FIELD: machine building.
SUBSTANCE: top drive comprises gripping device jointed thereto and arranged there under, and four grippers each being arranged on piston with gripping cylinder. Proposed method of pipe gripping above top drive comprises activating pistons and cylinders of above said device. Invention covers also top drive with drive shaft, component coupled with said shaft and gripping device with mouth suspended to top drive and provided with first splined element. Note here that said component has second splined element for engagement with first splined element to selectively decelerate component rotation for unlocking the joint with top drive driving shaft. Note also that gripper comprises two parts that move for opening the mouth. Proposed method comprises engaging said second splined element and decelerating component rotation for unlocking the joint.
EFFECT: normal operation of top drive, easier installation, smaller installation space.
30 cl, 6 dwg
