HYDRAULIC CATCHER Russian patent published in 2007 - IPC E21B31/113 

FIELD: underground (fundamental) maintenance of wells, possible use for extracting equipment stuck at the face.

SUBSTANCE: device contains body and spindly connected to working column and object being freed, connected by screw couple to lifting angle, providing for its non-self-braking mobility and forming a "cylinder-piston" couple with hollow, filled with liquid with forming a part of hollow in bored interval of cylinder. Connection of body and spindle is made with possible induction of angular and axial acceleration onto working column with following application of torsion and axial strike. When torsion strikes are required in reverse direction screw couple is made with reverse thread.

EFFECT: increased efficiency of operation, expanded functional capabilities.

1 dwg