Abstract: One embodiment of the present invention includes a waveguide. The waveguide comprises an elongated member having a conductive bottom surface and a hollow channel. The hollow channel is defined by a first conductive sidewall, a second conductive sidewall, and a conductive inner surface. The waveguide also comprises a plurality of conductive ridge portions projecting from the conductive inner surface and extending between the first conductive sidewall and the second conductive sidewall. The conductive ridge portions can partition the hollow channel into a plurality of hollow recesses. The waveguide further comprises a plurality of switches associated with each of at least one of the plurality of conductive ridge portions. At least one of the plurality of switches associated with a respective one of the plurality of conductive ridge portions can be activated to couple the respective one of the plurality of conductive ridge portions to the conductive bottom surface.

Abstract: A hard floor sweeping and scrubbing machine includes a mobile body comprising a frame supported on wheels for travel over a surface, a motorized cleaning head, a waste hopper, a hopper lift and a vacuum squeegee. The motorized cleaning head is attached to the mobile body and is configured to perform sweeping and scrubbing operations on the surface. The waste hopper is positioned on a rear side of the cleaning head and is configured to receive waste discharged from the cleaning head during the surface sweeping operations. The hopper lift is configured to raise the waste hopper from an operating position, in which the waste hopper is positioned adjacent the cleaning head, to a dumping position, in which the waste hopper is positioned to dump waste collected in the waste hopper. In one embodiment, the vacuum squeegee is attached to the hopper lift. Also disclosed is a method of cleaning a surface using embodiments of the machine.

Abstract: A cleaning head for use with a floor cleaning machine comprises first and second cleaning tools, at least one motor and a cleaning tool support. The at least one motor is configured to respectively drive rotation of the first and second cleaning tools about first and second horizontal axes. The first and second cleaning tools each have an exterior cleaning surface configured to engage the floor during floor cleaning operations. The cleaning tool support is configured to support the first and second cleaning tools for movement of the first and second horizontal axes relative to each other in a plane that is transverse to the first and second horizontal axes. Another embodiment of the invention is directed to a floor cleaning machine that includes embodiments of the cleaning head.