CHANGING DEVICE FOR RECONSTRUCTING TUNNEL

摘要

PROBLEM TO BE SOLVED: To provide a changing device for reconstructing a tunnel by which the position of a new tunnel can be arbitrarily shifted to construct it against the position of an existing tunnel. SOLUTION: A plurality of cam mechanisms 40 which are swingable around the axial center parallel to the axial center CT2 of the rear part 2b of an external crust 2 are radially arranged between the rear part 2b of the external crust 2 and the internal crust 20. The internal crust 20 is transferred against the rear part 2b of the external crust 2 to arbitrarily set the position of a new tunnel 60 by extending/contracting respective actuators 46 of these cam mechanisms 40 while adjusting the actuators. COPYRIGHT: (C)2003,JPO