JPH10203081A - Cap for writing instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cap for a writing instrument of direct ink storage type in which the number of parts is reduced and movable parts in the cap are eliminated. SOLUTION: When the end face of a seal cylinder 17 of superior elasticity provided in a cap 11 is brought into contact with the end of a mouthpiece 9 of a shaft cylinder 1 to seal a pen point 9 and an opening of an air vent, the opening edge of the seal cylinder 19 is fitted into a conical section from the middle of an opening of an air channel 12 of a conical section of an ink storage body 5 and an opening of the seal cylinder 19 is covered while being pressed and expanded in the radius direction, and when the end face of the seal cylinder 19 is brought into contact with the mouthpiece 10 and the covering of the cap 13 is completed, an inner opening edge 22 of the seal cylinder 19 follows the conical section of the storage body 5 and sealing can be carried out securely even when the axial center of the cylinder 19 is shifted from the axial center of the mouthpiece 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has an ink tank for directly storing ink without absorbing it into batting or the like, and ink pushed out of the ink tank when the air in the ink tank expands due to a temperature rise or the like. The present invention relates to an improvement in a writing instrument cap provided with an ink reservoir for temporarily retaining ink from dropping from a writing tip or an air hole.

[0002]

2. Description of the Related Art A conventional ink direct storage type writing implement cap has a seal cylinder which is movable in the axial direction so that the volume of the seal cylinder does not change when the cap is attached or detached. The cylinder is brought into contact with the conical surface of the base with an appropriate pressing force and sealed.

[0003] In a so-called batting-type writing instrument cap, the cap is attached to the barrel and seals the pen tip and the air hole, but when the cap is attached to the barrel to ensure the seal, the attachment is completed. Immediately before, the inner space of the cap is reduced while the seal portion of the shaft cylinder and the cap are closely fitted and the attachment is completed. Therefore, when the cap is attached, the inside of the cap is pressurized. Conversely, when the cap is removed, the pressure inside the cap is reduced because the space in the cap is expanded while the close fitting portion of the seal portion is released. However, since the inside of the cap and the rear half of the barrel containing the batting are continuous as a space through the air hole of the barrel, the whole writing instrument is pressurized and decompressed, and the ink reservoir and the pen tip The pressure does not change, and the action of ink flowing out of the pen tip or air hole when the cap is attached or detached does not work. However, in the direct storage type writing instrument, the volume in the seal cylinder is not changed when the cap is attached or detached. The air inside is compressed and the air passes through the ink reservoir through the ink reservoir and enters the ink tank as air bubbles, and the ink overflows and is retained in the ink reservoir. Conversely, when removing the cap from the shaft cylinder, the air in the seal cylinder will be depressurized contrary to the above phenomenon, so the ink in the ink tank will be drawn out and also retained in the ink reservoir. The ink is drawn from the pen tip. In this way, the amount of ink stored in the ink storage body increases each time the cap is attached and detached, and eventually exceeds the storage capacity, causing ink to flow out of the air hole or ink to leak out of the pen tip. I do. In order to prevent this phenomenon, a conventional ink direct storage type writing instrument cap employs the following structure.

[0004]

The cap of a conventional direct storage type writing instrument is designed so that a relatively hard seal cylinder made of polypropylene or polyethylene is not pressurized and depressurized and is sealed when the cap is removed. A structure that can be moved in the axial direction so that the opening edge is in close contact with the conical surface of the mouthpiece barrel of the writing implement barrel, complicating the structure, increasing the number of parts, increasing the product unit price and assembling costs due to the complexity of assembly It is also a factor of the rise. An object of the present invention is to make it possible to provide a cap that solves such a problem.

[0005]

In order to achieve the above-mentioned object, a writing instrument cap according to the present invention has a cup-shaped sealing cylinder made of rubber or the like, which is attached to the cap. At the time of attachment to the cylinder, the opening end of the base attached to the opening of the barrel comes into close contact with the opening end face of the seal cylinder, and seals the tip including the air hole on the side of the barrel. When the part comes into contact with the seal cylinder, the end face of the seal cylinder is compressed and the space in the seal cylinder is pressurized, but the cap is attached to the shaft cylinder so that the compression amount of the seal cylinder can be reduced to a small amount. By restricting the stop position, pressurization of the space in the seal cylinder does not pose a problem in practical use.

[0006]

FIG. 1 shows an embodiment of the present invention, which will be described in detail with reference to the drawings. The writing implement main body has an ink chamber 2 at the rear of the barrel 1 and an ink reservoir 5 having a number of peripheral grooves 3 and a longitudinal groove 4 communicating the peripheral grooves 3 on the outer peripheral surface in front.
The ink guide core 7 is penetrated in a vertical hole 6 penetrating in the axial direction at the center of the ink reservoir 5, and the tip of the ink guide core 7 abuts or stabs the center core 8. The core 8 is connected to a pen tip 9 at the tip, and ink is supplied from the ink chamber 2 to the pen tip 9 through the ink guide core 7 to the core 8.

Next, the cap 13 has an engagement projection 14 formed on the inner surface near the opening edge for engaging with the projection 15 of the barrel 1, and is engaged with the projection 15 of the barrel 1 and on the inner wall of the cap 13. The contact step portions 17 of the plurality of ribs 16 provided are brought into contact with the flange portion 11 of the base 10 which is tightly fitted to the barrel 1 so as to be attached to the barrel 1 at a fixed position. . Further, a locking step 18 is formed on the rib 16 of the cap 13, and a flange 20 of a seal cylinder 19 made of a cup-shaped rubber is applied to the locking step 18 and fitted to the rib 16 so that the inside of the cap 13 is formed. Locked in place. Here, when the cap 13 is attached, the inner opening edge 22 of the seal cylinder 19 is fitted from the middle of the opening 24 of the air groove 12 of the conical surface 23 of the ink reservoir 5 so that the opening of the seal cylinder 19 has a radius. The seal cylinder 19 is pushed and spread in the direction, but even if the axis of the seal cylinder 19 and the axis of the cylinder 1, that is, the axis of the base 10 are misaligned, the seal cylinder 19 is closed when the cap attachment is completed. The opening is deformed so that the end surface 21 of the seal cylinder 19 and the end 25 of the base 10 are securely brought into close contact with each other over the entire circumference, and the inner opening edge 22 of the seal cylinder 19 is conical with the ink reservoir 5. Face 23
The fitting of the air groove 12 in the middle of the opening 24 is such that the inside of the sealing cylinder 19 can be ventilated with outside air through the opening 24 of the air groove 12 until the cap attachment is completed. Is applied to prevent air from flowing in from the tip of the pen tip 9 and obstructing the outflow of ink, thereby causing no inconvenience in writing. Then, the contact step 1 of the cap 13
When the flange 11 of the base 10 comes in contact with the base 7 and the cap is completely attached, the end 25 of the base 10 is attached to the end face 21 of the seal cylinder 19.
The end 25 of the inlet 10 and the end face 21 of the sealing cylinder are brought into close contact with each other to seal the air groove 12 and the pen tip 9.

[0008]

In the writing implement constructed as described above, when the cap 13 is attached to the writing implement main body, the tip including the pen tip 9 and the air hole 12 enters the seal cylinder 19 and the end face 21 of the seal cylinder 19 is attached to the base 10. And then the micro-small barrel 1 enters the cap 13 and the flange 11 of the base 10 abuts against the contact step 17 of the cap 13 and stops. System projection 1 of cap 13
4 keeps the attached state of the shaft cylinder 1 and the cap 13, the end 25 of the base 10 slightly enters the end face 21 of the seal cylinder 19, and tightly seals the air groove 12 and the pen tip 9. Here, when the end portion 25 of the base 10 comes into contact with and comes into contact with the end surface 21 of the seal tube 19, the end surface 21 is compressed, the internal volume of the seal tube 19 is reduced, and the internal pressure of the seal tube 19 is increased.
Since the pressing length of the opening end 21 of the seal cylinder 19 at the end 25 of the zero is a very small amount, the inside of the seal cylinder 19 is only slightly compressed, and the inflow of ink into the ink reservoir 5 is also reduced. Since the ink that has entered the ink reservoir 5 due to the very small amount of ink consumed during actual use returns to the ink chamber 2, the ink reservoir 5 is full of ink, and the ink is filled from the air groove 12. It does not flow. When the cap is further attached, the inner opening edge 22 of the seal cylinder 19 fits in the middle of the opening 24 of the air groove 12 of the conical surface 23 of the ink reservoir, and pushes the opening of the seal cylinder 19 in the radial direction. Even when the axis of the seal cylinder 19 and the axis of the cylinder 1, that is, the axis of the base 10 are misaligned, the opening of the seal cylinder 19 is deformed when the cap is completely attached. Then, the end face 21 of the seal cylinder 19 and the end 25 of the base 10 are securely adhered over the entire circumference. The inner opening edge 22 of the seal cylinder 19 is formed by the opening 24 of the air groove 12 on the conical surface 23 of the ink reservoir 5.
Can be fitted from the middle of the seal cylinder 19, and the inside of the seal cylinder 19 can be ventilated with the outside air through the opening 24 of the air groove 12 until the cap attachment is completed. In addition, air does not flow in from the tip of the pen tip 9 and obstructs outflow of ink, so that there is no inconvenience in writing. In addition, the ink holding body 5 is extended to the writing tip so as to hold the writing portion, thereby helping to reduce the number of components and making it easy to secure the air groove 12.

[0010]

The construction and operation of the present invention are as described above. Since there is no need to make the cap movable while applying a pressing force inside the cap unlike the conventional inner cap, the number of parts is reduced and the assembly is simplified. It's easy. Therefore, it is possible to maintain good quality at low cost.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a writing instrument of the present invention.

FIG. 2 is a partial cross-sectional view of the tip of the writing instrument main body with the cap of FIG. 1 removed.

FIG. 3 is a partial cross-sectional view of the cap with the writing instrument main body of FIG. 1 removed.

FIG. 4 is a sectional view taken along the line AA in FIG. 2;

FIG. 5 is a view taken in the direction of arrow B in FIG. 3;

FIG. 6 is a reference diagram showing that the end face of the seal cylinder has begun to be fitted halfway through the opening of the air groove.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Shaft cylinder 2 Ink chamber 3 Peripheral groove 4 Vertical groove 5 Ink storage body 6 Vertical hole 7 Ink guide core 8 Middle core 9 Pen tip 10 Cap 11 Flange 12 Air groove 13 Cap 14 System projection 15 Convex part 16 Rib 17 Contact step 18 Locking step 19 Seal cylinder 20 Flange 21 End face 22 Inner opening edge 23 Conical surface 24 Opening 25 End

Claims (1)

[Claims] An ink direct storage type writing instrument having a tank for directly storing ink at a rear portion of a shaft cylinder and an ink storage body at a front portion of the shaft cylinder, wherein a cap for attaching a cap to a shaft is provided. The inside opening edge of the cup-shaped seal cylinder made of elastic resin or rubber mounted inside is fitted from the middle of the opening of the air groove in the conical surface at the tip of the ink reservoir, and the cap is attached. When writing is completed, the end of the base comes into contact with and presses against the end face of the sealing cylinder to seal the air groove and the nib.