Device for controlling the orientation of bore holes

摘要

A device for controlling the inclination of underground bore holes is in form of a drill guide rod having an outer element and an inner element which rotates coaxially in the outer element. Gib-shaped members can be pivoted out from the outer element in the same manner as the ribs of an umbrella, and electrical inclinometers in the rod furnish the signals which control the time and degree of such pivoting.