| 摘要 |
PURPOSE: To obtain the rock drill having a helically extending conveying groove for surely guiding a rock drill in a drill hole during the drilling work and causing only slight friction between the drill hole and an inner wall of the drill hole. CONSTITUTION: A rock drill includes a drill head 1, a shank 2 and a chuck end 3 located at an opposite position to the drill head 1. The shank 2 includes at least one helically extending conveying groove 4 and 5. Grooves 8 and 9 extending perpendicularly to the shank axis are formed in the top surface 6 and 7 of the helically extending conveying groove 4 and 5. |
