pantagraph

Pantograph Pan"to*graph, n. [Panto- + -graph: cf. F. pantographe.] An instrument for copying plans, maps, and other drawings, on the same, or on a reduced or an enlarged, scale. [Written also {pantagraph}, and incorrectly {pentagraph}.] [1913 Webster]

2. An electrical conducting device consisting of a collapsible frame resembling a pantograph[1], connected to the top of an electrically-powered vehicle such as a trolley, and used to conduct electrical current between the vehicle and an overhead electric wire, which supplies the power to the vehicle. The variable height of the pantograph ensures that it can move to follow variations in the height of the overhead wires, and thus make constant contact with the wires. [PJC]

{Skew pantograph}, a kind of pantograph for drawing a copy which is inclined with respect to the original figure; -- also called {plagiograph}. [1913 Webster]