JP2579699Y2 - 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 in which ink is prevented from evaporating by an inner cap provided in the cap.

[0002]

2. Description of the Related Art A cap for a writing instrument using water-based ink is provided separately from the cap with an inner cap which is pushed toward the opening end of the cap by a spring inside the cap. The inner cap is fitted to the writing tip to make the space at the writing tip airtight so that evaporation of the ink is prevented. In this case, the air in the space of the writing tip portion, which is confined when the inner cap is fitted to the writing tip portion, is pressurized by compression, or conversely, the pressure in the space when the inner cap is removed from the writing tip portion. When the pressure is reduced, the ink is excessively sucked out from the tip of the writing, causing the writing to be blurred or causing the ink to leak from the air holes provided in the writing instrument.

[0003] As a device for reliably achieving the airtight state of the space at the leading end of the writing by the above-mentioned inner cap and for preventing the application of pressure or decompression, there is an example of a device which is disclosed in Japanese Utility Model Application Publication No.
The -120087 discloses, discloses a structure shown in FIG. This is achieved by forming a ventilation hole 4 at the front end of the inner cap 2 pressed toward the opening end of the cap by a spring 3, attaching an annular elastic packing 5 to the front of the ventilation hole 4, and A communication hole 6 communicating with the outside air is formed on the side surface. With such a configuration, as shown in FIG. 6 from the state of FIG. 5 , the writing tool 7 inserted into the cap 1 pushes the inner cap 2 inward against the spring 3 against the spring 3, and the cap 1 is locked to the writing tool 7. In the state of FIG. 6 , the annular elastic packing 5 is pressed against the flat inner wall surface of the cap body 1, so that the space inside the inner cap 2 and the space communicating with the communication hole 6 outside the inner cap 2 are surely formed. Cut off. Further, when the air inside the inner cap 2 is confined, an increase in the pressure inside the inner cap 2 is not observed by the communication hole 6 communicating with the outside air.

[0004] Although not shown, a communication hole communicating with the outside air is formed at the center of the top of the cap, and an annular elastic seal is provided on the top surface of the inner cap. It is also known that the elastic seal member surrounds the communication hole and presses against the top surface of the cap to shut off the ventilation with the outside air (see Japanese Patent Publication No. 4-77676).

[0005]

When the member for pressing the flat surface of the cap is a packing material having high elasticity, it is possible to obtain a more reliable adhesion effect as compared with the case where the member is pressed with a relatively hard flat end surface. it can. However, as the number of parts increases by one,
The cost will be high.

Accordingly, an object of the present invention is to provide a writing instrument cap capable of reliably achieving the same effect without increasing the number of parts.

[0007]

Means for Solving the Problems The present invention provides a cap,
An inner cap pushed toward the opening end of the cap by a spring mounted in the cap, and in a state where the cap is fitted to a writing instrument, the inner cap is fitted to the writing tip and the writing tip is In a writing instrument cap that makes the space airtight, the cap forms a spindle-shaped protrusion at the center of the top inside, and a vent hole communicating with the outside air is formed on the top surface of the cap, and the inner cap is
The tip of the cap facing the spindle-shaped protrusion is a thin tapered cylindrical shape facing the tip. When the cap is fitted to the writing instrument, the tip of the inner cap is slightly expanded by the outer surface of the spindle-shaped protrusion. In this state, the contact is made uniform.

[0008]

[Operation] When a writing instrument is inserted from the opening end of the cap and the inner cap is pushed forward against the spring, the tip of the inner cap, which has a thin tapered cylindrical shape, is covered from outside the spindle-shaped projection of the cap. Immediately before engaging with the writing instrument, the inner surface at the tip of the inner cap abuts against the outer surface of the spindle-shaped protrusion, and as the fitting state progresses, even if it is initially in a single contact state, the entire circumference of the contact surface The inner cap corrects the posture to show even resistance. Thus, when the cap is locked to the writing instrument, the tip of the inner cap is uniformly spread while being slightly expanded by the outer surface of the spindle-shaped protrusion. As soon as the internal pressure rises in the process of trapping the air inside the inner cap, the pressure is released from the ventilation groove formed in the top of the cap, so that the internal pressure does not rise.
For the same reason, the internal pressure is not reduced when the cap is removed.

Further, when the cap is used alone, the ventilation hole formed in the top surface of the cap reaches the end opening of the cap via the opening of the tip of the inner cap, and a sufficiently large air flow path can be secured. Even so, suffocation death can be avoided.

[0010]

In FIG. 1, a feature of the cap 1 is that a spindle-shaped projection 8 is formed at the center of the inside of the top, and ventilation holes 9 and 9 (see FIG. 2) communicating with the outside air are formed on the top surface of the cap 1. It is a point that is drilled. Although the illustrated ventilation holes 9 have an arcuate shape and are provided to face around the base of the spindle-shaped projection 8, the position, the number and the shape are not limited to these. One piece may be opened in the outer peripheral portion. The annular projection 10 formed substantially at the center of the inside of the body of the cap 1 serves as both the locking of the inner cap 2 and the locking of the writing implement 7 as described later.

A feature of the inner cap 2 is that the tip portion 11 of the cap 1 facing the spindle-shaped projection 8 is formed into a thin tapered cylindrical portion toward the tip. In the illustrated example of the inner cap 2, a small-diameter cylindrical portion, a medium-diameter cylindrical portion, and a large-diameter cylindrical portion are continuously provided, and the small-diameter cylindrical portion that is the distal end portion 11 is a thin-walled tapered cylindrical portion as described above. The shoulder portion 12 of the middle diameter cylindrical portion is used as a bearing for the spring 3 disposed between the shoulder portion 12 and the outer peripheral portion inside the top portion of the cap 1. The small-diameter cylindrical portion and the medium-diameter cylindrical portion may be connected in a curved shape without any problem. When the inner cap 2 is resiliently pressed in the direction of the cap opening by the force of the spring 3, the outer end of the opening of the large-diameter cylindrical portion is engaged with the annular convex portion 10 of the cap 1. There's nothing like jumping out of.

By inserting the writing body 7 into the cap 1 and pressing the end surface 14 of the inner cap 2 with the pressing surface 15 of the writing body 7, the inner cap 2 can be pushed inward against the force of the spring 3. When the bulging portion 16 of the writing body 7 gets over the annular convex portion 10 of the cap 1 in this way, the cap 1 shown in FIG. In this state, the tip 11 of the inner cap 2 is
Are uniformly spread in a state of being slightly expanded by the outer surface of the spindle type projection 8.

The modification shown in FIG. 4 is an example in which a crown 13 is fitted to the cap of FIG. When the configuration in which the crown 13 is fitted as in this example is adopted, the ventilation hole 9 is also formed in the crown 13. This is because the internal pressure is released in the process of confining the air by fitting the inner cap 2, and also from the viewpoint of securing the air flow path for avoiding the suffocation death when the infant swallows the cap. is necessary.

[0014]

According to the present invention, the fitting structure of the spindle-shaped projection of the cap and the tip portion forming the thin-walled tapered cylindrical portion of the inner cap is in a state of a single contact at the initial stage of the fitting. In addition, as the fitting progresses, the posture of the inner cap is automatically corrected so that the inner cap is evenly contacted over the entire circumference, and a uniform close contact state can be reliably obtained at the stage of completion of the fitting. In addition, since the thin tapered cylindrical portion at the tip of the inner cap is easily elastically deformed, when the inner cap is fitted to the writing tip, it may be slightly expanded by the outer surface of the spindle-shaped protrusion. As a result, the space at the tip of the writing can be reliably made airtight, and the evaporation of ink can be prevented. Further, it is possible to return to the original state immediately after leaving the outer surface of the spindle-shaped protrusion, and since the deformation is slight, the sealing function does not deteriorate even if it is repeatedly used. Thus,
This eliminates the need for elastic packing and the need to increase the number of parts.

The vent hole formed in the top surface of the cap not only functions as a relief for preventing the internal pressure from rising in the process of confining the air by the inner cap, but also through the opening through the tip opening of the inner cap from the vent hole. The provision of a relatively large passage to the distal opening of the cap ensures that if a child accidentally swallows the cap, it will not be suffocated.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a writing instrument cap according to the present invention.

FIG. 2 is a plan view seen from the left side of FIG.

FIG. 3 is a cross-sectional view when the cap of FIG. 1 is attached to a writing instrument.

FIG. 4 is a sectional view showing a modification of the cap of FIG. 1;

FIG. 5 is a sectional view showing an example of a conventional writing instrument cap.

6 is a cross-sectional view when the cap of FIG. 5 is attached to a writing instrument.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cap 2 Inner cap 3 Spring 8 Spindle-shaped protrusion 9 Vent groove 11 Tip location

Claims (1)

(57) [Scope of request for utility model registration] 1. A cap 1 and an inner cap 2 pushed toward an opening end of a cap by a spring 3 mounted in the cap 1.
When the inner cap 2 is fitted to the writing tip, the inner cap 2 is fitted to the writing tip to make the space of the writing tip airtight. In the cap for the writing implement, the cap 1 forms a spindle-shaped protrusion 8 at the center inside the top. And a vent 9 communicating with the outside air
Is formed on the top surface of the cap 1, and the inner cap 2 is formed as a thin-walled tapered cylindrical portion with the front end portion 11 facing the spindle-shaped projection 8 of the cap 1 facing the front end. A tip portion 11 of the inner cap 2 is slightly expanded by the outer surface of the spindle-shaped projection 8 so that the tip portion 11 of the inner cap 2 is uniformly adhered to the tip portion of the inner cap 2.