Pantograph

Pantograph in action

Pantograph animation

Pantograph01

Eidographe2

Pantograph etching mechanism

Francis Galton's pantograph

Pantograph is a mechanical linkage connected in a manner based on parallelograms so that the movement of one pen, in tracing an image, produces identical movements in a second pen. If a line drawing is traced by the first point, an identical, enlarged, or miniaturized copy will be drawn by a pen fixed to the other. By adjusting the arms of the pantograph, the size of the copy can be changed. Pantographs can also be used to scale a three-dimensional object. The principle of the pantograph is used in various tools and devices, particularly in the fields of drafting, engineering, and metalworking.

History

The pantograph was invented in the 17th century by the German scientist and inventor Christoph Scheiner, who used it to copy and scale diagrams. Later, it became a crucial tool in the field of technical drawing and cartography before the advent of modern computing and digital imaging technologies.

Design and Operation

A pantograph comprises four flat, rigid rods connected in a diamond shape. One arm is fixed, while the opposite arm holds the tracing stylus. The other two arms are free to pivot, and a drawing implement is attached to one of these. As the tracing stylus moves over a diagram, the configuration of the parallelogram linkage causes the drawing implement to mimic the motion, thereby creating a copy of the diagram. The size of the output can be altered by changing the lengths of the arms, which adjusts the ratio of the movement between the tracing stylus and the drawing implement.

Applications

Drafting and Art

In the past, pantographs were widely used in drafting and art to create duplicates of plans, maps, and artworks. Artists, particularly those working on large projects, used pantographs to scale their preliminary sketches.

Engraving and Minting

Pantographs are also used in engraving and minting. In engraving, a pantograph is used to carve copies of a design into metal, wood, or other materials. In minting, pantographs are used to create the dies that stamp the designs onto coins or medals.

Rail Transport

In rail transport, a pantograph is a device mounted on the roof of an electric train, tram, or electric bus to collect power through contact with an overhead line. While functionally different from the mechanical linkage pantograph, it shares the principle of maintaining an optimal working position through a parallelogram arrangement.

Modern Developments

With the advent of digital technology, the use of pantographs in drafting and art has largely been supplanted by computer-aided design (CAD) software. However, pantographs still find applications in modern manufacturing processes, particularly in engraving and minting, where they are used alongside or integrated with digital technologies.

See Also

• Linkage (mechanical)
• Computer-aided design
• Engraving
• Rail transport