Underground horizon boring tool with directional control

摘要

The arrangement consists of a string of interconnected guide tubes (21) at the front end of which a boring head (30) with sloping front face is mounted. The string of tubes is mounted in an outer tube (20) which has a ring shaped boring head at its front end. The head with sloping front face can be pushed out off the outer tube and can be rotated to alter the direction of boring. Axial impacts can be imparted on the inner head e.g. when it meets a hard obstruction so that the head can bore through it. The front of the boring arrangement carries a magnet so that its position can be determined from above ground.