DEVICE FOR DRILLING WELLS Russian patent published in 1994 - IPC

FIELD: drilling wells. SUBSTANCE: device has bit, case coupled with the bit, and pipe received in the case. The pipe and case form a ring passage which is in communication with atmosphere through openings provided in the case. Check valves with spring- loaded valve members are set at outlet of the pipe and inlet of the ring passage. Rigidity of the spring of the valve member of the first valve is grater than rigidity of the spring of the valve member of the second valve. A moisture separator made of a reflector is set on the pipe between the valves. The reflector case and pipe form ring spaces. EFFECT: improved design. 1 dwg