JPH10203080A - 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 not required. SOLUTION: When the end of a seal cylinder 17 having a good 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 part of an air channel 10, first the end of a tip 8 is sealed by the bottom of a seal cylinder 18, and then an inner opening edge 20 of the seal cylinder 17 is fitted from the middle of a conical section 21 of an ink storage body 5 or a conical section 21 of a tip supporting body to cover an opening of the seal cylinder 17 while the opening is pressed and expanded in the radius direction, and when the end face of the seal cylinder 17 is brought into contact with the end of the mouthpiece 9 and the covering of the cap 11 is completed, the end face of the seal cylinder 17 is brought into contact with the end of the mouthpiece 9 all over the whole periphery.

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 pressure is depressurized. Since the pressure is the same as before, the ink does not flow out from the pen tip or air hole when the cap is attached or detached. 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 in the inside is compressed, and as much as that, the air enters the ink tank through the ink reservoir through the ink reservoir as air bubbles. Then, the ink is pushed out of the ink chamber by that amount and stored in the ink storage body. Conversely, if the cap is removed 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 stored in the ink storage body. Or pull ink out of the pen tip. In this way, the ink is stored in the ink storage body every time the cap is attached or detached, and finally the ink exceeds the storage capacity, causing the ink to flow out of the air hole or the pen tip to leak out. 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 and presses the opening edge against the conical surface of the mouthpiece barrel of the writing instrument barrel to make it tight, so the structure becomes complicated, the number of parts increases, and the assembly cost increases because of the increase in product unit price and the complexity of assembly. It is also a factor in rising costs. 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. When attaching to the cylinder, the above-mentioned problem is solved by the opening end of the base attached to the shaft cylinder opening being in close contact with the opening end face of the seal cylinder and sealing the tip including the air groove on the shaft side. Things.

[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.
A vertical hole 6 penetrating in the axial direction is formed at the center of the ink storage body 5, an ink guide core 7 is inserted through the vertical hole 6, and a tip of the ink guide core 7 is The ink is supplied from the ink chamber 2 to the chip 8 through the ink guide core 7.

Next, the cap 11 has an engagement projection 12 formed on the inner surface near the opening edge for engaging with the projection 13 of the barrel 1 so as to engage with the projection 13 of the barrel 1 and to open the cap 11 at the opening end. The portion comes into contact with a step portion 15 provided in the middle of the barrel 1 and is attached to the barrel 1 at a fixed position. Further, a locking step 16 is formed on the rib 14 of the cap 11, and a flange 18 of a sealing cylinder 17 made of rubber or the like having a high elasticity is applied to the locking step 16 and fitted into the rib 14. It is locked in a fixed position in the cap 11. Here, when the cap 11 is attached, the tip end of the chip 8 is brought into close contact with the bottom of the cup-shaped sealing cylinder 17 made of rubber or the like having a high elasticity to seal the ink outlet portion of the chip 8. ,
When the inner opening edge 20 of the seal cylinder 17 is fitted in the middle of the conical surface 21 at the front end of the ink reservoir 5 and the attachment of the cap 11 is completed, the end face 1 of the seal cylinder 17 is attached to the end 22 of the base 9.
9 is pressed against and brought into close contact, and the inner opening edge 20 of the seal cylinder 17 is already in close contact with the conical portion 21 of the ink reservoir 5, so that the opening 23 of the air groove 10 is closed.

Here, the opening edge 20 of the seal cylinder 17 is fitted from the middle of the conical surface 21 of the ink reservoir 5, and the seal cylinder 17 is adhered while expanding the opening of the seal cylinder 17 in the radial direction. This is because even when the axis of the seal cylinder 17 and the axis of the cylinder 1, that is, the axis of the base 9 are misaligned, the opening of the seal cylinder 17 is deformed upon completion of the attachment of the cap, so that the end face 19 of the seal cylinder 17 can be securely connected The end 23 of the base 9 and the conical surface 21 of the storage body 5 and the inner opening edge 20 of the seal cylinder 17 are in close contact with each other over the entire circumference. The tip of the tip is brought into close contact with the bottom of the sealing cylinder 17 to seal the ink outflow portion of the tip 8 before the fitting is performed from the middle of the conical surface 21 of the body 5 because the inner opening edge 20 of the sealing cylinder 17 is reserved. The fitting of the cap 11 from the middle of the conical portion 21 of the body 5 Although the inside of the seal cylinder 17 is slightly pressurized before completion, even if the pressurization is performed, air flows in from the ink outflow portion at the tip of the tip 8 so as to prevent the outflow of ink and to prevent inconvenience in writing. It is.

Further, when the open end of the cap 11 comes into contact with the step of the barrel 1 and the attachment of the cap 11 is completed, the base 9 is closed.
Is inserted into the end face 19 of the sealing cylinder 17 by about 0.05 to 0.5 mm, and the end 23 of the base 9 and the sealing cylinder 1
7, the opening 23 of the air groove 10 is sealed, but the pressure of the end surface 19 of the sealing cylinder 17 into the air groove 10 is very small, so that the pressure rise in the air groove 10 is also small. Then, since air enters the ink chamber 2 and the amount of ink stored in the storage body 5 by the air is small, the ink in the storage body 5 is consumed by writing and the ink in the ink chamber 2 is consumed. And there is no problem in actual use.

FIG. 4 shows another embodiment in which the tip of a ball-point pen is attached to the ink reservoir 25 via a chip support 28. In this embodiment, the inner opening edge of the seal cylinder 34 is shown. Reference numeral 35 is fitted from the middle of the conical surface 36 of the chip support 28.

[0011]

In the writing instrument constructed as described above, when the cap 11 is attached to the writing instrument body, a cup-shaped sealing cylinder 17 made of rubber or the like having a high elasticity firstly has a tip 8 on its bottom.
Of the chip 8 to seal the ink outlet portion of the chip 8, and then the inner opening edge 20 of the seal cylinder 17 is
When the attachment of the cap 11 is completed by fitting from the middle of the conical surface 21 at the end of the seal cylinder 17, the end face 19 of the seal cylinder 17 abuts against and presses against the end 22 of the base 9, and the inner opening of the seal cylinder 17. Since the edge 20 is already in close contact with the conical portion 21 of the ink reservoir 5, the opening 23 of the air groove 10 is closed. Therefore, even if the inside of the seal cylinder 17 is slightly pressurized, air does not enter from the ink outflow portion of the chip 8 and even if the axis of the seal cylinder 17 and the axis of the base 9 are misaligned.
The inner opening edge portion 19 is fitted into the conical surface 21 while deforming, and adheres over the entire circumference when the cap 11 is completely attached, and the end portion 22 of the base 9 and the end surface 19 of the seal cylinder 17 also cover the entire circumference. The opening 23 of the air groove 10 is also securely closed to ensure close contact. In addition, the ink holding body 5
By extending the writing portion so as to be able to hold the writing portion, it is possible to reduce the number of components and to easily secure the air groove 10.

[0012]

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 middle 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 another embodiment of the present invention.

FIG. 5 is a reference diagram showing a state in which the tip of a ballpoint pen tip is in contact with and in close contact with the bottom of the seal cylinder.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Shaft cylinder 2 Ink chamber 3 Peripheral groove 4 Vertical groove 5 Ink reservoir 6 Vertical hole 7 Ink guide core 8 Tip 9 Cap 10 Air groove 11 Cap 12 System projection 13 Convex part 14 Rib 15 Contact step part 16 Lock Step 17 Seal cylinder 18 Flange 19 End surface 20 Inner opening edge 21 Conical surface 22 End 23 Opening 24 Shaft cylinder 25 Ink storage body 26 Base 27 Air groove 28 Chip support 29 Ink guide core 30 Relay core 31 Chip 32 Cap 33 Rib 34 Seal cylinder 35 Inner opening edge 36 Conical surface

Claims (1)

[Claims] 1. An ink direct storage type water-based ballpoint pen having a tank for directly storing ink at a rear portion of a barrel and an ink reservoir at a front portion of the barrel, when a cap is attached to a shaft. First, the tip of the tip of the ballpoint pen is brought into close contact with the cup-shaped bottom made of elastic resin or rubber mounted inside the cap to seal the ink outflow portion of the tip, and then the inner opening edge of the seal cylinder is closed. When the fitting of the cap is completed by fitting from the middle of the conical surface of the tip portion of the ink reservoir or the conical surface of the chip support, the end of the cap comes into contact with and presses against the end surface of the seal cylinder, and the air groove is formed. Writing instrument cap that seals the opening and pen tip.