JOINING OF TUBE-FORMED EXPANSION BOLT

摘要

Tube-formed rock bolt intended for expansion into contact with the wall in a bore hole without stretching the periphery of the rock bolt. The rock bolt comprises an elongated tube (12) with closed cross section. The tube is provided with a longitudinal depressed part (13). End pieces (14, 24) are secured to the ends of the tube. Rock bolts according to the invention can be connected to arbitrary length through screwing them together. The end pieces are provided with axial channels (15, 35) whose peripheries sealingly cooperate through deformation of the material when the rock bolts are screwed together. Through connecting one end (30) of the assembled rock bolt to a high pressure pump (39) the entire assembled rock bolt can be expanded at the same time.