DRILL BIT MOUNTING FOR A DOWNHOLE DRILLING MACHINE

摘要

A downhole drilling machine (12) can be used for directional drilling for example for drilling through roadbeds. The drill bit (14) of the machine has an unsymmetrical face so that it drills a curved hole when it drills without being rotated. When it is rotated, it drills straight. The shank (16) of the drill bit has an unsymmetrical splined connection (18) with a sleeve (19) which in its turn has an unsymmetrical splined connection with the housing (21) of the machine. The machine adapter (11) has sensors that provide information of the direction and angular position of the adapter.