Patent ID: 8092282

Claim:
A device at a mobile grinding machine for stone materials and other hard flooring materials that includes a rotatably driven disc-shaped housing arranged to support a plurality of grinding disc holders rotatably driven by a motor, which holders are distributed along a circumference of the housing and are supported by shafts connected to the housing at a mutual distance from each other, the device comprising: a gear rim disposed internally in a casing surrounding the housing, situated concentrically with a driven center shaft, and non-turnably connected to the casing; at least one intermediate coupling cogwheel, wherein each shaft supporting a grinding disc holder supports an intermediate coupling cogwheel that cooperates non-turnably with the respective shaft and with the gear rim; and a seal arranged between the gear rim and the housing, formed of a grinding supporting drum, and extending along their outer peripheries; wherein the gear rim has a through opening for the shaft driven by the motor, and upon being driven by the motor, the grinding disc holders and the housing are driven to rotate in different directions in relation to each other.