| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a ball-point pen tip which shows no qualitative dispersion due to its working and a high wear resistance in a ball seat with which a ball comes into contact and further, a smooth ball rotation. <P>SOLUTION: This ball-point pen tip is of such a structure that a ball with a diameter of less than ϕ0.65 mm is embraced, in a freely rotatable manner, by caulking the apex edge of a tip body inward, inside a ball housing chamber of the tip body and a ball seat which is obtained by hammering the ball from the apex side of a tip and receives the ball, is formed on an internal bottom wall with radial grooves extending radially, communicating with an ink circulating hole with a diameter equal to a ball diameter. The tip body is manufactured of a stainless steel wire rod with a Vickers hardness of 300 to 320 Hv in the cross section of the stainless steel wire rod. In addition, the bottom wall which forms the ball seat is tilted 90 to 110° and the ball surface area of the ball seat is set to be 10 to 20% of the ball surface area. <P>COPYRIGHT: (C)2003,JPO |
