| 摘要 |
In a tip for a ball point pen including a cylindrical metallic tip body having a pointed end, a ball receiving hole having its opening at the pointed end of the tip body, a ball supporting seat of a plastic held in the bottom of the ball receiving hole, a bore for delivering ink to the ball receiving hole through the ball supporting seat and having its opening at the end of the tip body opposite to the pointed end, and a ball rotatably received within the ball receiving hole and supported on the seat, there is provided an improvement constituted by a recess formed in the bottom surface of the ball receiving hole, the recess having at least one angular portion, the ball supporting seat being deformed to fill all the corners of the bottom of the hole including the recess, thereby preventing the ball supporting seat from rotating in the bottom surface of the ball receiving hole. Further, by forming at least one protrusion in the vicinity of the upper edge around the recess, the rotation and the axial movement of the ball supporting seat can be prevented. There is also provided a method of making such an improved tip for a ball point pen. |
