Pantograph

A pantograph is a mechanical linkage system that is used for duplicating the shape of one object onto another. Its key feature is a parallelogram-shaped frame made of four bars. These bars are connected at their ends by pivots, allowing the frame to expand and contract while maintaining its rectangular shape. By keeping one point fixed and moving another point along a master drawing or template, a stylus attached to the opposite corner will trace an identical, enlarged, or reduced copy of the original shape. Early uses included drawing and engraving, allowing for accurate reproduction of artwork and maps.

Modern applications of the pantograph principle are found in various fields. In electric vehicles, such as trains and trams, a pantograph is a familiar sight mounted on the roof. This type of pantograph is an articulated arm that collects electric current from overhead wires. It uses a spring-loaded mechanism to maintain contact with the wire, ensuring a continuous power supply to the vehicle's motor. Another common use is in robotic arms and industrial machinery, where pantograph linkages provide precise and controlled movement for tasks like welding or assembly. The ability to scale movement is also utilized in some adjustable desks and lifting platforms.