected to the back of the ball-point pen tip has a statically high viscosity, and the viscosity decreases by the rotation of the tip ball during writing, and the ink flows out, so-called shear thinning ink. The rear end of the ink is filled with a grease-like follower that follows as the ink is consumed, and a resin member having substantially the same specific gravity is immersed in the follower. Further, a press-fitting cylinder part having a tip fitted to the tip and a joint in which an ink containing cylinder is fixed behind the rear end edge of the press-fitting cylinder part and the joint are appropriately eccentric with the tip rear end hole behind the tip fitting hole. In relation to this, the valve chamber in which the ball valve is loosely fitted is provided with a ball receiving seat at the rear of the valve chamber and a guide hole communicating with the ink containing tube is provided. Further, in the cap that is fitted and fixed to the tip of the shaft, an inner cap whose writing point is fitted in a small chamber in a substantially tight fit is integrally formed with the cap, and the cap between the cap and the inner cap is formed. A ventilation hole is provided from the insertion side to the rear end, and further, a seal plug body having a non-absorbent property and elasticity of discontinuous bubbles is arranged in the inner cap in a state where the tip of the chip is pressed against the inner cap. And Further, the ink containing cylinder is inserted from the front end hole of the shaft cylinder so that the front end edge of the shaft cylinder abuts against the rear end edge of the press-fitting cylinder portion of the joint, and a straight or curved slope is formed on the outer periphery of the press-fitting cylinder portion. The ribs provided are provided at the required locations, and a ring-shaped brim is formed at the rear end of the rib, the rear end of the rib is connected to the outer diameter of the brim, and the outer side of the rib is the inner step of the base. It is characterized in that the base is fixed to the shaft cylinder in a state of being bite-fitted to the shaft cylinder. Also, through the gap between the tip hole of the die protruding the tip, the gap between the inner circumference of the die and the ribs provided on the outer circumference of the press-fitting cylinder portion, and the notch provided at the front end of the barrel to the inner hole of the barrel. It is characterized in that a ventilating passage communicating therewith is provided.

[0005]

1 to 3 show an embodiment of the present invention. First, as shown in the figure, the joint 3 is provided with a press-fitting cylinder portion 7 in which a linear or curved rib 8 is provided at a required position in the first half, and a ring-shaped collar portion 16 is provided at the rear end of the rib 8. The ribs 8 are formed so that the rear ends thereof are connected to have substantially the same outer diameter as the flange 16. In addition, the fitting cylinder portion 11 is provided in the latter half, and the ink containing cylinder 4 is fixed to the fitting cylinder portion 11. The tip 5 holding the tip ball 5a is pressed into the tip fitting hole 10 at the tip of the press-fitting cylinder 7 from the rear end side.

The joint 3 is integrally formed of elastically deformable synthetic resin, and the tip fitting hole 10 is formed.
And a valve chamber 12 is provided at the rear of the valve chamber 12. Valve chamber 12
A conical ball receiving seat 13 is provided on the rear portion. Further, the valve chamber 12 is properly accommodated in the inner periphery of the tip fitting hole 10 such that the axial center of the hole of the valve chamber 12 is appropriately eccentric with respect to the axial center of the chip fitting hole 10 and one side of the valve chamber hole is provided. Groove 1
5 is provided, and the ball valve 14 is loosely fitted in the valve chamber 12. A guide hole 17 communicating with the ball receiving seat 13 is formed behind the valve chamber 12. By the way, the valve chamber 12
If the tip rear end hole is provided eccentrically with respect to the tip fitting hole 10, it is not necessary to provide it eccentrically.

Further, a cylindrical ink container 4 is press-fitted and fixed to the outer periphery of the fitting cylinder 11 with its tip abutting against the rear end of the collar 16, and the inner diameter of the ink container 4 is of the joint 3. Guide hole 17
Is in communication with The joint 3 and the ink containing cylinder 4 may be integrally provided. The ink containing cylinder 4 is filled with ink 19 having a statically high viscosity and a shear thinning property that reduces the viscosity by the rotation of the tip ball 5a during writing and allows the ink to flow out. The rear end of the ink is filled with a transparent or semi-transparent grease-like follower 20 that prevents the evaporation of the ink and is in contact with the ink surface as the ink is consumed and can move following it. A colored resin member having a specific gravity substantially equal to that of the follower is immersed in the follower 20. In the embodiment, the colored resin member is P
As a pipe material 21 made of P resin or the like, the follower 2 is provided on the inner and outer diameters.
In the state where 0 is filled, the buried shape or the rear end of the pipe member 21 is positioned in a protruding shape from the rear end of the follower 20 as appropriate. Further, the colored resin member is not limited to a pipe material, but a bar material,
It may be a ball material, and it is immersed in the follower with an outer diameter appropriately smaller than the inner diameter of the ink containing cylinder 4. The ink containing tube 4 is made of, for example, transparent PP that suppresses ink evaporation.
Resin molded products are used. The above-described configuration of the tip 5, the joint 3, and the ink containing cylinder 4 serves as a refill for the ballpoint pen. A tail plug 22 is fixed to the rear end of the barrel 1.

Next, the tip 5 of the shaft 1 is inserted into the joint 3 into the joint 3, and the refill having the ink container 4 filled with the ink and the follower is fixed, and the collar 16 of the joint 3 is attached to the front surface of the shaft 6. In a state in which the outer edge of the linear or curved rib 8 provided at a required position of the press-fitting cylinder portion 7 is abutted against the inner step portion 9 of the mouthpiece 2 by abutting the rear end edges thereof. The base 2 is screwed onto the shaft portion 6 of the barrel 1. A notch 6a is provided at a required position on the front end of the shaft portion 6 so that the rear end of the collar portion 16 of the joint 3 is in contact therewith. In addition, a transparent resin molded product is used for the barrel 1 so that the consumption of ink can be determined. With the above configuration, the shaft cylinder 1 is passed through the clearance between the tip hole projecting the tip 5, the inner circumference of the mouthpiece 2, the rib 8 of the press-fitting cylinder portion 7 and the rib 8 and the notch 6a of the shaft portion 6. An air passage communicating with the inner hole 1a is formed. If necessary, the inner hole 1a is communicated with the outside air, and a vent hole is provided on the side surface of the barrel 1 or a tail plug 22 or a vent hole between the tail plug and the barrel. If the ballpoint pen is disposable, the base 2 and the barrel 1 are not necessary, and the refill itself becomes the writing shaft of the ballpoint pen.

By the way, the cap 23 fitted on the tip of the shaft
The clip 24 is positioned on the outer peripheral side surface of the cylinder, and the rear end cylinder portion 30 is crimped to the rear end hole. Further, a ventilation hole 29 penetrates through the rear end of the tubular portion 30. In addition, a cylindrical inner cap 25 having a small chamber 27 behind the inner hole of the cap 23.
The inner cap 25 is integrally formed with a required number of ribs 26 provided between the inner cap 25 and the inner hole portion. As described above, a ventilation path communicating with the ventilation hole 29 from the cap insertion port is formed between the ribs. There are various means for forming the vent holes, and the structure is not particularly limited. Further, the cap 23 is provided with an engaging portion 32 at its insertion port, and is detachably fixed to the engaging portion 31 provided on the barrel 1. Incidentally, the engaging portion is formed by engagement of a convex portion or a concave portion which is usually used. Further, a seal plug 28 made of a non-liquid absorbing and non-continuous bubble elastic body is fixed to the tip of the small chamber 27 of the inner cap 25, and the tip of the tip 5 and the base 2 are tightly fitted in the small chamber 27. The tip ball 5a is appropriately pressed against the seal plug 28.

[0010]

With the tip 5 facing upward, the ball valve 14 is in circumferential contact with the ball receiving seat 13 of the valve chamber 12 and seals the guide hole 17, as shown in FIG. Can be prevented. Further, FIG. 2 shows a state in which the cap 23 is fixedly attached to the shaft tip, and since the tip of the tip 5 is in pressure contact with the seal plug 28, there is no problem that the tip ball 5a jumps out due to a drop impact. Further, since the ball valve 14 is loosely fitted in the valve chamber 12 in an appropriately eccentric relationship with the tip rear end hole 18, there is no problem that the ball valve bites by centrifugal separation after ink filling at the time of manufacturing the refill, Even if the ball valve 14 comes into contact with the tip rear end portion 18, the ball valve is biased and the ink inflow portion to the tip 5 is secured. Further, the colored resin member is immersed in the follower 20, so that the depleted state of the ink becomes clear, and even if the flow resistance of the follower is reduced, internal friction is reinforced and backflow is guaranteed, and the tip ball due to impact is The shock pressure applied to 5a is relieved, and the tip ball 5a is prevented from jumping out even when the cap 23 is not attached. Further, since the inner cap 25 is fitted tightly, the tip ball 5a is prevented from being dried and ink is prevented from being evaporated. Further, since the tip end hole of the mouthpiece 2 is communicated with the inner hole 1a of the shaft cylinder 1, pressurizing and depressurizing states are alleviated by removing and inserting the cap, so that the problem of bubbles flowing into the ink is also prevented. In addition, the ventilation holes 29 allow air to flow even if an infant accidentally swallows the cap. Further, in the refill type in which the refilling is possible as in the embodiment, the outer periphery of the rib 8 provided in the press-fitting cylinder portion 7 of the joint 3 abuts the inner step portion 9 of the mouthpiece 2 in a biting manner. The tip 5 is locked against the base 2.

[0011]

The structure and operation of the ball-point pen of the present invention are as described above, and it is possible to prevent the backflow of ink by upward writing or drop impact regardless of whether the cap is attached or not. or,
By providing the vent hole, pressurization and depressurization at the time of mounting the cap are suppressed, the inflow of air bubbles into the ink is prevented, and smooth writing performance becomes possible. In addition, the evaporation of ink and the drying of the writing tip can be prevented by a simple means. Moreover, the ballpoint pen of the present invention can avoid the risk of choking even if an infant accidentally swallows the cap and gets stuck in his throat. Further, since the resin member is immersed in the follower, the follower is not destroyed when the rear end is dropped and the like, and the end state of the writing becomes clear by coloring the resin member. Also, in the refill type that can be refilled, there is no play between the tip and the mouthpiece, so the writing feel is good. Further, since the ball valve is loosely fitted in the valve chamber in an appropriately eccentric relationship with the tip fitting hole, there is no problem that the ball valve bites during centrifugal separation.
In addition, since the joint is provided with a rib having a linear or curved inclined surface almost the same as the flange portion, when the centrifuge is loaded by loading a ball-point pen that forms a bundle into a cylindrical container during centrifugation, the joint is There is also an effect of avoiding the problem that the tip portions of the tips are entangled with each other to form a refill in which the tip end of the tip floats from the contact surface, and the ink is blown out from the tip end of the tip to stain the inside of the container.

[Brief description of the drawings]

FIG. 1 is a vertical cross-sectional view of a ball-point pen that is an embodiment of the present invention, showing a state in which a tip faces upward.

FIG. 2 is an enlarged cross-sectional view of the front half of a ball-point pen that is an embodiment of the present invention, showing a state in which the tip is facing upward.

FIG. 3 is an enlarged sectional view of the rear half of the ballpoint pen according to the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Shaft cylinder 1a Inner hole 2 Base 3 Joint 4 Ink storage cylinder 5 Chip 5a Tip ball 6 Shaft 6a Notch 7 Press fitting cylinder 8 Rib 9 Inner step 10 Tip fitting hole 11 Fitting cylinder 12 Valve chamber 13 Ball receiver Seat 14 Ball valve 15 Groove part 16 Collar part 17 Guide hole 18 Tip rear end hole 19 Ink 20 Follower 21 Pipe material 22 Tail plug 23 Cap 24 Clip 25 Inner cap 26 Rib 27 Small chamber 28 Seal plug 29 Vent hole 30 Cylinder part 31 Joint part 32 Engagement part

Claims (2)

(57) [Claims] 1. An ink containing cylinder is inserted from a front end hole of a shaft cylinder so that a front end edge of the shaft cylinder abuts a rear end edge of a press-fitting cylinder portion of a joint, and a linear or curved shape is formed on an outer periphery of the press-fit cylinder portion. Providing ribs at required places, forming a ring-shaped collar at the rear end of the rib and connecting the rear end of the rib to the outer diameter of the flange approximately the same, and engaging the outer side of the rib with the inner step of the die. Writing instrument with built-in ink characterized in that the base is fixed to the barrel in a state of being abutted against each other. 2. The ink-containing writing instrument according to claim 1, wherein the writing nib is a ballpoint nib.