Rock drill with sleeve on shank - has open forward end and connected to transverse passage at rear

摘要

The rock drill has a shank with a head at one end having a centring point and two or more radial ribs with cutting edges, and an open passage running from between the ribs towards the rear end. A sleeve (8) is mounted coaxially on the shank (2), its open forward end extending to near the head (4). Its closed rear end (9) joins onto one or more transverse passages (10) open to the outside of the sleeve. The outside diameter of the latter can be less or equal to that of the head, and it can be funnel-shaped at the head end. There can be an annular rib (12) on the inside of the sleeve at the rear end, acting as a seal against the shank, and pref. working against a shoulder formed on the latter.