HOLE REAMER Russian patent published in 2002 - IPC

FIELD: gas and oil industry. SUBSTANCE: proposed hole reamer is employed to widen shafts of holes in process of rotary drilling. Hole reamer includes case with central washing conduit and throttle installed in it and carries rock- breaking blade manufactured in the form of boss on side surface fitted with wear-resistant inserts. Hole reamer is equipped with aids for centering in hole coming in the form of limiting step made on case and located under rock-breaking blade protruding beyond side surface of case to one half of height of rock-breaking blade and of bearing blade with spherical surface located on side diametrically opposite to limiting step. EFFECT: effective, reliable and stable operation while forming diameter exceeding nominal diameter of hole. 3 dwg