JPH0616090U - Writing instrument cap - Google Patents

Abstract

(57) [Abstract] [Purpose] By attaching an elastic body to the inner cap that encloses the writing tip of the cap, the elastic body can be easily attached to the cap having a structure that improves airtightness in the inner cap. . [Structure] An elastic body 9 is produced in which an end portion 10 of a ring-shaped elastic body 11 is provided with an engagement piece 14 protruding in the axial direction. The engagement piece 14 has a shape in which a wide head portion 13 is provided at the tip of the leg portion 12. The inner cap 6 is provided with an engaging portion 17 formed by a concave groove connected to the opening end surface 8 or a through hole that communicates the inside and the outside of the inner cap 6. The shape of the engaging piece 14 is substantially the same as that of the engaging piece 14, although the length of the engaging piece 14 is short at the portion corresponding to the leg 12. The engaging piece 14 is engaged with the engaging portion 17, and the elastic body 9 is attached apart from the opening end surface of the inner cap 6 to form the writing instrument cap of the present invention.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a writing instrument cap for airtightly holding and covering a writing tip of a writing instrument.

[0002]

[Prior art]

 Conventionally, in writing instruments that store water-based ink, a cap is attached to the writing tip to prevent thirst so that the writing tip does not get dry when writing. Various cap structures have been proposed to improve the airtightness of the cap.

A well-known one is one in which an inner cap made of synthetic resin is provided inside the cap body, and a neck cylinder having a writing tip is fitted or abutted against 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 rises, and when the neck tube is separated from the inner cap when writing, the air inside the inner cap is suddenly decompressed. However, since the ink in the neck cylinder is pulled out to the outside, there is a problem that the ink is ejected from the pen tip and contaminates the inside of the cap. In addition, there is a problem in that the airtightness in the inner cap cannot be sufficiently maintained by simply abutting the tip of the neck cylinder on the inner cap. Therefore, in order to solve such a problem, a bottomed inner cap, which was filed by the applicant earlier, was inserted into the cap body with the opening of the inner cap facing the opening end side of the cap body. An elastic ring is attached to the elastic ring, and an air passage for blocking and opening communication between the inner cap and the outer part of the inner cap by contracting and restoring the elastic ring is formed in the elastic ring. ).

[0004]

[Problems to be solved by the device]

 A feature of the above invention is that an elastic ring is attached to the inner cap, and an air passage is formed in the elastic ring for blocking and opening the communication between the inside and the outside of the inner cap by contracting and restoring the elastic ring. By the way, the inventors of the present invention have made various studies and found that when the neck cylinder is detached from the inner cap, the air inside the inner cap is not decompressed. It is necessary to make the cross-sectional area of the air passage relatively large so that air can flow in, but if the cross-sectional area of the air passage is too large, it becomes difficult to cut off the communication between the inside and the outside of the inner cap. It was found that there are points that must be considered when determining the cross-sectional area of the air passage and its shape.

Therefore, the object of the present invention is to improve the invention described in Japanese Utility Model Publication No. 63-16549, which is the previous invention of the present applicant, by simplifying without considering the cross-sectional area and shape of the air passage. When the neck tube is fitted into the cap, the air inside the inner cap is hardly pressed and the airtightness inside the inner cap can be maintained. Furthermore, when the neck tube is removed from the cap, the air inside the cap is released. It is to obtain a cap for a writing instrument that can be easily assembled with almost no pressure reduction.

[0006]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention has a cap structure in which a cap having a bottomed inner cap for covering the writing tip end is inserted into the cap body. The end of the ring-shaped elastic body that has the end that can come into close contact with the end of the neck cylinder that has the writing tip and the end that can come into close contact with the end of the neck tube An elastic body provided with an elastic engaging piece having a wide head at the tip is formed at the end of the inner cap, and has a length corresponding to the leg of the engaging piece. The engaging piece is engaged with an engaging portion which is short but has substantially the same shape and which is connected to the opening end surface, and is attached to the inner cap so as to be separated from the end portion of the inner cap.

The engaging portion for engaging the engaging piece is formed by providing a concave groove on the outer peripheral surface or the inner peripheral surface of the inner cap, or by providing a through hole that communicates the inside and the outside of the inner cap. can do.

The size relationship between the engagement piece and the engagement portion is such that the engagement piece does not come into close contact with the wall surface of the engagement portion when the elastic body is attached to the inner cap, resulting in a slight gap. May be. However, when the cap is fitted to the neck tube (especially when the engaging part is formed by the through hole), the elastic piece is pressed by the tip part of the neck tube, so that the engaging piece moves inside the engaging part. It is necessary that the size of the shape is such that it can bulge out and eliminate the gap. Therefore, the shapes of the engaging piece and the engaging portion are not particularly limited, but it is important to have a shape that easily swells to eliminate the gap. Also, when the cap is fitted into the neck tube, the inner tube must be kept airtight by the neck tube, so both ends of the elastic body are the end of the inner cap on the open side and the neck. The space formed by the inner cap, the elastic body and the neck tube must be sealed against the tip of the tube.

A particularly important point in the writing instrument cap of the present invention is to attach the elastic body to the inner cap at a distance from the end of the inner cap on the opened side. The reason why this point is important is that the engaging piece engages with the engaging part of the inner cap in order to attach the elastic body to the inner cap, but the engaging part communicates the inside and outside of the inner cap. When the neck cylinder is fitted into the cap, the gap formed between the engaging piece and the engaging portion must be closed as described above when it is formed by the hole. This is because it is necessary for the engaging piece to be pressed and the engaging piece to bulge when the end of the elastic body is pressed by the tip of the neck cylinder.

Further, it is because the following advantages can be obtained by mounting the elastic body apart from the open end surface of the inner cap. Explaining with reference to FIGS. 6 and 7, when the cap 1 is fitted to the neck cylinder 19 and the elastic body 9 is attached to the inner cap 6 (FIG. 7), the inside of the inner cap 6 is kept airtight. In order to do so, after the tip portion (the tip surface in the figure) 20 of the neck tube 19 abuts the end portion (the end surface in the figure) 21 of the elastic body 11 of the elastic body 9, for example, from the point A on the solid line, Assuming that the head cylinder 19 is designed to move forward to point B on the dotted chain line, when the cap 1 is disengaged, in order for the inside of the inner cap 6 to communicate with the outside air, the neck tube 19 must extend from point B to point A. You have to step back. Therefore, the air in the inner cap 6 is decompressed by that amount, and the 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 cylinder 19 quickly abuts the elastic body 9 by the distance, but from the point A to the point B. Even if the neck cylinder 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 rate at the attachment point P 1 of the engaging piece 14 and a strong restoring force. The end portion (end face in the figure) 10 of the elastic body that is in contact with the end portion 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 being generated, the end portion 10 comes into contact with the open end surface 8 ′ of the inner cap 6. That is, the inside of the inner cap 6 is kept airtight only immediately before the point B. Therefore, when the cap 1 is detached, the inside of the inner cap 6 communicates with the outside air by a slight retreat of the neck cylinder 19 due to the opposite operation, so that the pressure reducing effect in the inner cap 6 is smaller than in the former case. .

To assemble the writing instrument cap of the present invention, first attach the cap to the inner cap and then attach the elastic body to the inner cap, or finish by attaching the elastic body to the inner cap first. After that, there is a method of attaching the inner 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 contract 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 Fig. 5, the engaging piece is fitted into the engaging portion to be attached, or the engaging piece is shaped so that the tip of the head as shown in Fig. 5 has a pointed shape. There is a method of mounting by inserting the head of the engaging piece from the open end surface of the section.

[0012]

[Action]

 When the cap is fitted to the neck cylinder with the writing tip, the writing tip is positioned inside the inner cap, and the tip of the neck cylinder collides with the elastic body attached to the inner cap, and the elastic body pushes toward the inner cap side. To be done. The elastic engagement piece swells because it is pressed from the rear with its head abutting against the wall surface of the engagement part of the inner cap, and bulges out, creating a gap between the engagement piece and the engagement part. Close up. The end of the elastic body on the inner cap side also abuts on the end of the inner cap, and the writing tip of the tip of the neck tube is blocked from the outside air in the inner cap and is inserted in a state of being hermetically sealed.

When the neck cylinder is detached from the cap, the elastic body returns to its original state due to the restoring force due to the retraction of the neck cylinder with respect to the inner cap, but the head of the engagement piece is Since it collides with the wall surface of the narrow part of the engaging part corresponding to the leg part, it does not fall off from the inner cap.

[0014]

【Example】

 An embodiment of the present invention will be described with reference to the drawings. In this embodiment, a case where the writing instrument is a fountain pen will be described, but the writing instrument is not limited to this.

The writing instrument cap 1 according to the present embodiment is configured such that a clip 5 is held by a cap screw 4 inserted in a tip portion 3 of a cap body 2, and a bottom portion 7 of an inner cap 6 is screwed to the inner cap 6. The end 8 on the open side of 6 is fixed to the open end side of the cap body 2.

An elastic body 9 is attached to the rear (rightward direction in FIG. 1) of the end portion 8 on the open side of the inner cap 6, and the elastic body 9 is provided with the elastic body 9 as shown in FIG. A ring-shaped elastic body 11 having an end portion (an end surface in the drawing, hereinafter referred to as an end surface) 10 that can be brought into close contact with an end surface 8 ′ of the end portion 8 and a leg projecting in the axial direction at the end portion 10. The portion 12 is composed of a substantially arrow-shaped elastic engaging piece 14 having a thick and pointed head 13 at the tip.

On the outer peripheral surface of the end portion 8 of the inner cap 6, at the portion corresponding to the leg portion 12 of the engaging piece 14 described above, the length is short, but the shape is substantially the same, and the open end surface 8 ′ is formed. Is shorter than the entire length of the engaging piece 14 that is formed by a concave groove 15 as shown in FIG. 3 or is formed by a through hole 16 as shown in FIG. 4 that communicates with the inside and outside of the inner cap 6. An engaging portion 17 is provided.

The method of attaching the elastic body 9 to the inner cap 6 is not particularly limited and may be freely attached as appropriate. As an example, in the present embodiment, the inner cap 6 is attached inside the cap body 2. It is better to attach it to the inner cap 6 before. More specifically, the engaging piece 14 of the elastic body 9 is expanded outward in diameter to face the engaging portion 17 of the inner cap 6, and the engaging piece 14 is returned to its original state to engage. The piece 14 is fitted into the engaging portion 17 and attached. Since the total length of the engaging portion 17 is shorter than the total length of the engaging piece 14, the elastic body 9 is attached apart from the open end portion 8 of the inner cap 6.

When the neck tube 19 having the writing tip pen 18 is fitted into the cap 1, first, the pen 18 portion at the tip of the neck tube 19 is inserted into the inner cap 6 and the tip portion of the neck tube 19 ( In the figure, a tip surface, hereinafter referred to as a tip surface, 20 closely contacts an end portion 21 of the elastic body 9 (an end surface in the figure, hereinafter referred to as an end surface). When the neck cylinder 19 further advances with respect to the inner cap 6, the elastic body 9 is pressed so that the end surface 10 thereof comes into close contact with the open end surface 8 ′ of the inner cap 6. At that time, even if the engaging portion 17 is formed by the through hole 16 and a gap is created between the engaging piece 14 and the engaging portion 17 to communicate the inside and the outside of the inner cap 6, Also, since it is pressed in the axial direction and bulges in the radial direction, the gap is closed. In this way, 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 tip end surface 20 of the neck cylinder 19 against the elastic body 9 weakens, and the restoring force of the elastic body 9 returns to the original state (position). The opening end surface 8 ′ of the cap 6 and the end surface 10 of the elastic body 9 are separated from each other, and the gap allows the inside and outside of the inner cap 6 to communicate with each other. As described above, the elastic body 11 is curved as shown in FIG. 6 due to the slight retreat of the neck cylinder 19 with respect to the inner cap 6, and the end surface 10 of the elastic body 9 and the opening end surface of the inner cap 6 are bent. Since a gap 22 (FIG. 6) is formed between the inner cap 6 and 8 ′, the air in the inner cap 6 is hardly decompressed. Further, when the elastic body 9 returns to its original state, the head portion 13 of the engaging piece 14 abuts the wall surface of the portion of the engaging portion 17 of the inner cap corresponding to the leg portion 12 of the engaging piece 14, so that the elasticity is reduced. The body 9 does not fall out of the inner cap 6.

[0021]

[Effect of device]

 Since the present invention is configured as described above, when the neck cylinder is fitted into the cap, the pen tip portion can be reliably sealed without compressing the air inside the inner cap, so that the pen tip can be dried. The writing performance is improved, and when the cap is released, the inside of the cap communicates with the outside air instantly, so the air inside the cap is hardly decompressed, so a writing instrument, especially a fountain pen, is provided that does not cause ink ejection. can do. Also, since the end of the elastic body collides with the tip of the neck tube, when the cap is fitted, the neck tube is easily rubbed against the cap by the external force such as vibration when carrying it due to the frictional force with the elastic body. Therefore, when the neck cylinder and the cap are screw-fitted, there is an advantage that the screw fitting is not loosened and the cap does not come off.

Further, the elastic body can be easily attached to the inner cap without requiring a jig or tool, which is advantageous in workability.

[Brief description of drawings]

FIG. 1 is a side view of the writing instrument cap of the present embodiment in a partially cross-sectional state.

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

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

FIG. 4 shows another embodiment of the engaging portion in FIG.
It is an end view of a 3 line part.

5 is a perspective view of an elastic body in FIG. 1. FIG.

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

FIG. 7 is a side view, partially in cross section, showing a state of the elastic body when the cap is detached from the neck tube 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]

 6 Inner cap 8 End part 8'Open end surface 9 Elastic body 10 End part 11 Elastic main body 12 Leg part 13 Head part 14 Engaging piece 17 Engaging part 19 Neck tube 20 Tip part 21 End part

Claims (1)

[Scope of utility model registration request] 1. A cap for a writing instrument, comprising a cap body and a bottomed inner cap for covering the writing tip, which is close to the open end (8) of the inner cap (6). End (10) of a ring-shaped elastic body (11) having a flexible end (10) and an end (21) which can be brought into close contact with the end (20) of a neck tube (19) having a writing tip. )
In the inner cap, an elastic body (9) provided with an elastic engagement piece (14) having a thick head (13) at the tip of the leg (12) protruding in the axial direction is attached to the inner cap. The opening end face (8 ') is formed in the end portion (8) of (6) and has substantially the same shape as the portion corresponding to the leg portion (12) of the engaging piece (14), although its length is short. The engaging piece (14) is engaged with the engaging portion (17) connected to the end portion (8) of the inner cap (6).
A writing instrument cap, characterized in that the cap is attached to the inner cap (6) at a distance from the inner cap.