JPH09378U - Ballpoint pen - Google Patents

Abstract

(57) [Summary] (Corrected) [Purpose] To prevent backflow of ink due to upward writing and drop impact, and to prevent suffocation when the cap is accidentally swallowed. [Structure] The joint 3 is provided with a valve chamber 12 provided with a ball valve behind the tip fitting hole at a position eccentric to the tip fitting hole. The ink containing tube 4 is filled with ink having a shear thinning property, and the rear end of the ink is filled with a transparent or semi-transparent grease-like follower 20 which follows its consumption, and the follower is colored with substantially the same specific gravity. Immerse the resin member. An inner cap 25 that seals the tip of the writing brush in a small chamber is formed integrally with the cap 23, and a vent hole 29 extending from the cap insertion side to the rear end is provided between the cap and the inner cap.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an improvement of a ball-point pen that uses ink having a so-called shear thinning property, which has a statically high viscosity, and the viscosity is reduced by the rotation of the ball during writing to cause the ink to flow out.

[0002]

[Prior art]

 Conventionally known are so-called oil-based ball-point pens that use high-viscosity ink and so-called water-based ball-point pens that incorporate ink into fibrous batting and guide the ink to a ball-point pen tip through an ink guide core. Each of them has some drawbacks, but one of the shortcomings is that the oil-based ball-point pens have a low ink drop and writing density due to the high viscosity of the ink. In addition, since the water-based ballpoint pen uses a batting that contains ink, there are disadvantages that the cost of the member is high and the cost is high, and the consumption of the ink is unknown. In addition, under such circumstances, it had a high viscosity statically for the purpose of improving each defect, and had a shear thinning property that the viscosity was lowered by the rotation of the ball during writing and the ink was leaked. A ballpoint pen using ink is known. However, a ball-point pen that uses ink with shear thinning viscosity has the property that ink easily evaporates and the writing tip easily dries, and the amount of ink that flows out is large (to increase the writing density). The diameter is thickened to increase the amount of ink loaded. Moreover, since the viscosity of the ink is smaller than that of the ink of the oil-based ballpoint pen, the flow resistance to the ink containing tube is small. Therefore, there is a problem that ink leakage (ink flows back to the rear end of the ink containing tube) easily occurs due to its own weight and impact, and the tip ball easily pops out due to a drop impact. Therefore, it usually prevents the evaporation of the ink at the trailing edge of the ink and moves following the consumption of the ink during writing, but it is a grease-like material 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 immersed in a follower is disclosed in Japanese Utility Model Publication No. 49-30035. The applicant also discloses, in Japanese Utility Model Publication No. 4-52067, a backflow prevention mechanism for a ballpoint pen provided with a valve chamber in which a ball (ball valve) is loosely fitted. This product is provided 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 with a synthetic resin mouth plastic, and is formed between the protrusions when writing. The ink is made to flow to the chip by communicating with the gaps. The mouth plastic is obtained by injection molding, but it is difficult to obtain the dimensional accuracy because the ridges are undercut at the time of mold release, and it is troublesome to prevent the ridges from being damaged by inserting the ball valve. In addition, at the time of manufacturing, centrifugal treatment is performed to remove bubbles entrapped after ink filling, but at that time there is the inconvenience that the ball valve elastically sticks to 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 of the mouthpiece and the tip, there is a problem that the tip swings during writing and the writing feel is bad. When not in use, the tip ball is pressed against a non-liquid absorbing and non-continuous bubble elastic seal stopper provided on the cap. Usually, the tip of the chip is tightly fitted on the tip of the shaft and the cap made of resin 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 part of the air It flows into the ink through a slight gap between the ball and the chip that holds it. Since the air that flows in does not have a place to escape by the follower, it remains as air bubbles in the ink, which has the drawback of hindering smooth ink outflow during writing. Therefore, a ventilation means is provided between the tip of the writing brush and the cap to prevent it, but this has a bad effect on the evaporation of the ink.

[0003]

[Problems to be solved by the device]

 An object of the present invention is to improve a ball-point pen that uses ink having a shear thinning property in which statically high viscosity is exhibited, and the viscosity is lowered by the rotation of the ball during writing, causing the ink to flow out. , The backflow of ink and follower due to upward writing, drop impact, etc. and the pop-out of the tip ball due to the impact of falling are surely prevented. Centrifugation is suspended in order to remove air bubbles, but the tip of the bundled refills is designed to hit all the contact surfaces in the centrifuge container so that only defoaming can be performed reliably. Also, it is possible to prevent the inflow of air bubbles into the ink by suppressing the increase of the internal pressure when the cap is attached, and to prevent the evaporation of the ink by a simple means and prevent the rattling of the mouthpiece during writing. . Moreover, even if an infant accidentally swallows the cap and gets stuck in his throat, air communication will be possible and suffocation and other dangers can be avoided.

[0004]

[Means for Solving the Problems]

 The ball-point pen of the present invention devised to achieve the above object has a press-fitting cylinder part having a tip fitted with a tip and a joint and a joint in which an ink containing tube is fixed behind the rear end edge of the press-fitting cylinder part. Behind the tip fitting hole is a valve chamber in which a ball valve is loosely fitted in an appropriately eccentric relationship with the tip rear end hole, and at the rear of the valve chamber, a ball receiving seat is provided to communicate with the ink containing tube. In addition, the ink containing tube has a high static viscosity, and the viscosity of the tip of the ball during writing decreases to cause the ink to flow out. The end is filled with a transparent or semi-transparent grease-like follower that follows as the ink is consumed, and a resin member having approximately the same specific gravity is immersed in the follower. When the front edge of the shaft cylinder is made to abut against the edge, Providing a rib with a straight or curved slope on the circumference at a required location, forming a ring-shaped collar part at the rear end of the rib and connecting the rear end of the rib to approximately the same outer diameter as the collar part, With the outer part of the rib abutting against the inner step of the base in a biting manner, the base is fixed to the shaft cylinder, and the gap between the tip hole of the base protruding from the tip and the inner circumference of the base and the press-fitting cylinder An air passage communicating with the inner hole of the barrel is provided through a gap between the ribs provided on the outer periphery of the shaft and a notch provided at the front end of the barrel, and is fitted and fixed to the tip of the barrel. In the cap, an inner cap that tightly fits the brush tip in a small chamber is formed integrally with the cap, and a ventilation hole is provided between the cap and the inner cap from the insertion side of the cap to the rear end. It has non-absorbent and discontinuous bubble elasticity in the state where the tip of the tip is pressed. Characterized by being arranged a seal stopper was.

[0005]

【Example】

 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 straight 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 rib 8 is formed so that the rear end of the rib 8 is connected to the flange 16 so as to have the same outer diameter. Further, there is a fitting cylinder portion 11 in the latter half, and the ink containing tube 4 is fixed to the fitting cylinder portion 11. Further, the tip 5 holding the tip ball 5a is press-fitted into the tip fitting hole 10 at the tip of the press-fitting cylinder portion 7 from the rear end side.

Further, the joint 3 is integrally formed of elastically deformable synthetic resin, and communicates with the tip fitting hole 10 and a valve chamber 12 is provided on the rear side. A conical ball receiving seat 13 is provided at the rear of the valve chamber 12. In addition, the valve chamber 12 is properly eccentric with respect to the axial center of the tip fitting hole 10 in a state where the valve chamber 12 is accommodated in the inner circumference of the chip fitting hole 10. A groove portion 15 is provided on the side, and a 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, if the tip rear end hole of the valve chamber 12 is provided eccentrically with respect to the tip fitting hole 10, it does not need to be provided eccentrically.

Further, a cylindrical ink containing tube 4 is press-fitted and fixed to the outer periphery of the fitting cylindrical portion 11 by abutting the tip of the cylindrical ink containing tube 4 to the rear end of the collar section 16, and the inner diameter section of the ink containing tube 4 is of the joint 3. It communicates with the guide hole 17. The ink containing tube 4 is filled with an ink 19 having a statically high viscosity and a shear thinning property that allows the ink to flow out by decreasing the viscosity by the rotation of the tip ball 5a during writing. Further, 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 contacts the ink surface as the ink is consumed and can move following it. A resin member having a specific gravity substantially equal to that of the follower 20 is immersed in the follower 20. In the embodiment, the resin member is used as the pipe member 21 and is embedded in the follower 20 with its inside and outside diameters filled with the follower 20. The above-described configuration of the tip 5, the joint 3, and the ink containing tube 4 constitutes the refill of the ballpoint pen. A tail plug 22 is fixed to the rear end of the barrel 1.

Next, the tip 5 of the shaft cylinder 1 is inserted into the joint 3 into the joint 5, and the refill in which the ink storage tube 4 filled with the ink and the follower is fixed is inserted, and the collar portion of the joint 3 is attached to the front surface of the shaft portion 6. A state in which the outer periphery of a 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 of 16 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, and the rear end of the collar portion 16 of the joint 3 is in contact therewith. Further, the shaft cylinder 1 is made of a transparent resin molded product so that the consumption amount of the ink can be known. With the above-described structure, the gap between the tip hole projecting the chip 5, the inner periphery of the base 2, the gap formed between the rib 8 of the press-fitting cylinder portion 7 and the rib 8 and the notch 6a of the shaft portion 6 are used to form the shaft cylinder. An air passage communicating with the inner hole 1a is formed. If necessary, the inner hole 1a is communicated with the outside air, and an air hole is provided on the side surface of the shaft cylinder 1 or a vent hole is formed between the tail plug 22 or the tail plug and the shaft cylinder.

By the way, in the cap 23 fitted on the shaft tip, the clip 24 is positioned on the outer peripheral side surface of the cap 23, and the tubular portion 30 at the rear end is crimped to the rear end hole. Further, a ventilation hole 29 penetrates through the rear end of the tubular portion 30. A cylindrical inner cap 25 having a small chamber 27 is provided behind the inner hole of the cap 23, and the inner cap 25 is integrally formed with a required number of ribs 26 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. The cap 23 is provided with an engaging portion 32 at the 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. 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]

[Action]

 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. 2, so that ink does not flow backward when writing upward. It can be prevented. Further, FIG. 2 shows a state in which the cap 23 is attached to the tip of the shaft, and since the tip of the tip 5 is in pressure contact with the seal plug 28, there is no problem of the tip ball 5a jumping 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 during manufacturing of 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, even if the flow resistance of the follower is reduced, the internal friction is reinforced and the backflow is guaranteed, and the shock pressure applied to the tip ball 5a due to the impact is relieved. Is prevented. Further, since the inner cap 25 is closely fitted, 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 barrel 1, the pressurization and depressurization state can be eased by inserting and removing the cap, so that the problem that air bubbles flow into the ink is prevented. . In addition, the ventilation hole 29 allows air to flow even if an infant accidentally swallows the cap. Further, since the outer periphery of the rib 8 provided on the press-fitting cylinder portion 7 of the joint 3 abuts against the inner step portion 9 of the mouthpiece 2 in a biting manner, the chip 5 is prevented from rattling with respect to the mouthpiece 2.

[0011]

[Effect of the invention]

 The structure and operation of the ball-point pen of the present invention are as described above, and the pressurization and depressurization at the time of mounting the cap are suppressed to prevent the inflow of air bubbles into the ink, thereby enabling smooth writing performance. In addition, the evaporation of ink and the drying of the writing tip can be prevented by simple means. Also, since the joint is provided with ribs that have a linear or curved inclined surface almost the same as the collar, the bundled refills are entangled at the joint site during centrifugation and the tip of the tip touches inside the centrifuge container. It is possible to avoid the problem that a refill floats from the contact surface and ink is blown out from the tip of the tip to stain the inside of the container. 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, and backflow of ink is prevented by upward writing. In addition, since the colored resin member is immersed in the follower, the final state of writing can be clarified, and it is possible to prevent ink from backflowing and jumping out of the tip ball due to drop impact regardless of whether the cap is attached or not. In addition, the ballpoint pen of the present invention can avoid the risk of choking even if an accident that an infant accidentally swallows the cap and clogs the throat occurs. Furthermore, since there is no play between the tip and the mouthpiece when writing, the writing feel is good.

[Brief description of 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 cross-sectional view of the rear half of the ball-point pen that is an embodiment of the present invention.

[Explanation of symbols]

 1 Shaft cylinder 1a Inner hole 2 Base 3 Joint 4 Ink storage tube 5 Chip 5a Tip ball 6 Shaft part 6a Notch 7 Press-fitting cylinder part 8 Rib 9 Inner step part 10 Tip fitting hole 11 Fitting cylinder part 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 Tube part 31 Joint part 32 Engagement part

Claims (2)

[Utility model registration claims] 1. A press-fitting cylinder part having a tip fitted with a tip, a joint to which an ink containing tube is fixed behind a rear end edge of the press-fitting cylinder part, and a tip rear end hole in the joint behind the chip fitting hole. A valve chamber in which a ball valve is loosely fitted in an appropriately eccentric relationship is provided, a ball receiving seat is provided at the rear of the valve chamber, and a guide hole communicating with the ink containing pipe is provided. Has a high viscosity, and the viscosity of the ink decreases due to the rotation of the tip ball during writing, causing the ink to flow out. A ball-point pen, characterized in that the follower is filled and a resin member having substantially the same specific gravity is immersed in the follower. 2. A rib having a straight or curved slope is provided at a predetermined position on the outer periphery of the press-fitting cylinder part, while the front end edge of the shaft cylinder is abutted against the rear end edge of the press-fitting cylinder part of the joint. A state in which a ring-shaped brim is formed at the rear end, the rear end of the rib is connected to the outer diameter of the brim approximately the same, and the outer part of the rib is bite-shaped against the inner step of the die. The ball-point pen according to claim 1, wherein the base is fixed to the barrel by means of.