GEAR TO DRILL HOLES Russian patent published in 2002 - IPC

FIELD: design of gears to drill large-diameter holes by submersible pneumatic striker with use of rotor-bit drilling rig. SUBSTANCE: gear includes pneumatic striker which body houses piston-striker through which axial hole air distribution tube is passed. Drill bit is put on tube for interaction with piston- striker. Air distribution tube is passed through axial hole of drill bit. Cone drill bit whose diameter is less than diameter of drill bit is positioned on this end of air distribution tube. Body is screwed on to drill pipe string of drilling rig. EFFECT: reduced energy consumption, expanded technological capabilities of energy-saving low-power cone drilling rigs. 2 dwg