The invention relates to a floor working machine for the surfaces of Floors and more particularly to a floor sanding machine comprising at least one rotary work plate which is adapted to perform such working or processing of the Floor during operation by means of a work means arranged on it, and is mounted on the lower side of the machine and which is connected for the transmission of rotation with a holding part, which is arranged coaxially over it, bears with at least a part of the weight of the machine on the work plate and is adapted to be driven by a motor of the machine.

Such a machine may be utilized for the sanding and brushing of floors, more especially wooden floors such as parquet floors, for the removal of any dirt adhering to the floor such as for example remains of fitted carpets and adhesives, and for the polishing of floors and the like. Such machines as a rule possess a chassis so that they can be moved over the floor by pushing or pulling. In this respect the work plates and the support wheels are so set in level in relation to each other that the work means applied to the lower side of the plate is planted on the floor and is then loaded by the weight of the machine to the extent that the weight is not taken up by the chassis or running gear.

If a conventional floor working machine is employed on an uneven, undulating floor the results generally leave to be desired. When a working plate arrives at a depression in the floor it will move over it leaving the depression more or less unprocessed, dependent on the depth thereof. When on the contrary it arrives at a projecting part of the floor there is the danger that the edge of the plate will plow into the surface of the floor.