JPH09365U - Ballpoint pen - Google Patents

Abstract

(57) [Summary] (Correction) [Problem] To prevent backflow of ink in upward writing and to prevent backflow of ink and follower when trailing edge is dropped. SOLUTION: In a state in which a tip 5 is directed upward, a ball 19 is positioned in a ball receiving seat 15 of a valve chamber 14 and a guide hole 18 is formed.
Since the ink is sealed, even if the ink is written upward and the ink immediately below the ball of the chip is exhausted, the head does not hit the ink and the ink does not flow back. When the ball-point pen falls from the rear end side, the head portion 28 of the cushioning member 25 absorbs the impact, so that backflow of the follower 22 is prevented.

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. Ballpoint pens that use ink are also known. However, a ball-point pen that uses ink with shear thinning viscosity has the property that the ink easily evaporates, and the amount of ink that flows out is large (to increase the writing density). Have many. Further, 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, ink leakage (ink flows back to the rear end of the ink containing tube) is likely to occur due to changes in atmospheric pressure and temperature, or impact due to dropping. Normally, a grease-like follower is provided at the trailing edge of the ink to prevent it from evaporating and move according to the consumption of ink during writing, but to prevent the ink from flowing back against changes in atmospheric pressure and temperature. Has been. However, even if a follower is provided, when writing upwards, if the ink immediately below the ball of the chip runs out, the ink head is added directly, causing a noticeable backflow, which contaminates the inside of the barrel and the ventilation hole provided in the barrel. There is a risk of ink leaking from them and soiling your hands and clothing. In addition, there is a problem in that the rear part of the follower flows backward due to the inertia caused by the impact when it drops from the rear end side. The situation is not a ratio of the situations that occur with oil-based ballpoint pens.

[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 that statically exhibits a high viscosity, and the viscosity of the ball is lowered by the rotation of the ball during writing, causing the ink to flow out. Even when the atmospheric pressure or temperature changes, the impact from falling from the rear end, or the upward writing, the ink or follower flows backward, and it is possible to prevent the inside of the shaft cylinder, hands, and clothes from becoming dirty. Also, it is possible to prevent rattling of the writing tip.

[0004]

[Means for Solving the Problems]

 The ball-point pen of the present invention devised to achieve the above-mentioned object has a locking cylinder part, a flange part, and a fitting cylinder part from the front of the joint, and the press-fitting fitting part at the tip of the joint has a ball-point pen tip. The rear end is crimped, and a valve chamber with a ball seat at the rear end is provided behind the tip rear end of the press-fitting fitting part. The end of the ink container is pressed into the ink container by abutting the tip of the ink container on the rear end of the collar, and the ink container has a statically high viscosity. The ink that has shear thinning viscosity that allows it to flow out and the rear end of the ink are filled with a grease-like follower that prevents the evaporation of the ink and contacts the ink surface as the ink is consumed and can move following it. The storage tube is inserted from the front end of the barrel, and the collar of the joint is attached to the front of the barrel. With the end edge abutted and the inner surface of the mouthpiece abutted against the locking cylinder of the joint, the mouthpiece is fixed to the tip of the barrel, and the tail plug is attached to the rear end of the barrel. A cushioning member made of an elastic material such as rubber is fixed to the tail plug with its head located at the rear end of the barrel.

[0005]

【Example】

 In the embodiment of the present invention shown in FIGS. 1 and 2, a locking cylinder portion 7 is provided in the front half and a fitting cylinder portion 13 is provided in the rear half, and the locking cylinder portion 7 on the front side is provided with a shaft at a required position on the circumference. A joint 3 is provided which is provided with a slit 8 in the direction so that the tip end thereof can be elastically deformed in the diameter reducing direction. In the inner hole of the locking cylinder portion 7, a chip fitting hole 12 from the rear end and a sandwiching portion 11 having substantially the same outer diameter as the chip 5 and a gap 10 having an inner diameter appropriately larger than the outer diameter of the chip 5 are formed at the front end. The tip 5 is press-fitted into the inner hole of the locking cylinder portion 7 from the rear end side.

The joint 3 is integrally formed of an elastically deformable synthetic resin, and has a valve chamber 14 provided at the rear side in communication with the chip fitting hole 12. A concave spherical ball receiving seat 15 is provided on the rear portion of the valve chamber 14, and an axial ridge 16 is provided on the inner surface of the front portion so that the diameter of the virtual inscribed circle is smaller than the diameter of a ball 19 described later. Are provided at a plurality of positions on the circumference, and the balls 19 are inserted between the ball receiving seat 15 and the ridges 16 while elastically deforming the ridges 16 from the direction of the ridges 16 to allow play in the valve chamber 14. It is fitted. Further, a guide hole 18 communicating with the ball receiving seat 15 is formed at the rear of the valve chamber 14.

A flange 17 is provided at the rear end of the locking cylinder 7 of the joint 3, and a fitting cylinder 13 is extended behind the flange 17. The cylindrical ink storage tube 4 is press-fitted and fixed to the outer periphery of the fitting cylinder portion 13 by abutting the tip of the ink collection tube 4 to the rear end of the collar portion 17, and the inner diameter portion of the ink storage tube 4 is fitted into the guide hole 18 of the joint 3. It is in communication. The ink containing tube 4 is filled with an ink 21 having a shear thinning property that statically has a high viscosity and the viscosity of the ball is reduced by the rotation of the ball during writing to allow the ink to flow out. The rear end of 21 is filled with a grease-like follower capable of preventing the vaporization of the ink and being able to move in contact with the ink surface as the ink is consumed. The ink storage tube 4 is made of, for example, a transparent PP resin molded product or the like that suppresses the evaporation of ink.

Next, the tip 5 of the shaft cylinder 1 is inserted into the joint 3 into the writing portion to which the tip 5 and the ink containing tube 4 filled with ink are fixed, and the front of the shaft portion 6 is provided with the collar portion 17 of the joint 3 The shaft 2 of the shaft cylinder 1 with the ends 2 abutted against each other and the base 2 having the tapered portion 9 provided on the inner surface thereof abutted against the front end edge of the locking cylinder 7 of the joint 3. It is screwed to the part 6. Further, a ventilation hole 20 communicating with the inner hole of the shaft cylinder 1 is formed at an appropriate position of the shaft cylinder 1, and a tail plug 23 is press-fitted and fixed to the rear end of the shaft cylinder 1. The barrel 1 is made of a transparent resin molded product so that the amount of ink consumed can be understood. Further, a buffer member 25 having a head portion 28 at the rear end in the inner hole portion of the tail plug 23 and a locking portion 27 at the tip end of the shaft portion 26 extending forward is formed into the inner hole portion of the shaft portion 26. It is fitted to the portion and is locked to the front end of the tail plug 23 by the locking portion 27, and the head portion 28 is positioned in contact with the rear end of the barrel 1.

[0009]

[Action]

 FIG. 1 shows a writing state in which the tip 5 is directed downward. At that time, the ball 19 comes into contact with the ridge 16 of the valve chamber 14 and enters the valve chamber 14 from the ink containing tube 4 through the guide hole 18. The ink 21 passes by the side of the ball 19, passes between the ridges 16, and is guided to the tip of the chip 5. The ink statically exhibits high viscosity, but the rotation of the ball at the tip of the tip 5 causes the viscosity to decrease, and a large amount of ink is flown out. Further, FIG. 2 shows a state in which the tip 5 is directed upward, and at that time, since the ball 19 is located in the ball receiving seat 15 of the valve chamber 14 and closes the guide hole 18, the ball of the tip is written upward. Even if there is no ink right underneath, the head does not hit the ink and does not flow backward. Further, in the present invention, since the tip 5 is press-fitted into the tip fitting hole 12 of the locking cylinder portion 7 of the joint 3, and the front end edge of the locking cylinder portion 7 abuts the inner taper portion 9 of the base 2, An external force in the radial direction (radius reduction direction) toward the axial center is applied to the tip of the locking cylinder portion 7 by the taper portion 9, and the tip 5 located inside thereof is clamped by the holding portion 11 with a tightening force. Will increase. Further, the tip of the locking cylinder portion 7 is appropriately reduced in diameter by the gap 10 by the tapered portion 9 so that the tip 5 is prevented from rattling with the base 2. Further, when the ball-point pen falls from the rear end side, the head portion 28 of the cushioning member 25 absorbs the impact, so that backflow of the follower 22 is prevented.

[0010]

[Effect of the invention]

 The structure and operation of the ball-point pen of the present invention are as described above. A valve chamber is provided at an intermediate portion that communicates the tip and the ink containing tube, and the ball that is loosely fitted into the valve chamber allows the ink container and the valve chamber to be written upward. Since the space between the shaft cylinder is sealed and the shock absorbing part is provided at the rear end of the shaft cylinder, it is possible to prevent an accident that the ink or the follower flows backward and stains the inside of the shaft cylinder, hands, clothes and the like. In addition, since the force to fix the press-fitting part of the tip and the joint is strengthened, there is no risk of ink leakage or the chip falling out even if the fitting is loosened a little, and the press-fitting part deteriorates over time. Since it also guarantees that the dimensional accuracy will be reduced, the process will be reduced and the defective rate will be reduced, which will reduce the cost, and the press-fitting state of the chip will be stable for a long time. It will be possible to provide high quality products. Further, since the tip and the clasp are prevented from rattling, there is an effect such as good writing feeling.

[Brief description of drawings]

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

FIG. 2 is a vertical cross-sectional view of a main part of a ball-point pen that is an embodiment of the present invention, showing a state in which the tip faces upward.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Shaft cylinder 2 Base 3 Joint 4 Ink storage tube 5 Chip 6 Shaft part 7 Locking cylinder part 8 Slit 9 Tapered part 10 Gap 11 Holding part 12 Tip fitting hole 13 Fitting cylinder part 14 Valve chamber 15 Ball receiving seat 16 Projection Article 17 Collar part 18 Guide hole 19 Ball 20 Vent hole 21 Ink 22 Follower 23 Tail plug 24 Collar part 25 Buffer member 26 Shaft part 27 Locking part 28 Head

Claims (1)

[Utility model registration claims] 1. The joint is provided with a locking cylinder portion, a collar portion, and a fitting cylinder portion from the front, and the rear end portion of the ball-point pen tip is crimped to the press-fitting fitting portion at the tip of the joint so that the tip of the press-fitting fitting portion is located behind the tip. A valve chamber having a ball receiving seat at the rear end is provided behind the end,
A ball is loosely fitted in the valve chamber, and the ink storage tube is press-fitted and fixed to the outer periphery of the fitting cylinder part by abutting the tip of the ball to the rear end of the collar part, and has a high static viscosity in the ink storage tube. , The viscosity of the ball is reduced by the rotation of the ball during writing, and the ink can flow out. The ink has shear thinning and the ink is prevented from evaporating at the trailing edge of the ink, and the ink surface is consumed and the ink surface is followed. Is filled with a movable grease-like follower, the ink storage tube is inserted from the front end of the barrel, the rear edge of the collar of the joint is brought into contact with the front of the barrel, and the inner surface of the base is connected to the joint. The base is fixed to the tip of the barrel in a state of abutting against the locking barrel, and the cushioning member made of elastic material such as rubber is attached to the rear of the barrel with its head behind the barrel. Ballpoint pen characterized by being fixed at the end.