A pantograph for rail lines is a hinged electric-rod device that collects electric current from overhead lines

Overhead lines

Overhead lines or overhead wires are used to transmit electrical energy to trams, trolleybuses or trains at a distance from the energy supply point...

 for electric train

Train

A train is a connected series of vehicles for rail transport that move along a track to transport cargo or passengers from one place to another place. The track usually consists of two rails, but might also be a monorail or maglev guideway.Propulsion for the train is provided by a separate...

s or tram

Tram

A tram is a passenger rail vehicle which runs on tracks along public urban streets and also sometimes on separate rights of way. It may also run between cities and/or towns , and/or partially grade separated even in the cities...

s. The pantograph typically connects to a one-wire line, with the track acting as the ground wire. The term stems from the resemblance to pantograph lever-rod devices

Pantograph

A pantograph is a mechanical linkage connected in a special manner based on parallelograms so that the movement of one pen, in tracing an image, produces identical movements in a second pen...

 for copying handwriting and drawings.
A flat slide-pantograph was invented in 1895 at the Baltimore & Ohio Railroad and in Germany in 1900 by Siemens

Siemens

Siemens may refer toSiemens, a German family name carried by generations of telecommunications industrialists, including:* Werner von Siemens , inventor, founder of Siemens AG...

 & Halske.
The familiar diamond-shaped roller pantograph was invented by John Q.