Kabushiki Kaisha Pilot Corporation

Minoru Machida

Michiaki Kuramoto

Norio Moriyama

Kazuhiko Sasaki

A ballpoint pen refill has an ink-accommodating tube (,) containing an ink (,) having a thixotropic property and a greaselike ink follower (,) capable of moving together with the ink (,) as the ink (,) is consumed so as to be contiguous with the rear end of the ink (,) to prevent the reverse flow of the ink (,). The ink-accommodating tube (,) has a small diameter portion (,) formed at a front side and a large diameter portion (,) having a diameter greater than the diameter of the small diameter portion (,) and extending rearward from the small diameter portion (,). A ballpoint pen tip (,) rotatably holding a ball (,) is inserted in the small diameter portion (,) of the ink-accommodating tube (,). A regulating member (,5) has a column (,) which is press-fitted in the small diameter portion (,). The column (,) of the regulating member (,) has an inclined end surface (,) at its front end inclined at a predetermined angle to a plane perpendicular to the axis (O) of the ink-accommodating tube (,). The regulating member (,) is provided in its side surface (,) of the column (,) with a fluid passage (,) extending rearward from the rear end of the inclined end surface (,) to enable the ink and air to flow therethrough in the ink-accommodating tube (,).

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Isesaki, Japan

Minoru Machida