An apparatus having a highly autonomously, self-moving system which reacts flexibly to impediments in the environment. It must be specifically noted in this context that such apparatus were known not used in shafts or channels and that the nature of the motion on the basis of bracing legs and motions...http://www.google.es/patents/US5574347?utm_source=gb-gplus-sharePatente US5574347 - Apparatus for locomotion in enclosed spaces
