JPS6029360B2 - Ballpoint pen nib and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a ballpoint pen nib that allows the clearance between a pole and a ball holder in a ball holding part to be designed with high accuracy, and a method for manufacturing the same.

Conventionally, various structures and manufacturing methods have been researched for ballpoint pen nibs in which the ball holder and ball seat member are separate parts, since it is possible to select the desired material for characteristics such as writing feel and abrasion resistance. .

For example, ■ A seat member inserted into a ball holder is constricted by a part of the ball holder.

■ The rear end or stepped portion of the catch member is locked with the stepped portion or rear end of the ball holder.

■ A ball holder and a ball holder that are attached to each other.

■ Ball holder and catch member glued together.

etc. At least one of the major problems in these problems is the variation in the clearance between the ball and the ball holder, which has the most significant effect on ink outflow control. That is, if the clearance is too large, there will be problems such as excessive ink outflow, droplets, and ball flying due to unnecessary wear of the small opening for holding the ball during writing; conversely, if the clearance is too small, there will be insufficient ink outflow. This results in drawbacks such as blurred writing marks and increased writing resistance, but each product often has large variations. The present invention, which was made in view of the above points, includes a ball holder having a through hole in the direction of the bag;
a catch part village forming a ball catch inserted into the through hole;
It consists of a chip into which the ball holder is inserted and fixed, and a ball which is held by the ball holder and the seat member and can have a clearance between the ball holder and the ball into which the ball holder is inserted into the hole of the chip. A ballpoint pen pen characterized in that a fixed step part supporting the rear end of the ball holder and a support step part supporting the rear end of the catch member are formed such that a step difference between the two step parts corresponds to the clearance. First, and its manufacturing method,
After inserting the ball and the material for the seat member into the ball holder in which the small opening for holding the pole was formed, the rear end of the ball holder and the rear end of the seat member were made flush, and the molded product thus obtained was , has an insertion hole, and has a fixed step in the insertion hole and a support step behind the fixed step, and the step between the two steps is formed between the ball holding small opening of the pole holder and the ball. The gist of the present invention is a method for manufacturing a ballpoint pen nib, characterized in that the ball holder is inserted into a tip insertion hole formed to correspond to a clearance until the ball holder is locked to the fixed step. Detailed description will be given below with reference to the attached drawings. FIG. 1 is a vertical cross-sectional view of a main part of an embodiment of the ballpoint pen nib of the present invention, in which reference numeral 1 is a ball holder having a through hole in the vertical direction, and 2 is a ball holder having a through hole in the vertical direction. A seat member inserted into the through hole of the holder 1, 3 a chip for inserting and fixing the ball holder, 4 a small oral part l of the pole holder 1
This is a ball held by a and the tip of the seat member 2.

Two step portions 3a and 3b are formed in the hole into which the ball holder of the chip 3 is inserted, and the step difference between the step portions 3a and 3b is such that the ball 4 is connected to the small diameter opening la of the ball holder. This corresponds to the clearance that may be available. Stepped portion 3a
supports the rear end of the ball holder that is fixed to the chip 3, so it is hereinafter referred to as a fixed step, and the step 3a
The step portion 3b formed at the rear supports the rear end of the seat member 2, but since the seat member 2 does not need to be fixed, it is hereinafter referred to as a contact step portion. Note that reference numeral 5 is an ink relay section inserted from the rear of the chip 3. Ink is supplied from an ink chamber (not shown) housed in a rut cylinder through an ink relay member 5 through an ink distribution hole 2a of an arbitrary shape formed in a receiving seat village 2 as shown in FIG. Alternatively, the ink is guided to the ball through the ink circulation groove 2b and/or the groove lb formed in the inner hole of the ball holder 1 as shown in FIG. 4. It reaches the writing surface through clearance with the oral part la. Of course, the ink storage method may be a so-called fresh ink structure, and the ink relay member 5 may also adopt various known structures such as a fiber aggregate, a resin pongee body, or a metal pipe. The fixed step portion 3a and the contact step portion 3b of the chip 3 do not need to be flat, for example, so-called arrow grooves 3c as shown in FIGS. 4 and 5 and/or as shown in FIG. A concave plate 3d may be formed to contribute to ink supply performance.

In addition, the catch member 2 may be composed of two or more members as shown in FIGS. 7 and 8. In this case, the catch member 2 has the advantage that one with excellent wear resistance and one with excellent ink circulation can be used at the same time. have

However, when using the same D circular pipe-shaped seat member as shown in FIG. It is preferable that the arrow-shaped groove 3c or the concave groove 3d be formed.
Alternatively, a groove may be formed on the rear end surface of the D circular pipe-shaped seat member. Furthermore, in the case of using the same circular pipe-shaped seat member, the chip 3 is formed with a multi-stage abutting step portion that supports each or several pipe members of the same circular pipe-shaped seat member. This has the effect that it is not necessary to form a recess for the ball seat in advance in the seat area. Of course, in the present invention, it is optional whether or not to form a ball catch recess in the catch member, and when using a catch member other than a concentric pipe-shaped catch member, It is also possible to use a multi-stage support section, in which case,
The stepped portion that does not abut the seat member will be involved in ink supply performance, similar to the above-mentioned arrow-shaped grooves and the like. Next, the method of manufacturing the ballpoint pen nib of the present invention will be explained by taking as an example the case of manufacturing the ballpoint pen of the embodiment shown in FIG.
In FIG. 9, a ball 4 is inserted into a through hole of a ball holder in which a small diameter opening la is formed in advance by a method such as caulking, molding, or piercing, and a seat member material 2' in which a ball seat 2c is formed in advance. Insert the ball 4 at the small diameter opening la.
When the seat member 2' is inserted to the point where the ball holder 1 is restrained, the ball holder 1 is appropriately cut with a cutter c along the rear end, as shown in FIG.

The key point is to make the rear end surface of the ball holder and the rear end surface of the seat member 2 flush, so there is no need to cut the material 2' for the seat member at the rear end of the ball holder 1. However, for example, if a new rear end surface that is flush with the rear end surface of the seat village 2 is formed on the ball holder 1, the cutting etc. must be done sharply, otherwise the process described below will be adversely affected. In this case, appropriate post-processing such as polishing should be performed. In this way, the rear end of the pole holder 1 and the rear end of the seat village 2 are shaped like a plane, and as shown in FIG. The ball holder 1 is inserted and fixed into the hole of the chip 3 having the stepped portion 3b until the rear end portion of the ball holder 1 touches the fixed stepped portion 3a.

Here, the ball holder 1 may be fixed to the chip 3 by adhesive or by metallurgy or the like. Further, as for the receiving seat village 2, as described above, it is optional whether or not the rear end portion is fixed at a position where it touches the rear step portion 3b.

That is, when the seat member 2 is fixed, the clearance given to the ball 4 is always constant, and the seat member 2
If relative displacement between the ball holder 1 and the ball holder 1 is allowed, the clearance given to the ball 4 will change depending on the pressure applied to the writing surface during writing, but in any case, when writing, the clearance between the ball 4 and the ball holder 1 will change. This is because a clearance corresponding to the difference in level between the fixed step portion 3a of the tip 3 and the bale step portion 3b is provided between the tip and the small opening of the holder 1. In this way, the state of engagement between the seat member 2 and the ball holder 1 is completely arbitrary, but methods for fixing include a method using close contact or applying a thin layer of non-immediate adhesive to the inner circumference of the ball holder 1 in advance. It may be applied by any method. When or after fixing the ball holder to the chip 3, by applying an external force via the ball 4, the seat member 2 can be easily fixed at a position where it supports the support step 3b. In the case of a close team, it is also possible to keep the ball 4 in the small opening la of the ball holder 1 until you start writing.
It can also be used to prevent ink dry lines. however,
The use of adhesive may impede ink circulation when using a catch member with grooves on the outer periphery, as illustrated in Figure 2b and Figure 3, or a pole holder with grooves on the inner periphery. I don't like it because it is. Further, when the catch member is not fixed, minute vibrations of the catch member contribute to improving ink circulation during writing. Now, how to provide clearance between the ball 4 and the ball holder 1 or the catch member 2, but this depends on the material of each member, the insertion force of the catch member 2' into the ball holder, etc. .

For example, when inserting the seat member material 2' made of a resin sintered body into a metal ball holder 1, it can be inserted with considerable force, but in this case, due to the material of the resin sintered body, the seat member 2 is Due to the slight elastic deformation, the obtained clearance is not equal to the step difference between the fixed step 3a and the abutment step 3b of the tip 3. Therefore, it is necessary to fully understand the relationship between the insertion force and the deformation, and to design it to be large enough to accommodate the clearance between the stepped portions 3a and 3b.
Furthermore, especially when using the ball holder 1 made of resin, the small oral part la should be supported from the outside as shown in Fig. 12 to prevent the ball from flying beyond the oral part la due to the insertion force. It is also possible to use means to do so. Here, regarding the materials of the ball holder and seat member that can be used in the present invention, those used for the pen nibs of conventional ballpoint pens, resin pens, fiber pens, composite pens, fountain pens, etc. can of course be used. Examples of preferred combinations include [stainless steel, polyacetal resin], [stainless steel, gold], [polyacetal resin, polyacetal resin], [polyamide resin, gold], and [Monel, ceramics]. This will be explained below using examples.

Example: A ruby ball with a diameter of 0.600 mm and polyacetal resin were placed in a stainless steel ball holder with a length of 8.0 mm and an internal strain of 0.620, in which a small opening with a diameter of 0.56 mm was formed by caulking in advance. After inserting the manufactured catch member material with a force of 200 yen, the catch member material was cut with a knife along the rear end surface of the ball holder.

This was inserted into a boriacetal chip having a step difference of 0.015 feet between the fixed step and the rear step, and a ball holder and a seat member were fixed to each step. When we produced 10 pens made by assembling the above nib set into a writing instrument, all of them had a good writing feel and no phenomena such as ink smearing or ball flying were observed even after 500 reviews.

For comparison, in the example, length 7. When we produced one book using a tip with a striped catch and a single step, 7 of them felt good writing quality, and ink smudged compared to 500 times writing. There were two cases in which the ball was thrown, and one case caused the ball to fly. This is thought to be due to the influence of the accuracy of length design of each member, the accuracy of caulking, etc. As described above, according to the present invention, the clearance between the ball and the small diameter opening of the ball holder is the most important for ink outflow.
This can be achieved simply by providing a step corresponding to the clearance between the fixing step and the abutting step of the chip, and there is no need to provide accuracy in advance to the length of the ball holder or the length of the seat member.

In addition, not only is it easier to mold the small diameter opening of the ball holder using methods such as caulking, injection molding, and splitting, but
Forming a step on the tip can be done extremely easily and accurately by injection molding, Liu Ki, etc., so it goes without saying that the ink flow path is obstructed when the ball holder is constricted. , it is possible to reduce the variation in overall quality due to the molding precision of each member, and it is possible to contribute to cost reduction.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view of a main part showing one embodiment of the ballpoint pen nib of the present invention, FIG. 2 is a cross-sectional view showing various embodiments of the seat member, and FIGS. 3 to 8 are various modified examples. A cross-sectional view showing
FIG. 5 shows a cross-sectional view taken along the line A--A in FIG. 4. Moreover, FIGS. 9 to 12 are cross-sectional views showing one implementation step of the method for manufacturing the ballpoint pen nib of the present invention. 1...
... Ball holder, 2... Seat member, 3...
...Chip, 4...Ball, lb, 2b...Ink circulation groove, 2a...Ink circulation hole, 3a...
Fixed step section, 3b...support step section. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 12 Figure 11

Claims (1)

[Scope of Claims] 1. A ball holder having an axial through hole, a seat member inserted into the through hole forming a ball seat, a chip for inserting and fixing the ball holder, and the ball holder and the seat. The ball is held by a seat member and can have a clearance between it and the ball holder; A ballpoint pen nib, characterized in that the abutment stepped portion supporting the rear end of the seat member is formed such that a step between both stepped portions corresponds to the clearance. 2. After inserting the ball and the material for the catch member into the ball holder with a small diameter opening for holding the ball, the rear end of the ball holder and the rear end of the catch member were made flush with each other. The molded product has an insertion hole, a fixing step in the insertion hole, and an abutting step at the rear thereof, and the step between the two steps is connected to the small diameter opening for holding the ball of the ball holder and the ball. A method for manufacturing a ballpoint pen nib, characterized in that the ball holder is inserted into a tip insertion hole formed to correspond to the clearance between the tip and the tip until the ball holder is locked to the fixed step.