| 摘要 |
FIELD: process engineering.SUBSTANCE: invention relates to well boring. Proposed tool comprises multistep cutters. Note here that separate leading teeth row is spaced from subsequent row of the other cutter in bit axis by (0.04-0.06)D with step width of (0.02-0.04)D, where D is tool diameter, said ratios being maintained at cutter outer cones.EFFECT: higher rate of drilling owing to horizontal and vertical cutting to make stepped surface with steps to be destructed during their formation.6 dwg |
