CORE GRIPPER Russian patent published in 2000 - IPC

FIELD: drilling equipment. SUBSTANCE: invention relates to devices for extraction and holding of core presented by rocks with low strength characteristic and alternating hardness. Body of core gripper has windows in which three long and three short levers spring-loaded by restoring plates are mounted in turn. Thick-walled ring is put on outer side of body. Ring has longitudinal ducts along entire length on outside uniaxial to windows of body for flow of drilling fluid that presses tail parts of levers downwards and has through holes in radial direction in points of location of levers. Enclosure made of elastic antifriction material is mounted on outer surface of ring. Levers are manufactured in the form of rocker and are installed to shut off through holes in ring by tail parts. EFFECT: prevention of break- down of core in process of drilling and filling of core container. 4 dwg