3. Current collector: pantograph

The pantograph is one of the two components of the overhead line feeder system. Its name derives from an old-fashioned drawing tool in the shape of a double-jointed rhombus, which was used to copy an outline. Until the 1960s, locomotive pantographs were shaped like hinged rhombuses. Since then, they have been simplified in the form of a double articulated frame (figure 20 ).

Roof-mounted, it equips most electrically-powered rolling stock, including tramways, operating on DC or single-phase voltage. Its main functions are electrical and mechanical