| 摘要 |
PROBLEM TO BE SOLVED: To prevent a rod part from getting into the peripheral edge end part of an ink outflow gap in assembling. SOLUTION: An inward fore end edge part 21 is provided in the fore end of a tip main body 2 made of metal. A plurality of inward projecting parts 22 are provided inside the tip main body 2 in the rear of the fore end edge part 21 by inward pressing deformation. A ball 3 is held rotatably between the fore end edge part 21 and the inward projecting parts 22. The ink outflow gap 4 extending outward diametrically and radially from the central part is formed among the inward projecting parts 22. The rod part 51 urging the ball 3 forward and bringing it into close contact with the inner surface of the front end edge part 21 is inserted through the ink outflow gap 4. The diameter of an imaginary inscribed circle of the central part of the ink outflow gap 4 is set to be larger than the outside diameter of the rod part 51. The minimum dimension of the ink outflow gap 4 is set to be smaller than the outside diameter of the rod part 51. |
