Abstract: An apparatus for making earth bores with simultaneous emplacement of pipe, especially for making well bores, includes an earth boring device (10) with a drive device (12) and a displacement head (14) coaxial with the drive device (12). The outer diameter of the displacement head is larger than that of the drive device (12) and of the surrounding pipe (16) with the pipe being connected to the drive device with a releasable force fit connection, wherein at least three pressure fluid jet nozzles (18) are arranged on the displacement head (14) pointing nearly in the boring direction and arranged at least nearly symmetrical to the longitudinal axis of the displacement head (14).

Abstract: In an earth boring device of either the impact ram or static type wherein the device is driven forwardly either by the impacts of an impact piston or by a forward pressure exerted on the device through a rod, directional control of the device is achieved by arranging a plurality of pressure fluid ejecting nozzles on the head of the device symmetrically with respect to its longitudinal axes, and by individually controlling the pressure and/or amount of pressure fluid supplied to each nozzle to deflect the device in one direction away from what would otherwise be its forward drive path.

Abstract: A percussion drill provided with additional control phases in the form of a gentle braking phase for controlling the rearward movement, and a progressive braking phase for controlling forward movement. To this end, the control slide valve of the drill has a clearly defined gentle braking control edge, a new type of control channel having a cross-section which is variable along its length. The main advantages which are achieved as a consequence are substantially reduced compressed air consumption, substantially smoother operation even in relatively loose soil, and a considerably prolonged effective life.

Abstract: A percussion drilling apparatus has a control unit in which a displacement reversing unit is arranged axially adjacent to a piston control unit, with the result that the control edges for the apparatus advance and apparatus return can be arranged in separate control sleeves. This control unit makes it possible to achieve better apparatus characteristics and higher overall efficiency of the apparatus.

Abstract: A driving head which can be used for pneumatic pile drivers and can serve as an attachment head for rods or pipes which are to be driven in pile drivers. The driving head has an essentially circular front end and a conically expanding surface over the periphery of which are uniformly distributed a plurality of longitudinal grooves which start from the front end. Also provided is at least one transversely extending section which extends around the surface in a circle. The longitudinal grooves have a V-shaped cross section, and the surface of the driving head is formed by a plurality of conical sections which are offset in the manner of steps via jumps in the diameter. The end faces formed between the individual conical sections are disposed at an angle in a range of from 45.degree. relative to 90.degree. to the longitudinal center line of the driving head.

Abstract: A control device for working cycles of a self-propelled pneumatic boring device with a non-rotatable axially displaceable impact piston controllable by control edges of a control sleeve supported axially non-displaceably but rotatably and at its front end forming a control head with the control edges. The control head engaging in a cylindrical recess at a rear end of the impact piston cooperates with a radial main control opening formed in the impact piston in the vicinity of the recess. The control edges form two different pairs of the control edges, offset peripherally as well as axially such that respectively in one rotated position of the control sleeve only one of the pairs is aligned for cooperation with the main control opening. The impact piston is formed with at least one additional control opening which cooperates with the other pair and has a flow cross-section considerably smaller than that of the main control opening.

Abstract: A ram head for self-driven pneumatic ram drills for producing boreholes in the earth, having a generally tubular housing within which there is movable axially back and forth an impact piston whose impact energy can be transmitted to the ram head arranged at the front end of the housing. In order on the one hand, to crush obstacles by high energy and, on the other hand, to avoid too strong a compacting of small particles of earth in front of the apparatus and in addition make it possible to drive pipes, the generally conical ram head is provided with a central axial bore within which an impact bolt is mounted for longitudinal displacement between two end positions which are limited by stops, at the front end position of which supported by a spring the impingement surface of the impact bolt for the impact piston lies within the anvil surface of the ram head and at the rear end position of which the impingement surface projects from the anvil surface in the direction towards the impact piston.

Abstract: Control device for the forward movement and rearward movement of self-driven pneumatic ram boring devices with an impact piston which is axially displaceable between two abutments in a tubular housing, with the axial forward movement and rearward movement of the ram boring device being controllable by rigid control edges of an adjustable control sleeve, the latter being supported on a bearing ring arranged in the rear part of the housing. Through the bearing ring there is led a part of the control sleeve forming a feed tube for the compressed air for connection to a compressed air hose, the sleeve having a piston-like control head containing the control edges; the control head engaging in a cylindrical recess at the rear end of the impact piston cooperates with radial control bores which are formed in the area of the recess in the impact piston. The control sleeve is mounted non-displaceably in the axial direction however rotatably in the bearing ring and is provided with at least four control edges.

Abstract: A self-propelled pnuematic burrowing device having an axially reciprocating percussion plunger arranged inside a tubular casing so as to strike a percussion head at the forward extremity of the casing, thereby advancing the device through the ground by crushing and/or displacing the material in the path of the device, the percussion head being freely displaceable between axial abutments defined by a guide sleeve of the casing, the displaceability being slightly in excess of the advance of the device per stroke and adjustable through the insertion and removal of split spacer rings. The air controls of the device, located in the rear portion of the casing, include a control barrel with an enlarged control head and a gradually widening central air supply channel.