PIPE-GRIPPING DEAR FOR THREAD CONNECTION OF TUBULAR MEMBER Russian patent published in 1997 - IPC

FIELD: mechanical engineering, drilling keys, joining of drill pipes and casings. SUBSTANCE: pipe-gripping gear has lower jaw holder and upper jaw holder, each including upper and lower discs between which toothed sectors are hinged. Teeth of sectors engage teeth of rotor near wheels supported in rolling bearings. Bell-cranks with blocks are attached to planes on internal side of toothed sectors. Hydrocylinders which rods rest against bottom of brake are built in lower jaw holder. Brake incorporates friction discs, springs and braces. Friction discs have slot recesses and are engaged with immobile bushing. Other group of friction discs is matched with internal side to lower disc by means of same slot recesses. Rotor gear wheels rotate in different directions under action of drive. With increase of torque upper jaw holder overcomes resistance in discs and rotates with simultaneous gripping of upper tubular member. EFFECT: manufacture of gripping gear in the form of fast separable cassettes with provision of mounting and location areas common for all types of pipes, simplified design expanded functional capabilities, improved operational characteristics and enhanced reliability. 4 cl, 1 dwg