Patent attributes
A robotic device for carrying loads is movable in a vertical direction between rails arranged in multiple rows at various levels with respect to ground. The robotic device has a frame, wheels coupled to the frame for moving the frame along the rails, and a platform provided on the frame to carry a first load when the frame is moved in a vertical direction between first rails and second rails arranged above the first rails. Movable carriages are configured for being moved in the vertical direction at distance greater than a distance between the first rails and the second rails. A lifting mechanism moves the carriages in the vertical direction with respect to the frame. Support handles are arranged on the movable carriages and configured for providing engagement with the first or second rails to raise the frame above the respective rails to a level sufficient to disengage the wheels from the respective rails.