telescopic pipe for the pouring of concrete behind a abschalung of roadway support in mining and tunnelling

摘要

The system for depositing wet concrete behind a tunnel lining, in mining and tunnelling operations, uses equipment which includes a concrete pump which forces the concrete along a line to a telescopic tube (28, 29). The delivery end of this tube then fits inside a connecting sleeve (4) attaching to the tunnel lining. The region of the sliding joint between the two tubes incorporates a sealing arrangement which prevents the cement from being forced ino the joint. The inner tube (29) carries annular strip guides (33, 37) between which locate two sealing rings (43, 44) with a gap between. These are retained by braking rings (32, 47) which fit into grooves in the inner pipe. An intermediate sleeve (34) fits between the sealing rings and the outer tube (28), and an intermediate seal (45) fits between the innermost locking ring (47) and the innermost annular strip guide (37).