Abstract: The invention proposes a grinder having a rocking shaft adapted to set a grinding tool into an oscillating movement about a rocking axis fixed to the device, the grinding tool having a grinding surface comprising at least one corner area. For the purpose of extracting the grinding dust, there is provided a suction hood, which can be fixed on the device and which communicates with a suction pipe. In order to prevent the risk of surface marks forming during micro-finishing of surfaces, and at the same time to guarantee efficient dust removal, the grinding surface is designed as a continuous, closed surface, without any openings, the suction hood enclosing the grinding tool from above and at least part of the lateral faces of the grinding tool. The suction pipe opens laterally into the suction hood in an area opposite the corner area of the grinding surface. Further, the suction hood comprises a suction chamber extending from the suction pipe to the corner area of the grinding tool.

Abstract: The invention proposes a method for grinding plastics or glass, in particular for grinding acrylic glass, where a mechanically driven grinding tool is moved across a surface to be finished (44). Grinding is effected by a dry process, without any liquid working agent, the grinding tool performing an orbital movement, or oscillating about a fixed rotary axis at high frequencies, while the grinding dust is extracted from the marginal area. The grinding tool comprises a closed abrasive with resiliently embedded abrasive grains, a plurality of the resiliently embedded abrasive grains having, preferably, level front surfaces which are delimited by relatively sharp edges at the transition to their lateral surfaces, the greatest part of the front surfaces being oriented to extend substantially in parallel to the surface to be worked (44). The method enables plastic and glass surfaces to be micro-finished to a particularly high grade (FIG. 1).

Abstract: An adapter for a grinding tool suited for standard attachment to a grinding machine is provided. The standard attachment comprises a receiving threaded bolt and an attachment nut for securing a supplementary tool in a usual manner. The grinding machine includes a motor-driven hollow spindle, to which a counterflange is firmly connected. A bolt receiving the standard attachment at one end thereof and guided by a flange can be screwed into the hollow spindle. Spring elements are provided for pressing the bolt and thereby the flange against the counterflange of the hollow spindle, in order to secure the standard attachment to the grinding tool. The hollow spindle can be axially displaced by a manual actuating device between an assembly position, in which the adapter may be taken off or attached, and a secured position, in which the adapter is secured against rotation and against axial movement within the hollow spindle.