DEVICE FOR WORKING UNDERGROUND PRESSING PIPES UNDER THE SOIL PRINCIPLE.

摘要

1. An apparatus which operates on the earth removal principle for pressing pipes forward underground, having a support tube (1) and a conveyor screw (2) which is arranged therein and which at the advance end carries a first boring tool (4), and a further cutting tool (5, 6) which is rotatably mounted on the support tube (1) and which concentrically surrounds the first boring tool (4) and which is provided with its own drive (12) independently of the conveyor screw (2), characterised in that the further cutting tool, in the form of a cutting ring (5, 6), forms with the first boring tool (4) and the corresponding end of the conveyor screw (2), an entry cone (13) over which the cutting teeth (6) of the cutting ring (5, 6) extend.