OUTSIDE SPEAR Russian patent published in 2002 - IPC

FIELD: oil producing industry, particularly, fishing tools for well workover. SUBSTANCE: outside spear has body with windows between which stops are accommodated. Collet unit includes blades with projections having bevels and installated in body windows. Collet turning mechanism consists of bushing having recesses with bevels engageable with pin rigidly connected to body. Projections of collet blades have longitudinal teeth engageable with external surface of body of pipe to be caught. Conjugated surfaces on body stops and projections of collet blades are inclined at an angle to body axis. Said surfaces in body cross-section form profile excluding tangential displacement of ocntacting stops of body and collet blade projections. Torque is reliably transmitted from working string to fishing pipes through spear for lifting emergency pipes by parts, by turning them in their thread connection. EFFECT: improved mechanical properties. 5 dwg