| 摘要 |
FIELD: mining. ^ SUBSTANCE: drilling bit includes bit blank with slots on the end, in each of them there installed is a group of carbide-cutting tools including main cutting tools, well-forming and core-forming cutting tools. Cutting tools of each group are bow-shaped in vertical and horizontal planes. Cutting tools of one group are faced with their convex surface to well axis and cutting tools of the other group - to well walls, at that main cutting tools of one group are installed covering gaps between main cutting tools of neighbouring group. ^ EFFECT: improving drilling bit operating efficiency. ^ 2 cl, 2 dwg |
