| 摘要 |
PROBLEM TO BE SOLVED: To immediately confirm the residual amount of a liquid-like ink on the inner wall surface 7 of a writing instrument body 1 by clearly and instantly moving the ink without retaining the ink on the surface 7 by smoothly moving the ink contained in the body 1 by means of a capillarity by a protrusion 8 provided on the surface 7 of the body 1. SOLUTION: The writing instrument body comprises the liquid-like ink retained as a liquid therein and held replaceably with an air by a valve mechanism or a pectinated transfer element or a transfer member for replacing the ink with the air, and a nib or the like at its end. The body also comprises a protrusion axially parallel to the overall surface of the inner wall of the body and continuously provided circumferentially to the perpendicular direction to the axis in such a manner that the number of the protrusion is 5 or more and the angle θ of the protrusion is 0<=θ<=160 deg.. The sectional circumferential shape of the protrusion is a sawtooth shape. |
