| 摘要 |
A safety arrangement which pertains to drill bits for reamer drilling and which is intended to prevent the drill bit from falling freely down the hole in the event of a breakage in an element that connects the drill bit with an overlying rotatable carrier element, the element forming part of a drill string that carries the drill bit, wherein the element includes a longitudinal hole that extends internally along at least a part of the length of the element, and the hole has disposed therein a safety device which functions to capture the element and therewith also the drill bit should the element break, the capture being achieved by virtue of the safety device being connected to a threaded part of the overlying element and also to a part of the element located at a distance from the threaded part of the element. |
