Pantograph - AbsoluteAstronomy.com

A pantograph is a mechanical linkage

Linkage (mechanical)

A mechanical linkage is an assembly of bodies connected together to manage forces and movement. The movement of a body, or link, is studied using geometry so the link is considered to be rigid. The connections between links are modeled as providing ideal movement, pure rotation or sliding for...

connected in a special manner based on parallelogram

Parallelogram

In Euclidean geometry, a parallelogram is a convex quadrilateral with two pairs of parallel sides. The opposite or facing sides of a parallelogram are of equal length and the opposite angles of a parallelogram are of equal measure...

s 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.

Because of their effectiveness at translating motion in a controlled fashion, pantographs have come to be used as a type of motion guide for objects large and small. A common example of the use of a pantograph assembly as mechanical guide frame is the extension arm of an adjustable wall-mounted mirror.

History

The first pantograph was constructed in 1603 by Christoph Scheiner

Christoph Scheiner

Christoph Scheiner SJ was a Jesuit priest, physicist and astronomer in Ingolstadt....

, who used the device to copy and scale diagrams, but he wrote about the invention over 27 years later, in "Pantographice" (Rome 1631).
One arm of the pantograph contained a small pointer, while the other held a drawing implement, and by moving the pointer over a diagram, a copy of the diagram was drawn on another piece of paper. By changing the positions of the arms in the linkage between the pointer arm and drawing arm, the scale of the image produced can be changed. A more complicated version called the eidograph was developed by William Wallace

William Wallace (mathematician)

William Wallace was a Scottish mathematician and astronomer who invented the eidograph.-Biography:Wallace was born at Dysart in Fife, where he received his school education...

(1768–1843) in 1831.

Drafting

The original use of the pantograph was for copying and scaling

Scaling (geometry)

In Euclidean geometry, uniform scaling is a linear transformation that enlarges or shrinks objects by a scale factor that is the same in all directions. The result of uniform scaling is similar to the original...

line drawings

Technical drawing

Technical drawing, also known as drafting or draughting, is the act and discipline of composing plans that visually communicate how something functions or has to be constructed.Drafting is the language of industry....

. Modern versions are sold as toys.

Sculpture and minting

In sculpture, a three-dimensional version of the pantograph was used, usually a large boom connected to a fixed point at one end, bearing two rotating pointing needles at arbitrary points along this boom. By adjusting the needles different enlargement or reduction ratios can be achieved. This device, now largely overtaken by computer guided

Computer-aided manufacturing

Computer-aided manufacturing is the use of computer software to control machine tools and related machinery in the manufacturing of workpieces. This is not the only definition for CAM, but it is the most common; CAM may also refer to the use of a computer to assist in all operations of a...

router

CNC Router

A Computer Numerical Controlled router is a computer controlled machine for composites, aluminum, steel, plastics, wood and foams. It is a specific version of a CNCtool....

systems that scan

3D scanner

A 3D scanner is a device that analyzes a real-world object or environment to collect data on its shape and possibly its appearance . The collected data can then be used to construct digital, three dimensional models....

a model

Scale model

A scale model is a physical model, a representation or copy of an object that is larger or smaller than the actual size of the object, which seeks to maintain the relative proportions of the physical size of the original object. Very often the scale model is used as a guide to making the object in...

and can produce it in a variety of materials and in any desired size, was first invented by inventor and steam pioneer James Watt

James Watt

James Watt, FRS, FRSE was a Scottish inventor and mechanical engineer whose improvements to the Newcomen steam engine were fundamental to the changes brought by the Industrial Revolution in both his native Great Britain and the rest of the world.While working as an instrument maker at the...

(1736–1819) and perfected by Benjamin Cheverton (1796–1876) in 1836. Cheverton's machine was fitted with a rotating cutting bit to carve reduced versions of well-known sculptures. Of course a three-dimensional pantograph can also be used to enlarge sculpture by interchanging the position of the model and the copy.

Another version is still very much in use to reduce the size of large relief

Relief

Relief is a sculptural technique. The term relief is from the Latin verb levo, to raise. To create a sculpture in relief is thus to give the impression that the sculpted material has been raised above the background plane...

designs for coin

Coin

A coin is a piece of hard material that is standardized in weight, is produced in large quantities in order to facilitate trade, and primarily can be used as a legal tender token for commerce in the designated country, region, or territory....

s down to the required size of the coin.

Acoustic cylinder duplication

One advantage of phonograph

Phonograph

The phonograph record player, or gramophone is a device introduced in 1877 that has had continued common use for reproducing sound recordings, although when first developed, the phonograph was used to both record and reproduce sounds...

and gramophone discs over cylinders in the 1890s—before electronic amplification was available—was that large numbers of discs could be stamped quickly and cheaply. In 1890, the only ways of manufacturing copies of a master cylinder were to mold the cylinders (which was slow and, early on, produced very poor copies), to record cylinders by the "round", over and over again, or to acoustically copy the sound by placing the horns of two phonographs together or to hook the two together with a rubber tube (one phonograph recording and the other playing the cylinder back). Edison

Thomas Edison

Thomas Alva Edison was an American inventor and businessman. He developed many devices that greatly influenced life around the world, including the phonograph, the motion picture camera, and a long-lasting, practical electric light bulb. In addition, he created the world’s first industrial...

, Bettini

Gianni Bettini

Gianni Bettini was an early audiophile. He made a number of high-end phonographs that are highly sought after today. He invented a playback device which improves the sound quality of recordings; The Micro-reproducer...

, Leon Douglass

Leon Douglass

Leon Forrest Douglass was an American inventor and co-founder of the Victor Talking Machine Company who registered approximately fifty patents, mostly for film and sound recording techniques.-Life and professional career:...

and others solved this problem (partly) by mechanically linking a cutting stylus and a playback stylus together and copying the "hill-and-dale" grooves of the cylinder mechanically. When molding improved somewhat, molded cylinders were used as pantograph masters. This was employed by Edison and Columbia

Columbia Records

Columbia Records is an American record label, owned by Japan's Sony Music Entertainment, operating under the Columbia Music Group with Aware Records. It was founded in 1888, evolving from an earlier enterprise, the American Graphophone Company — successor to the Volta Graphophone Company...

in 1898, and was used until about January 1902 (Columbia brown waxes after this were molded). Some companies like the United States Phonograph Co. of Newark, New Jersey

Newark, New Jersey

Newark is the largest city in the American state of New Jersey, and the seat of Essex County. As of the 2010 United States Census, Newark had a population of 277,140, maintaining its status as the largest municipality in New Jersey. It is the 68th largest city in the U.S...

, supplied cylinder masters for smaller companies so that they could duplicate them, sometimes pantographically. Pantographs could turn out about 30 records per day and produce up to about 150 records per master. In theory, pantograph masters could be used for 200 or 300 duplicates if the master and the duplicate were running in reverse and the record would be duplicated in reverse. This, in theory, could extend the usability of a pantograph master by using the unworn/lesser worn part of the recording for duplication. Pathé

Pathé

Pathé or Pathé Frères is the name of various French businesses founded and originally run by the Pathé Brothers of France.-History:...

employed this system with mastering their vertically-cut records until 1923; a 5 inches (127 mm), 4 or master cylinder, rotating at a high speed, would be recorded on. This was done as the resulting cylinder was considerably loud and of very high fidelity. Then, the cylinder would be placed on the mandrel of a duplicating pantograph that would be played with a stylus on the end of a lever, which would transfer the sound to a wax disc master, which would be electroplated and be used to stamp copies out. This system resulted in some fidelity reduction and rumble, but relatively high quality sound. Edison Diamond Disc Records

Edison Disc Record

The Edison Disc, also known as a Diamond Disc record, was a type of audio disc record marketed by Edison Records from 1912 to 1929. They were known as Diamond disc because the reproducer fitted to the matching Edison disc player was fitted with a diamond stylus...

were made by recording directly onto the wax master disc.

Milling machines

Before the advent of control technologies such as numerical control

Numerical control

Numerical control refers to the automation of machine tools that are operated by abstractly programmed commands encoded on a storage medium, as opposed to controlled manually via handwheels or levers, or mechanically automated via cams alone...

(NC and CNC) and programmable logic control

Programmable logic controller

A programmable logic controller or programmable controller is a digital computer used for automation of electromechanical processes, such as control of machinery on factory assembly lines, amusement rides, or light fixtures. PLCs are used in many industries and machines...

(PLC), duplicate parts being milled on a milling machine

Milling machine

A milling machine is a machine tool used to machine solid materials. Milling machines are often classed in two basic forms, horizontal and vertical, which refers to the orientation of the main spindle. Both types range in size from small, bench-mounted devices to room-sized machines...

could not have their contours mapped out by moving the milling cutter

Milling cutter

Milling cutters are cutting tools typically used in milling machines or machining centres . They remove material by their movement within the machine or directly from the cutter's shape .-Features of a milling cutter:Milling cutters come in several shapes and many sizes...

in a "connect-the-dots" ("by-the-numbers") fashion. The only ways to control the movement of the cutting tool were to dial the positions by hand using dexterous skill (with natural limits on a human's accuracy and precision

Accuracy and precision

In the fields of science, engineering, industry and statistics, the accuracy of a measurement system is the degree of closeness of measurements of a quantity to that quantity's actual value. The precision of a measurement system, also called reproducibility or repeatability, is the degree to which...

) or to trace a cam, template, or model in some way, and have the cutter mimic the movement of the tracing stylus. If the milling head was mounted on a pantograph, a duplicate part could be cut (and at various scales of magnification besides 1:1) simply by tracing a template. (The template itself was usually made by a tool and die maker

Tool and die maker

Tool and die makers are workers in the manufacturing industry who make jigs, fixtures, dies, molds, machine tools, cutting tools , gauges, and other tools used in manufacturing processes...

using toolroom

Toolroom

The term toolroom can refer to three related concepts. The concepts have evolved over the past two centuries as technology itself has evolved.- Storing tools :...

methods, including milling via dialing followed by hand sculpting with files

File (tool)

A file is a metalworking and woodworking tool used to cut fine amounts of material from a workpiece. It most commonly refers to the hand tool style, which takes the form of a steel bar with a case hardened surface and a series of sharp, parallel teeth. Most files have a narrow, pointed tang at one...

and/or die grinder

Die grinder

A die grinder is a handheld power tool used to grind, sand, hone, polish, or machine material, typically metal but also plastic or wood. They are usually pneumatically driven, although versions with electric and flexible shaft drive also exist...

points.) This was essentially the same concept as reproducing documents with a pen-equipped pantograph, but applied to the machining

Machining

Conventional machining is a form of subtractive manufacturing, in which a collection of material-working processes utilizing power-driven machine tools, such as saws, lathes, milling machines, and drill presses, are used with a sharp cutting tool to physical remove material to achieve a desired...

of hard materials such as metal, wood, or plastic. Pantograph routing, which is conceptually identical to pantograph milling, also exists (as does CNC routing).

The development and dissemination throughout industry of NC, CNC, PLC, and other control technologies provided a new way to control the movement of the milling cutter: via feeding information from a program to actuators (servo

Servo

Servo may refer to:* Servomechanism, or servo, a device used to provide control of a desired operation through the use of feedback** Servo , a small, cheap, mass-produced actuator used for radio control and small robotics** Servo bandwidth...

s, selsyns, leadscrew

Leadscrew

A leadscrew , also known as a power screw or translation screw, is a screw designed to translate turning motion into linear motion...

s, machine slides, spindles

Spindle (tool)

In machine tools, a spindle is a rotating axis of the machine, which often has a shaft at its heart. The shaft itself is called a spindle, but also, in shop-floor practice, the word often is used metonymically to refer to the entire rotary unit, including not only the shaft itself, but its bearings...

, and so on) that would move the cutter as the information directed. Today most commercial machining is done via such programmable, computerized methods. Home machinists are likely to work via manual control, but computerized control has reached the home-shop level as well (it's just not yet as pervasive as its commercial counterparts). Thus pantograph milling machines are largely a thing of the past. They are still in commercial use, but at a greatly reduced and ever-dwindling level. They are no longer built new by machine tool builders, but a small market for used machines still exists. As for the magnification-and-reduction feature of a pantograph (with the scale determined by the adjustable arm lengths), it is achieved in CNC via mathematic calculations that the computer applies to the program information practically instantaneously. Scaling functions (as well as mirroring functions) are built into languages such as G-code

G-code

G-code is the common name for the most widely used computer numerical control programming language, which has many implementations. Used mainly in automation, it is part of computer-aided engineering. G-code is sometimes called G programming language...

Other uses

Perhaps the pantograph that is most familiar to the general public is the extension arm of an adjustable wall-mounted mirror.

In another application similar to drafting, the pantograph is incorporated into a pantograph engraving machine with a revolving cutter instead of a pen, and a tray at the pointer end to fix precut lettered plates (referred to as 'copy'), which the pointer follows and thus the cutter, via the pantograph, reproduces the 'copy' at a ratio to which the pantograph arms have been set. The typical range of ratio is Maximum 1:1 Minimum 50:1 (reduction) In this way machinists can neatly and accurately engrave

Engraving

Engraving is the practice of incising a design on to a hard, usually flat surface, by cutting grooves into it. The result may be a decorated object in itself, as when silver, gold, steel, or glass are engraved, or may provide an intaglio printing plate, of copper or another metal, for printing...

numbers and letters onto a part.

The device which maintains electrical contact with the contact wire

Railway electrification system

A railway electrification system supplies electrical energy to railway locomotives and multiple units as well as trams so that they can operate without having an on-board prime mover. There are several different electrification systems in use throughout the world...

and transfers power from the wire to the traction unit

Railway electric traction

Railway electric traction describes the various types of locomotive and multiple units that are used on electrification systems around the world.-History:...

, used in electric locomotive

Electric locomotive

An electric locomotive is a locomotive powered by electricity from overhead lines, a third rail or an on-board energy storage device...

s and 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, is also called a "pantograph

Pantograph (rail)

A pantograph for rail lines is a hinged electric-rod device that collects electric current from overhead lines for electric trains or trams. The pantograph typically connects to a one-wire line, with the track acting as the ground wire...

".

Certain types of trains on the New York City Subway

New York City Subway

The New York City Subway is a rapid transit system owned by the City of New York and leased to the New York City Transit Authority, a subsidiary agency of the Metropolitan Transportation Authority and also known as MTA New York City Transit...

use end pantograph gates (which, to avoid interference, compress under spring pressure around curves while the train is en-route) to prevent passengers on station platforms from falling into the gaps between the cars.

Herman Hollerith

Herman Hollerith

Herman Hollerith was an American statistician who developed a mechanical tabulator based on punched cards to rapidly tabulate statistics from millions of pieces of data. He was the founder of one of the companies that later merged and became IBM.-Personal life:Hollerith was born in Buffalo, New...

's "Keyboard punch" used for the 1890 U.S. Census was a pantograph design and sometimes referred to as "The Pantograph Punch".

An early 19th-century device employing this mechanism is the polygraph

Polygraph (duplicating device)

A Polygraph is a device that produces a copy of a piece of writing simultaneously with the creation of the original, using pens and ink.Patented by John Isaac Hawkins in 1803, it was most famously used by the third U.S. president, Thomas Jefferson, who acquired his first polygraph in 1804, later...

, which produces a duplicate of a letter as the original is written.

Longarm quilting

Longarm quilting

Longarm quilting is the process by which a longarm sewing machine is used to sew together a quilt top, quilt batting and quilt backing into a finished quilt.The longarm sewing machine typically ranges from 10 to 14 feet in length...

machine operators may trace a pantograph, paper pattern, with a laser pointer to stitch a custom pattern onto the quilt.

Linn Boyd Benton

Linn Boyd Benton

Linn Boyd Benton was an American typeface designer and inventor who invented the Benton Pantograph, an engraving machine which was capable not only of scaling a single font design pattern to a variety of sizes, but could also condense, extend, and slant the design...

invented a pantographic engraving machine for type design, which was capable not only of scaling a single font design pattern to a variety of sizes, but could also condense, extend, and slant the design (mathematically, these are cases of affine transformation

Affine transformation

In geometry, an affine transformation or affine map or an affinity is a transformation which preserves straight lines. It is the most general class of transformations with this property...

, which is the fundamental geometric operation of most systems of digital typography today, including PostScript

PostScript

PostScript is a dynamically typed concatenative programming language created by John Warnock and Charles Geschke in 1982. It is best known for its use as a page description language in the electronic and desktop publishing areas. Adobe PostScript 3 is also the worldwide printing and imaging...

).

Pantographs are also used as guide frames in heavy-duty applications including scissor lifts, material handling equipment

Material handling equipment

Material handling equipment is all equipment that relates to the movement, storage, control and protection of materials, goods and products throughout the process of manufacturing, distribution, consumption and disposal...

, stage lifts and specialty hinges (such as for panel doors on boats and airplanes).

Richard Feynman

Richard Feynman

Richard Phillips Feynman was an American physicist known for his work in the path integral formulation of quantum mechanics, the theory of quantum electrodynamics and the physics of the superfluidity of supercooled liquid helium, as well as in particle physics...

used the analogy of a pantograph as a way of scaling down tools to the nanometer scale in his talk There's Plenty of Room at the Bottom

There's Plenty of Room at the Bottom

There's Plenty of Room at the Bottom is the title of a lecture given by physicist Richard Feynman at an American Physical Society meeting at Caltech on December 29, 1959...

External links

The source of this article is wikipedia, the free encyclopedia. The text of this article is licensed under the GFDL.