METHOD FOR EXTRACTION OF HOLLOW OBJECT PLACED IN EARTH Russian patent published in 1999 - IPC

FIELD: construction, applicable in extraction of a hollow object, for example, a lead pipe from earth. SUBSTANCE: a hose is placed in the pipe with no pressure inside it, pressure is built up inside the hose; as a result, it is pressed to the inner wall of the hollow object-pipe, and maintaining pressure inside the hose, the pipe is extracted from the earth in the longitudinal direction with the aid of the hose without their relative axial displacement. A new pipe may be attached to the lead pipe or hose behind its rear end. An additional traction member may be introduced in the pipe together with the hose, which when pressure is applied inside the hose gets pressed to the pipe inner wall, and which independently or jointly with the hose may be used for extraction of the pipe. EFFECT: enhanced reliability of extraction of pipe from the earth due to prevention of its breakage. 20 cl, 9 dwg