UNIVERSAL DRIVE OF SLIP-TYPE PREVENTER Russian patent published in 1997 - IPC

FIELD: well drilling equipment. SUBSTANCE: located symmetrically relative to preventer body are cylinders. Positioned in each cylinder is piston with hollow rod. Load screw with non-selfbraking thread is inserted through cylinder cap and interacts with load nut. Load screw is spline-connected with hollow rod. Load nut is provided with outer splines corresponding to inner splines of piston. Also provided is slip movement synchronizer in the form of shaft with two driving and two driven gears and spring-loaded eccentric or ratchet stop interacting with outer ring of freewheeling coupling. Cap is made with main bush having tapered seat which is corresponding to stopping cone made on load screw. Installed between cone and main bush is expansion spring. Installed in piston is compression spring intended for interaction with load nut. Device is operated from hydraulic energy-carrier or from torque applied to drive journals or both type of drive can be used simultaneously. Device ensures quick hermetic sealing of well head with automatic locking of mechanism to prevent spontaneous loss of hermetic sealing, also ensures automatic pressing of slips to string which can be necessary due to wear of slip lining by rotating or axial movement of string. EFFECT: high efficiency. 3 dwg