JP3262555B2 - Tip for ballpoint pen - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tip for a ball-point pen, and more particularly to a tip for a ball-point pen suitable for a ball-point pen using a shear-thinning ink.

[0002]

2. Description of the Related Art Conventionally, in a pen for a ballpoint pen, a constricted ink introduction hole and a ball house at the tip end thereof communicate with each other in the chip, and ink is supplied to a transfer ball from an ink groove at a rear side of the ball house. The transfer ball is urged from behind by a resilient member so as to be in close contact with the inward tip edge of the chip in order to prevent writing scuff, writing, and ink leakage due to drying of the tip inside the chip. There have been proposed various arrangements for performing such operations. For example, Japanese Unexamined Utility Model Publication No. 7-12280 discloses a ballpoint pen tip in which a transfer ball is urged by a spring whose tip is gradually reduced in a conical shape. By the way, in this ballpoint pen tip, the ink introduction hole is formed in a so-called straight channel having a plurality of vertical grooves on its inner peripheral surface. This is because the flow resistance of the ink due to the spring is large, so that the vertical groove on the inner peripheral surface of the ink introduction hole communicates with the ink passage hole on the rear side of the ball house, so as to secure the flow amount of the ink during writing. It is. However, in the straight channel, when a back shock, that is, an impact to the rear of the writing instrument due to the attachment / detachment of the cap or the impact to the tail plug, is applied, the ink is ejected.
Since it is easy to flow back from the inside of the housing to the vertical groove on the inner peripheral surface of the ink introduction hole, there is a concern that writing blur or non-writing may occur.

In another conventional example, a straight pressing portion is formed at the tip of a spring, and the transfer ball is pressed by the tip of the pressing portion (JP-A-7-251592). reference). In this ballpoint pen tip, since the pressing portion is straight, the flow resistance of the ink is small and the ink is discharged well during writing. In addition, there is a risk that the tip of the straight pressing portion may bite between the ink groove in the ball house or the inner surface of the ball house and the transfer ball.

In another conventional example, there is a structure in which a movable member is provided at the distal end side of a spring and the transfer ball is pressed by the movable member. During the degassing process in the process, there is a problem that the movable member becomes a barrier for the bubbles moving backward, and the bubbles easily remain in the chip.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and has as its object to prevent non-writing and writing blur due to back shock, and to perform after deaeration processing. An object of the present invention is to provide a tip for a ball-point pen using a shear-thinning ink in which no bubbles remain in the tip.

[0006]

According to a first aspect of the present invention, a transfer ball is rotated in a ball house which communicates with an ink passage through an ink introduction hole. In a ball-point pen tip that is held as possible and urges the transfer ball from behind by a resilient member, and is filled with shear-thinning ink, the ink introduction hole has a peripheral wall that does not reach the ink passage. A small-diameter spring portion which is inserted into the ink introduction hole and presses the transfer ball at the tip thereof, and a large-diameter spring portion formed on the rear side of the small-diameter spring portion. The small-diameter spring portion has an end winding portion in which the coils on the tip side are in close contact with each other ,
The large-diameter spring part has a parts feeder
Characterized in that it has an enlarged diameter portion that is enlarged to be suspended from the sending portion .

According to the above technical means, since the length of the ink groove does not reach the ink passage, the ink does not flow backward from the ink groove toward the ink passage during a back shock. In addition, the small-diameter spring portion has an end winding portion located at the front end side and a coil interval opened behind the end portion, so that the flow resistance of the ink in the ink introduction hole during normal writing is reduced and the refill is reduced. During the degassing process in the manufacturing process, the bubbles do not hinder the backward movement.
Further, since the distal end side of the resilient member is a small diameter spring portion, it does not bite between the transfer groove and the ink groove in the ball house or the inner surface of the ball house.

Preferably, in order to reduce the flow resistance of the ink in the ink introduction hole, the end winding portion has a length in the axial direction. Make the distance from the leading end to the trailing end of the ink groove approximately 約.

According to a third aspect of the present invention, the transfer ball is rotatably held in a ball house communicating with the ink passage through the ink introduction hole, and the transfer ball is urged from behind by a resilient member. In a ballpoint pen tip filled with shear-thinning ink, the ink introduction hole has an ink groove on a peripheral wall thereof that does not reach the ink passage,
The resilient member includes a pressing portion that is loosely inserted into the ink introduction hole and presses the transfer ball at the tip thereof, and a spring portion formed on the rear side of the pressing portion, and the pressing portion is a straight portion. distally, it has a curved portion which is brought into contact with a curved surface which is bent formed on the transfer ball, the spring section
At the rear end of the part feeder
It has a diameter-enlarging part that has been enlarged so that the curved part is straight.
It is characterized in that the distal end side of the portion is formed by bending in an annular shape .

According to the above technical means, since the ink groove has a length that does not reach the ink passage, the ink does not flow backward from the ink groove toward the ink passage during a back shock. In addition, since the curved portion formed by bending contacts the transfer ball on the curved surface, the sliding contact resistance at that time is small. Therefore, the pressing portion is bent by being slid in contact with the transfer ball which rotates at the time of writing, so that the curved portion at the tip bites into the ink groove on the rear side of the ball house or the inner surface of the ball house and the transfer ball. Nothing. Further, the pressing portion has a curved portion located on the front end side and a rear side formed in a straight shape, so as to reduce the flow resistance of the ink in the ink introduction hole at the time of normal writing, and in the refill manufacturing process. During the deaeration process, the bubbles do not hinder the backward movement.

[0011]

[0012] Oite to claim 3, in order to reduce ink flow resistance in the ink introduction hole, as described in claim 4, the radius of the curved portion, the ink from the pressing tip Preferably, the distance is about 1/2 of the distance to the rear end of the groove.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 show an example of a ballpoint pen tip according to the present invention. This chip X1 is provided with a transfer ball 1 in a tapered holder 10 having a substantially cylindrical shape.
A resilient member 20 for urging the transfer ball 1 from behind and a receiving member 30 for receiving the rear end of the resilient member 20 are provided.

The inside of the holder 10 is arranged in order from the front end side.
Each part of the ball house 11 holding the transfer ball 1, the ink introduction hole 12 on the rear side of the ball house 11, and the ink passage 13 whose leading end side is gradually reduced in diameter toward the ink introduction hole 12 are communicated. Let me.

The ball house 11 has an inward leading edge 11a.
The transfer ball 1 is rotatably held between the transfer ball 1 and the ball seat 11b.

As shown, the diameter of the ink introduction hole 12 is narrower than that of the front and rear ball houses 11 and the ink passage 13, and a plurality of ink grooves 12a are formed radially in front of the diameter (see FIG. 2A). ) And the ink groove 1
The ink groove 12a is formed to have a length that does not reach the ink passage 13 with the rear end 12b of the 2a facing the rear side of the ink introduction hole 12. That is, in the case of the conventional straight channel,
Although a plurality of vertical grooves communicating with the front ink groove are formed on the rear inner peripheral surface, in the ink introduction hole 12 according to the present application,
The rear inner peripheral surface is formed in a flat surface shape without unevenness (see FIG. 2B).

The resilient member 20 is loosely inserted into the ink introduction hole 12 and has a small-diameter spring portion 21 which presses the transfer ball 1 at the tip thereof, and a large-diameter member integrally formed on the rear side of the small-diameter spring portion 21. And a spring portion 22.

The small-diameter spring portion 21 has a coil whose outer diameter is smaller than that of the large-diameter spring portion 22 on the rear side.
Having.

The number of turns of this end winding portion 21a is set to about two turns so that the axial length A1 is reduced by the number of turns of the end winding portion 2a.
It is formed to be about 約 of the distance A2 from the front end of the ink groove 12a to the front end of the ink groove 12a. In addition, the end winding part 21
If the length A1 is larger than about 1/2 of the distance A2, the flow resistance of the ink in the ink introduction hole 12 during normal writing becomes too large. If the length A1 is smaller than about 1/2 of the distance A2, the number of turns of the end turn 21a may be reduced, and the contact between the end turn 21a and the transfer ball 1 may become unstable. is there.

The large-diameter spring portion 22 urges the transfer ball 1 in cooperation with the small-diameter spring portion 21. The large-diameter spring portion 22 is expanded at its rear end side so as to be hung from the feeder of the parts feeder when manufacturing the chip X1. An enlarged diameter portion 22a having a diameter and having the coils closely contacted is formed. That is, Tamahatsu member 20 during the manufacture of the chip X1 in a state where the small diameter spring portion 21 side is directed downward by its weight balance, suspended the delivery portion of the transverse cross-section recessed by the enlarged diameter portion 22a, transmitted from said transmission detecting section Is done.

The outer diameter surface of each part of the small diameter spring part 21 and the large diameter spring part 22 and the holder 10
A clearance H for moving bubbles backward during the degassing process in the refill manufacturing process is provided between the inner surface and the inner surface.
Is provided. In other words, the refill obtained by fitting the chip X1 to the ink containing tube is manufactured in a process of fitting the chip X1 to the ink containing tube filled with ink in advance. The air bubbles contained therein, the air bubbles that entered when the chip X1 was fitted, or the fine air bubbles generated by splitting these air bubbles remain. Then, these air bubbles are subjected to a deaeration treatment in a subsequent step. In this deaeration process, the ball 1 of the chip X1
By centrifuging the refill with its side facing the centrifugal direction, air bubbles having a specific gravity smaller than that of the ink are moved to the rear of the ink storage tube and deaerated from the rear end opening. Therefore, the air bubbles in the tip X1 smoothly move rearward by passing through the clearance H around the inside of the small-diameter spring portion 21 and the large-diameter spring portion 22 and around the small-diameter spring portion 21 and the large-diameter spring portion 22. .

The receiving member 30 is formed in a cross shape with a vertical cross section so as to abut on the rear end face of the enlarged diameter portion 22a of the large diameter spring portion 22 (see FIG. 2 (c)). This space is used to smoothly move bubbles backward during the deaeration process in the refill manufacturing process. And
The receiving member 30 is pressed into the holder 10 and the rear end of the holder 10 is caulked, so that the resilient member 2
It is securely fixed in a state where it receives the rear end of zero.

According to the chip X1 having the above structure,
In the event of back shock, the ink passage 1
The ink does not flow backward toward 3. Therefore, non-writing and writing blur due to the backflow of the ink at the time of the back shock are prevented. In addition, since the small-diameter spring portion 21 has a coil interval at the rear end side thereof, the flow resistance of the ink on the rear side inside the ink introduction hole 12 is reduced at the time of normal writing and the deaeration in the refill manufacturing process is performed. Does not hinder the backward movement of the bubble. Further, since the end winding portion 21a on the distal end side of the small diameter spring portion 21 has a coil shape, it does not bite between the transfer groove 1 and the ink groove 12a or the inner surface of the ball house 11.

[0024] Next, a description is given of another example of the ballpoint pen tip according to the present invention are shown in FIG. In addition, Chi-up X 2 is,
To chip X1 of the configuration is omitted, because it is configured by replacing the elastic member 20, For the other parts, the repeated description by attaching the same reference numerals.

The resilient member 40 of the chip X2 shown in FIG.
It comprises a pressing portion 41 which is loosely inserted into the ink introduction hole 12 and presses the transfer ball 1 at its tip, and a spring portion 42 integrally formed on the rear side of the pressing portion 41.

The pressing portion 41 has a curved portion 41a formed at the distal end by bending the distal end of the straight portion 41b into an annular shape. The curved portion 41a abuts the curved surface (the foremost surface of the curved portion 41a) formed on the transfer ball 1 to reduce the sliding contact resistance when the transfer ball 1 rotates during writing. .

The relationship between the radius B1 from the center of the curved portion 41a to the outer diameter and the distance B2 from the tip of the curved portion 41a to the rear end of the ink groove 12a is such that the radius B1 is about 1/1/2 of the distance B2. Preferably, it is configured to be 2. That is,
If the radius B1 is too large, there is a concern that the flow resistance of the ink in the ink introduction hole 12 during normal writing will be too large, and if the radius B1 is too small, the curved portion 41a will There is a concern that it becomes easier to bite between the inner surface of the transfer ball 11 and the transfer ball 1.

The end of the spring portion 42 has an end turn 42a formed by closely contacting the coils, and the rear end has an enlarged diameter portion 42b similar to the resilient member 20 of the chip X1. Is formed. Then, the distal end portion of the seat winding portion 42a is bent toward the center of the spring portion 42 constitute together a scan tray over preparative portion 41b of the pressing portion 41.

The spring portion 42 smoothly moves air bubbles backward between the outer diameter surface and the inner surface of the holder 10 during the degassing process in the refill manufacturing process, similarly to the tip X1 of the above embodiment. Clearance H is provided.

According to the chip X2 having the above structure,
As in the case of the chip X1, the backflow of the ink from the ink groove 12a to the ink passage 13 is prevented at the time of the back shock. Further, since the pressing portion 41 is formed in a substantially straight rear side, the flow resistance of the ink in the ink introduction hole 12 during normal writing is reduced, and the depressurization during the refill manufacturing process is performed. Does not hinder the movement of bubbles to the air. Further, since the curved portion 41a is in contact with the transfer ball 1 by the curved surface at the tip thereof, the pressing portion 41 is not bent by slidingly contacting the transfer ball 1 which rotates during writing. Therefore, the curved portion 41 a does not bite between the transfer groove 1 and the ink groove 12 a or the inner surface of the ball house 11.

[0031]

[0032]

[0033]

[0034] Incidentally, if <br/> comparison chip X1, X 2 of the above two embodiments, thereby bite the tip portion of the elastic member between the ink channels 12a and the ball house 11 inner surface and the transfer ball 1 from the viewpoint of no, X1 is good preferable that the formation of the small diameter spring portion 21 on the distal end side. Also, Hey <br/> Te in the chip X 2, the bending portion 41 a in order to ensure that no bite ensured by the ink grooves 12a, the ink channels 12a that wire diameter
Is preferably larger than the width dimension.

[0035]

According to the present invention, in the event of a back shock,
Backflow of ink from the ink groove toward the ink passage is prevented, and the leading end of the resilient member does not bite between the ink groove or the inner surface of the ball house and the transfer ball. Can be prevented. In addition, since the resilient member has a shape that reduces the flow resistance of the ink, good ejection of the ink is usually ensured during writing, and no bubbles remain in the chip after the degassing process during refill manufacturing. . In addition, on the rear end side of the large diameter spring part of the resilient member
Due to the enlarged diameter part, the resilient member must be
The small-diameter spring side is below the feed section of the feeder.
And can be hung in a state.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an example of a ballpoint pen tip according to the present invention.

FIG. 2A is a sectional view taken along line aa in FIG. 1;
2B is a sectional view taken along line bb in FIG. 1, and FIG. 2C is a sectional view taken along line cc in FIG. 1.

FIG. 3 is a longitudinal sectional view showing another example of the ballpoint pen tip according to the present invention .

[Explanation of symbols]

1: Transfer ball 10: Holder 11: Ball house 12: Ink introduction hole 12a: Ink groove 12b: Rear end of ink groove 20: Resilient member 21: Small diameter spring part 21a: End winding part 22: Large diameter spring part 4 0: resilient member 4 : 1: pressing part 41 a: curved part 41 b: straight part 42: spring part X1, X 2:
Chips

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP 2001-191679 (JP, A) JP 2001-146087 (JP, A) JP 2001-121869 (JP, A) JP 2001-10281 (JP, A A) JP-A-8-295095 (JP, A) JP-A-8-11478 (JP, A) JP-A-8-267985 (JP, A) JP-A-8-142569 (JP, A) JP-A-8 −39982 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B43K 1/08 B43K ^7/ 00-7/12

Claims (4)

(57) [Claims] 1. A transfer ball rotatably held in a ball house communicating with an ink passage through an ink introduction hole,
In a ball-point pen tip in which the transfer ball is urged from behind by a resilient member and filled with shear-thinning ink, the ink introduction hole has an ink groove in a peripheral wall of the ink supply hole having a length that does not reach the ink passage. The resilient member includes a small-diameter spring portion that is loosely inserted into the ink introduction hole and presses the transfer ball at the tip thereof, and a large-diameter spring portion formed on the rear side of the small-diameter spring portion. spring portion has a seat winding portion which is brought into close contact between the windings of the distal end side, the large diameter spring portion has at its rear end, part fees
A ball-point pen tip having a diameter-expanding portion that is enlarged to be suspended from a delivery portion of a bottle . 2. The end winding part has a length in the axial direction,
2. The ball-point pen tip according to claim 1, wherein the distance from the end of the end winding portion to the rear end of the ink groove is about 1/2. 3. A transfer ball is rotatably held in a ball house communicating with an ink passage through an ink introduction hole.
In a ball-point pen tip in which the transfer ball is urged from behind by a resilient member and filled with shear-thinning ink, the ink introduction hole has an ink groove in a peripheral wall of the ink supply hole having a length that does not reach the ink passage. The resilient member includes a pressing portion that is loosely inserted into the ink introduction hole and presses the transfer ball at the tip thereof, and a spring portion formed on the rear side of the pressing portion. A front end of the portion, a curved portion for bringing the curved surface formed into contact with the transfer ball, and the spring portion has a part feeder at the rear end side.
The bent portion has a diameter-enlarged portion which is expanded so as to be hung on the sending portion, and the bent portion is formed by bending the distal end side of the straight portion into an annular shape.
A tip for a ballpoint pen, comprising: 4. The ball-point pen tip according to claim 3 , wherein a radius of the curved portion is approximately one half of a distance from a front end of the pressing portion to a rear end of the ink groove.