175 / | HD | BORING OR PENETRATING THE EARTH |
207 | DF | WITH ABOVE-GROUND MEANS FOR HANDLING DRILLING FLUID OR CUTTING {9} |
209 | .~ Fluid or cuttings directing or receiving means engaging bore entrance {2} | |
210 | DF | .~.~> Anchored to bore wall |
211 | DF | .~.~> Axially supported by tool shaft |