Tunneling machine with radially sweeping tool carriers

PCT No. PCT/EP91/02345 Sec. 371 Date May 19, 1993 Sec. 102(e) Date May 19, 1993 PCT Filed Dec. 6, 1991 PCT Pub. No. WO92/10647 PCT Pub. Date Jun. 25, 1992.In order to drift underground roads, tunnelling machines are used that have a rotatively driven boring head base body, a rigid first bit and rail heads that can radially sweep around axes of rotation between the working point in a conductor shaft and gallery faces by means of thrusting piston gears that carry at least one roller boring tool. In order to improve the coordination between an opening of the conductor shaft and under cutting, which are carried out simultaneously, a first bit. (2) is designed as a ring borer (2) that breaks out a drilling core (3) through slits of an annular cavity (4). The ring borer (2) has two parallel arms (6) spaced apart from a central axis (5) that carry boring tools (7) articulated on a cross-beam (10) of a carrying frame (9) that has an advancing device (11). The carrying frame (9) surrounds the thrusting piston gears (18) for radially sweeping rail heads (12), and perpendicularly arranged to the rail heads (12) and extends parallel to the central axis (5) at the boring head base body (1).