JP2865581B2 - Ballpoint pen refill - Google Patents

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 refill which is mounted on a knock-type writing instrument.

[0002]

2. Description of the Related Art There are various types of knock-type writing instruments, one example of which is Japanese Utility Model Publication No. 4-7999 filed by the present applicant. This is designed so that the clip cannot be pinched by a clipped portion such as a breast pocket while the writing tip protrudes, so that clothes are not stained by the writing tip. In general, a contact pin with a stopper piece protruding is provided, and when a writing instrument is inserted into a breast pocket or the like, it engages with the pocket rim and pushes up the stopper piece so that the clip can be clamped, and external force is applied to the rear end of the knock bar. In addition, when the knock bar is about to move in the distal direction, it does not move because it is engaged with the stopper piece or the pocket edge, so the knock bar does not move, preventing the writing tip from projecting from the shaft tip. We made some ingenuity. That is, when the clip 4 is sandwiched between the pocket edges in the structure shown in the vertical cross-sectional view of FIG. 3, the clothes (pocket edge) inserted between the spring plate 7 and the stopper piece 6a engage with the projection 6e of the stopper piece 6a. And the stopper piece 6a,
The contact pin 6 is pushed up against the coil spring 16. In this engaged state, even if the tail plug 13 at the upper end of the knock rod 11 is pushed down by an external impact, it does not move in the direction of the tip of the shaft 1, so that the writing tip does not protrude from the tip hole of the tip 18.

The applicant of the present application discloses a mechanism for preventing backflow of ink of a ball-point pen provided with a valve chamber into which a ball is loosely fitted, in Japanese Utility Model Publication No. 4-52067. 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 low-viscosity ink or ink having low viscosity and low shear viscosity has a large amount of outflow of ink (to increase the writing density).
The diameter of the ink storage tube is increased 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.
In particular, when attached to a knock-type writing instrument, frequent knocking impacts may cause backflow of ink and writing blurring due to the influence thereof. 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 provided to be loosely inserted into the follower. 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 danger that the ink and 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 direct current problem that the ink bleeds when a gap is formed between the tip ball and the chip holding portion when the tip side is directed downward.

[0005]

A refill for a ball-point pen mounted on a knock-type writing instrument, wherein the refill is a low-viscosity oil-based ink or a shear in which the viscosity is reduced by rotation of a ball during writing and the ink flows out. It uses water-based inks with reduced viscosity,
It is possible to prevent the reverse flow of ink caused by knock impact and direct current when the tip side is placed downward, inside the writing instrument and hand,
It is possible to prevent clothes from being stained. In addition, to prevent writing scuffing caused by running out of ink due to air entrapment immediately below the tip ball when upward writing, knock impact, etc., and in the case of water-based ink, the tip ball and the inner edge of the chip holding portion It is possible to prevent handwriting caused by drying due to incomplete sealing.

[0006]

A ballpoint pen refill according to the present invention devised to achieve the above object has a tip of a ballpoint pen and an ink storage portion at a rear end. Is a low-viscosity oil-based ink or basically a low-viscosity ink, but has a high viscosity statically, and the viscosity is reduced by the rotation of the tip ball during writing, so that the ink flows out. A viscous aqueous ink is filled, a grease-like follower is provided at the rear end of the ink that moves following the consumption of the ink, and a refill that abuts the knock portion when attached to a knock-type writing instrument. An elastic body for absorbing shock is provided at the rear end to prevent backflow of ink and writing blur due to shock. In addition, a spring is inserted into the chip inner hole, and the rear end of the tip ball rotatably held at the tip of the tip is pressed by the tip of the spring so that the tip ball comes into close contact with the inner edge of the ball holding portion of the chip. As a result, the outflow of the ink is prevented, and writing blurring due to drying can be prevented. In addition, a valve chamber is provided at the rear in communication with the rear end of the chip at the axis of the joint of the refill, and a tapered or spherical ball receiving seat is provided at the rear of the valve chamber. The valve is in close contact with the ball receiving seat, the guide hole is sealed, and the backflow of ink is prevented,
When the tip side faces downward, the sealed state is released and ink can flow into the tip through the guide hole and the valve chamber.
The ball valve supports a large head of ink in the ink container, reduces air entrapment when writing upwards, and covers the close uncertainty of the tip ball portion (processing variation, adhesion of solids, etc.). Ensure the prevention of ink backflow.

[0007]

1 and 2 show an embodiment of the present invention. FIG. 3 shows the above-described knock-type writing instrument to which a refill of a ball-point pen is attached. First, FIG.
The refill 20 is composed of a chip 22, a joint 25, an ink storage tube 27, and a tail plug 21 in appearance. The joint 25 is formed of a synthetic resin by integral molding. A large diameter portion 25c, a medium diameter portion 25b, and a small diameter portion 25a are formed in the first half, and a shaft portion 25d to be pressed against the ink storage tube 27 is formed in the second half. I have. A hole penetrates the shaft center, and a shaft portion 23c behind the tip 22 of the ballpoint pen is crimped to the tip hole of the small diameter portion 25a. Shaft 2
A valve chamber 25e is provided in contact with the rear end of the valve chamber 25c.
e, a tapered or spherical ball seat 25 at the rear end.
i is formed. Also, from the middle diameter portion 25b to the large diameter portion 25
A ventilation groove 25h is formed at a required location so as to hang around the outer peripheral portion of c. (This is necessary for ventilation when attaching the refill to a cap-type writing instrument)

By the way, in the embodiment, the chip 22
A valve chamber 25e is provided eccentrically with respect to the axis of the shaft portion 23c, and a tapered or spherical ball receiving seat 25i is formed at the rear of the valve chamber 25e so as to communicate with the guide hole 25f. A groove 25g through which ink can flow is formed on one side of the inner wall of the valve chamber 25e. Further, the ball valve 26 is loosely fitted in the valve chamber 25e, and the ball valve 26 abuts against the rear end of the shaft portion 23c of the chip in a state where the chip 22 faces downward. The ink flowing from the guide hole 25f through the holes flows into the chip. The valve chamber is provided at the shaft center of the joint 25, the ball valve is loosely fitted in the valve chamber, and the ink is conducted into the chip in a state where the chip faces downward. Further, in the present embodiment, the joint 25 and the ink containing tube 27 are provided separately, but they may be formed by an integral resin molded product. Further, at least the ink storage portion (ink storage tube) is selected from a transparent resin so that the remaining amount of ink can be determined.

On the other hand, the tip 22 is caulked so that the tip ball 22a is rotatably held with the tip ball 22a substantially in contact with a seat having a channel into which ink can flow. Further, a spring 24 is inserted into the inner hole 23b of the chip 22, the rear end of the shaft portion 23c of the chip is appropriately caulked, and the rear end of the spring 24 is provided so as not to be pulled out. An upright straight portion 24a is formed at the tip of the spring 24, and the tip of the straight portion 24a is pressed against the back surface of the tip ball 22a. The tip ball 22a is brought into close contact with the inner edge of the ball holding portion (formed by caulking or the like) of the chip 22 by pressing the spring 24.

As described above, when the tip side is downward, the ball valve 26 abuts on the rear end of the caulking portion 23d in a state of being biased , and the ink 28 passes through the guide hole 25f, the valve chamber 25e, the groove 25g, etc. 23b, and conducts to the rear end of the tip ball 22a.

A cylindrical ink storage tube 27 is pressed against the outer periphery of the shaft portion 25d of the joint 25 by abutting its leading end against the rear end of the large-diameter portion 25c. It communicates with 25 conducting holes 25f. The ink container 27 has a low-viscosity oil-based ink or a low-viscosity ink that is basically low-viscosity, but has a high static viscosity, and the viscosity is reduced by rotation of the ball during writing, so that the ink can flow out. A water-based ink 28 having the following shear thinning property is filled, and the rear end of the ink 28 is filled with a grease-like follower 29 that can move following the ink surface as the ink is consumed. A follower rod 30 made of resin having a specific gravity substantially equal to that of the follower 29 is immersed in the follower 29. The follower rod 30 is provided as necessary (a thick ink storage tube and a large ink head, and the viscosity of the ink is low so that the ink head cannot be supported). It is designed according to the conditions such as the shape and the cup shape.
A tail plug 21 made of an elastic material having a shock absorbing property is fixed to the rear end of the ink containing tube 27, and a ventilation groove 21a for ventilating the inside and the outside of the ink containing tube 27 is provided. I have.

FIG. 2 shows a second embodiment. The configuration of this embodiment is the same as that of the first embodiment, and only the differences will be described below. As shown in the figure, the refill 31 is configured such that a tail plug 32 is fixed to the rear end of the ink storage tube 27 and an elastic body 33 having a shock absorbing property is fixed to the center hole of the tail plug 32 so as to protrude appropriately. . A ventilation groove 32 a is provided between the center hole of the tail plug 32 and the elastic body 33.

[0013]

Next, the operation will be described. In FIG.
When the rear end is knocked down and pushed down, the knock bar 11 pushes the rear end of the refill 14 (corresponding to the refills 20 and 31 of the embodiment of the present invention) to move forward, but the stopper piece 6a
Is moved by the predetermined gap Sa to move the lower edge 3a of the window 3
And is prevented from moving forward. At this time, the stopper piece 6
The projection 6 e of “a” is located within the range of the window 3. Further, when the tail plug 13 is advanced, only the knock bar 11 advances while the stopper piece 6a is fixed, and the ball portion 5 of the clip 4 and the concave portion of the knock bar 11 engage with each other at the locking portion. Then, the writing tip 17 is fixed in a protruding state (see FIG. 4) . Next, when the pressing portion 4a of the clip 4 is pressed against the surface of the shaft 1, the engaged state is released, and the writing tip and the like return to the immersed state.

Next, as shown in the sectional view of FIG. 5, when the clip 4 is inserted into a pocket or the like, the clothes a (pocket portion) inserted between the spring plate 7 and the stopper piece 6a are placed thereon. The edge contacts the protrusion 6e of the stopper piece 6a, and the stopper piece 6a and the contact pin 6 are connected to the coil spring 16
Push up against. Even if the stopper piece 6a is pushed into the shaft 1 at the time of insertion when the garment a is thick, the protrusion 6e moves without being prevented from retreating because the protrusion 6e is in contact with or facing the outer surface of the shaft 1. Press 4 to the correct depth. Further, since the projection 6e is engaged with the pocket edge, even if the tail plug 13 is knocked by an external impact, the tail plug 13 does not move in the direction of the tip of the shaft 1 (however, the stroke of S moves).
The writing tip 17 does not protrude from the tip hole of the tip metal 18.

Also, by attaching the refill of the present embodiment,
Even when the knocking operation is repeated, even if the rear end of the refill impacts against the knocking portion, the impact is absorbed by the elastic body, so that the backflow of the ink and the writing blur can be prevented. The double and triple prevention means described below are combined depending on the performance of the ink, the diameter and length of the ink container, and the reliability under severe conditions. First, when the tip 22 is turned upward by the refill 20, the ball valve 26 closely contacts the ball receiving seat 25i of the valve chamber 25e and seals the guide hole 25f. Even if the ink runs out, the ink does not flow backward. Therefore, when the chip 22 is turned downward, the ink can immediately flow out,
Writing is prevented. (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, causing blurring. In addition, repetition of upward writing Air entrainment is accumulated)

Before writing with the tip 22 facing down, the ball valve 26 comes into contact with the rear end of the tip shaft portion 23c, and the guide hole 25f is opened. Ink storage tube 27
The ink 28 that has entered the valve chamber 25e through the guide hole 25f flows into the inner hole 23b of the chip through the groove 25g and is conducted to the rear end of the tip ball 22a. In this state, since the tip ball 22a is brought into close contact with the inner edge of the chip holding portion by the pressing of the straight portion 24a of the spring 24, the direct current of the ink 28 is prevented. In addition, the tip ball 2
Since 2a is slightly retracted, a gap is generated to allow ink to flow out, and writing causes ink to flow out by rotation of the tip ball 22a, thereby enabling writing.

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 22a. A straight portion of a spring 24 is provided in a center hole of the channel. 24a penetrates. The ink in the chip is guided directly below the tip ball 22a through the ink inflow groove and the gap between the center hole and the straight portion 24a.

Further, since the tip ball 22a is always in close contact with the inner edge of the tip holding portion, it is possible to prevent handwriting by drying the tip portion. Further, even when upward writing or impact is applied by the cooperative action of the tip ball 22a and the ball valve 26, the entrainment of air is alleviated, so that writing blur is prevented. The direct current and the reverse flow of the ink are caused by the tip ball 22a by the spring 24.
Can be achieved by pressing the tip ball 2 due to the processing variation of the tip holding portion by providing the ball valve 26.
2a and the incomplete state when solids adhere to the gap between the tip holding portion and the tip ball 22a, and support a large ink head to ensure the backflow of ink. And to reduce air entrainment (prevent flaring).

[0019]

The constitution and operation of the refill of the ballpoint pen according to the present invention are as described above. Thus, it is possible to provide a knock-type writing instrument which is excellent in writing performance without shading. Further, the problem of ink backflow and writing blur due to knock impact caused by using low-viscosity ink can be prevented by the elastic body at the rear end of the refill. Further, the problem can be reliably avoided by combining the following means in a double or triple manner according to severe setting conditions. The refill, which has a tip with a built-in spring that presses the final tip ball, a ball valve, and a follower rod in the follower, has the tip ball in close contact with the inner edge of the tip holding part except when writing, so that the ink flows backward or faces downward. Direct current is prevented when placed in the shaft, and accidents that stain the inside of the barrel, hands, clothes, etc. can be prevented even under severe conditions.
In addition, handwriting due to drying is prevented. In addition, even if the tip ball and the tip holding part are not in close contact with each other, the backflow of ink is surely prevented by upward writing or impact by the ball valve that loosely fits in the valve chamber, and it is possible to support a large ink head. Therefore, there is an effect that the ink immediately follows after the upward writing or the impact and the writing blur is further prevented.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a refill of a ballpoint pen according to a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view showing a refill of a ballpoint pen according to a second embodiment of the present invention.

FIG. 3 is a longitudinal sectional view showing the entirety of a knock-type writing instrument to which a ballpoint pen refill of the present invention is attached.

FIG. 4 is a half sectional view of a main part when a writing tip protrudes.

FIG. 5 is a half sectional view of a main part when the clip is held.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 axis | shaft 2 axis | shaft window part 3 axis | shaft window part 4 clip 6 contact pin 6a stopper piece 6c base end part 6e convex part 11 knock bar 20 refill 21 tail plug 21a ventilation groove 22 tip 22a tip ball 23b inner hole 23c shaft part 23d Caulking part 24 Spring 24a Straight part 25 Joint 25a Small diameter part 25b Medium diameter part 25c Large diameter part 25e Valve chamber 25f Guide hole 25g Groove part 25h Vent groove 25i Ball receiving seat 26 Ball valve 27 Ink storage tube 28 Ink 29 Follower 30 Follower rod 31 Refill 32 Tail plug 32a Vent groove 33 Elastic body

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B43K 7/01 B43K 7/02 B43K 7/08 B43K 7/12

Claims (4)

(57) [Claims] 1. A refill of a ball-point pen having a tip of a ball-point pen attached to a knock-type writing instrument and having an ink container at the rear, wherein the ink container has a low-viscosity oil-based ink or a low-viscosity ink. The ink is filled with water-based ink having a so-called shear-thinning viscosity. A ball-point pen refill, wherein a grease-like follower that moves following the consumption of ink is provided, and an elastic body for absorbing shock is provided at a rear end of the refill that abuts the knock portion. 2. A tip is inserted into a chip inner hole, and a rear end of a tip ball rotatably held at a tip end portion of the tip is pressed by a tip of the spring so that the tip ball of the tip ball holding portion is pressed. 2. The ballpoint pen refill according to claim 1, wherein the refill is arranged so as to be close to the inner edge to prevent outflow of ink. 3. A valve chamber is provided at the rear of the shaft center of the joint of the refill so as to communicate with the rear end of the chip, and a tapered or spherical ball receiving seat is provided at the rear of the valve chamber. When the valve is loosely fitted and the tip side is upward, the ball valve is in close contact with the ball receiving seat and the guide hole is sealed to prevent the backflow of ink, and when the tip side is downward, the sealed state is released and the ink inside the chip is released. ballpoint pen refill of the preceding claims 1 or 2, wherein There, characterized in that it is configured to flow. 4. A greasy therewith within follower formed by dipping the resin follower rod having a specific gravity substantially equal ballpoint pen of the claims 1, 2 or 3, wherein the refill.