| 摘要 |
FIELD: mining. ^ SUBSTANCE: invention refers to rock destructing tools and can be implemented as boring tool for driving of wells of various purposes in coal layers. The bore bit contains a holder with replaceable cutters in form of a round bar with several conic projections. One end of the holder has a threaded hole for connection with the boring rod. An advancing cutter-starter is adjusted to the other conic end. At that each of the conic projections of the holder is equipped with conic nests and reaming cutters installed into the latter at amount of not less, than three around the circumferential line of cutting. In the interval between coupled teeth on the projection of the holder there are cut chip path-through grooves. ^ EFFECT: simplification of design of bore bit and upgraded efficiency of drilling. ^ 2 dwg |
