Patent attributes
A system 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 vehicles is disposed in a non-inverted position above the skin and the other is inverted and 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. The 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 system further comprises means for maintaining the magnetic attraction force within a range as the vehicles move along a portion of the skin having a varying thickness.