| 摘要 |
<p>The drilling head is for drilling holes for insertion of explosive charges for mining operations and has a cylindrical body (20) with recesses at the top, holding tungsten carbide cutting inserts (14). Each insert, which can have a rectangular body with a roof shaped tip (15) is secured by a resin, without being held in by e.g. a compressive force. A set of e.g. four inserts may be used, equally spaced to form a cross, and the cutting surface formed by the four tips is formed by the end of the cylindrical body. There are channels (17) between the inserts which communicate with the hollow interior of the head.</p> |
