OVERSHOT Russian patent published in 2005 - IPC

FIELD: grapping tools, particularly to remove pipes or rods from wells.

SUBSTANCE: overshot comprises sub, body with gripping members and split holder made as a number of segmented inserts. Inner surfaces of the inserts have conical surface which expands upwards and provided with longitudinal grooves. Outer surfaces of gripping members have inclined flat surfaces mating inclined flat surfaces of longitudinal grooves of the inserts. Gripping members are arranged in longitudinal grooves so that side surfaces may cooperate with side surfaces of the grooves. Gripping members are connected to inserts so that they may move in longitudinal direction along groove surfaces and are arranged in lower extreme position on annular body ledge. Inclined flat groove surfaces may engage pipes or rods having different diameters under projected annular members formed on pipe or on rod. Inner surfaces of gripping members are tangential to outer pipe or rod surface.

EFFECT: increased operational reliability.

3 dwg