Background Art Generally, writing instruments are divided into a ball type writing instrument and an ink retainer type writing instrument. In the ball type writing instrument, a ball is provided to a distal, that is, lower end of the writing instrument, and, by revolution of the ball, ink is fed to enable note-taking. In the ink retainer type writing instrument, ink stored in a cylindrical ink storage member is fed to a writing tip. An ink retaining substance such as a sponge, and the like, is inserted in the cylindrical ink storage member. A predetermined amount of ink is retained by the ink retaining substance. Retained ink is continuously fed to the writing tip by a capillary phenomenon.

A typical example of the ink retainer type writing instrument as disclosed in U. S. Patent No. 6,322, 269 will be described hereinafter with reference to FIG. 1.

FIG. 1 is a cross-sectional view illustrating component elements associated with ink-feeding in the conventional writing instrument. Referring to FIG. 1, the writing instrument includes a body 10 which defines an ink accommodating chamber 15. Ink 14 is filled in the ink accommodating chamber 15. The writing instrument further includes an ink feeding tube 12 and an ink storage member 13.

One end of the ink feeding tube 12 extends into the ink accommodating chamber 15, and the other end of the ink feeding tube 12 is connected with a writing tip 11. The ink storage member 13 stores ink to be delivered into the ink feeding tube 12.

The ink storage member 13 serves as a buffer. The ink storage member 13 has a cylindrical configuration and is fitted around the ink feeding tube 12. As described above, ink stored in the ink storage member 13 is delivered into the ink feeding tube 12. That is to say, due to the fact that the ink feeding tube 12 is

surrounded by the ink storage member 13, ink stored in the inlc storage member 13 is fed to the writing tip 11 tluough the medium of the ink feeding tube 12.

However, the conventional ink retainer type writing instrument constructed as mentioned above suffers from defects in that, since the ink feeding tube 12 and the ink storage member 13 should be formed separately from each other, the manufacturing procedure is complicated. Also, ink stored in the ink storage member 13 is likely to be unevenly distributed by external impact. Further, while a length and a diameter of the ink storage member 13 must be enlarged to increase the amount of ink stored in the ink storage member 13, design limitations cannot but be imposed due to a size, a shape, and a function of a writing instrument.

Accordingly, the present invention has been made in an effort to solve the problems occurring in the related art, and an object of the present invention is to provide a writing instrument in which an ink storage member and an ink feeding tube are integrated with each other to feed a constant amount of ink.

Disclosure of the Invention In order to achieve the above object, according to the present invention, there is provided a writing instrument capable of feeding constant amount of ink comprising a body, an ink accommodating chamber defined in the body, an ink feeding tube whose upper end extends into the ink accommodating chamber, a writing tip connected with a lower end of the ink feeding tube to be brought into contacting with a writing surface, and an ink storage/adjustment member positioned in the inlc feeding tube to store ink transferred from the ink accommodating chamber and to adjust ink flow.

Brief Description of the Drawings The above objects, and other features and advantages of the present invention will become more apparent after reading the following detailed description when taken in conjunction with the drawings, in which: FIG. 1 is a cross-sectional view illustrating component elements associated with ink-feeding in the conventional writing instrument; FIG. 2 is a cross-sectional view illustrating component elements associated with ink-feeding in a writing instrument in accordance with a first embodiment of

the present invention; and FIG. 3 is a cross-sectional view illustrating component elements associated with ink-feeding in a writing instrument in accordance with a second embodiment of the present invention.

Best Mode for Carrying Out the Invention Reference will now be made in greater detail to a preferred embodiment of the invention, an example of which is illustrated in the accompanying drawings.

Wherever possible, the same reference numerals will be used throughout the drawings and the description to refer to the same or like parts.

FIG. 2 is a cross-sectional view illustrating component elements associated with ink-feeding in a writing instrument in accordance with a first embodiment of the present invention.

Referring to FIG. 2, the writing instrument according to this first embodiment of the present invention includes a body 20 which defines an ink accommodating chamber 15. Ink 14 is filled in the ink accommodating chamber 15. The writing instrument further includes an ink feeding tube 21. An upper end of the ink feeding tube 21 extends into the ink accommodating chamber 15, and a lower end of the ink feeding tube 21 is connected with a writing tip 11. The ink feeding tube 21 is defined with a vent hole 24 at the upper end thereof. Adjacent to the upper end, the ink feeding tube 21 is defined with a hole 23. An ink storage/adjustment member 22 is positioned in the ink feeding tube 21 to store ink transferred from the ink accommodating chamber 15 and adjust ink flow. The ink storage/adjustment member 22 is formed of an ink retaining substance. As shown in FIG. 2, the ink feeding tube 21 in which the ink storage/adjustment member 22 is positioned is bent twice each by 180° in a manner such that the upper end thereof vertically extends upward. The ink feeding tube 21 is configured to feed ink to the writing tip 11.

As can be readily seen from FIG. 2 and above description, the ink feeding tube 21 which extends into the ink accommodating chamber 15 is defined, adjacent to the vent hole 24, with the hole 23. The hole 23 is defined to ensure reliable ink transmission even when an ink surface is positioned lower than the vent hole 24. At this time, it is to be noted that a plurality of holes 23 can be defined in the ink feeding tube 21. When the vent hole 24 is not so much high, the hole 23 may not

be defined in the ink feeding tube 21. Due to the fact that the ink feeding tube 21 in which the ink storage/adjustment member 22 is positioned is bent twice each by 180°, in such a way as to allow the upper end thereof to extend vertically upward, a constant amount of ink can be fed to the writing tip 11. Consequently, note-taking is enabled while a constant ink flow is maintained.

FIG. 3 is a cross-sectional view illustrating component elements associated with ink-feeding in a writing instrument in accordance with a second embodiment of the present invention.

Referring to FIG. 3, the writing instrument according to this second embodiment of the present invention includes a body 30. The body 30 is defined at an upper end thereof with a vent passage A which communicates an ink accommodating chamber 15 with the outside. The vent passage A is defined in such a way as to have a zigzagged pattern, and an ink leakage preventing member 31 is disposed in the course of the vent passage A. The ink leakage preventing member 31 functions to allow air bubbles produced in the ink accommodating chamber 15 to be discharged to the outside and prevent outflow of ink. Here, the ink leakage preventing member 31 is made of Gore-Tex.

An upper end of an ink feeding tube 21 extends into the ink accommodating chamber 15 to feed ink to a writing tip 11. An ink storage/adjustment member 22 is positioned in the inlc feeding tube 21 to store ink transferred from the ink accommodating chamber 15 and adjust ink flow. The ink storage/adjustment member 22 is formed of an ink retaining substance. As best shown in FIG. 3, the ink feeding tube 21 in which the ink storage/adjustment member 22 is positioned has a shape of a spring and is configured to feed ink to the writing tip 11. Therefore, due to the fact that the ink feeding tube 21 has the shape of a spring and the ink storage/adjustment member 22 is positioned in the ink feeding tube 21, it is possible to feed a constant amount of ink to the writing tip 11.

The ink feeding tube 21 is fastened at both upper and lower ends thereof by fastening members 32, respectively, to prevent fluctuation. While two fastening members 32 are respectively provided at both upper and lower ends of the ink feeding tube 21, it can be envisaged that only one fastening member 32 is provided to the lower end of the ink feeding tube 21.

In the case that the ink feeding tube 21 is too long, capillarity is degraded, and in the case that the ink feeding tube 21 is too short, ink storage capacity is lowered. Therefore, a person skilled in the art will readily recognize that a length

of the ink feeding tube 21 should be determined so as to obtain appropriate capillarity and ink storage capacity.

Industrial Applicability As apparent from the above description, the writing instrument according to the present invention provides advantages in that, since the ink storage member and the ink feeding tube are integrated with each other, the manufacturing procedures is simplified, and impact resistance is rendered. Further, through modification of the shape of the ink feeding tube, a constant amount of ink can be fed to the writing tip.