METHOD OF MANUFACTURE OF EXPANDING ANCHOR MEMBER Russian patent published in 1997 - IPC

FIELD: manufacture of expanding tubular anchor members for supporting of rocks. SUBSTANCE: the offered method includes three stages of formation of longitudinal closed hollow on middle part of pipe with convexity facing inside pipe: reinforcing of end parts of pipe by their squeezing at all three stages simultaneously with formation of hollow; sealing of pipe ends by installation of plugs into cavity of end parts and their rolling in pipe walls simultaneously with squeezing of end parts at the second stage of formation and making hole for supply of working fluid; squeezing during the third stage of one of end parts is accomplished on the length exceeding that of opposite part by 0.15-0.3 Dp to produce lateral corrugation, where Dp is pipe diameter. EFFECT: higher efficiency. 6 dwg