CORE CATCHER Russian patent published in 2003 - IPC

FIELD: drilling of oil and gas wells, means for core sampling. SUBSTANCE: core catcher is provided with body in the form of conical collet ring with longitudinal protrusions and grooves in outer side of these protrusions to accommodate swivel rollers of short and long levers coming in the form of frames with openings. Core catcher is fitted with clamp in the form of ring with springy protrusions in peripheral part which come in pairs in diametrical directions perpendicular one another. Body is equipped with arc-shaped leaf springs placed on inner side of tail part of longitudinal protrusions uniaxially with levers and made fast in lower part. Width of arc-shaped leaf springs exceeds width of openings in frames. Inner side of frames of levers are positioned at equal distances from axes of swivel rollers. Levers are fixed by clamp in initial position, springy protrusions of clamp can be removed from levers when they interact with core. Inner diameter of body is equal or exceeds nominal diameter of core. EFFECT: increased functional reliability of core catcher. 3 dwg