Writing instrument
AssigneeMitsubishi Pencil Company, Limited
InventorTakao Koyama
Life of this patent
Estimating the term…
Abstract
In a writing instrument in which an ink for a writing instrument such as a water-based ink and an oil-based ink impregnated into an ink occlusion body in a barrel is fed to a pen tip in a writing part, in order to provide a writing instrument in which a sign of exhausting the ink can readily and surely be detected, the above writing instrument is provided with a structure in which the ink impregnated into the ink occlusion body in the barrel is fed to the pen tip in the writing part, wherein the ink impregnated into the ink occlusion body described above is fed to the pen tip via an ink guiding feed having visibility, and a sign of exhausting the ink fed from the ink occlusion body is detected by visually observing the ink guiding feed described above via a visible part formed in the barrel.
Claims42
1-20. (canceled)
A writing instrument comprising:
- an ink occlusion body disposed in a barrel, the ink occlusion body including a capillary material impregnated with ink;
- a pen tip including a capillary material disposed in a writing part of the writing instrument, wherein the ink impregnated in the ink occlusion body is fed to the pen tip via an ink guiding feed;
- wherein ink flows from the capillary material of said occlusion body by virtue of capillary force and ink flows into the capillary material of said pen tip by virtue of capillary force, said ink guiding feed lacking any capillary material therewithin;
- wherein said ink guiding feed is tubular and has a cross-sectional area of 0.5 to 20 mm2 such that it does not have capillary force and said ink guiding feed is disposed within the barrel between the ink occlusion body and the pen tip so as to prevent outside air from flowing in when the ink occlusion body is impregnated with ink, and allowing outside air to flow into the barrel as ink in the ink occlusion body is depleted;
- and
- wherein said ink guiding feed has visibility such that a sign of exhausting the ink fed from the ink occlusion body to the pen tip is detected by visually observing the empty ink guiding feed via a visible part formed in the barrel.
A writing instrument of a twin type in which an ink impregnated into an ink occlusion body in a barrel is fed to respective pen tips in writing parts disposed at both sides of the barrel, wherein the ink fed to either of the pen tips is fed to the pen tip via an ink guiding feed having visibility, and a sign of exhausting the ink fed from the ink occlusion body is detected by visually observing the ink guiding feed described above via a visible part formed in the barrel.
A writing instrument comprising:
- a barrel having a visible portion;
- an ink occlusion body disposed in the barrel;
- a writing part including a pen tip;
- and
- an ink guiding feed defined by a hollow tubular body without any capillary material within the hollow tubular body and lacking capillary force therethrough, and formed of a transparent or translucent material disposed between the ink occlusion body and the pen tip in the barrel;
- wherein ink impregnated in the ink occlusion body is fed to the pen tip under capillary force via the ink guiding feed, and a sign of exhausting the ink fed from the ink occlusion body is detected by visually observing an empty tubular body of the ink guiding feed through the visible portion of the barrel.
Dependencies are inferred from the claim text.