Apparatus and method for cleaning façades on multi-story buildings

Abstract

The present invention relates to an automatic cleaning apparatus () for cleaning facades on multi-story buildings. The apparatus comprises a rotating brush () arranged rotatable about its longitudinal axis, a drive mechanism () for rotating the brush, a container () for housing a cleaning fluid, and a fluid feeding device adapted to feed the rotating brush with cleaning fluid from the container by means of capillarity forces. The apparatus is designed to engage to steering guides () provided on the facade. The apparatus is designed so that a downward movement of the apparatus is solely powered by gravity forces acting on the apparatus. The drive mechanism for rotating the brush comprises at least one drive wheel () arranged to be in contact with the surface of the facade and to generate a friction powered torque during downward movement of the cleaning apparatus, and a transmission unit arranged to transfer the torque of the drive wheel to the rotating brush to make the brush rotate during the downward movement. The apparatus further comprises a wiper device () arranged above the rotating brush and adapted to be in contact with the facade during cleaning to wipe off used cleaning fluid from the facade, and a fluid collecting member arranged to collect the cleaning fluid wiped off by the wiper device, and to transport the collected cleaning fluid to the container for reuse.