JPH0120149Y2 - - Google Patents

Description

[Detailed description of the invention] This writing instrument has a multi-stage attachment of the cap to the main body, which makes it both secure in attachment when not in use for long periods of time, and easy to attach and detach when not in use for short periods of time. Regarding.

The methods of attaching the cap to the main body of conventional general writing instruments are broadly classified into two methods: screwing and sliding. Examples of the latter, which do not require rotational force when attaching and detaching the cap, include friction fitting and concave-convex fitting.

Comparing the two based on the original purpose of the cap, which is to protect the pen tip and prevent stains from other objects, we find that while screw-on caps are secure, they are troublesome to attach and detach, and sliding caps are troublesome to attach and detach. On the other hand, it does not take
Insufficient adhesion force may cause unnecessary separation, or conversely, sufficient adhesion force may require excessive separation force.

However, above all, there is certainty in screwing, and there is simplicity in sliding. In particular, when it comes to sliding, if the product is not carried in a pocket of clothes or is used, for example, when it is placed on a desk, there is no particular problem even if the adhesion strength is slightly insufficient, so there will be no disadvantages. You can make use of your strengths.

The present invention has been devised in view of the above-mentioned points, and hereinafter, a small tube type writing instrument will be described as a preferred embodiment with reference to the accompanying drawings. here,
The reason for using a small tube type writing instrument as an example is that although the present invention does not apply to ballpoint pens, fountain pens, or sharp pencils, the cap can also be used for ink in addition to the aforementioned purposes of protecting the pen tip and preventing stains. This is because one of the main purposes of writing instruments that use ink is often to prevent the ink from drying out, and small tube type writing instruments are a typical example of this. Another typical example is a metal pipe ballpoint pen, which has recently become a mainstream water-based ballpoint pen.

In FIG. 1, A indicates the main body and B indicates the cap. As the structure of the main body A, we took as an example a type that uses a member having a comb-like ink reservoir groove, a so-called bellows, and each reference numeral indicates 1.
is a shaft, 2 is a tip having an air hole slit 2a, 3 is a small tube nib, 4 is a needle body, 5 is a weight, and 6 is a bellows. A structure in which the needle body 4 is displaced within the small tube 3 based on the weight of the weight 5 is well known. On the other hand, for the cap B side, 7 is the outer cap, 8 is the inner cap, and 9 is the outer cap.
is a pen tip sealing material that has elasticity.

FIG. 1 shows a state in which the main body A and the cap B are only frictionally fitted between the sliding portions 1a and 8a of the shaft 1 and the inner cap 8, respectively. Positioning is done by a simple method of abutting threaded portions formed on the main body A and the cap B, respectively. The friction fit may occur not at the shaft 1 and the inner cap 8, but at any appropriate position on the main body A and the cap B, for example, between the chip 2 and the inner cap 8, or between the shaft 1 and the outer cap 7. You may also do it as shown below. This latter is
Generally, this is applicable to writing instruments having a nib made of a fiber bundle or an extruded resin body, where the cap B does not include an inner cap 8 or a nib sealing material 9. It is also possible to form a sliding part on the rear side of the threaded part of the main body A, and to form a sliding part on the opening side of the threaded part of the cap B.

Many people have experienced that while using a small tube type writing instrument, the ink at the tip of the pen often dries out even if it is left for a while, and they have to go to great lengths to make it reusable. You probably have it. In the state shown in FIG. 1, the pen tip sealing material 9 has already fulfilled its role. During use, when the cap is left temporarily unattended, it is not common to fasten the cap B as shown in FIG.

FIG. 2 shows a state in which the cap B is fixed more deeply than the state shown in FIG. 1. Note that only the outer edge of the main body A is shown.

Figure 2 shows how the cap is attached when it is being carried around or not being used for a long period of time.
The friction fit between the shaft 1 and the inner cap 8 is correspondingly deeper from FIG.
In addition, the pen tip sealing material 9 has a larger deformation due to its elasticity, and the inner cap 8 is in pressure contact with the tip edge of the shaft 1, and the air hole (see the slit 2a of the tip 2 in Fig. 1) is removed from the inner cap 8. Suppresses moisture evaporation.

It is preferable that the sliding portions 1a and 8a of the shaft 1 and the inner cap 8 form a circumferential sealed portion from the viewpoint of preventing the ink from drying out. However, suppose that for some reason the ink inside the main body A has adhered to the air holes. In such a case, when removing cap B from Fig. 2, if the circumferential sealing part as described above always exists, negative pressure may occur in the inner cap 8, causing ink to leak from the air holes. do not have. Therefore, if there is such a concern, the air hole may be formed to open in the sliding portion 1a of the shaft 1, or the shape of the sliding portions 1a and 8a may be made polygonal, for example.

Furthermore, when moving from the state shown in FIG. 1 to the state shown in FIG. 2, rotational force is applied to the sliding parts 1a and 8a of the shaft 1 and inner cap 8 due to the rotation during screwing, causing wear and gradual friction. If the fitting force becomes weak and undesirable, it is sufficient to make the outer cap 7 and the inner cap 8 rotatable relative to each other.
This also shows that it is preferable to form the threaded part and the sliding part in separate members, rather than in the same member, since it is possible to select materials suitable for each part.

Next, FIG. 3 shows another example of a state corresponding to FIG. 2. The same parts as in the previous example are given the same reference numerals, but this example is based on the idea that when attaching the cap B to the main body A, it is sufficient that it is screwed together, and this example is different from the previous example. The biggest difference is that the sliding parts of main body A and cap B are large diameter parts and small hole parts, respectively. That is, the main body A has a large diameter part 2b and a small diameter part 2c at the rear part that follows it, and the cap B has a small hole part 8b and a large hole part 8c at the rear part that follows it. However, in a state corresponding to the example shown in FIG. 1, there is a friction fit between the large diameter portion 2b and the small hole portion 8b.

By the way, in the two examples described above, friction fitting is used as an example of sliding. Sliding essentially indicates a fastening method that does not require rotational force, and there are other means besides friction fitting. Therefore, we will discuss concave-convex fitting, which is considered to be a typical example. In contrast to friction fitting, which uses at least friction pressure input as its main force, concave-convex fitting can be said to use engagement force as its main force.
A member having elasticity is fixed by engaging with another member, and includes a convex portion formed around the entire circumference or an appropriate number of convex portions, and a concave portion or a concave portion formed corresponding to the convex portion. Since it is sufficient to make the convex portions engage with each other (or should we say “cross over” in the case of convex portions), for example, a concave portion having a circumferential shape on the circumferential wall of the large diameter portion 2b of the main body A in FIG. form,
This can be achieved by forming the small hole 8b of the cap B with an appropriate number of inward protrusions. Concave-convex fitting has an advantage over friction fitting in that it can play a leading role in determining the fastening position. However, on the other hand, it tends to have disadvantages in terms of lateral vibration. Therefore, when using concave-convex fitting,
It is desirable to form the concave and convex portions sufficiently long or to provide them at different positions in the longitudinal direction. Of course, a combination with friction fitting is also a preferable example.

As mentioned above, in the writing instrument of the present invention, the cap B is fixed to the main body A through screw engagement and sliding engagement performed in the preceding stage.
Not only can it be securely fastened by screwing when carried or not used for a long period of time, but also when used on a desk.
In cases where it is acceptable even if the adhesion force is insufficient, that is, when there is no need to hang the main body A by the cap B, the ease of attachment and detachment by sliding can be utilized, which is more convenient. It's something that doesn't exist.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention; Fig. 1 is a vertical sectional view of the main part with the cap and main body only slid together, and Fig. 2 is a main part of the example shown in Fig. 1 with the cap and main body screwed together. A longitudinal sectional view, FIG. 3 is a longitudinal sectional view of a main part of another example corresponding to FIG. 2. A...Body, B...Cap, 1...Shaft, 7...
...Outer cap, 8...Inner cap, 1a, 8a...
...Sliding part, 2b...Large diameter part serving as sliding part, 8b...
The small hole is the sliding part.

Claims (1)

[Scope of utility model registration request] In a writing instrument in which a cap is fixed to a main body by screwing, a sliding portion is provided at a relative position between the main body and the cap so that the cap slides against the main body at a stage before starting the screwing. A writing instrument characterized by being formed.