Abstract: An air spring hammer device that includes a drive piston, moving axially back and forth, with a front face of hollow embodiment and a hammer piston moving in said hollow. A ventilation slot is embodied in a guide wall of the drive piston. The drive piston may be guided in a guide tube. The guide tube comprises several idle openings. A moving control element is arranged on the exterior of the guide tube, in which control openings, corresponding to the idle openings, are provided. In an idle operating mode, the control element is in an open position, via which the ventilation slot, the idle openings and the control openings can be brought into connection with the environment.

Abstract: The invention relates to an air-cooled frequency converter, especially for construction site equipment, such as internal and external vibrators which are operated at a higher frequency than the existing electricity supply, said frequency converter comprising a housing and preferably being connected to a separation transformer for producing a protective extra-low voltage. The housing is divided into a converter receiving element surrounding a plate chamber, and a housing section connected to the receiving element and used as a cooling region, inside which cooling air channels and a fan for conveying the cooling air through the cooling air channels are arranged. The configuration of the housing in the cooling region are created by annular profiled elements which are cross-cut as desired, surround each other in an interspaced manner, and are coaxially arranged in relation to each other.

Abstract: A concrete finishing trowel comprising at least one rotor which is mounted on a frame and is provided with a rotatably driven shaft and several blades that are mounted on the driven shaft. A blade deflection mechanism moves the blades on a path that deviates from a circular path relative to the drive shaft.

Abstract: A device for a drilling hammer and/or percussive hammer has a tool holding fixture for holding a tool and for transmitting a torque to the tool. A component of the tool holding fixture consists of a hollow cylindrical tool holder, which has an insertion opening for an insertion end of the tool, and has an impact opening, via which a percussive action can be applied to the insertion end. A stopping surface, which is stationary with regard to the tool holder and which acts in an axial direction of the tool holder, is provided in the tool holder in the area of the impact opening. The tool holding fixture is particularly suited for insertion ends according to the SDS-max standard.

Abstract: Disclosed is a drilling and/or striking hammer that includes a lubricating device having a lubricant reservoir and a volume of lubricant contained therein. The lubricating device conveys lubricant to at least one a transmission system within the hammer's housing, a percussion system, and/or a tool holder at a variable dosing or flow rate. The dosing or flow rate varies as a function of tool stress which can include use intensity and/or temperature. A flexible tube extends between the reservoir and the lubricated component(s). At lease part of the flexible tube vibrates with the lubricated components during use and modifies a viscosity of the lubricant therein, based on tool use intensity. A pressure generating device can pressurize the lubricant, helping convey the lubricant to a targeted area for lubricating movable parts.