Devices for moving on vertical surfaces, tools for cleaning vertical surfaces and systems for cleaning vertical surfaces

A system for cleaning a substantially vertical surface, the system comprising:

• a device for moving on the substantially vertical surface, the device comprises:
• a cleaning tool connector,
• a frame,
• a first arm connected to the frame and rotatable with respect to the frame about a first axis,
• a first vacuum suction cup connected to the first arm,
• a second arm connected to the frame and rotatable with respect to the frame about a second axis that is substantially parallel to the first axis,
• a second vacuum suction cup connected to the second arm,
• a vacuum pump in fluid communication with the first vacuum suction cup and the second vacuum suction cup,
• a first valve to control generation of vacuum in and release of vacuum from the first vacuum suction cup,
• a second valve to control generation of vacuum in and release of vacuum from the second vacuum suction cup, and
• a controller to control:
• rotation of the first arm and the second arm, and
• operation of the vacuum pump, the first valve and the second valve;
• and
• a cleaning tool connectable to the cleaning tool connector, the cleaning tool is movable with respect to the device in a substantially vertical direction to clean the substantially vertical surface.