| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent frequent collision of a ball against a holder due to lead and delay without causing reduction of rigidity of a column part of the holder and an insufficient connection space in a connection part. <P>SOLUTION: A shape of a pocket 5a of the holder 5 is an elliptic shape provided with a clearance δ in the direction of rotation between the ball 4 and it, and this clearance δ in the direction of rotation is 4 to 10% of diameter D of the ball 4, preferably, 6 to 10% to prevent frequent collision of the ball 4 against the holder 5 due to lead and delay without causing reduction of rigidity of the column part of the holder. <P>COPYRIGHT: (C)2007,JPO&INPIT |
