Male portion drill bit and threaded joint for per cussive rock drilling

摘要

The male part includes parts with a reduced cross-section and at least one threading (12) for carrying out percussion drilling in a male part end section (16). A stop surface (14) at the end of the male part is used to transmit shock waves to the rock. The length (L) of the threaded end section is defined as the length of a cylinder (C) which extends from the stopper surface plane (P) and forms a tangent with the external diameter (Dy) of the threading. The threaded end section length/cylinder diameter ratio is 2:1. Independent claims are also included for (a) drill bit and (b) a percussion drilling method.