| 摘要 |
PURPOSE:To keep an ink flow ideal in writing or in storage by a method wherein an inward protruding part is formed at an opening of a radial hole opened to an ink fountain so as to extend toward the ink fountain. CONSTITUTION:An ink flow path 4 for supplying ink to a ball chamber 2 is made up of a center hole 4a and a radial hole 4b. The center hole 4a is opened to an ink fountain 5 and a ball receiving seat of the ball chamber 2 to allow ink to relatively freely flow. An inward protruding part 6 is formed at an opening of the radial hole 4b opened to the ink fountain 5 so as to extend toward the ink fountain 5. When the radial hole 4b is machined, a cut and released piece is not completely separate from an inner ballpoint pen chip but remains between the radial hole 4b and the ink fountain 5 as the inward protruding part 6. A part of the opening of the radial hole 4b open to the ink reservoir 5 is covered with the inward protruding part 6. In this manner, with the use of pigment ink, the radial hole 4b is prevented from being clogged with sediment, such as of the pigment, to the utmost. |
