| 摘要 |
PURPOSE: To provide a suction device, simplify the construction and avoid damage to the aperture area of a drilled hole and the drilling device. CONSTITUTION: A depth stopper is provided with a resilient and ring-shaped cushioning element 10, the cushioning element is supported by a bearing washer 11 and connected to a suction bell 12. The bearing washer 11 has a convexly curved sliding face, and the sliding face abuts on a concavely curved end face of a collar 3 formed on a drill shank 2. |
