Mitsubishi Pencil Kabushiki Kaisha

Yosuke Mito

Kazuhiko Furukawa

Takeshi Kobayashi

Seiichi Kobayashi

Yusuke Kobayashi

Hiroaki Koyama

Kazuaki Matsumoto

Yojiro Sano

Hisashi Iida

Shigeru Okumura

A writing implement includes a cylindrical shaft member, a pen tip member which is fixed to one end of the shaft member and from which colored ink seeps out, liquid for ink which is stored in the shaft member and which comprises a major component of the colored ink seeping out from an end of the pen tip member, colorant to be added to the liquid for ink, and a valve member for isolating the colorant from the liquid for ink. In the writing implement, at least a part of a cylindrical side surface of the shaft member corresponding to a part where the liquid for ink is stored is formed to be transparent, the valve member is positioned between the storing part of the liquid for ink and the colorant, and the storing part of the liquid for ink is provided with a pressure-regulating part.

Writing implement

A direct-feed type writing implement having two ends includes an ink tank and a pair of writing points, arranged at opposite ends of the ink tank. An ink collector is provided for each writing point. An air/liquid exchanger adjusts the internal pressure inside the ink tank by use of capillarity. An ink feeder is provided for each writing point. Each ink feeder includes a center core for feeding ink to the writing point. Air is inhibited from flowing into the ink tank through the ink collector air/liquid exchanger located at one end while the pen is being used for writing at the opposite end.

Double ended direct-feed type writing implement

A direct-feed type writing implement includes: a point assembly having a writing point at the tip thereof; an ink tank directly storing a relatively low viscosity ink having a viscosity of 2 to 100 mPa&middot;S at room temperature; an ink collector for adjusting the internal pressure in the ink tank by utilizing capillarity; a feeder including a center core, for feeding ink from the ink tank to the writing point; a duct pipe connecting the ink collector and the ink tank; and a duct pipe ink storage portion provided for the duct pipe. In another embodiment, ink is supplied to the center core as the ink feeder only through the duct pipe.

Direct-feed type writing implement

A direct-feed type writing implement includes: a point assembly having a writing point at the tip thereof; an ink tank directly storing a relatively low viscosity ink having a viscosity of 2 to 100 mPa.S at room temperature; an ink collector made up of a multiple number of vanes for adjusting the internal pressure of the ink tank by utilizing capillarity; a feeder including a center core, for feeding ink from the ink tank to the writing point; an ink absorber connected to the center core as the ink feeder; and a duct pipe connecting the ink collector and the ink tank; and preferably, ink is supplied to the center core as the ink feeder only through the ink absorber and the duct pipe.

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Yokohama, Japan

Yosuke Mito