| 摘要 |
PURPOSE: To effectively and quickly grind a button by obliquely extending a finger to engage with the grinding button to the inside on both side of a disc when the grinding disc is engaged with the button. CONSTITUTION: When engaging a button 6 ground together with the positive spring action of a finger 24 with a grinding disc 4, the finger 24 bends inside or outside as much as possible. As a result, the finger 24 successively/sufficiently/automatically straightens, and also returns to a former position. Therefore, when the grinding disc 4 is held so as to be joined to the button 6, the finger 24 is always held so as to be elastically joined to the end surface 27 of a drill bit 5, so that a grip is always maintained around the button 6 in the vicinity of the base part to thereby effectively and quickly grind the button 6. |
