Abstract: In a rammer for internal ramming of pipes, having its rear end connected with the rear end (viewed in the direction of advance) of the driven pipe, the application of the driving force is improved by a mechanically simple connection.

Abstract: In a ram boring machine that has a striking piston reciprocating in a tubular housing and a striking tip that may be formed as a chisel and projects from the housing, connection of the striking tip to the housing by means of a bayonet joint makes installation and removal or replacement of the striking piston or a worn chisel possible in a simple manner.

Abstract: In a device for driving-in pipes by means of a connecting piece engaging in the rear end of the pipe and a rammer engaging in the connecting piece, flanging of the back end of the pipe can be prevented by forming the connecting piece as an expanding ring having a cylindrical outer face and an inner cone.

Abstract: In a process for laying underground service lines without excavation by means of a ram boring machine, old pipe lines already buried underground are replaced by new service lines without having to tear up the ground or destroy the old pipe line. To enable the new line to be laid accurately in position and to be accurately targeted the ram boring machine is provided with a guiding bore passing axially through the casing and is guided on the old line.

Abstract: In a ram boring machine that has a striking piston displaceable in a tubular housing, a displaceably mounted chisel passing through a housing tip has a collar by which it is guided in a bore in the housing that has a front and a rear stop limiting the stroke of the chisel, and has a shank that projects into the working chamber of the striking piston, rebounding blows are avoided by making the length of projection of the shank is smaller than the maximum stroke of the collar between the stops.

Abstract: In a ram boring machine having a striking piston that can be moved axially in a housing and whose movements are controlled by a control pipe that is connected to a compressed air hose and is mounted in an elastic intermediate piece arranged in the housing, arranging the elastic intermediate piece on the control pipe and/or in the housing facilitates the assembly of the intermediate piece. Furthermore there is less damage to the housing, the control pipe and the compressed air hose and even the control pipe can be mounted and disassembled easier.

Abstract: A ram boring machine having a striking piston that is axially displaceable in a housing, of which the forward and backward movement is controlled by a control sleeve connected to a supply hose and which engages in a cylinder chamber of the striking piston, and by one or more corresponding control openings in the striking piston, wherein the control sleeve is loaded both axially and torsionally, has axial and rotational stops and is rotatable and axially displaceable in a guide sleeve arranged at the rear end of the housing.

Abstract: An inclination sensor, in particular for measuring an inclination of service lines and/or ram boring machines, comprising a pendulum arranged in a measuring cell and at least one displacement sensor measuring the deflection of the pendulum. The pendulum comprises a body moving on a circular arcuate path in the measuring cell, the length of the pendulum being the same as the radius of the path. In this way a pendulum length can be obtained that is larger than the diameter of the measuring cell so as to obtain a large deflection of the body for a given angle and thereby achieve high sensitivity and accuracy of measurement.

Abstract: A ram boring machine for laying service lines in the ground without excavation, having a striking piston axially displaceable in a tubular housing and driven by means of a pressure medium via a supply hose connected to the housing, in which the supply hose is connected to the front end of the housing in the direction of advance and does not obstruct work on new pipes pushed into the passage made in the ground or drawn in simultaneously by the ram boring machine.

Abstract: A ram boring machine having a pull-and-turn reversing gear which comprises a striking piston axially displaceable in a tubular housing and a rotatably mounted control pipe with control openings such that forward and backward movement of the machine is controlled by moving the control openings over corresponding radial control openings in the striking piston, the control pipe having at least two parts with the rear part (viewed in the ramming direction) being connected to a supply hose, being relieved of the working pressure, and being connected to the bearing pipe by way of a force-loaded locking device which can be unlocked axially by traction on the supply hose against the loading force. This arrangement on the one hand prevents undesired reversal and on the other hand enables reversal to be effected under pressure.

Abstract: An apparatus for making tunnels and for laying supply lines in the ground comprises an earth displacing machine which is guided by a sword projecting out of the ground to allow the attachment of a power drive engaging the free end of the sword, and makes it possible to lay the supply lines accurately over long stretches, in particular along walls or the line of roadways or paths or the like.