A floating self-propelled cleaning device (10) for water surfaces, in
particular swimming pools, comprises a central floating body (11) and two
side floating elements (12) to it connected at opposite sides by two arms
(14) to which two net-shaped collecting containers (13) are fastened. The
net-shaped containers (13) have openings (17) that allow the inlet of
impurities, but prevent the outlet thereof during possible stops or under
the action of waves that can occur during the travel on the water
surface. The floating device (10) is driven by propelling means (20) and
(30) that substantially cause the side floating elements (12) to rotate
about an instantaneous centre of rotation located approximately at the
central body (11). The rotation of the side floating elements (12) is
associated to a shifting movement caused by at least a distribution
element (15) movable with respect to the floating body (10). The sum of
these two effects provides a resulting trajectory of the device (10) that
causes the net-shaped containers (13) to sweep the whole water surface.