JPH10250281A - Refill for ballpoint pen - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent reverse and direct flow of ink by providing a tapered receiving seat at an axial center of a coupling in a direction opposite to a tip rear end and a center part having a jaw portion with a tapered portion provided at a center thereof and a small diameter portion at a shaft portion extending forward, and a shaft portion extending rearwardly integrally. SOLUTION: A refill constructed by securing an ink accommodation tube 4 filled with ink and a tip 5 to a couping 3 is inserted into a shaft tube 1, a rear end edge of a jaw portion 26 of the coupling 3 is brought into impact abutment with a front face of a shaft portion 6, and a metal base 2 having a stepped portion 9 formed on an inner surface is threadingly secured to the shaft portion 6 of the shaft tube 1 in a state in which the stepped portion 9 of the metal base 2 is in impact abutment with the circumferential surface of a rib 8 of the coupling 3. In addition, a tip end ball 5a is brought into tight contact with an inner edge of a holding portion in a pressed state by a small diameter portion 18, and furthermore a tapered portion 17a is brought into tight contact ith a circumferentially contacting rib 14. Due to this, a reverse of ink is prevented that would be caused when a ballpoint pen is oriented upwardly or an impact is imparted, and in addition, a direct flow of ink is prevented when the pen is oriented downwardly. Thus, an accident is prevented in which the inside of the shaft tube, hand or clothing gets dirty by ink.

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 case, 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 at the time of 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. In addition, since the viscosity of the ink is low and the amount of outflow is large, if the tip side faces downward and the gap between the tip ball and the tip caulking portion occurs, the ink bleeds (DC).
The problem exists.

[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. To prevent backflow of ink caused by upward writing or impact and direct current when the tip side is placed downward, and to prevent contamination of the inside of the barrel for mounting the ballpoint pen refill, hands, and clothes.

[0004]

SUMMARY OF THE INVENTION In order to achieve the above object, a ballpoint pen refill according to the present invention has a ballpoint pen tip at the tip of a joint and a statically high viscosity at the rear end. Viscosity is reduced by the rotation of the ball, and the ink flows out. So-called shear-thinning ink is filled, and the rear end of the ink is filled with a grease-like follower that comes in contact with the ink surface as the ink is consumed. In the refill of a ball-point pen to which an ink storage tube is fixed, a tapered receiving seat is provided at the axis of the joint in a direction facing the rear end of the chip, while the top is provided with a flange having a tapered portion substantially at the center. A portion having a small-diameter portion at the tip of a shaft portion extending forward thereof and a shaft portion extending rearward are provided integrally with each other. Closely prevents ink inflow At the same time, the tip of the small diameter portion contacts the rear end of the tip ball, the tip ball comes into close contact with the inner edge of the holding portion at the tip end of the tip, and a spring is urged to prevent the ink from flowing out. The top is retracted with a slight transition in the axial direction of the tip ball, the close contact state is released, and the ink can flow out.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the embodiment of the present invention shown in FIGS. 1 and 2, 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. A rib 8 inclined forward in the axial direction is provided 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.

The joint 3 is made of an elastically deformable synthetic resin and is integrally formed. The joint 3 communicates with the chip fitting hole 10 and has a tapered shape on the side facing the rear end of the shaft 11 of the chip 5 rearward. A receiving seat 13 is provided. Further, a circumferential contact rib 14 is formed at a required position of the receiving seat 13 so as to bulge appropriately. A slit portion 21 is formed at a required position on the rear end side of the fitting tube portion 12 so that the rear end portion can be appropriately expanded by elastic deformation. In addition, a tapered surface 25 is provided at the rear end of the fitting cylindrical portion 12, and an inner step portion 22 is formed at the rear end of the inner hole communicating with the receiving seat 13.

The top 15 has a flange portion 17 provided with a tapered portion 17a at the approximate center thereof so as to be able to come into close contact with the receiving seat 13, and an ink guide groove 16 and a front end are provided at required locations on the outer periphery of a shaft portion extending forward. And a shaft portion 20 extending rearward. The tip 5 is swaged 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.

[0008] The top 15 is fitted to the fitting cylinder 12 of the joint 3.
Is inserted from the rear end with the rear end elastically expanded, and a spring 23 is urged between the step 19 at the rear end of the flange 17 and the inner step 22 of the joint 3. The shaft portion in front of the top 15 is inserted into the inner hole of the chip 5, and the tapered portion 17a is brought into close contact with the circumferential rib 14 of the receiving seat 13, so that the inflow of ink is prevented and the small diameter portion is formed. The tip of the tip 18 abuts the rear end of the tip ball 5a, and the tip ball 5a comes into close contact with the inner edge of the holding portion at the tip of the tip 5.

A flange 26 is provided at the rear end of the engaging cylinder 7 of the joint 3, and the fitting cylinder 12 is provided behind the flange 26.
Is extended. A cylindrical ink storage tube 4 is press-fitted and fixed to the outer periphery of the fitting tube portion 12 with its front end abutting on the rear end of the flange portion 26. The ink container 4 is filled with an ink 24 having a statically high viscosity and a shear-thinning viscosity that allows the ink to flow out by rotating the tip ball 5a during writing. The rear end of the ink 24 is filled with a grease-like follower that can move following the ink surface while contacting 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 portion 6. The rear end edge of the flange 26 abuts, and the base 2 provided with the step 9 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 shaft tube 1. Is screwed to the shaft portion 6.

[0011]

First, FIG. 1 shows a state before writing with the chip 5 facing down, and at this time, the top 15 has a small diameter portion 18 at the tip.
Is in contact with the rear end of the tip ball 5a, and the tapered portion 17a of the flange portion 17 is
Close to. In this state, the tip ball 5a is pressed in close contact with the inner edge of the holding portion by the small-diameter portion 18, so that direct current is prevented. In addition, the tapered portion 17a is
, Which prevents upward flow of ink. In addition, when writing upward, the backflow of the ink is prevented by the cooperation of the top 15 and a grease-like follower (not shown) provided at the rear end of the ink.

FIG. 2 shows a writing state in which the tip ball 5a is slightly retracted by the writing pressure, so that a gap is formed and ink flows out. Also, at this time, the top 15 retreats in conjunction with the tip ball 5a, so that the close contact between the tapered portion 17a and the circumferential rib 14 is released, and ink passes through the ink guide groove 16 through the gap to cause the tip ball 5a. Is guided to the rear end. In addition, the viscosity is reduced by the rotation of the tip ball 5a due to the writing, and a large amount of ink is flown out.

In addition, when the refill of the ballpoint pen of the embodiment is mounted on the barrel 1, the base 2 is screwed in a state in which the flange 20 of the joint 3 abuts 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.

[0014]

The structure and operation of the refill of the ballpoint pen according to the present invention are as described above. It is possible to prevent the ink from flowing backward due to upward or impact, and to prevent direct current when the ink is placed downward. Accidents that stain hands, clothes, etc. are prevented. Further, when the refill of the ballpoint pen according to the embodiment is mounted on the shaft cylinder, the tip and the base are rattled, so that the effect of giving a good brush feel is exhibited.

[Brief description of the drawings]

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

FIG. 2 is a vertical sectional view of a main part of a ballpoint pen according to an embodiment of the present invention, showing a state during writing.

[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 11 Shaft part 12 Fitting cylinder part 13 Receiving seat 14 Peripheral contact Rib 15 Frame 16 Ink guide groove 17 Flange 17a Taper 18 Small diameter 19 Step 20 Shaft 21 Slot 22 Inner step 23 Spring 24 Ink 25 Tapered surface 26 Flange

Claims (1)

[Claims] 1. A tip of a ballpoint pen at a tip of a joint,
The rear end has a statically high viscosity, and the viscosity of the ink drops due to the rotation of the tip ball during writing, causing the ink to flow out. And a ball-point pen refill in which an ink container filled with a grease-like follower that comes into contact with and follows the ink surface is fixed. On the other hand, the top has a flange portion having a tapered portion in the approximate center and a small-diameter portion at the tip of a shaft portion extending forward and a shaft portion extending rearward. In the above-mentioned piece, the flange portion is in close contact with the receiving seat of the joint to prevent the inflow of ink, and the leading end of the small diameter portion contacts the rear end of the tip ball, so that the tip ball holds the tip end. Close to the inner edge of the holding section, preventing ink from flowing out A ball refill is characterized in that a spring is biased to retreat the top with a slight transition in the axial direction of the tip ball accompanying writing, so that the close contact state is released and ink can flow out. .