PERFORATOR Russian patent published in 2004 - IPC

FIELD: mining and construction industry, drilling of blast-holes in loose rock. SUBSTANCE: invention is related to drilling of blast-holes in loose rocks with decreased resistance to spalling and hard inclusions, for instance, of apatite- nepheline ore, to rocks displaying face with bumpy surface when drilling blast-holes and holes. Perforator has rock-breaking tool anchored on rod, body, air distribution system, rotary and limit boxes. Body houses rotary mechanism and twin piston-striker including main and auxiliary bullets put on air feeding tube. Perforator has also lock anchored on main bullet on side of auxiliary bullet, additional working space formed between two bullets in rotary box, provided with recess to accommodate lock. Air feeding tube has slot communicating its duct with additional working space in point of connection of main and auxiliary bullets. Relation of masses and sections of main and auxiliary bullets is chosen from inequality (S₁/m₁)>(S₂/m₂), where S₁ is section area of auxiliary bullet, sq m; S₂ is section area of main bullet, sq m; m₁ is mass of auxiliary bullet, kg; m₂ is mass of main bullet, kg. EFFECT: enhanced efficiency of impact. 6 dwg