DOUBLE CORE-ISOLATING TOOL Russian patent published in 2003 - IPC

FIELD: mining industry, aids for drilling and core sampling with preservation of formation medium. SUBSTANCE: double-core isolating tool includes body with rock-breaking tool in which core- taking tube with external ducts is located on round bearing. Core-taking tube is filled with antifriction insulating fluid and is shut from beneath by means of mobile piston with sealing element and rod. Rod protrudes beyond edge of rock- breaking member. Outer side surface of mobile piston is provided on side of bases with longitudinal grooves interrupted by annular grooves and limited by beads. Rubber washers fixed with the aid of springy bushings are placed between beads. Springy bushings are located between rubber washers. Outer diameter of rubber washers exceeds inner diameters of core-taking tube. Peripheral part is provided with triangular recesses which vertexes are directed towards axis of piston and are arranged at level of outer surfaces of springy bushings. End of rod comes in the form of bent cone. Sealing element is put on protrusion between annular grooves. Round bearing is leak-tight and is filled with oil. EFFECT: increased informativity of core material thanks to enhanced reliability of winning representative core with preservation of its water saturation. 3 dwg