Abstract: A fluid-powered impact vibrator (5), in particular a hydraulic hammer, comprising a fluid-powered percussion hammer (8) with a percussion piston (18) that is moved back and forth under the effect of a control means (10) and comprising a guide unit (7) on which the percussion hammer is supported, wherein the impact vibrator is additionally provided with a control valve, designed as a pressure monitor, for adaptation to the supplied input power. The control valve preferably is a pressure shut-off valve or a pressure-limiting valve (25) that is connected to the input pressure line (3) provided with the operating pressure, and automatically stops the percussion hammer (8) if the operating pressure resulting from the input power exceeds a specified maximum value. To stop the percussion hammer (8), either the pressure line (3) is blocked or the control means (10) is held in one of its end positions, i.e., the operating stroke or the return stroke positions.

Abstract: A method and a device for determining the operating time and the operating condition of a hydraulic percussion unit, in particular a hydraulic hammer, having a percussion piston which is guided inside a housing and, under the effect of a controller, alternately performs an operating stroke in an impact direction and a return stroke in a return direction. The method and device obtain information to determine whether the percussion unit requires maintenance operations. Signals are generated during the consecutive, individual operational segments of the percussion unit. The number of signals is proportional to the strokes performed by the percussion piston in one movement direction. The number of the signals is continuously added and is stored as a total number. The current total number of signals can be displayed at least at times for indicating the operating condition of the percussion unit.

Abstract: A fluid-operated percussion device (1) having a percussive piston (3), which alternately executes a work stroke and a return stroke due to the effect of a control. To avoid no-load strikes, in one embodiment of the percussion device (1), the percussive piston (3) is shut down if it has overshot the extended position occurring in normal operation (long- and/or short-stroke operation) by a predetermined distance in the work-stroke direction (arrow 3e) and reached a no-load-strike position. For this purpose, the interior (2d) of the work cylinder (2) that receives the percussive piston (3) additionally has a no load-strike opening (20a), which is connected to the pressure line (8) of the percussion device (1) with an interposed safety element (21) that can be switched between an inoperative position and an operative position.

Abstract: A fluid-operated percussion device (1) having a percussive piston (3), which alternately executes a work stroke and a return stroke due to the effect of a control. To avoid no-load strikes, in one embodiment of the percussion device (1), the percussive piston (3) is shut down if it has overshot the extended position occurring in normal operation (long- and/or short-stroke operation) by a predetermined distance in the work-stroke direction (arrow 3e) and reached a no-load-strike position. For this purpose, the interior (2d) of the work cylinder (2) that receives the percussive piston (3) additionally has a no-load-strike opening (20a), which is connected to the pressure line (8) of the percussion device (1) with an interposed safety element (21) that can be switched between an inoperative position and an operative position.

Abstract: A fluid-powered percussion tool includes a percussion piston which, under the effect of a control alternately performs a working stroke and a return stroke with the aid of a control valve. The control valve assumes a working stroke or a return stroke position, depending on the position of the percussion piston. In the working stroke position, the percussion piston is admitted with working pressure such that it performs a working stroke counter to the effect of a continuous reset force. In contrast, the percussion piston is connected in the return stroke position to a discharge line so that it performs a return stroke under the effect of the reset force. The control valve is admitted during the working stroke with working pressure and is thereby held in the working stroke position.

Abstract: A fluid-operated striker assembly includes a working cylinder and a striker piston slidably received in the working cylinder for executing working (forward) and return strokes. The striker piston delivers a blow to a tool bit during the working stroke when the striker piston is either in a limit position or in an advanced position which is beyond the limit position in the direction of the working stroke. A control arrangement applies an alternating fluid pressure to the striker piston to execute the working and return strokes. Further, a precontrol arrangement is provided for affecting the control arrangement dependent on whether the striker piston has exceeded its limit position.