HYDRAULIC PIPE WRENCH Russian patent published in 2001 - IPC

FIELD: mining industry. SUBSTANCE: hydraulic pipe wrench has detachable body, rotary clamping device located inside body, hydraulic engine, stop and torque measuring system. Reversible rotary clamping device is made in the form of open gear fixed between rollers and provided with circular slots on its upper and lower surfaces. Gear inner surface is positioned between upper and lower interconnected flanges provided with guide recesses. Interchangeable gripping heads are disposed in guide recesses and provided with springs adapted for urging heads so as to bring them apart. Upper flange is connected to brake device which is fixed on cover of rotary clamping device. Fingers with rollers are secured in circular slot and fixed to flanges of rotary clamping device to prevent flanges from rotation in axial and radial directions. Retainer is located on upper flange for engagement with stop on gear. Pair of gears are positioned in symmetry so as to cooperate with open gear and hydraulic engine gear. Pipe wrench is further provided with flap and catch for providing forced closing of body of clamping device. Flanges are provided with opening. Pipe wrench of such construction provides for high torque and may be used for screwing and unscrewing of threaded connections for drilling and repairing of wells. EFFECT: simplified construction and increased efficiency by reliable gripping and retaining of pipes of any diameter without necessity for replacement of cams. 2 cl, 7 dwg