Abstract: In a quick-action clamping device for axially securing a disk-shaped tool, particularly a grinding wheel on a flange of a driven spindle that has a clamping part provided with a thread that can be screwed to the thread of the spindle. The disk-shaped tool is held clamped between contact surfaces of the flange and the clamping part whose spacing from one another can be changed. It is proposed to avoid complete release of the tension nut during spindle stop operation in that the tool is pressed against the flange by means of at least one additional holding surface via a spring force, and that this additional holding surface is connected to the spindle in a manner secured against relative rotation.

Abstract: An electric motor has a ferrous core extending along, rotatable about, and centered on an axis. This core is formed with axial slots and has opposite end edges centered on the axis. A winding extends along the slots of the core and has opposite axial ends extending axially beyond the core. A fan on the core circulates air axially over the core and winding. Respective deflector cages on the winding ends each include an inner ring, an outer ring fitted over the respective end edge of the core, and a plurality of ribs extending axially and radially between the rings and projecting generally axially from the respective winding end. The ribs are spaced apart on the respective winding end such that the winding end is exposed between the ribs. Thus on rotation of the rotor, particles blown by the fan are deflected by the ribs before they engage the winding ends.

Abstract: A portable electric grinder wherein the grinding wheel is held against rotation relative to the spindle by two annular clamping rings. The spindle has a motor-driven hollow outer shaft and an inner shaft which is installed in the outer shaft and can be held against rotation with the outer shaft by a manually depressible arresting member. One of the clamping rings rotates with the hollow shaft and the other clamping ring mates with the inner shaft. When the inner shaft is held against rotation and the motor is started for a short interval of time, the hollow shaft rotates the one clamping ring which rotates the grinding wheel and the other clamping ring by friction so that the grip of the clamping rings upon the grinding wheel is loosened and the grinding wheel can be fully separated from the spindle by completing the unscrewing of the other clamping ring from the inner shaft. The motor drives the hollow shaft through the medium of a step-down transmission.