pantograph

pan·to·graph   (pān'tə-grāf')    n.   An instrument for copying a plane figure to a desired scale, consisting of styluses for tracing and copying mounted on four jointed rods in the form of a parallelogram with extended sides. A similarly jointed framework, such as a power-collecting trolley on an electric locomotive or an extensible telephone arm. [Greek panto-, all; see pantomime + -graph.] pan'to·graph'ic adj.

Main Entry: pan·to·graph
Pronunciation: 'pant-&-"graf
Function: noun
: an instrument for copying (as from a radiograph) on a predeterminedscale consisting of four light rigid bars jointed in parallelogram form

pantograph

instrument for duplicating a motion or copying a geometric shape to a reduced or enlarged scale. It consists of an assemblage of rigid bars adjustably joined by pin joints; as the point of one bar is moved over the outline to be duplicated, the motion is translated to a point on another bar, which makes the desired copy according to the predetermined scale. In the the links 2, 3, 4, and 5 are connected by pin joints at O, A, B, and C. Joint O is fixed to a support, while joints A, B, and C are free to move. Link 5 is a solid bar continuing on to Q. Point P is the guided point and is usually fixed on link 4. As P is guided on a specific path, such as the square in the , point Q will follow a similar path on an enlarged scale. Conversely, if point Q is guided, point P will follow a similar path on a reduced scale

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