JP2559363Y2 - Writing instrument cap - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a writing instrument cap for covering a writing instrument while keeping the writing tip airtight.

[0002]

2. Description of the Related Art Conventionally, in a writing instrument storing water-based ink, a cap is fitted to the writing tip so as to prevent the writing tip from drying out and making it impossible to start writing. Various proposals have been made on the cap structure in order to improve the airtightness of the cap.

[0003] A well-known one is to provide an inner cap made of a synthetic resin inside a cap body, and to fit or abut a neck cylinder having a writing tip to the inner cap to maintain airtightness. is there. However, when the neck tube is fitted to the inner cap, the air inside the inner cap is compressed and the pressure increases, and when the neck tube is separated from the inner cap during writing, the air inside the inner cap is rapidly reduced in pressure, and Since the ink in the cylinder is drawn out to the outside, there has been a problem that the ink jumps out of the pen tip and contaminates the inside of the cap. In addition, there is another problem that airtightness in the inner cap is not sufficiently maintained only by abutting the tip of the neck tube on the inner cap. Therefore, in order to solve such a problem, a bottomed inner cap is inserted into the cap body, filed by the present applicant, with the opening of the cap body having the opening end side of the cap body, and the cap is inserted into the inner cap. A writing instrument cap (Japanese Utility Model Publication No. 63-16549) in which an elastic ring is attached, and an air passage for blocking and opening communication between the inside and the outside of the inner cap by contraction and restoration of the elastic ring is formed in the elastic ring has been proposed. is there.

[0004]

The feature of the above invention is that an elastic ring is mounted in the inner cap, and the air passage which cuts off and opens the communication between the inside and the outside of the inner cap by contraction and restoration of the elastic ring. It is to form. By the way, the inventors of the present invention have studied variously, and found that when the neck tube is detached from the inner cap, in order to prevent the air inside the inner cap from being decompressed, a slight retreat of the neck tube instantaneously causes a large amount of air to flow into the inner cap. It is necessary to make the cross-sectional area of the air passage relatively large so that air flows in. However, if the cross-sectional area of the air passage is too large, it is difficult to shut off the communication between the inside and the outside of the inner cap. It has been found that there is a point to be considered in determining the cross-sectional area and the shape of the air passage.

Therefore, the object of the present invention is to improve the invention described in Japanese Utility Model Publication No. 63-16549, which was an earlier invention of the present applicant, and to simply make it possible without considering the cross-sectional area and shape of the air passage. It can be manufactured, and when the neck tube is inserted into the cap, the air inside the inner cap can be kept airtight with almost no pressure on the air inside the inner cap, and when the neck tube is detached from the cap, the air inside the inner cap is almost depressurized. An object of the present invention is to provide a writing instrument cap that can be easily assembled without being performed.

[0006]

In order to achieve the above object, the present invention provides a cap for a writing instrument comprising a cap body and a bottomed inner cap for enclosing a writing tip in a cap body. An axial center is attached to the end of the ring-shaped elastic body having an end that can be in close contact with the end on the open side of the inner cap and an end that can be in close contact with the tip of a neck tube having a writing tip. An elastic body provided with an elastic engaging piece having a wide head at the tip of the leg protruding in the direction corresponds to the leg of the engaging piece formed at the end of the inner cap. The engaging piece is engaged with an engaging portion connected to the opening end surface which has a short length, but is substantially the same shape, and is separated from the end of the inner cap, and attached to the inner cap. Structure.

The engaging portion for engaging the engaging piece is provided with a concave groove on the outer peripheral surface or the inner peripheral surface of the inner cap.
Alternatively, it can be formed by providing a through hole communicating the inside and outside of the inner cap.

The relationship between the shape of the engaging piece and the shape of the engaging portion is such that when the elastic body is attached to the inner cap, the engaging piece does not come into close contact with the wall surface of the engaging portion and a slight gap is generated. You may. However, when the cap is fitted to the neck tube (especially when the engaging portion is formed by a through hole), the elastic piece is pressed by the distal end portion of the neck tube so that the engaging piece expands in the engaging portion. It is necessary that the size of the shape be such that the gap can be eliminated. For this purpose, the shapes of the engaging pieces and the engaging portions are not particularly limited, but it is important that the engaging pieces and the engaging portions have a shape that easily swells to eliminate the gap.
Further, when the cap is fitted to the neck tube, the inside of the inner cap must be kept airtight by the neck tube, so both ends of the elastic body are provided at the open end of the inner cap and the tip of the neck tube. The space formed by the inner cap, the elastic body and the neck tube must be sealed.

A particularly important point in the writing instrument cap of the present invention is that the elastic body is attached to the inner cap at a distance from the open end of the inner cap. The reason why this point is important is to engage the engaging piece with the engaging portion of the inner cap to attach the elastic body to the inner cap,
When the engaging portion is formed by a through hole communicating between the inside and the outside of the inner cap, when the neck tube is fitted to the cap, the gap generated between the engaging piece and the engaging portion as described above is removed. Must be closed, for that, the engagement piece is pressed by the end of the elastic body is pressed by the tip of the neck tube,
This is because the engagement pieces need to bulge.

[0010] Further, there is the following advantage by mounting the elastic body away from the open end face of the inner cap. Referring to FIGS. 6 and 7, when the cap 1 is fitted to the neck tube 19 and the elastic body 9 is attached to the inner cap 6 in contact with the inner cap 6 (FIG. 7), the inside of the inner cap 6 is kept airtight. For this purpose, after the distal end portion (the distal end surface in the figure) 20 of the neck cylinder 19 abuts against the end portion (the end surface in the figure) 21 of the elastic body 11 of the elastic body 9, for example, two points from the point A of the solid line portion If the cap 1 is designed to move forward to the point B in the chain line, when the cap 1 is detached, the neck tube 19 moves backward from the point B to the point A in order to allow the inside of the inner cap 6 to communicate with the outside air. Must.
Accordingly, the air in the inner cap 6 is reduced in pressure correspondingly, and ink is drawn out from the pen tip. On the other hand, when the elastic body 9 is attached to the inner cap 6 at a distance (FIG. 6), the neck tube 19 comes into contact with the elastic body 9 earlier by the distance, but from the point A to the point B. Even if the neck tube 19 moves forward, the elastic body 11 is compressed after pressing the engaging piece 14, so that the elastic body 9 has a high compression ratio at the location P where the engaging piece 14 is attached, and the restoring force is strong. The end (end face in the figure) 10 of the elastic body that is in contact with the end 8 (open end face 8 ′ in the figure) of the inner cap 6 is curved, and a gap 22 is formed between the inner cap 6 and the elastic body 11. After it occurs,
The end 10 comes into contact with the open end face 8 ′ of the inner cap 6. That is, the inside of the inner cap 6 is kept airtight for the first time immediately before the point B. Therefore, when removing the cap 1,
By the reverse operation, the inside of the inner cap 6 communicates with the outside air by a slight retreat of the neck tube 19, so that the pressure reducing effect in the inner cap 6 can be smaller than in the former case.

In order to assemble the writing instrument cap of the present invention, the cap is first attached to the inner cap and then the elastic body is attached to the inner cap, or the elastic body is attached to the inner cap first and then the inner cap is attached. There is a method of attaching the cap to the cap to complete it. To attach the elastic body to the inner cap, expand the engaging piece of the elastic body to the outside of the diameter or close it to the inside of the diameter, position it at the engaging portion of the inner cap, and remove the engaging piece. By returning to the state of the above, the engaging piece is fitted and attached to the engaging portion, or the shape of the engaging piece is changed to the pointed shape of the tip of the head as shown in FIG.
There is a method of mounting by inserting the head of the engaging piece from the open end face of the engaging portion.

[0012]

When the cap is fitted to the neck cylinder having the writing tip, the writing tip is located in the inner cap, and the tip of the neck cylinder abuts the elastic body attached to the inner cap, and the elastic body becomes the inner cap. Pressed to the side. The elastic engagement piece is swelled because it is pressed from the rear while its head is in contact with the wall surface of the engagement portion of the inner cap, so that the gap formed between the engagement piece and the engagement portion is reduced. Close up. The end of the elastic body on the side of the inner cap also abuts on the end of the inner cap, and the writing end of the end of the neck cylinder is inserted into the inner cap in a state of being shut off from outside air and kept airtight.

When the neck tube is detached from the cap, the elastic body returns to its original state by a restoring force due to the retraction of the neck tube with respect to the inner cap. Because it contacts the wall of the narrow part of the engaging part corresponding to the part,
It does not fall out of the inner cap.

[0014]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. In this embodiment, the case where the writing implement is a fountain pen will be described, but the present invention is not limited to this.

In the writing instrument cap 1 of this embodiment, a clip 5 is clamped by a cap crown screw 4 inserted into a tip 3 of a cap body 2, and a bottom 7 of an inner cap 6 is screwed.
The end 8 of the inner cap 6 on the open side is fixed to the open end of the cap body 2.

An elastic body 9 is mounted behind the open end 8 of the inner cap 6 (to the right in FIG. 1), and the elastic body 9 is attached to the inner cap 6 as shown in FIG. A ring-shaped elastic body 11 having an end portion 10 (an end surface in the figure, hereinafter referred to as an end surface) which can be in close contact with an end surface 8 ′ of the end portion 8, and a leg portion projecting in the axial direction at the end portion 10. A substantially arrow-shaped resilient engaging piece 14 having a wide and sharp head 13 at the tip of the reference numeral 12.

On the outer peripheral surface of the end portion 8 of the inner cap 6,
In a portion corresponding to the leg portion 12 of the engagement piece 14 described above,
Although the length is short, it has substantially the same shape and is connected to the opening end face 8 ′, and is formed of a concave groove 15 as shown in FIG. 3 or communicates with the inside and outside of the inner cap 6, and as shown in FIG. An engaging portion 17 formed of a hole 16 and having a dimension shorter than the entire length of the engaging piece 14 is provided.

The method of attaching the elastic body 9 to the inner cap 6 is as follows.
Although it is not particularly limited and may be freely attached as appropriate, in one embodiment, the inner cap 6 may be attached to the inner cap 6 before the inner cap 6 is attached to the cap body 2.
More specifically, the engagement piece 14 of the elastic body 9 is expanded outward in the diameter to face the engagement portion 17 of the inner cap 6, and the engagement piece 14
By returning to the original state, the engagement piece 14 is fitted into the engagement portion 17 and attached. Since the entire length of the engaging portion 17 is shorter than the entire length of the engaging piece 14, the elastic body 9 is attached at a distance from the open end 8 of the inner cap 6.

When the neck tube 19 having the pen 18 at the writing tip is fitted into the cap 1, first, the pen 18 at the tip of the neck tube 19 is inserted into the inner cap 6, and the tip of the neck tube 19 (FIG. In (2), it is the tip surface, hereinafter referred to as the tip surface.
Numeral 0 is in close contact with an end portion (end surface in the figure, hereinafter referred to as an end surface) 21 of the elastic body 9. When the neck tube 19 further advances with respect to the inner cap 6, the elastic body 9 is pressed, and the end face 10 comes into close contact with the open end face 8 ′ of the inner cap 6. At this time, the engaging portion 17 is formed by the through hole 16, and even if a gap is formed between the engaging portion 14 and the engaging portion 17 to communicate the inside and outside of the inner cap 6, the engaging portion 14 Is also pressed in the axial direction and swells in the radial direction, so that the gap is closed. Thus, the air in the inner cap 6 is completely sealed.

When the neck cylinder 19 is detached from the cap 1, the pressing of the distal end surface 20 of the neck cylinder 19 against the elastic body 9 is weakened, and the elastic body 9 returns to the original state (position) by the restoring force.
The opening end face 8 ′ of the inner cap 6 and the end face 10 of the elastic body 9 are separated from each other, and the gap communicates the inside and outside of the inner cap 6. As described above, the slight retreat of the neck tube 19 with respect to the inner cap 6 causes the elastic body 11 to bend as shown in FIG. 6, and the end face 10 of the elastic body 9 and the open end face 8 ′ of the inner cap 6. A gap 22 (FIG. 6) is formed between the inner cap 6 and the inner cap 6.
The air inside is hardly decompressed. Further, when the elastic body 9 returns to the original state, the head 13 of the engaging piece 14 comes into contact with the wall surface of the portion corresponding to the leg 12 of the engaging piece 14 of the engaging portion 17 of the inner cap. The body 9 does not fall off the inner cap 6.

[0021]

[Effects of the Invention] Since the present invention is constructed as described above, when the neck cylinder is fitted to the cap, the pen tip can be sealed tightly without almost compressing the air inside the inner cap. The pen tip is prevented from drying out, the writing performance is improved, and when the cap is detached, the inside of the inner cap is instantaneously communicated with the outside air. Can provide, especially fountain pens. Also, since the end of the elastic body abuts on the tip of the neck tube, when fitting the cap,
The neck tube does not easily rotate with respect to the cap due to external force such as vibration when carrying, due to the frictional force with the elastic body, so if the neck tube and the cap are screwed, the screw fitting will loosen. There is also an advantage that the cap does not come off.

Further, the elastic body can be easily attached to the inner cap without requiring any jigs and tools, which is advantageous in workability.

[Brief description of the drawings]

FIG. 1 is a side view of a writing instrument cap according to the present embodiment in a partially sectioned state.

FIG. 2 is a side view showing a state in which a neck tube having a writing tip is fitted to a cap in FIG.

FIG. 3 is an end view taken along the line 3-3 in FIG. 1;

FIG. 4 shows another embodiment of the engaging portion in FIG. 1;
It is an end elevation of a three-line part.

FIG. 5 is a perspective view of an elastic body in FIG.

FIG. 6 is a partially sectional side view showing a state of the elastic body when the cap is detached from the neck tube in the writing instrument cap of the present embodiment.

FIG. 7 is a partially sectional side view showing a state of the elastic body when the cap is detached from the neck cylinder in the writing instrument cap in a state where the elastic body is in contact with and attached to the inner cap.

[Explanation of symbols]

 Reference Signs List 6 inner cap 8 end 8 'open end face 9 elastic body 10 end 11 elastic body 12 leg 13 head 14 engaging piece 17 engaging part 19 neck tube 20 tip 21 end

Claims (1)

(57) [Scope of request for utility model registration] A cap for a writing instrument in which a bottomed inner cap enclosing a writing tip is inserted into a cap body, and can be closely contacted with an open end (8) of the inner cap (6). End (10) of the ring-shaped elastic body (11) having an end (21) that can be in close contact with the tip (20) of the neck tube (19) having a writing tip. )
And an elastic body (9) provided with an elastic engaging piece (14) having a wide head (13) at the tip of a leg (12) projecting in the axial direction. An opening end face (8 ') formed at the end (8) of (6) and corresponding to the leg (12) of the engaging piece (14) has a shorter length but has substantially the same shape and an almost same shape. The engaging piece (14) is engaged with an engaging portion (17) connected to the end portion (8) of the inner cap (6).
A cap for a writing instrument, further attached to the inner cap (6).