Abstract: The invention relates to a turning mechanism for driving in or extracting piles by means of tangential rotary blows being imparted by a rocker arm equipped with balance weights and arranged in a rotary manner relative to the pile. In order to render superfluous the hitherto necessary noise-damping, additional damping means, damping members made from an incompressible, elastic material are used, which are placed in recesses in at least one stop of a pair of stops in such a way that there is a deformation, particularly at right angles to the impact direction, which is within the elastic limit of the member and prevents direct contact between the stop pairs. These members are arranged on all parts of the rocker arm which, in operation, form noise sources.

Abstract: A drilling device which can be lowered in a drill hole consists of a drive device, a drill which is rotated by this drive device and a clamping device formed as a unit which can be engaged with the inside wall of the drill hole and serves to transfer the torque of the drive to the drill. The drill consists of a ring-shaped housing, the outside diameter of which corresponds with the diameter of the drill hole and the upper part of is closed off by a plate. The housing contains several cutting tools which are equipped with bore crowns which serve to cut out a drill core and which are arranged at uniform distances and parallel with the longitudinal axis of the drilling device. Using additional drive devices, the cutting tools are designed to impart impact impulses and/or additional rotational movements in an axial direction. All drive devices are fluid actuated in such a manner that the clamping device is actuated initially and the drill is subsequently activated by the increasing pressure of the fluid medium.

Abstract: A device for the control of the internal pressure in a drill pipe or tremie is disclosed. The tremie is used in footings and especially in the construction of compressed concrete footings. The tremie has a valve located in a lid that serves for the tight seal of the tremie. The valve is subjected to a counter-pressure which is greater than the effective power of the internal pressure of the tremie. A hoisting cable is connected to the valve stem and the power of the hoisting cable under normal operating conditions in combination with the internal pressure of the tremie is large enough to overcome the counterpressure. The valve is shifted to vent the internal pressure of the tremie when the same is rapidly removed from the footing bore due to a decrease in ground friction.

Abstract: A device which includes a ram and a tube, which device can be used for the production of earth holes and poles which are located in these holes and which poles are made of poured or compressed concrete and a process using this device.

Abstract: A drilling grab for pile foundations and well boreholes wherein the drilling grab comprises a grab body supporting circular grab spades which tilt from an open position to a closed position about pivot pins carried by the grab body. A radially projecting abutment interchangeably connected to the outer periphery of the grab body is engageable with the back of the grab spades when the same are in an open position. The abutment overlaps the periphery of the grab body and is characterized in that they consist of extension members adapted to grab spades of different sizes. The members are supported on radially projecting ribs located on the grab body.