Abstract: A system for transfer of data or electric current for a steerable horizontal boring machine for laying and destructive replacement of supply lines, which is suitable both for percussive and for rotary drilling operation and permits reliable and problem-free use of a cable connection between a consumer or sensor and a power supply or a data utilising unit, preferably comprises three elements (machine adapter, string adapter, transmitter adapter) for connecting the cable.

Abstract: In a percussion boring machine for producing or widening earth boreholes, the housing is equipped with nozzles and houses a striking piston caused to reciprocate axially by means of compressed air and means of generating pressure which supplies the nozzles with a flushing, cutting, lubricating and/or steering liquid. Since the liquid pressure required for the excavation of the ground surrounding the machine and/or for causing the machine to travel on a curved path is generated in the machine itself, the machine only needs to be supplied through a supply line with a liquid at a slightly raised pressure.