Patent attributes
A system is disclosed comprising a tractor vehicle, at least one trailer vehicle and a skin between and in contact with the tractor and trailer vehicles. One of the tractor and trailer vehicles is disposed in a non-inverted position above the skin and the other is disposed in an inverted position below the skin. The trailer vehicle comprises one or more magnets, while the tractor vehicle comprises one or more magnets magnetically coupled to each opposing magnet on the trailer vehicle. For example, the tractor and trailer vehicles may have mutually opposing permanent magnets in one-to-one relationship. Alternatively, each permanent magnet on the trailer vehicle could be opposed by one or more electro-permanent magnets on the tractor vehicle. The magnetic coupling between the magnets on the tractor and trailer vehicles produces an attraction force. The system further comprises means for maintaining the attraction force within a range as the tractor and trailer vehicles move along a portion of the skin having a varying thickness.