| 摘要 |
Drill head 1 comprising a drill casing 2 which is provided with a hollow inner chamber and at one end is provided with one or more drilling teeth 3 and at the other end is provided with a connection piece 6 for connecting the drill head to a drilling installation, and means for discharging chippings and dust which are produced during use, at least comprising one helical groove 10 arranged on the outer circumference of the drill casing 2; furthermore, one or more slots 8 may be made in the drill casing 2, for the purpose of discharging chippings and/or dust which accumulate inside the drill casing 2. <IMAGE>
|
