JPH0617979U - Ballpoint pen - Google Patents

Abstract

(57) [Abstract] [Purpose] A ball-point pen that uses ink with so-called shear thinning, which has statically high viscosity and whose viscosity decreases with the rotation of the ball during writing, causing the ink to flow out. Therefore, it is possible to prevent backflow of ink in upward writing. A chip is fixed to the tip of a barrel, an ink containing pipe communicating with the chip is arranged in the barrel, and an ink and a follower are provided at the rear end of the ink in the ink containing pipe.
The joint for fixing the tip is made of an elastically deformable resin molded product and can be connected to the rear end of the chip to provide a valve chamber at the rear, or elastically deformable at the rear end of the barrel or the rear end of the ink storage tube. A tail plug made of a different resin molded product is fixed in a tight fit, and a valve chamber is provided in front of the tail plug facing the follower, a coma receiving seat is provided at the rear of the valve chamber, and an inner surface of the front is provided. Is characterized in that a shaft-shaped top having an axial projection and a taper portion at the rear portion is loosely fitted therein so as not to be pulled out.

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 ballpoint pens that use high-viscosity ink and so-called water-based ballpoint pens that incorporate ink into fibrous batting and guide the ink to the ballpoint pen tip through the 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 batting that contains ink, there are disadvantages that the material cost is high and the ink consumption 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) easily occurs due to changes in atmospheric pressure and temperature. Therefore, it usually prevents the ink from evaporating to the trailing edge of the ink and moves following the consumption of the ink during writing, but suppresses the backflow of the ink against changes in atmospheric pressure and temperature. A grease-like follower is provided. However, even if a follower is provided, when ink is written right below the ball of the tip when writing upwards, the head of the ink is added directly, causing a remarkable backflow, which contaminates the inside of the barrel and the ventilation holes provided in the barrel. There is a risk of ink leaking from them and soiling your hands and clothing. The situation is not a ratio of the situations that occur with oil-based balls.

[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. In addition, it is possible to prevent the ink from flowing back even when the atmospheric pressure or temperature changes, or when writing upwards, so that the inside of the barrel, hands, and clothes are not soiled.

[0004]

[Means for Solving the Problems]

 The ballpoint pen of the present invention devised to achieve the above object has a tip fixed to the tip of the barrel, and an ink containing tube communicating with the tip is provided in the barrel and the ink containing is accommodated. The tube has a statically high viscosity, and the viscosity decreases with the rotation of the ball during writing, causing the ink to flow out. A follower that can move following ink consumption is provided, and the joint that fixes the tip is made of an elastically deformable resin molded product that communicates with the rear end of the tip and is provided with a valve chamber in the rear or a shaft. A tail plug made of an elastically deformable resin molded product is fixed to the rear end of the cylinder or the rear end of the ink containing tube in a close-fitting manner to face the follower of the ink containing tube and a valve chamber is provided in front of the tail plug. There is a tapered top seat on the rear of the valve chamber and an axial direction on the inner surface of the front. A ridge, characterized in that the shaft-like piece having a tapered portion that closely enables the frame receiving seat provided loosely fitted so as not to extraction therebetween.

[0005]

【Example】

 In the first 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. A joint 3 is provided which has an axial slit 8 at a position and is elastically deformable in the radial direction at the tip. In the inner hole of the locking tubular portion 7, a chip fitting hole 12 from the rear end and a holding portion 11 having substantially the same outer diameter as the tip 5 and a gap 10 having an inner diameter appropriately larger than the outer diameter of the tip 5 are formed at the front end. The tip 5 is press-fitted from the rear end side into the inner hole of the locking cylinder portion 7.

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 tapered piece receiving seat 15 is provided at the rear portion of the valve chamber 14, and an axial ridge is formed on the inner surface of the front portion so that the diameter of the virtual inscribed circle is smaller than the axial diameter of a later-described piece 19. 16 are provided at a plurality of positions on the circumference, and a shaft-shaped top 19 having a tapered portion 20 at the rear portion between the top receiving seat 15 and the ridge 16 elastically deforms the ridge 16 from the direction of the ridge 16. While being inserted, it is loosely fitted in the valve chamber 14. Further, a guide hole 18 communicating with the top receiving seat 15 is formed in the rear of the valve chamber 14. The ink passes through a gap formed between the inner circumference of the valve chamber 14 and the outer circumference of the top 19, but if necessary, the outer circumference of the top 19 is allowed to communicate with the ink except for the tapered portion 20. Therefore, a groove or the like is provided.

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 the ink 22 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 so that the ink can flow out. At the rear end of 22 is filled with a grease-like follower 23 which prevents the evaporation of the ink and is movable 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 that suppresses ink evaporation.

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 21 communicating with an inner hole portion of the shaft cylinder 1 is formed at an appropriate position of the shaft cylinder 1, and a tail plug 24 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.

The second embodiment of the present invention shown in FIG. 3 and FIG. 4 is that a locking cylinder portion 7 ″ is provided in the first half and a fitting cylinder portion 13 ″ is provided in the second half, and the locking cylinder portion 7 ″ on the front side is provided. Has an axial slit 8 "at the required position on the circumference and a joint 3" that allows the tip to be elastically deformed in the radial direction. In the inner hole of the locking cylinder 7 ', there is a clearance from the rear end to the tip fitting hole 12' and the holding portion 11 'which is almost the same as the outer diameter of the chip 5 and the inner diameter at the tip is appropriately larger than the outer diameter of the chip 5. A space of 10 "is formed, and the tip 5 is press-fitted from the rear end side into the inner hole of the locking cylinder 7".

The joint 3'is integrally formed of an elastically deformable synthetic resin, and is provided with a guide hole 14 'in the rear thereof so as to communicate with the tip fitting hole 12'. Further, a flange 16 "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 16 ". On the outer circumference of the fitting cylinder portion 13 ', a cylindrical ink storage tube 4 is press-fitted and fixed by abutting its tip to the rear end of the collar portion 16', and the inner diameter portion of the ink storage tube 4 is guided to the joint 3 '. It communicates with hole 14 ". The ink containing tube 4 is filled with the ink 22 having a statically high viscosity and a shear thinning property that reduces the viscosity by the rotation of the ball during writing and allows the ink to flow out. The rear end is filled with a grease-like follower 23 that prevents the evaporation of the ink and contacts the ink surface as the ink is exhausted and can move following it. The ink storage tube 4 is made of, for example, a transparent PP resin molded product that suppresses ink evaporation.

Next, from the tip of the shaft cylinder 1 to the joint 3 ′, the writing portion to which the tip 5 and the ink containing tube 4 filled with the ink are fixed is inserted, and the collar portion 16 of the joint 3 ′ is attached to the front surface of the shaft portion 6. ｀ The rear end edge is made to abut, and the base 2 provided with the taper part 9 on the inner surface is abutted against the front end edge of the locking cylinder part 7 ″ of the joint 3 ″ and the shaft 2 is brought into contact with the shaft. It is screwed onto the shaft portion 6 of the cylinder 1. Further, a ventilation hole 21 communicating with an inner hole portion of the shaft cylinder 1 is formed at an appropriate position of the shaft cylinder 1, and a tail plug 25 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 consumption amount of ink can be known.

By the way, the tail plug 25 is integrally formed of elastically deformable synthetic resin, and is press-fitted and fixed in a rear end hole of the shaft cylinder 1 in a substantially close-fitting manner. The pipe 4 is tightly fitted in the rear end inner hole portion. Further, a valve chamber 26 is provided at the front end portion of the tail plug 25, a tapered piece receiving seat 28 is provided at the rear portion of the valve chamber 26, and a virtual inscribed circle diameter is formed on the inner surface of the front portion. A plurality of axial projections 27 are provided on the circumference so as to be smaller than the shaft diameter of the top 30, and a top 30 having a taper portion 31 at the rear portion between the top receiving seat 28 and the projection 27 is provided. Is inserted from the direction of the ridge 27 while elastically deforming the ridge 27 and loosely fitted in the valve chamber 26. Further, a vent hole 29 communicating with the top receiving seat 28 is provided at the rear of the valve chamber 26 up to the rear end of the tail plug 25.

FIG. 5 shows a third embodiment of the present invention. The difference from the second embodiment is that the tail plug 25 'is tightly fitted in the rear end hole of the ink containing tube 4. Is. Also in this case, the valve chamber 26 'is provided at the front end of the tail plug 25' facing the rear end of the follower 123, the shaft receiving seat 28 'and the ridge 27' are provided, and the shaft having the taper portion 31 'at the rear is provided. A frame-shaped top 30 "is loosely fitted in the valve chamber 26". In addition, a ventilation hole 29 ′ extending to the rear end of the tail plug 25 ″ is provided behind the top receiving seat 28 ″, and the rear end of the shaft cylinder 1 ″ is closed to provide a predetermined side surface of the shaft cylinder 1 ″. A second vent hole 21 'communicating with the inner hole is provided.

[0014]

[Action]

 First, in the first embodiment, FIG. 1 shows a writing state in which the tip 5 is directed downward, and at that time, the top 19 is brought into contact with the ridge 16 of the valve chamber 14 and the guide hole from the ink containing tube 4 is brought into contact. The ink 22 that has entered the valve chamber 14 via 18 passes by the side of the top 19, passes between the ridges 16 and is guided to the tip of the tip 5. The ink statically has a 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 the ink to flow out. Further, FIG. 2 shows a state in which the tip 5 is directed upward. At that time, since the taper portion 20 of the top 19 is located at the top receiving seat 15 of the valve chamber 14 and seals the guide hole 18, the writing is performed upward. Even if there is no ink right under the ball of the chip, the head does not hit the ink and the ink does not flow back. Further, in the present invention, since the tip 5 of the upper locking cylinder portion 7 in which the tip 5 is press-fitted into the chip fitting hole 12 of the locking cylinder portion 7 of the joint 3 abuts the inner taper portion 9 of the base 2, the locking is achieved. An external force in the radial direction (diameter reduction direction) toward the axial center is applied to the tip of the tubular portion 7 by the taper portion 9, and the clamping force of the tip 5 located inside the tip portion 5 increases. Further, the tip of the locking cylinder portion 7 is appropriately reduced in diameter by the taper portion 9 by the gap 10 so that the tip 5 is prevented from rattling with the base 2.

Further, in the second embodiment, FIG. 3 shows a writing state in which the tip 5 is directed downward, and at that time, the top 30 of the tail plug 25 is in contact with the ridge 27 of the valve chamber 26. Since the rear end of the ink containing tube 4 communicates with the outside air through the vent hole 29 of the tail plug 25, the ink 22 is guided from the ink containing tube 4 to the tip of the chip 5 through the guide hole 14 '. Although the ink statically has a high viscosity, the rotation of the ball at the tip of the tip 5 causes the viscosity to decrease and a large amount of the ink flows out. Further, FIG. 4 shows a state in which the tip 5 is directed upward, and at that time, since the taper portion 31 of the top 30 is located at the top receiving seat 28 of the valve chamber 26 and seals the vent hole 29, the writing is directed upward. When there is no ink right under the ball of the chip and the head is applied and the follower 23 retracts together with the ink 22, the air in the space between the follower 23 and the valve chamber 26 is compressed, and the follower 23 is prevented from further retracting. Therefore, backflow of ink is prevented. Also, in the case of FIG. 5 showing the third embodiment, the operation is exactly the same, and therefore its explanation is omitted. Also, in the second embodiment, the tip 5 is press-fitted into the tip fitting hole 12 "of the locking cylinder 7" of the joint 3 ", and the front end edge of the locking cylinder 7" is the inner surface of the base 2. Since it abuts against the tapered portion 9, an external force in the radial direction (radial reduction direction) toward the axial center is applied by the tapered portion 9 to the tip of the locking tubular portion 7 ′, and the locking cylinder portion 7 is positioned inside thereof. The tightening force of the chip 5 is increased by the sandwiching portion 11 '. Further, the tip of the locking cylinder portion 7'is appropriately reduced in diameter by the taper portion 9 by the gap 10 'so that the tip 5 is prevented from rattling with the base 2.

[0016]

[Effect of device]

 The structure and operation of the ball-point pen of the present invention are as described above, and a valve chamber is provided in a tail plug tightly fitted to the rear end of the joint or the barrel or the rear end of the ink containing tube, and the ball chamber is loosely fitted into the valve chamber. It is possible to prevent accidents where ink flows backward when writing upwards and stains the inside of the barrel, hands, clothes, etc. 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 is possible to provide a high-quality product as described above, and also the effect that the writing feeling is good because the tip and the base are locked.

[Brief description of drawings]

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

FIG. 2 is a longitudinal sectional view of a main part of the ball-point pen which is the first embodiment of the present invention, showing a state in which the tip is facing upward.

FIG. 3 is a vertical cross-sectional view of a main part of a ball-point pen that is a second embodiment of the present invention, showing a state in which the tip faces downward.

FIG. 4 is a longitudinal sectional view of a main part of a ball-point pen which is a second embodiment of the present invention, showing a state in which the tip faces upward.

FIG. 5 is a cross-sectional view of an essential part of a third embodiment of the present invention,
It shows a state in which the chip is facing upward.

[Explanation of symbols]

 1 Shaft 1 Shaft 2 Shaft 3 Joint 3 Joint 3 Joint 4 Ink Storage Tube 5 Chip 6 Shaft 7 Locking Tube 7 Locking Tube 8 Slit 8 ”Slit 9 Taper 10 Gap 10” Gap 11 Grip 11 "Clamping part 12 Chip fitting hole 12" Chip fitting hole 13 Fitting cylinder part 13 "Fitting cylinder part 14 Valve chamber 14" Guide hole 15 Top receiving seat 16 Protrusion 16 "Collar part 17 Collar part 18 Conduction hole 19 Frame 20 Tapered portion 21 Vent hole 21 'Vent hole 22 Ink 23 Follower 24 Tail plug 25 Tail plug 25' Tail plug 26 Valve chamber 26 'Valve chamber 27 Ridge 27' Ridge 28 frame receiving seat 28 'Frame receiving seat 29 Vent hole 29 'Vent hole 30 Top 30' Top 31 Taper section 31 'Taper section

Claims (1)

[Scope of utility model registration request] 1. A tip is fixed to a tip of a barrel, and an ink containing tube communicating with the tip is disposed in the barrel.
The ink containing tube has a statically high viscosity, and the viscosity of the ink decreases due to the rotation of the ball during writing, causing the ink to flow out. Whether the follower that can move following the evaporation of ink and the consumption of ink is provided, and the joint that fixes the chip is made of an elastically deformable resin molded product that communicates with the rear end of the chip and has a valve chamber behind it. A tail plug made of an elastically deformable resin molded product is fixed to the rear end of the shaft cylinder or the rear end of the ink containing tube in a close-fitting manner to face the follower of the ink containing tube and to the front of the tail plug. Is provided with a tapered piece receiving seat at the rear part of the valve chamber, and an axial shape having a taper portion having an axial projection on the inner surface of the front part so as to be in close contact with the piece receiving seat. A ball-point pen characterized by being provided by loosely fitting the top of the above.