JP3197444B2 - Knock-type writing instrument - 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 knock-type writing instrument using a low-viscosity oil-based ink or an aqueous ink having a low-shear viscosity which is basically low-viscosity.

[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 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 9 of the tip 18. .

[0003] The applicant of the present invention 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 aqueous ink having a shear-thinning property, 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 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, 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]

SUMMARY OF THE INVENTION A ballpoint pen refill using a low-viscosity oil-based ink or a water-based ink having a shear-thinning viscosity, in which the viscosity is reduced by rotation of a ball during writing and the ink is discharged, can be mounted. A knock-type writing instrument, which can prevent backflow of ink caused by impact and direct current when the tip side is placed downward, and can prevent stains in the writing instrument, hands, and clothes. 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]

The knock-type writing instrument of the present invention devised to achieve the above object has a low-viscosity oil-based ink or a basically low-viscosity ink in an ink container. Is filled with water-based ink having a so-called shear-thinning property. A refill of a ballpoint pen provided with a grease-like follower that moves following the refill is detachably mounted. When the refill is mounted on a knock-type writing instrument, an impact of a knock portion that abuts on a rear end of the refill is provided. An elastic body for absorbing the impact is provided at the contact portion, so that it is possible to prevent the backflow of the ink and the writing blur due to the drop and the knock impact. The refill to be attached to the knock-type writing instrument has a tip of a ball-point pen at the tip and an ink container at the rear end, and a spring is inserted into the tip bore so that the tip of the tip is located at the tip of the spring. Pressing the back of the tip ball rotatably held by the tip, the tip ball comes into close contact with the inner edge of the ball holding portion of the chip, preventing ink from flowing out and preventing writing screeching due to drying And
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 and the guide hole is sealed to prevent backflow of ink. When the tip side is downward, the sealed state is released, and ink can flow into the chip 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. Knock-type writing implements (known in the art) are designed so that the tip of the writing penetrates when the clip is clamped, regardless of the thickness of the fabric, and the stopper piece is pushed up firmly with the insertion of the fabric so that it can be inserted to the correct depth. This makes it impossible to prevent clothes from being stained by ink suction.

[0007]

Embodiments of the present invention will be described below. First, FIG. 1 is a longitudinal sectional view of an upper portion of a shaft in which a refill 20 is accommodated in a shaft 1 at a retracted position. The lower window portion 2 allows the ball portion 5 of the clip 4 to be fitted therein, and the upper window portion 3 projects the stopper piece 6a of the contact pin 6 toward the rear surface of the clip 4, and guides the stopper pin 6 so that it can move up and down. It is. 1
Reference numeral 1 denotes a knock bar, which is vertically movable inside a vertical center hole of the shaft 1 and projects upper and lower small diameter portions 11a outward from the crown 9.
The decoration tube 12 is fitted around the outer periphery, and the tail plug 13 is attached to the inner periphery of the small-diameter portion 11a inserted into the inner periphery of the decoration tube 12. At the position where the clip 4 of the knock rod 11 is located, a vertically long window hole 11 is provided.
b, the annular groove 11c is provided at the lower end, and the concave hole 11d is further provided below the annular groove 11c, and the refill 20 is mounted. Further, a spherical elastic body 19 is provided in contact with the rear end of the refill 20 with the knock bar 11, and the elastic body 19 is fixed to the concave groove portion 19a. The elastic body is not limited to a spherical shape, but is also provided in a shaft shape. The refill 20 is provided with a tip 1 under the shaft 1.
The rear end of the tail plug 13 projects outward from the rear end of the shaft 1 and is always pressed by the coil spring 15 provided between the shaft 8 and the refill 20 to maintain the knocking operation.

[0008] The knock rod 11 is provided with a substantially middle large-diameter portion 11.
Step 1 in which small area 11a can be formed above e
1f abuts on the lower end of the screw tube 8 to restrict upward movement.
Reference numeral 11g denotes a vertically long guide window hole provided facing the portion of the small diameter portion 11a where the clip 4 is located.
Guide the up and down movement. The contact pin 6 is inserted into the upper small-diameter portion 11a of the knock rod 11, and is provided with an axial ridge 6d on the outer periphery facing the clip 4 to form the guide window hole 11d.
The stopper piece 6a protrudes in the direction of the clip 4 so as to be deviated downward in accordance with g, and a small-diameter guide rod 6b is provided at the upper end, and is constantly urged by the coil spring 16 toward the writing tip 17 side.

The stopper piece 6a is formed by knocking the base end 6c with the knock bar 1.
The protrusion 6e protrudes from the vertically long window hole 11b of the knock rod 11 and the window portion 3 above the shaft 1 corresponding thereto while being received by the lower edge of the window hole 11h connected to the annular recess 11c. Make the tip elastically contact. The lower edge of the window hole 11h connected to the annular concave portion 11c is positioned above the lower edge 3a of the window portion 3 of the shaft 1 by a gap Sa having a predetermined dimension. As a result, the convex portion 6e of the stopper piece 6a is located above the upper edge 3b of the window portion 3 so as to contact or face the outer surface of the shaft 1.

FIG. 4 shows a refill of the ballpoint pen according to the embodiment. The refill 20 is composed of a chip 22, a joint 25, an ink container 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 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 against the rear end of the caulking portion 23d in a biased state, and the ink 28 flows through the guide hole 25f, the valve chamber 25e, and the groove 25g.
Flows into the inner hole 23b of the chip through
Conduction continues to the rear end of 2a.

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 storage tube 27, and a center hole 21a and a lateral hole 21 that allow the inside and the outside of the ink storage tube 27 to ventilate.
b, a ventilation groove 21c is provided.

[0014]

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 20 to move forward, but the stopper piece 6a moves by the predetermined gap Sa and comes into contact with the lower edge 3a of the window 3 and Blocked from moving forward. At this time, the projection 6e of the stopper piece 6a is located within the range of the window 3. Furthermore,
When the tail plug 13 is advanced, only the knock bar 11 advances while the stopper piece 6a is fixed, and the ball 5 of the clip 4 is moved.
And the concave portion of the knock bar 11 are engaged with each other at the locking portion, and the writing tip 17 is fixed in a protruding state. (See FIG. 2) Next, when the pressing portion 4a of the clip 4 is pressed against 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 cross-sectional view when the pocket is mounted in FIG. 3, 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.

Further, even if the rear end of the refill impacts against the elastic body 19 of the knock bar 11 when the knocking operation is repeated, the impact is absorbed by the elastic body, and the backflow of ink and the handwriting 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 tip 22 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 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 is in 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 the chip inner hole) is provided directly below the tip ball 22a, and a straight portion of the 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.

Since the tip ball 22a is always in close contact with the inner edge of the tip holding portion, the tip portion is dried to prevent handwriting. 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).

[0020]

The structure and operation of the refill of the ballpoint pen according to the present invention are as described above, and are obtained by using a low-viscosity oil-based ink or a low-viscosity aqueous ink having a shear-thinning viscosity. It is possible to provide a knock-type writing instrument which is excellent in writing performance without shaving. 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.

Further, in the knock-type writing instrument according to the embodiment, even if an inadvertent external force is applied to the knock bar when the pocket is mounted, the knock spring is absorbed by the coil spring 16 and further depression is restricted by the edge of the pocket. The writing tip does not protrude from the shaft tip, and the stain on the clothes can be reliably prevented. In addition, even when the clip is forcibly attached to a thick cloth or the like, the projection 6e of the stopper piece is in contact with or opposed to the outer surface of the shaft 1, so that the clip does not enter the window 3 and is prevented from retreating smoothly. It can be moved and inserted to the correct depth for mounting. Further, when the writing tool is pulled out between the protrusion 6e and the clip 4 with thin fabric or clothes that are easy to catch, the coil spring 15 biased between the tip metal and the refill when the writing implement is pulled out.
The knock bar 11 and the stopper piece 6a move forward against
Since the protruding portion 6e is located within the range of the window portion 3 of the shaft 1, when an excessive force is applied, the protruding portion 6e is immersed in the shaft from the window portion and is easily released from the cloth, and the clothes and the stopper piece are damaged. Accidents can be prevented.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing the entirety of a knock-type writing instrument of the present invention, in which a writing tip is immersed.

FIG. 2 is a sectional view of a main part in a state where a writing tip is knocked out and a writing tip is projected.

FIG. 3 is a half sectional view of a main part when a clip is held.

FIG. 4 is a longitudinal sectional view showing a refill of the ballpoint pen according to the embodiment.

[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 19 elastic body 19a concave groove part 20 refill 21 tail plug 21a center hole 21b side hole 21c ventilation Groove 22 Tip 22a Tip ball 23b Inner hole 23c Shaft portion 23d Caulking portion 24 Spring 24a Straight portion 25 Joint 25a Small diameter portion 25b Medium diameter portion 25c Large diameter portion 25e Valve chamber 25f Guide hole 25g Groove portion 25h Vent groove 25i Ball receiving seat 26 Ball Valve 27 Ink storage tube 28 Ink 29 Follower 30 Follower rod

──────────────────────────────────────────────────続 き Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B43K ⁷ /00-7/12 B43K 24/08

Claims (5)

(57) [Claims] In a knock-type writing instrument in which a refill of a ballpoint pen can be freely attached, a low-viscosity oil-based ink or a basically low-viscosity ink is provided in an ink accommodating portion of the refill. A grease that is filled with a so-called shear-thinning aqueous ink, and the ink moves out following the consumption of the ink at the rear end of the ink. A knock-type writing instrument comprising: a follower; and an elastic body for absorbing shock is provided at a contact portion of the knock portion where the rear end of the refill abuts. 2. A knocking rod is knocked to engage an engaging part provided at the tip of the clip with a locking part provided on the knocking rod, thereby protruding the writing tip part from the shaft tip, and connecting the rear end of the clip to the shaft. By pressing in the direction of the outer peripheral surface of the knocking rod, the engagement is released and the writing tip is immersed in the shaft. In the knock-type writing instrument in which the contact pin is urged by a coil spring interposed between the guide rod and the tail plug, when the contact pin 6 advances, the base end portion 6c of the stopper piece 6a is moved below the window 3 of the shaft 1. The protrusion 6e of the stopper piece 6a is provided within the range of the window 3 and the base end 6c of the stopper piece 6a is positioned below the window 3 of the shaft 1 when the writing tip 17 is immersed. Step provided on knock bar 11 above edge 3a 2. The knock-type writing implement according to claim 1, wherein the engagement is restricted, and the projection 6e of the stopper piece 6a is positioned on the outer surface of the shaft above the window 3. 3. 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 is in a ball holding portion of the tip. 3. The knock-type writing instrument according to claim 1, wherein a refill of a ball-point pen, which is configured to be in close contact with the inner edge and to prevent the outflow of ink, can be mounted. 4. 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 seat is provided at the rear of the valve chamber, and a ball valve is provided in the valve chamber. When the tip is upward, 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 downward, the sealed state is released and ink flows into the chip. The refill of a ball-point pen configured to perform the refill can be mounted.
Knock-type writing implement as described. 5. A ballpoint pen refill in which a resin follower rod having substantially the same specific gravity as a grease-like follower is immersed in a grease-like follower.
Knock-type writing implement according to 2, 3, or 4.