A power supply chain having a pair of parallel chain strands spaced by connecting webs provided with cross arms and separators defining openings for the accommodation of power lines. The cross arms, the separators, or both are adjustable to enable the sizes of the openings to be varied to fit power lines...http://www.google.es/patents/US4198812?utm_source=gb-gplus-sharePatente US4198812 - Power supply chain
