| 摘要 |
<P>PROBLEM TO BE SOLVED: To certainly perform the operation of an operation assist mechanism for a long period of time by enhancing the engagement durability of a cylindrical member and a cylindrical member retaining member. <P>SOLUTION: An inner edge of a linear engagement part 35b is positioned at a border of an engagement surface 33h<SB>1</SB>and a front end surface 33i<SB>1</SB>of a retaining member intrusion recess 33i, and the linear engagement part 35b is not intruded into the retaining member intrusion recess 33i. When an abrasion surface β is formed on the inner edge of the linear engagement part 35b by repeating BA operation for a long period of time, the linear engagement part 35b is moved in a contraction/closure direction e according to an abrasion amount of the abrasion surface β of the inner edge and is intruded into the retaining member intrusion recess 33i. Thereby, the abrasion surfaces α, β are formed, an engagement margin γ of the engagement surface 33h<SB>1</SB>of the engagement part 33h and a front surface 35b<SB>1</SB>of the linear engagement part 35b is secured. Accordingly, the engagement durability of the cylindrical member retaining member 35 and the cylindrical member 33 for BA is enhanced. <P>COPYRIGHT: (C)2009,JPO&INPIT |
