Abstract: In the case of an earth boring apparatus, preferably a thrust boring apparatus, the head of which is actuated by a pneumatically operated reciprocating ram, a supply hose (5) provides the connection from a compressor as an example to the thrust boring apparatus which also serves to reverse the direction of operation by the rotation of the hose. To ensure error-free control over greater lengths of hose and to avoid kinking—partly due to the pressure from surrounding ground—the hose (5) is equipped with a snugly fitting corset (12) in the form of a spring wire spiral or a woven wire support.

Abstract: A positive connection between a pipe and a ring inserted into the pipe, in particular between the housing of a ram boring device and a stop ring inserted into the housing, wherein the inside wall of the pipe has a convex groove consisting of a section of a surface of a sphere and the ring has a corresponding convex outer surface with the same radius, the inside wall of the pipe possessing at least one axial groove permitting insertion into the pipe or the outer surface of the ring possessing at least one flattened portion permitting insertion into the pipe, or the ring being axially divided into two or more preferably unequal segments.

Abstract: In a ram drilling tool for producing bores in the ground and having a percussion piston which is moved to and fro in a casing, a control sleeve is guided such that it can be displaced on a control pipe projecting into a percussion-piston chamber and whose axial position determines the direction of movement of the tool. In order to permit the movement to be reversed, a control chamber connected to a control-air line is arranged between the control pipe and the control sleeve, and its front end terminates flush with a collar at the front end of the control pipe.

Abstract: The invention pertains to a method for introducing and removing rod sections into and from the push/pull axis of a push/pull unit, the individual rod sections being essentially arranged one after another and being joined to one another or detached from one another by being rotated in or out about an axis located essentially perpendicular to the axis of the rod section.

Abstract: In a ram drilling tool having a steering element, for example a steering head, which is mounted in the tool casing such that it can move, for example rotate, the tool casing is connected to a pressure-medium line such that it cannot rotate and to a sleeve pipe such that it can rotate; it may therefore be adjusted with low friction by means of rotation with the aid of the pressure-medium line with respect to the steering element, which is firmly held by the ground.

Abstract: An apparatus for longitudinal splitting, in particular longitudinal slitting, of pipes laid underground and for the simultaneous trenchless pulling-in of a new pipeline comprises a carriage in the form of a frame, in which a cutting wheel for cutting open the pipe wall and a support roller, which serves as an abutment and is supported on the pipe wall, are arranged above one another. The carriage or frame has a base which engages in a form-fitting manner in a frame-like window of a pull and/or push linkage.

Abstract: An apparatus for longitudinal splitting, in particular longitudinal slitting, of pipes laid underground and for the simultaneous trenchless pulling-in of a new pipeline comprises a carriage in the form of a frame, in which a cutting wheel for cutting open the pipe wall and a support roller, which serves as an abutment and is supported on the pipe wall, are arranged above one another. The carriage or frame has a base which engages in a form-fitting manner in a frame-like window of a pull and/or push linkage.

Abstract: In apparatus for producing and expanding earth boreholes and for destroying and replacing underground pipelines or for driving in pipes, a feed drive and a rotary drive having a plug-in coupling comprising a chuck and a locking portion at the end of a string is located in a frame. The string comprises a plurality of sections or lengths having an internal screw thread at one end and an external screw thread on the locking portion at the other end, which at the same time is provided with a key face to hold fast said string section while it is screwed together with the next following string section.

Abstract: An apparatus for widening microtunnels and/or for the destruction and replacement of ground-laid pipework and for the laying of new pipework possesses a tool which displaces the earth and/or destroys and/or displaces pipework laid in the earth, having a housing which is provided with an axial linkage seating, for example a housing passage for a linkage and with a linear drive which moves the tool, for example, on the linkage automatically from a launch pit to an arrival pit and simultaneously lays a follow-up pipe or a follow-up cable in the earth.

Abstract: In an apparatus for drilling in earth, a push-pull linkage, especially a ladder-type linkage consisting of individual sections connected together in each case by a plug-in coupling, is connected to a push-pull drive, and a stationary locking pawl and a thrust pawl which is moveable in the longitudinal direction of the linkage and is connected to the drive, with two mutually opposite directions of action, can each be brought into active connection with the linkage in order to move the linkage forward stepwise and lock it temporarily after each movement step.

Abstract: In directional boring using a boring apparatus having a driven string and a drill head with an excavating tool moving in an orbit about the longitudinal axis of the string, the tool moves with substantially constant angular velocity when boring straight ahead, but when boring along a curve it is stopped and set in vibration in order to obtain more accurate control of the curve.

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.

Abstract: The invention pertains to a method for steering a ground drilling machine, in particular, a pipe string assembly with a drilling head which is driven in the ground in rotative, propulsive and, if so desired, percussive fashion, in which at least one deflection pulse is exerted upon the rotating drilling head or the pulses acting upon the drilling head are interrupted when the angular position of the drilling head relative its axis corresponds to the position in which the deflection should take place.

Abstract: In a machine for horizontal or inclined percussion boring in the ground having a percussion boring string which has an oblique-face boring head at one end and an impact mechanism at the other end, the impact mechanism is mounted beside the rotary drive in order to reduce the length of the machine.

Abstract: The invention relates to an automatically driven pile-driver drilling device for drilling into the earth with a percussion piston moving axially inside a casing, driven by a pressure medium and changeable from a forward stroke to a backstroke, with a working space having radial control openings, a guide pipe with radial control openings extending into the working space and forming a rigid part of the housing, and a control box guided into an annular chamber of the guide tube and axially adjustable in a spring-pneumatic manner.

Abstract: In a percussion drill apparatus for soil drilling with a percussion piston which is moving to and fro within a housing, a control sleeve is mounted on a control tube which protrudes into the percussion piston chamber, the axial position of which determines the direction of movement of the apparatus. In order to make a reversal of movement possible a reversing chamber is connected with a control air line which runs inside the control tube and an approach chamber is connected by way of a drilling with the interior of a control tube which feeds the operating air into the percussion piston chamber. Consequently the control sleeve is moved into one direction with the aid of the control air and in the other direction with the aid of the operating air.

Abstract: In a method for directional drilling with the aid of a drilling device having a drill pipe and a mining tool which moves on an orbit, the tool moves at an essentially constant angular velocity during straight drilling and the angular velocity is periodically changed during curved drilling, in order to thus create a smooth transition from straight drilling to curved drilling and to achieve more precise curve control.

Abstract: With a boring machine having a multistrand rod assembly (3) for producing boreholes in the ground, comprising a rotatable inner rod (29), an outer rod (19), at least one steering and digging tool (5; 33, 35, 36) driven by the inner rod and having an axis of rotation (22) inclined at an angle of for example 90.degree. to the axis of the rod (23), and a linear drive for the rod assembly (3, 19, 20), it is possible to perform both straight-ahead boring and, if only the steering and digging tool is driven, curve boring.

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.