Abstract: Provided is a valve type writing instrument, eliminating the need for frequently making a core pushing-in operation, thus being long-lasting, and causing no blurring of a written character. The valve type writing instrument includes an ink tank barrel; a valve housing cylinder, fitted into the ink tank barrel; and a core, slidably held in the valve housing cylinder, in which an ink reservoir member, reservoiring ink, and a valve unit case, incorporating a valve mechanism are loaded. The ink reservoir member has a truncated cone shape, a core insertion hole being formed so as to be penetrated through the central portion thereof, one half part of core being slidably housed therein, a number of slits for reservoiring ink being radially formed from the core insertion hole, and ink reservoired in the slits being capable of permeating into the housed portion of core in the core insertion hole as needed.

Abstract: Provided is a valve type writing instrument, eliminating the need for frequently making a core pushing-in operation, thus being long-lasting, and causing no blurring of a written character. The valve type writing instrument includes an ink tank barrel; a valve housing cylinder, fitted into the ink tank barrel; and a core, slidably held in the valve housing cylinder, in which an ink reservoir member, reservoiring ink, and a valve unit case, incorporating a valve mechanism are loaded. The ink reservoir member has a truncated cone shape, a core insertion hole being formed so as to be penetrated through the central portion thereof, one half part of core being slidably housed therein, a number of slits for reservoiring ink being radially formed from the core insertion hole, and ink reservoired in the slits being capable of permeating into the housed portion of core in the core insertion hole as needed.

Abstract: Problem to be Solved To provide a writing instrument and a method for disposing of a sealing means in the writing instrument that allow automatically and efficiently assembling a means for sealing between a barrel and the in-barrel fitting part of a core holder or that of a tail plug with no need for manpower, whereby being capable of substantially improving the efficiency of assembling the writing instrument. Solution A writing instrument, including a core holder 3 and a tail plug 11, or core holders 3, that are fitted to a barrel 1 through a sealing means, the barrel incorporating a cotton pad or an ink reservoir, the sealing means being a ring-like seal 8, 13 that is formed by the secondary molding onto the in-barrel fitting part 7, 12 of the core holder 3 and the tail plug 11 that have been primarily molded in the molding operation by the double molding method.