Writing tool provided with refill
AssigneeMitsubishi Pencil Company, Limited
InventorsTakayuki Ikai, Seiichi Maruyama, Kiyoshi Iwamoto
Life of this patent
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Abstract
A writing tool includes a refill having an ink reservoir tube formed to be a straight cylinder whose wall thickness is less than 0.56 mm; and a writing tip or a relay member holding the writing tip attached to a first end of the ink reservoir tube, wherein the refill is detachably attached to a barrel, wherein in the refill, amounting strength between the writing tip or the relay member holding the writing tip and the ink reservoir tube is set higher than a mounting strength between the barrel and a connecting portion of the ink reservoir tube. There is provided a writing tool that can prevent the occurrence of a problem such as leakage of ink at a time of replacement of refills and perform replacement of refills smoothly.
Claims1
A writing tool, comprising:
- a refill, comprising:
- an ink reservoir tube having a straight cylinder shape whose wall thickness is less than 0.56 mm;
- a first connection portion at which a writing tip or a relay member holding the writing tip attached to a first end of the ink reservoir tube;
- a barrel;
- a second connecting portion at which the refill is detachably attached to the barrel;
- a cylinder formed in the writing tip or the relay member and the cylinder to which a front end portion of the ink reservoir tube is inserted;
- a garter spring housed in a bottom portion of the cylinder and pressure-fitted to the tip portion of the ink reservoir tube;
- and
- a pressing ring housed in the cylinder to position the garter spring at the bottom portion of the cylinder, wherein
- the ink reservoir tube is joined to the writing tip or the relay member by the garter spring, and
- a mounting strength of the refill between the writing tip or the relay member holding the writing tip and the ink reservoir tube is set higher than a mounting strength between the barrel and the second connecting portion of the ink reservoir tube.
Dependencies are inferred from the claim text.