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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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pantographic Knife
A pantographic knife or paratrooper knife is a 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 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 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 A paratrooper is a military parachutist—someone ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Engraving
Engraving is the practice of incising a design onto a hard, usually flat surface by cutting grooves into it with a burin. 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 images on paper as prints or illustrations; these images are also called "engravings". Engraving is one of the oldest and most important techniques in printmaking. Wood engraving is a form of relief printing and is not covered in this article, same with rock engravings like petroglyphs. Engraving was a historically important method of producing images on paper in artistic printmaking, in mapmaking, and also for commercial reproductions and illustrations for books and magazines. It has long been replaced by various photographic processes in its commercial applications and, partly because of the difficulty of learning the technique, is much less common in printmaking, wher ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 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 (1739–1805) and John Playfair, to whom his abilities had become known. After various changes of situation, dictated mainly by a desire to gain time for s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scissor Lift
An aerial work platform (AWP), also known as an aerial device, elevating work platform (EWP), cherry picker, bucket truck or mobile elevating work platform (MEWP) is a mechanical device used to provide temporary access for people or equipment to inaccessible areas, usually at height. There are distinct types of mechanized access platforms and the individual types may also be known as a "cherry picker", "boom lift" or "scissor lift". They are generally used for temporary, flexible access purposes such as maintenance and construction work or by firefighters for emergency access, which distinguishes them from permanent access equipment such as elevators. They are designed to lift limited weights — usually less than a ton, although some have a higher safe working load (SWL) — distinguishing them from most types of cranes. They are usually capable of being set up and operated by a single person. Regardless of the task they are used for, aerial work platforms may prov ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 contra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hero Of Alexandria
Hero of Alexandria (; grc-gre, Ἥρων ὁ Ἀλεξανδρεύς, ''Heron ho Alexandreus'', also known as Heron of Alexandria ; 60 AD) was a Greek mathematician and engineer who was active in his native city of Alexandria, Roman Egypt. He is often considered the greatest experimenter of antiquity and his work is representative of the Hellenistic scientific tradition. Hero published a well-recognized description of a steam-powered device called an ''aeolipile'' (sometimes called a "Hero engine"). Among his most famous inventions was a windwheel, constituting the earliest instance of wind harnessing on land. He is said to have been a follower of the atomists. In his work ''Mechanics'', he described pantographs. Some of his ideas were derived from the works of Ctesibius. In mathematics he is mostly remembered for Heron's formula, a way to calculate the area of a triangle using only the lengths of its sides. Much of Hero's original writings and designs have been lost ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Technical Drawing
Technical drawing, drafting or drawing, is the act and discipline of composing drawings that visually communicate how something functions or is constructed. Technical drawing is essential for communicating ideas in industry and engineering. To make the drawings easier to understand, people use familiar symbols, perspectives, units of measurement, notation systems, visual styles, and page layout. Together, such 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 meanings are multiply determined. Technical drawings are understood to have one intended meaning. A drafter, dra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
