PERFORATOR Russian patent published in 1995 - IPC

FIELD: mining industry. SUBSTANCE: perforator has piston with labyrinth grooves made in the form of profile, whose bottom portion is defined by arc of a circle making continuation of front portion of profile inclined at an acute angle with respect to piston axis. Profile rear portion is defined by straight line extending perpendicular with respect to piston axis. Depth of groove is equal to diameter of arc of circle of bottom portion of profile. Groove bottom portion circle arc diameter and distance between piston edge and first groove and groove spacing are selected so that their optimum value depends on distance between piston and cylinder. EFFECT: increased efficiency in drilling wells and enhanced reliability in operation by increased percussion power and increased wear resistance of perforator. 3 cl, 2 dwg