Abstract: The invention relates to a device for locating percussion boring machines using a transmitter and a receiver which allows the radio transmitter to be connected to the percussion boring machine in a simple manner and preferably without breaking the connection between the compressed air line and the percussion boring machine; which does not hinder the manoeuvrability of the hammer drill; which is less susceptible to mechanical influences during the boring; and which can easily be disassembled. This is achieved by fastening a housing with a receptacle for the transmitter or the receiver on a fluid line.

Abstract: A securing and tensioning device for a towing cable that is secured to a percussion boring machine and connects a pipe that is to be pulled in to the boring machine, comprising a thrust member bearing on the free end of the pipe that is to be pulled in, a clamping unit that is adjacent to the thrust member and clamps when a force acts on the towing cable in the direction of the pipe that is to be pulled in, and a tensioning unit arranged coaxially with the clamping unit that clamps when a force acts in the direction of the pipe that is to be pulled in and is movable in the direction opposite to that of the pipe that is to be pulled in.

Abstract: In a method of operating a ram boring machine having a rotatory-thrust drill rod an impact force is applied to the rear end of the drill rod. The boring machine includes a thrust unit and a striking tool that are combined to form a thrust/percussion aggregate.

Abstract: In a percussion mach in particular a self-propelled ram boring machine, with a percussion piston which is axially movable in the machine housing, has a hollow piston rod and is acted on by a pressure medium via a supply hose connected to the rear end of the housing, a piston rod bore communicates with the pressure medium supply when the percussion piston is in the front end position and communicates with a discharge opening when the percussion piston is in the rear end position.