JP3148504B2 - Ballpoint pen - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses an ink having a so-called shear thinning viscosity, which has a high viscosity statically and whose viscosity is reduced by rotation of a ball at the time of writing to cause ink to flow out. Regarding improvement of ballpoint pens.

[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 ink having shear thinning viscosity has a large amount of ink flowing out (to increase the writing density), and has a large diameter of the ink storage tube to increase the amount of ink loaded. or,
Since the viscosity of the ink is smaller than that of the oil-based ball-point pen ink, the flow resistance to the ink storage tube is small. Therefore,
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 purpose, a grease-like follower is provided at the rear end of the ink, which normally moves following the consumption of ink during writing, but suppresses the backflow of the ink against its own weight or impact. However, even when the follower is provided, if the ink immediately below the ball of the chip runs out when writing upward, there is a risk that a remarkable backflow occurs because the ink head is added directly and the hands and clothes are stained. Further, since the viscosity of the ink is low and the amount of outflow is large, there is a problem that the ink bleeds (DC) if a gap is formed between the tip ball and the chip holding portion when the tip side is directed downward.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to improve a ball-point pen using ink having a shear-thinning property in which the viscosity is reduced by the rotation of the ball during writing and the ink flows out. In this way, it is possible to prevent reverse flow of ink caused by upward writing or impact and direct current when the tip side is placed downward, thereby preventing contamination of the inside of the barrel of the ballpoint pen, hands, and clothing. In addition, it is caused by writing upward, preventing writing blur caused by running out of ink due to air entrapment immediately below the tip ball when an impact is applied, and drying caused by incomplete sealing between the tip ball and the inner edge of the tip holding portion. It is possible to prevent handwriting.

[0004]

A ballpoint pen according to the present invention devised to achieve the above object is a ballpoint pen having a tip of a ballpoint pen fixed to a joint end and an ink storage tube fixed to a rear end. A valve chamber is provided at the rear in communication with the rear end of the chip at the axis of the joint, and a tapered or spherical ball receiving seat is provided at the rear of the valve chamber, and a spring is inserted into the chip inner hole. The spring is provided so as not to be pulled out from the rear end of the tip, 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 tip. The ball valve is in close contact with the ball receiving seat when the tip side is upward, and the guide hole is sealed to prevent backflow of ink when the tip side is upward, and the sealed state is released when the tip side is downward. Lead with , Ink can can flow into the chip through valve chamber.

[0005]

1 and 2 show a first embodiment of the present invention. First, as shown in the figure, a locking cylinder 7 is provided in the first half of the joint 3 and a fitting cylinder 12 is provided in the second half of the joint 3.
Is provided with a rib 8 inclined forward in the axial direction at a required position on the circumference. A tip fitting hole 10 is formed in the locking cylinder part 7 from the front end, and the chip 5 is press-fitted into the tip fitting hole 10 from the rear end side. In order to prevent the chip 5 from being pulled out, a convex engaging portion 11a is formed on the shaft portion 11 of the chip as necessary, so that the chip fitting hole 10 is formed as a slightly small hole behind the chip fitting hole 10. The locking portion 11a is bitely locked in the hole 10 #.

[0006] The joint 3 is made of an elastically deformable synthetic resin and is integrally formed.
A valve chamber 13 is provided at the rear in communication with 0 °. or,
A tapered or spherical ball seat 14 is provided at the rear end of the valve chamber 13, and a required number of ridges 16 are provided on the front peripheral wall of the valve chamber 13.

A ball receiving seat 14 is provided behind the valve chamber 13.
The ball valve 15 elastically deforms the ridge 16 in the valve chamber 13 and is loosely fitted in the valve chamber 13 so that it cannot be pulled out. Note that an ink guide groove is formed between the ridges with which the ball valve 15 contacts.

On the other hand, the tip 5 is caulked so that the tip ball 5a is rotatably held with the tip ball 5a substantially in contact with a seat having a channel 5b into which ink can flow. Further, a spring 17 is inserted into the inner hole of the chip 5 in a state where the rear end thereof is in contact with the step 16a, and the rear end of the shaft 11 of the chip is appropriately caulked, so that the rear end of the spring 17 cannot be pulled out. It is provided in. An upright rod portion 18 is formed at the tip of the spring 17.
Abuts against the rear end of the tip ball 5a in a pressing manner.
The tip ball 5a is brought into close contact with the inner edge of the ball holding portion (formed by caulking or the like) of the chip 5 by the pressing.

As described above, when the tip side is downward, the ball valve 15 comes into contact with the rear end of the ridge 16,
The ink can flow into the rear end of the tip ball 5a through the guide hole 20, the valve chamber 13, the ink guide groove between the ridges, and the inner hole of the tip 5.

A flange 19 is provided at the rear end of the engaging cylinder 7 of the joint 3, and a fitting cylinder 12 is provided behind the flange 19.
Is extended. A cylindrical ink storage tube 4 is press-fitted and fixed to the outer periphery of the fitting cylindrical portion 12 with its front end abutting on the rear end of the flange portion 19, and the inner diameter portion of the ink storage tube 4 is formed in the guide hole 2 of the joint 3.
It communicates with 0. The ink accommodating tube 4 is filled with an ink 21 having a high viscosity statically, and having a shear-thinning viscosity that allows the ink to flow out by rotating the ball at the time of writing so that the ink can flow out. The rear end 21 is filled with a grease-like follower that can move in contact with and follow the ink surface as the ink is consumed. (Not shown)

As described above, the refill of a ballpoint pen formed by fixing the chip 5 and the ink containing tube 4 filled with ink to the joint 3 is inserted into the shaft cylinder 1, and the joint 3 is attached to the front surface of the shaft 6. The rear end edge of the flange 19 is abutted, and the base 2 having the step 9 provided on the inner surface thereof is brought into contact with the peripheral surface of the rib 8 of the joint 3 while the step 9 is brought into contact with the sleeve 3. A ballpoint pen is formed by screwing to the shaft portion 6 of the ballpoint pen.

FIG. 3 shows a second embodiment of the present invention. Since it is basically the same as the first embodiment, only the differences will be described. The front end of the spring 32 inserted into the chip 5 forms a seat, and a push body 30 having a rod shaft portion 31 is disposed at the front portion thereof. The tip of the rod shaft portion 31 is the rear end of the tip ball 5a. Abuts on the pressing member.

FIG. 4 shows a third embodiment of the present invention. Since it is basically the same as the first embodiment, only the differences will be described. A front portion of the spring 40 has a tapered winding portion 41 along a tapered inner hole in front of the tip 5, and an upright bar shaft portion 42 is formed at the front end.
Also, since the inner hole of the chip is usually formed by a stepped drilled hole, it may be formed in a spring having a step-shaped winding portion reduced in a stepped shape along the stepped hole. is there. In addition, the foremost end of the winding portion may be brought into contact with the tip ball 5a. (Not shown)

FIGS. 5 and 6 show a fourth embodiment of the present invention. This is also basically the same as the first embodiment, and only the differences will be described. As shown in FIG.
A valve chamber 51 which is appropriately eccentric with respect to the axis of the chip 5 is provided at the axis of the tip 5. A tapered or spherical ball receiving seat 52 is formed at the rear of the valve chamber 51 so as to communicate with the guide hole 54.
A groove 53 through which ink can flow is formed on one side of the inner wall of the valve chamber 51. The ball valve 5 is provided in the valve chamber 51.
5 is loosely fitted, the ball valve 55 in a state in which the chip 5 downward abuts against the state of being biased to the rear end of the shaft portion 11 of the chip, ink that has flowed from the guide hole 54 through the groove 53 and the like chips It is configured to flow into.

[0015]

First, in the first embodiment, FIG.
Is shown in a state before writing, with the ball valve 15 in contact with the rear end of the ridge 16 at that time.
Is released. The ink 21 that has entered the valve chamber 13 from the ink storage tube 4 through the guide hole 20 passes through the ink guide groove formed between the ridges and is guided to the rear end of the tip ball 5a. In this state, the tip ball 5a is brought into close contact with the inner edge of the chip holding portion by the pressing of the rod shaft portion 18, so that direct current of ink is prevented. Also, the tip ball 5a is determined by the writing pressure.
Is slightly retracted, so that a gap is generated and ink can flow out. By writing, the viscosity of the tip ball 5a is reduced by rotation, and a large amount of ink is flown out.

A channel 5 is provided immediately below the tip ball 5a.
channel 5b (a seat for a tip ball having a plurality of ink inflow grooves penetrating toward a chip inner hole).
The rod portion 18 penetrates through the center hole. The ink in the chip is guided directly below the tip ball through an ink inflow groove and a gap between the center hole and the rod shaft portion 18.

FIG. 2 shows a state in which the tip 5 is directed upward. At this time, the ball valve 15 is in close contact with the ball receiving seat 14 of the valve chamber 13 to seal the guide hole 20. Even if the ink immediately below 5a runs out, the ink does not flow backward. Therefore, when the chip 5 is turned downward, the ink can immediately flow out, and the writing is prevented from being flared.
(By the way, in the structure without the ball valve, the ink acts in the backward direction in the upward writing, so that air is trapped in the chip, and the ink does not immediately follow in the downward writing, resulting in rubbing.
Further, air entrapment is accumulated by repeating upward writing. )

Further, since the tip ball 5a is always in close contact with the inner edge of the tip holding portion, the writing of the tip portion is prevented from drying out at the tip portion. Further, even if upward writing or impact is applied by the cooperative action of the tip ball 5a and the ball valve 15, air entrainment is prevented, so that writing is prevented.

Further, when the refill of the ballpoint pen of the embodiment is mounted on the barrel 1, the base 2 is screwed with the flange 19 of the joint 3 abutting against the front end of the shaft 6. Since the ribs 8 of the stopper tube 7 bite against the step 9 of the base 2, play is stopped between the chip 5 and the base 2.

Since the second to fourth embodiments are basically the same as the first embodiment, only the essential points will be described. First, in the second embodiment, a separate pushing body 30 is provided at the front end of the spring 32, so that the rod shaft portion 31 has good swingability, and the tip ball 5a
It is possible to select the friction resistance (material, shape) of the portion that comes into contact with the brush, so that the writing feel is good. In the third embodiment, a tapered or stepped winding portion is provided along the inner hole of the chip 5 so that the rod shaft portion 42 has good stability on the axial center, and the ink guiding bias and the like are improved. The contact resistance with the tip ball is stabilized. or,
In the fourth embodiment, unlike the first embodiment, there is no ridge for contacting the ball valve so that the ball valve cannot be pulled out, so that the mold accuracy and molding conditions for molding the joint 50 are simplified. (By the way, the ridge is undercut due to mold release, so it is difficult to obtain dimensional accuracy.)
In addition, the ball valve can be easily inserted and inserted into the valve chamber (the projection is damaged because the projection is damaged because the ball valve is inserted using elastic deformation).

[0021]

The configuration and operation of the ballpoint pen according to the present invention are as described above, and the backflow of ink due to upward writing or impact can be prevented by the ball valve loosely fitted in the valve chamber.
In addition, 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 ball is placed downward, and accidents that stain the inside of the shaft cylinder, hands, clothes, and the like are prevented. In addition, the ink immediately follows after upward writing or impact, so that blurring is prevented. In addition, handwriting due to drying is prevented. Further, in the ball-point pen of the embodiment, since the tip and the base are loosened through the joint, the effect of a good brush feeling can be obtained.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a main part of a ballpoint pen according to a first embodiment of the present invention, showing a state where a chip is directed downward.

FIG. 2 is a longitudinal sectional view of a main part of the ballpoint pen according to the first embodiment, showing a state in which a chip is directed upward;

FIG. 3 is a vertical sectional view of a main part of a ballpoint pen according to a second embodiment, showing a state in which a chip is directed upward;

FIG. 4 is a vertical sectional view of a main part of a ballpoint pen according to a third embodiment, showing a state in which a chip is directed upward;

FIG. 5 is a vertical sectional view of a main part of a ballpoint pen according to a fourth embodiment, showing a state in which a chip is directed downward.

FIG. 6 is an enlarged view of a ball-point pen according to a fourth embodiment, which is a cross-sectional view of a valve chamber portion of a joint.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Shaft cylinder 2 Base 3 Joint 4 Ink storage tube 5 Tip 5a Tip ball 5b Channel 6 Shaft part 7 Locking cylinder part 8 Rib 9 Step part 10 Chip fitting hole 10 孔 Chip fitting hole 11 Shaft part 11a Lock part 11b Caulking part 12 Fitting cylinder part 13 Valve chamber 14 Ball receiving seat 15 Ball valve 16 Ridge 17 Spring 18 Bar shaft part 19 Flange part 20 Guide hole 21 Ink 30 Push body 31 Bar shaft part 32 Spring 40 Spring 41 Winding part 42 Rod Shaft 50 Joint 51 Valve chamber 52 Ball receiving seat 53 Groove 54 Guide hole 55 Ball valve

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A 6-17977 (JP, U) JP-A 6-12095 (JP, U) JP-A 57-193578 (JP, U) JP-A 6-197578 17982 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B43K ⁷ /00-7/02 B43K 7/10

Claims (6)

(57) [Claims] 1. A tip of a ballpoint pen at a tip of a joint,
By fixing the ink containing tube in the rear end, intravenously into the ink containing tube
Has a high viscosity, and the rotation of the tip ball during writing causes
Has a so-called shear thinning property, which causes ink to flow out due to reduced
Is filled with ink, and the ink is
In a ball-point pen filled with a grease-like follower that follows with wear , a valve chamber is provided at the rear in communication with the rear end of the chip at the axis of the joint, and a taper is formed at the rear of the valve chamber. A spherical or spherical ball seat is provided in the valve chamber.
A ball valve is loosely fitted to the tip hole, and a spring is inserted into the tip inner hole so that the spring cannot be pulled out from the rear end of the tip. The tip ball is rotatably held at the tip end of the tip at the tip of the spring. Pressing the rear end, the tip ball is in close contact with the inner edge of the ball holding portion of the chip, preventing ink from flowing out. When the tip side is upward, the ball valve is in close contact with the ball receiving seat and the guide hole is sealed. A ballpoint pen characterized in that the backflow of ink is prevented and the closed state is released when the tip side is downward, and the ink flows into the chip through the guide hole and the valve chamber. 2. A required number of ridges are provided on a front peripheral wall of a valve chamber, and a ball valve capable of closely contacting a ball receiving seat elastically deforms the ridges so that the ball valve cannot be pulled out into the valve chamber. 2. The ballpoint pen according to claim 1, wherein the ball valve abuts on the ridge so that ink can flow into the chip through the guide hole, the valve chamber, and the ink guide groove formed between the ridges. 3. The valve chamber is provided so as to be appropriately eccentric with respect to the chip axis, and a ball valve loosely fitted in the valve chamber is biased and abutted to the rear end of the chip to form an ink flow path through which ink can flow into the chip. The ballpoint pen according to claim 1, wherein the ballpoint pen is configured. 4. An upright bar shaft is formed in front of the spring, and the front end of the bar shaft presses the rear end of the tip ball, and the rear end of the tip is caulked, so that the spring cannot be pulled out. The ballpoint pen according to claim 1. 5. A pusher having a rod shaft portion at the front end of the spring is inserted so as to be axially movable so that the tip of the rod shaft portion presses the rear end of the tip ball, and the rear end of the tip is caulked, so that the spring is moved. 2. The ballpoint pen according to claim 1, wherein the ballpoint pen is provided so as not to be pulled out. 6. The ballpoint pen according to claim 1, wherein the diameter of the spring is reduced in a tapered or stepped shape toward the front in accordance with the shape of the chip inner hole.