JP2000135892A - Ballpoint pen - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow a refill of a first ballpoint pen using an ink having a low viscosity or shear-rate thinning and a refill of a second aqueous ballpoint pen using an ink storage material or an ink reservoir to be chargeable in a common writing instrument body. SOLUTION: The ballpoint pen comprises a refill 20 of the pen having a tip of the pen at a front end of a front barrel and integrally having an ink containing tube 43 rear of the front barrel in such a manner that ink having a low viscosity or high viscosity in a steady state and the viscosity lowered in the case of rotating a tip ball at the time of writing so that the ink flows out, so-called shear-rate thinning is filled in the tube, and a grease-like follower 45 movable by following as the ink is consumed and filled in a rear end of the ink. Further, a spring is inserted into an inner hole of the tip. At the time of pressing a rear end of the tip ball, the end ball 24 is brought into close contact with an inner edge of the ball holding part of the tip to prevent the ink from flowing out. A vent part for communicating a rear end of the refill with the atmosphere is formed by a groove provided at the connecting part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a ballpoint pen capable of changing a refill.

[0002]

2. Description of the Related Art The applicant of the present invention discloses, in Japanese Utility Model Publication No. 4-52067, a mechanism for preventing backflow of ink of a ballpoint pen provided with a valve chamber into which a ball is loosely fitted. In this device, a required number of protrusions are provided in a valve chamber in which a ball is loosely fitted with a synthetic resin mouth plug to prevent the ball from being pulled out, and a gap formed between the protrusions during writing. And the ink flows to the chip. Further, a ballpoint pen using an ink having a shear thinning viscosity, in which the viscosity is reduced by the rotation of the tip ball during writing and the ink flows out, is known.

In general, a ballpoint pen using an ink having shear thinning viscosity has a large amount of outflow of ink (to increase the writing density), and has a large diameter of an ink containing tube 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. Accordingly, ink leakage (ink flows backward at the rear end of the ink storage tube) easily occurs due to the ink's own weight or impact. For this reason, the ink usually moves following the consumption of ink at the time of writing at the rear end of the ink, but a grease-like follower that suppresses the backflow of the ink due to its own weight or impact, and a follower as necessary. A rod is loosely inserted in the follower. However, even if the follower is provided, when ink is written immediately below the ball of the chip when writing upwards, there is a danger that the ink or the head will be added directly, causing a remarkable backflow and soiling the hands and clothes. In addition, since the viscosity of the ink is low and the amount of outflow is large, there is a problem that the ink bleeds (DC) when a gap is formed between the tip ball and the chip holding portion when the tip side is directed downward.

[0004] In addition, a refill of an aqueous ball-point pen using an ink occlusion body or an ink storage body and a rear shaft are joined to each other,
(The rear end of the refill is closed and has a vent hole in front of the lip.) The tip of the tip and the lip are inserted into the inner hole of the inner cap fixed to the inner hole of the cap. The outer periphery is closely attached to the insertion opening of the inner cap,
There is known an aqueous ballpoint pen in which a tip ball and a ventilation hole are closely fitted in an inner hole portion of an inner cap to prevent evaporation of ink and drying of a tip ball portion.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a ball-point pen and an ink using a low-viscosity ink or an ink having a shear-thinning viscosity in which the viscosity is reduced by rotation of a ball during writing and the ink is discharged. The refill of an aqueous ballpoint pen using an occluding body or an ink reservoir can be interchangeably loaded into a writing implement body composed of the same rear shaft and cap. It is possible to prevent reverse flow of ink caused by impact and direct current when the tip side is placed downward, and it is possible to prevent contamination of the inside of the shaft cylinder of the ballpoint pen, hands, and clothes.

[0006]

In order to achieve the above object, a ballpoint pen according to the present invention has a tip of a ballpoint pen and a tip of a ballpoint pen, and an ink storage tube integrally provided at the rear of the pointed shaft. And a ballpoint pen formed by joining a rear shaft to a front shaft portion of the refill, wherein the ink storage tube has low-viscosity ink or statically high viscosity, The ink is filled with ink having a so-called shear thinning property in which the viscosity is reduced due to the rotation of the ball, and the ink is filled with a so-called shear-thinning ink, and the rear end of the ink is filled with a grease-like follower that can move with the consumption of the ink. ,
Also, a spring is inserted into the chip inner hole, and the tip of the spring presses the rear end of the tip ball rotatably held at the tip end of the tip, so that the tip ball is the inner edge of the ball holding portion of the chip. The rear end of the refill is connected to the outside air by a groove formed at the junction between the front shaft and the rear shaft.

[0007]

1 and 2 show an embodiment of the present invention. First, as shown in FIG.
3, externally composed of the tip portion 30, the ink storage tube 43, and the tail plug 21. The front shaft portion 30 is integrally formed of a synthetic resin, and has a lip portion 31 at the front thereof and an outer cylinder portion 3 at the rear thereof.
3 are integrally formed. A hole penetrates the shaft center, and a tip of the tip portion 31 has a ball-point tip 2.
3 is crimped. A valve chamber 35 is provided in contact with the rear end of the shaft portion 26 behind the chip 23, and a tapered or spherical ball receiving seat 36 is formed at the rear end of the valve chamber 35.

By the way, in the embodiment, the chip 23
A valve chamber 35 is provided eccentrically with respect to the axis of the shaft section 26, and a tapered or spherical ball receiving seat 36 is formed at the rear of the valve chamber 35 so as to communicate with the guide hole 39. or,
A groove 37 into which ink can flow is provided on one side of the inner wall of the valve chamber 35.
Are formed. Further, the ball valve 40 is loosely fitted in the valve chamber 35, and the ball valve 40 abuts against the rear end of the shaft 26 of the chip with the tip 23 facing downward, and the groove 37 Thus, the ink flowing from the guide hole 39 through the hole flows into the chip. The valve chamber is provided at the axis of the lip portion 31, the ball valve is loosely fitted in the valve chamber, and the ink is conducted inside the chip in a state where the chip is directed downward. The embodiment has been previously filed by the present applicant.

On the other hand, the tip 23 is caulked so that the tip ball 24 is rotatably held with the tip ball 24 substantially in contact with a seat having a channel into which ink can flow. A spring 28 is inserted into the chip inner hole 25, the rear end of the shaft 26 of the chip is appropriately caulked, and the rear end of the spring 28 is provided so as not to be pulled out. An upright bar shaft 29 is formed in front of the spring 28, and the tip of the bar shaft 29 presses against the rear end of the tip ball 24 in a pressing manner. The tip ball 24 is brought into close contact with the inner edge of the ball holding portion (formed by caulking or the like) of the chip 23 by the pressing.

As described above, when the tip side is downward, the ball valve 40 comes into contact with the rear end of the caulking portion 27 while being biased, and ink flows through the guide hole 39, the valve chamber 35, the groove 37, and the like. To be conducted to the rear end of the tip ball 24.

The front shaft portion 30 has an inner cylindrical portion 32 extending rearward of the guide hole 39, and has an outer periphery ahead of the inner cylindrical portion 32, a lip portion 31, and a front end of the outer cylindrical portion 33. A required number of ribs 34 are formed around the circumference. In addition, a cylindrical ink storage tube 43 is pressed against the outer periphery behind the inner cylindrical portion 32 by abutting its front end on the rear end of the rib 34, and the inner diameter portion of the ink storage tube 43 communicates with the guide hole 39. . The ink 44 has a low viscosity ink or a low viscosity ink which has a high viscosity statically, and has a viscosity reduced by the rotation of the ball during writing, and has a shear thinning viscosity which allows the ink to flow out. Is filled and ink 4
4 is filled with a grease-like follower 45 which is movable in contact with and following the ink surface as the ink is consumed. A follower rod 46 made of resin is loosely inserted into the follower 45. The follower rod 46 is provided as necessary (the ink container tube is thick, the ink head is large, and the viscosity of the ink is low and the ink head cannot be supported). A tail plug 21 having a vent hole 22 communicating with the outside air is pressure-bonded to the rear end of the ink storage tube 43.

The refill 20 of the ball-point pen is configured as described above, and as shown in FIG. 1, the front shaft portion 30 and the rear shaft 16 are screw-connected to form a shaft cylinder. Further, the front shaft portion 30 has a screw portion 41 at a rear end, and a groove portion 42 is provided at a required portion of the screw portion 41.
Are formed, and a ventilation path 14 and a ventilation hole 15 are formed, which are connected to the outside air when joined to the rear shaft 11 described later.

A screw tube 12 is crimped to a rear end of the rear shaft 11, and a tail plug 16 is fixed to a rear end of the rear shaft 11 with a fixing member 17 located in the rear hole of the rear shaft 11. A spring 18 is provided upright at the axis of the tool 17.

The rear shaft 11 of the refill 20 is screwed to the screw portion 41 of the front shaft portion 30. At this time, the rear end of the tail plug 21 of the refill contacts the front end of the spring 18, and the refill 30 is urged forward in a pressing manner. Note that the spring 18 acts as a mutual stop at the screw joint between the front shaft portion 30 and the rear shaft 11, but is not necessary for the purpose of the present application.

The crown 3 is crimped to the rear end hole of the cap 1 by holding the clip 2 between the fixture 4 and the crown 3.
Further, an inner cap 5 having a closed rear end is inserted into the inner hole of the cap 1, and the rear end of the inner cap 5 is crimped to the fixture 4. Front inner hole 7 of inner cap 5
A seal stopper 6 made of a non-liquid-absorbing elastic body (for example, made of rubber) is fixed to the rear end. Further, an insertion hole 8 for the inner hole portion is formed in front of the inner hole portion 7, and an outer cylinder portion 9 is formed outside the insertion hole 8. An inward projection is formed on the inner peripheral surface of the outer cylinder portion 9 near the front end thereof. Is formed.

As described above, the tip shaft portion of the refill 20 is fitted into the cap 1, the tip ball 24 is pressed into the seal plug 6 in a biting manner, and the outer peripheral portion of the mouth portion 31 is attached to the inner cylinder. The cap 1 is fixed by closely contacting the insertion opening 8 of the portion, and the engaging portion 10 of the outer cylindrical portion is elastically engaged with the engaging groove 38 of the tip portion. In addition, the tip ball portion is the inner hole 7
However, since the spring 28 presses the rear end of the tip ball 24 before the tip ball 24 comes into contact with the seal plug 6, air is drawn into the chip inner hole 25 by pressurization. It is not. Also, the front shaft portion 30 and the rear shaft 11
Air flows between the outside air and the rear end of the follower 45 through the ventilation hole 22 of the tail plug 21 of the refill 20 through the ventilation path 14 and the ventilation hole 15 formed at the screw joint portion between the outside and the rear.

By the way, the ventilation hole 15 can be provided by drilling a ventilation hole in the outer cylindrical portion 33 of the front shaft portion or the side surface of the rear shaft 16 separately from the embodiment. Further, in the embodiment, the tip shaft portion 30 and the ink containing tube 43 are provided separately by the refill 20, but they may be formed integrally for the convenience of design. In addition, if the ink storage tube 43 is formed of a transparent resin molded product and the tip shaft portion 30 is formed of a transparent resin molded product, the remaining amount of ink can be seen through. Also, the outer cylindrical portion 3 of the tip shaft portion
An opaque print or the like may be applied to the peripheral surface of No. 3 so that only necessary portions can be seen through. Further, it is also possible to make the front shaft portion opaque so that a window portion is formed in the peripheral surface of the outer cylindrical portion so as to allow see-through.

[0018]

First, the refill 20 shown in FIG. 2 shows a state in which the tip 23 is directed upward. At this time, the ball valve 40 comes into close contact with the ball receiving seat 36 of the valve chamber 35 and the guide hole 3 is formed.
Since the ink 9 is sealed, the ink does not flow backward even if the ink immediately below the tip ball 24 is exhausted by upward writing. Therefore, when the chip 23 is turned downward, the ink can immediately flow out, and the writing is prevented from being blurred. (By the way, in the structure without the ball valve, the ink head acts in the backward flow direction in upward writing, so that air is entrapped in the chip, and ink does not immediately follow in downward writing, resulting in blurring. Air entrainment is accumulated.)

Before writing with the tip 23 facing down, the ball valve 40 comes into contact with the rear end of the tip shaft 26, and the guide hole 39 is opened. The ink 44 that has entered the valve chamber 35 from the ink storage pipe 43 through the guide hole 39 is supplied to the groove 37.
And flows into the chip inner hole 25 to be conducted to the rear end of the tip ball 24. In this state, the tip ball 24 is brought into close contact with the inner edge of the chip holding portion by the pressing of the rod shaft portion 29 of the spring 28, so that the direct current of the ink 44 is prevented.
In addition, since the tip ball 24 slightly retreats due to the writing pressure, a gap is generated and ink can flow out. By writing, the ink flows out by rotation of the tip ball 24 and writing becomes possible.

A channel (a seat for a tip ball having a plurality of ink inflow grooves penetrating toward a chip inner hole) is provided directly below the tip ball 24. A rod shaft of a spring 28 is provided in a center hole of the channel. The part 29 penetrates. The ink in the chip is filled with the ink inflow groove and the center hole and the rod shaft 2.
9 is guided directly below the tip ball 24 through the gap between the ball 9 and the ball 9.

[0021]

The configuration and operation of the ballpoint pen of the present invention are as described above. The ballpoint pen refill using ink having low viscosity or ink having shear thinning property and the aqueous solution using ink occluding material or ink storing material. The ballpoint pen refill can be loaded into a common writing instrument body. or,
Since the tip ball is in close contact with the inner edge of the tip holding portion except when writing, direct current is prevented when the ink flows backward or is placed downward, thereby preventing accidents that stain the inside of the barrel, hands, and clothes.
In addition, handwriting due to drying is prevented.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a ballpoint pen according to an embodiment of the present invention, which is partially non-sectional.

FIG. 2 is a longitudinal sectional view of a ballpoint pen refill used in the present invention, showing a state in which a chip is directed upward.

[Description of Signs] 1 Cap 2 Clip 3 Crown 4 Fixing Tool 5 Inner Cap 6 Seal Plug 7 Inner Hole 8 Insertion Hole of Inner Hole 9 Outer Cylindrical Unit 10 Locking Unit 11 Rear Shaft 12 Screw Tube 13 Screw Unit 14 Ventilation path 15 Vent hole 16 Tail plug 17 Fixture 18 Spring 20 Refill 21 Tail plug 22 Vent hole 23 Tip 24 Tip ball 25 Tip bore 26 Shaft 27 Caulking portion 28 Spring 29 Rod shaft portion 30 Shaft portion 31 Tip 32 Inner cylinder part 33 Outer cylinder part 34 Rib 35 Valve chamber 36 Ball receiving seat 37 Groove part 38 Lock groove 39 Guide hole 40 Ball valve 41 Screw part 42 Groove part 43 Ink storage tube 44 Ink 45 Follower 46 Follower rod

Claims (1)

[Claims] 1. A tip of a ballpoint pen at a tip of a tip shaft portion,
In a ballpoint pen refill having an ink storage tube integrally provided behind a front shaft portion and a ballpoint pen formed by joining a rear shaft to a front shaft portion of the refill, the ink storage tube has a viscous The ink has a low viscosity or a high viscosity statically, and the viscosity is reduced by the rotation of the tip ball at the time of writing, and the ink flows out. A grease-like follower that can move following the ink consumption is filled, and a spring is inserted into the chip inner hole, and a tip ball rotatably held at the tip end of the tip at the tip of the spring. By pressing the rear end, the front end ball is brought into close contact with the inner edge of the ball holding portion of the chip so that the outflow of ink can be prevented, and furthermore, the groove provided at the joint between the front shaft portion and the rear shaft is used to refill the Communication between rear end and outside air Ballpoint pen, characterized in that the formation of the vent that.