Telescopic double shield boring machine

Abstract

The invention relates to a boring machine for digging tunnels in a wide variety of qualities of ground, of the type comprising a first front shield, containing the boring head, and the members for driving the same, and a second shield, fitted with posts or "grippers" for providing the anchorage necessary for the advancement of the boring machine, in which a third shield is provided, arranged between said first and said second shield, such that the first shield overlaps partly with it and is able to slide axially with respect to the third shield itself and that the assembly first shield/third shield is able to vary its advancing direction with respect to the second shield; guide means being provided between said first and said third shield, which guide means allow these latter to perform a relative movement in the longitudinal axial direction only, and means being provided for advancing said first shield with respect to said third sh shield, as well as means for setting at an angle the assembly first shield/third shield with respect to said second shield.

Dependencies are inferred from the claim text.