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Pantograph
A pantograph (, from their original use for copying writing) 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. Using the same principle, different kinds of pantographs are used for other forms of duplication in areas such as sculpting, minting, engraving, and milling. Because of the shape of the original device, a pantograph also refers to a kind of structure that can compress or extend like an accordion, forming a characteristic rhomboidal pattern. This can be found in extension arms for wall-mounted mirrors, temporary fences, pantographic knives, scissor lifts, and other scissor mechanisms such as the pantograph used on electric locomotives and trams. History The ancient Greek engineer Hero of Alexandria described pant ...
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Pantograph In Action
A pantograph (, from their original use for copying writing) 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. Using the same principle, different kinds of pantographs are used for other forms of duplication in areas such as sculpting, minting, engraving, and milling. Because of the shape of the original device, a pantograph also refers to a kind of structure that can compress or extend like an accordion, forming a characteristic rhomboidal pattern. This can be found in extension arms for wall-mounted mirrors, temporary fences, pantographic knives, scissor lifts, and other scissor mechanisms such as the pantograph used on electric locomotives and trams. History The ancient Greek engineer Hero of Alexandria described pant ...
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Pantograph01
A pantograph (, from their original use for copying writing) 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. Using the same principle, different kinds of pantographs are used for other forms of duplication in areas such as sculpting, minting, engraving, and milling. Because of the shape of the original device, a pantograph also refers to a kind of structure that can compress or extend like an accordion, forming a characteristic rhomboidal pattern. This can be found in extension arms for wall-mounted mirrors, temporary fences, pantographic knives, scissor lifts, and other scissor mechanisms such as the pantograph used on electric locomotives and trams. History The ancient Greek engineer Hero of Alexandria described pant ...
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Pantograph Animation
A pantograph (, from their original use for copying writing) 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. Using the same principle, different kinds of pantographs are used for other forms of duplication in areas such as sculpting, minting, engraving, and milling. Because of the shape of the original device, a pantograph also refers to a kind of structure that can compress or extend like an accordion, forming a characteristic rhomboidal pattern. This can be found in extension arms for wall-mounted mirrors, temporary fences, pantographic knives, scissor lifts, and other scissor mechanisms such as the pantograph used on electric locomotives and trams. History The ancient Greek engineer Hero of Alexandria described pant ...
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Pantograph (rail)
A pantograph (or "pan" or "panto") is an apparatus mounted on the roof of an electric train, tram or electric bus to collect power through contact with an overhead line. By contrast, battery electric buses and trains are charged at charging stations. The pantograph is a common type of current collector; typically, a single or double wire is used, with the return current running through the rails. The term stems from the resemblance of some styles to the mechanical pantographs used for copying handwriting and drawings. Invention The pantograph, with a low-friction, replaceable graphite contact strip or "shoe" to minimise lateral stress on the contact wire, first appeared in the late 19th century. Early versions include the bow collector, invented in 1889 by Walter Reichel, chief engineer at Siemens & Halske in Germany, and a flat slide-pantograph first used in 1895 by the Baltimore and Ohio Railroad The familiar diamond-shaped roller pantograph was devised and patented b ...
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Christoph Scheiner
Christoph Scheiner SJ (25 July 1573 (or 1575) – 18 June 1650) was a Jesuit priest, physicist and astronomer in Ingolstadt. Biography Augsburg/Dillingen: 1591–1605 Scheiner was born in Markt Wald near Mindelheim in Swabia, earlier markgravate Burgau, possession of the House of Habsburg. He attended the Jesuit St. Salvator Grammar School in Augsburg from May 1591 until 24 October 1595. He graduated as a "rhetor" and entered the Jesuit Order in Landsberg am Lech on 26 October 1595. At the local seminary, he served his biennial novitiate (1595–1597) under the tutelage of Novice Master Father Rupert Reindl SJ. From 1597 to 1598, he finished his lower studies of rhetoric in Augsburg. He took his first vows before Father Melchior Stör, SJ and received the minor orders from the Augsburg suffragan bishop Sebastian Breuning. He spent the years 1598–1601 in Ingolstadt studying philosophy (metaphysics and mathematics). In 1603, Scheiner invented the pantograph, "Lake Cou ...
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Linkage (mechanical)
A mechanical linkage is an assembly of systems connected 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 example, and are called joints. A linkage modeled as a network of rigid links and ideal joints is called a kinematic chain. Linkages may be constructed from open chains, closed chains, or a combination of open and closed chains. Each link in a chain is connected by a joint to one or more other links. Thus, a kinematic chain can be modeled as a graph in which the links are paths and the joints are vertices, which is called a linkage graph. The movement of an ideal joint is generally associated with a subgroup of the group of Euclidean displacements. The number of parameters in the subgroup is called the degrees of freedom (DOF) of the joint. Mechanical linkages are usually designed to tra ...
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Scissor Mechanism
A scissors mechanism uses linked, folding supports in a criss-cross 'X' pattern. Workings Extension is achieved by applying pressure to the outside of a set of supports located at one end of the mechanism, elongating the crossing pattern. This can be achieved through hydraulic, pneumatic, mechanical or simply muscular means. It may require no power to return to its original position, but simply a release of the original pressure. Also used in kinematics of mechanisms Uses This mechanism is used in devices such as lift tables and scissor lifts. Modern low-profile computer keyboards make an extensive use of it as well, installing each key on a scissor support to ensure their smooth vertical movement, allowing the use of a cheap and reliable rubber dome contact set, instead of expensive and complex array of mechanical switches. See also * Pantograph * Telescopic cylinder * Linear actuator A linear actuator is an actuator that creates motion in a straight line, in contrast ...
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Pantographic Knife
A pantographic knife or paratrooper knife is a Pocketknife, folding knife whose blade is opened by a unique scissors method. The blade has a slightly longer tang than a folding knife heel. The handle is symmetrically segmented and articulated to fold away on both sides to grip the longer tang. The manner is similar to a butterfly knife (also called a Balisong knife after its modern place of origin)—with which it is often confused. Unlike the balisong knife handles that swing freely and independently, the pantographic knife uses a pantograph Linkage (mechanical), linkage to keep the handles aligned during opening and closing. The pantographic knife is very strong when compared to most other folding knife designs, being joined at several points and along several Plane (mathematics), planes—this increases the force required to break the blade away from the handle. By enclosing the blade on both sides, double edged blades can be used. This knife is also known as a ''paratrooper kni ...
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William Wallace (mathematician)
William Wallace LLD (23 September 176828 April 1843) was a Scottish mathematician and astronomer who invented the eidograph (an improved pantograph). Life Wallace was born at Dysart, Fife, Dysart in Fife, the son of Alexander Wallace, a leather manufacturer, and his wife, Janet Simson. He received his school education in Dysart and Kirkcaldy. In 1784 his family moved to Edinburgh, where he himself was set to learn the trade of a bookbinder. In 1790 he appears as "William Wallace, bookbinder" living and trading at Cowgatehead, at the east end of the Grassmarket. His taste for mathematics had already developed itself, and he made such use of his leisure hours that before the completion of his apprenticeship he had made considerable acquirements in geometry, algebra and astronomy. He was further assisted in his studies by John Robison (physicist), John Robison (1739–1805) and John Playfair, to whom his abilities had become known. After various changes of situation, dictated ...
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Scaling (geometry)
In affine geometry, uniform scaling (or isotropic scaling) is a linear transformation that enlarges (increases) or shrinks (diminishes) objects by a ''scale factor'' that is the same in all directions. The result of uniform scaling is similarity (geometry), similar (in the geometric sense) to the original. A scale factor of 1 is normally allowed, so that congruence (geometry), congruent shapes are also classed as similar. Uniform scaling happens, for example, when enlarging or reducing a photograph, or when creating a scale model of a building, car, airplane, etc. More general is scaling with a separate scale factor for each axis direction. Non-uniform scaling (anisotropic scaling) is obtained when at least one of the scaling factors is different from the others; a special case is directional scaling or stretching (in one direction). Non-uniform scaling changes the shape of the object; e.g. a square may change into a rectangle, or into a parallelogram if the sides of the squar ...
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Technical Drawing
Technical drawing, drafting or drawing, is the act and Academic discipline, discipline of composing Plan (drawing), drawings that Visual communication, visually communicate how something functions or is constructed. Technical drawing is essential for communicating ideas in Manufacturing, industry and engineering. To make the drawings easier to understand, people use familiar symbols, Perspective (graphical), perspectives, units of measurement, notation systems, visual styles, and page layout. Together, such Convention (norm), conventions constitute a visual language and help to ensure that the drawing is unambiguous and relatively easy to understand. Many of the symbols and principles of technical drawing are codified in an international standard called ISO 128. The need for precise communication in the preparation of a functional document distinguishes technical drawing from the expressive drawing of the visual arts. Artistic drawings are subjectively interpreted; their meanin ...
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Pathé News
Pathé News was a producer of newsreels and documentaries from 1910 to 1970 in the United Kingdom. Its founder, Charles Pathé, was a pioneer of moving pictures in the silent era. The Pathé News archive is known today as British Pathé. Its collection of news film and movies is fully digitised and available online. History Its roots lie in 1896 Paris, France, when Société Pathé Frères was founded by Charles Pathé and his brothers, who pioneered the development of the moving image. Charles Pathé adopted the national emblem of France, the cockerel, as the trademark for his company. After the company, now called Compagnie Générale des Éstablissements Pathé Frère Phonographes & Cinématographes, invented the cinema newsreel with ''Pathé-Journal''. French Pathé began its newsreel in 1908 and opened a newsreel office in Wardour Street, London in 1910. The newsreels were shown in the cinema and were silent until 1928. At first, they ran for about four minutes and were ...
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