Abstract: A safety system is provided for a machine tool which has a frame and a tool. The safety system has a clamping device and a motion device. The clamping device is movable by the motion device from a working position, in which the tool is extended and can be used for working, to a safety position, in which the tool is retracted. The motion device has a first magnetic means connected to or arranged on the tool and a second magnetic means connected to or arranged on the frame, such that movement of the tool by the motion device from the working position to the safety position can be triggered and/or at least partially performed by magnetic force.

Abstract: A method is provided for detecting a substance, preferably human tissue, in the vicinity of a mobile tool, wherein the substance to be detected has different electrical characteristics from a material that can be processed by the mobile tool. In the method, a change is detected in a capacitance formed by the tool and a counter electrode that is electrically insulated from the tool. A periodic change in the capacitance is detected and the change is produced by the presence of the substance in a region in relation to the tool and by a periodic change in a geometrical characteristic of the tool in this region as the tool moves.