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Universal Joints
A universal joint (also called a universal coupling or U-joint) is a joint or coupling connecting rigid shafts whose axes are inclined to each other. It is commonly used in shafts that transmit rotary motion. It consists of a pair of hinges located close together, oriented at 90° to each other, connected by a cross shaft. The universal joint is not a constant-velocity joint. U-joints are also sometimes called by various eponymous names, as follows: * Cardan joint, after Gerolamo Cardano, a polymath of the 16th century who contributed to knowledge of various clever mechanisms, including gimbals * Hooke joint or Hooke's joint, after Robert Hooke, a polymath of the 17th century who contributed to knowledge of various clever mechanisms * Spicer joint, after Clarence W. Spicer and the Spicer Manufacturing Company, who manufactured U joints * Hardy Spicer joint, after the Hardy Spicer brand, a successor to the Spicer brand History The main concept of the universal joint is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Universal Joint
A universal joint (also called a universal coupling or U-joint) is a joint or coupling connecting rigid shafts whose axes are inclined to each other. It is commonly used in shafts that transmit rotary motion. It consists of a pair of hinges located close together, oriented at 90° to each other, connected by a cross shaft. The universal joint is not a constant-velocity joint. U-joints are also sometimes called by various eponymous names, as follows: * Cardan joint, after Gerolamo Cardano, a polymath of the 16th century who contributed to knowledge of various clever mechanisms, including gimbals * Hooke joint or Hooke's joint, after Robert Hooke, a polymath of the 17th century who contributed to knowledge of various clever mechanisms * Spicer joint, after Clarence W. Spicer and the Spicer Manufacturing Company, who manufactured U joints * Hardy Spicer joint, after the Hardy Spicer brand, a successor to the Spicer brand History The main concept of the universal joint is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ballistae
The ballista (Latin, from Greek βαλλίστρα ''ballistra'' and that from βάλλω ''ballō'', "throw"), plural ballistae, sometimes called bolt thrower, was an ancient missile weapon that launched either bolts or stones at a distant target. Developed from earlier Greek weapons, it relied upon different mechanics, using two levers with torsion springs instead of a tension prod (the bow part of a modern crossbow). The springs consisted of several loops of twisted skeins. Early versions projected heavy darts or spherical stone projectiles of various sizes for siege warfare. It developed into a smaller precision weapon, the '' scorpio'', and possibly the ''polybolos''. Greek weapon The early ballistae in Ancient Greece were developed from two weapons called oxybeles and gastraphetes. The gastraphetes ('belly-bow') was a handheld crossbow. It had a composite prod and was spanned by bracing the front end of the weapon against the ground while placing the end of a slider ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dynamometer
A dynamometer or "dyno" for short, is a device for simultaneously measuring the torque and rotational speed (RPM) of an engine, motor or other rotating prime mover so that its instantaneous power may be calculated, and usually displayed by the dynamometer itself as kW or bhp. In addition to being used to determine the torque or power characteristics of a machine under test, dynamometers are employed in a number of other roles. In standard emissions testing cycles such as those defined by the United States Environmental Protection Agency, dynamometers are used to provide simulated road loading of either the engine (using an engine dynamometer) or full powertrain (using a chassis dynamometer). Beyond simple power and torque measurements, dynamometers can be used as part of a testbed for a variety of engine development activities, such as the calibration of engine management controllers, detailed investigations into combustion behavior, and tribology. In the medical terminology, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exposition Universelle (1867)
The International Exposition of 1867 (french: Exposition universelle 'art et d'industriede 1867), was the second world's fair to be held in Paris, from 1 April to 3 November 1867. A number of nations were represented at the fair. Following a decree of Emperor Napoleon III, the exposition was prepared as early as 1864, in the midst of the renovation of Paris, marking the culmination of the Second French Empire. Visitors included Tsar Alexander II of Russia, a brother of the King William and Otto von Bismarck of Prussia, Prince Metternich and Franz Josef of Austria, Ottoman Sultan Abdülaziz, and the Khedive of Egypt Isma'il. Conception In 1864, Napoleon III issued a decree stating that an international exposition should be held in Paris in 1867. A commission was appointed with Prince Jerome Napoleon as president, under whose direction the preliminary work began. The site chosen for the Exposition Universelle of 1867 was the Champ de Mars, the great military parade ground ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
French Language
French ( or ) is a Romance language of the Indo-European family. It descended from the Vulgar Latin of the Roman Empire, as did all Romance languages. French evolved from Gallo-Romance, the Latin spoken in Gaul, and more specifically in Northern Gaul. Its closest relatives are the other langues d'oïl—languages historically spoken in northern France and in southern Belgium, which French ( Francien) largely supplanted. French was also influenced by native Celtic languages of Northern Roman Gaul like Gallia Belgica and by the ( Germanic) Frankish language of the post-Roman Frankish invaders. Today, owing to France's past overseas expansion, there are numerous French-based creole languages, most notably Haitian Creole. A French-speaking person or nation may be referred to as Francophone in both English and French. French is an official language in 29 countries across multiple continents, most of which are members of the ''Organisation internationale de la Francophonie'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beauchamp Tower
Beauchamp Tower (13 January 1845 – 31 December 1904) was an English inventor and railway engineer who is chiefly known for his discovery of full-film or hydrodynamic lubrication. Early life Beauchamp Tower was born the son of Robert Beauchamp Tower, rector of Moreton, Essex and educated at Uppingham School, Rutland. He decided at the age of 16 that he wanted to become an engineer and received early training at the Armstrong Works at Elswick, where he stayed for a few months as a draughtsman after completing his four-year apprenticeship. Inventions Beauchamp Tower held several patents regarding an apparatus for maintaining a constant plane in a floating vessel. The apparatus is based on the gyroscopic principle. One of the possible applications of this patent was steadying guns on shipboard. In 1977, he was named by Duncan Dowson as one of the 23 "Men of Tribology". Influence Tower's work on lubrication influenced many other engineers, including Osborne Reynolds, wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brace (tool)
A brace is a hand tool used with a bit (drill bit or auger) to drill holes, usually in wood. Pressure is applied to the top and the tool is rotated with a U-shaped grip. Bits used come in a variety of types but the more commonly used Ridgeway- and Irwin- pattern bits also rely on a snail point (called the snail), which is a tapered screw point shaped the same as a wood screw thread, which helps to pull the bit into the wood as the user turns the brace handle and applies pressure The U-shaped part is a kind of crank. It gives the brace much greater torque than other kinds of hand-powered drills. A brace and bit can be used to drill much wider and deeper holes than can a geared hand-powered drill. The price of the greater torque is lower rotational speed; it is easy for a geared hand drill to achieve a rotational speed of several hundred revolutions per minute, but it requires considerable effort to achieve even 100 rpm with a brace. The front part of the brace consists of a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shay Locomotive
The Shay locomotive is a geared steam locomotive that originated and was primarily used in North America. The locomotives were built to the patents of Ephraim Shay, who has been credited with the popularization of the concept of a ''geared steam locomotive''. Although the design of Ephraim Shay's early locomotives differed from later ones, there is a clear line of development that joins all Shays. Shay locomotives were especially suited to logging, mining and industrial operations and could operate successfully on steep or poor quality track. Development Ephraim Shay (1839–1916), was a schoolteacher, a clerk in an American Civil War hospital, a civil servant, a logger, a merchant, a railway owner, and an inventor who lived in Michigan. In the 1860s, he became a logger and wanted a better way to move logs to the mill than on winter snow sleds. He built his own tramway in 1875, on gauge track on wooden ties, allowing him to log all year round. Two years later he develope ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jean-Victor Poncelet
Jean-Victor Poncelet (; 1 July 1788 – 22 December 1867) was a French engineer and mathematician who served most notably as the Commanding General of the École Polytechnique. He is considered a reviver of projective geometry, and his work ''Traité des propriétés projectives des figures'' is considered the first definitive text on the subject since Gérard Desargues' work on it in the 17th century. He later wrote an introduction to it: ''Applications d'analyse et de géométrie''. As a mathematician, his most notable work was in projective geometry, although an early collaboration with Charles Julien Brianchon provided a significant contribution to Feuerbach's theorem. He also made discoveries about projective harmonic conjugates; relating these to the poles and polar lines associated with conic sections. He developed the concept of parallel lines meeting at a point at infinity and defined the circular points at infinity that are on every circle of the plane. These discoverie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Robert Willis (engineer)
The Reverend Robert Willis (27 February 1800 – 28 February 1875) was an English academic. He was the first Cambridge professor to win widespread recognition as a mechanical engineer, and first to set the scientific study of vowels on a respectable foundation. He is now best remembered for his extensive writings on architectural history, including many studies of mediaeval cathedrals and a four-volume treatise on the architecture of the University of Cambridge. He was described by Pevsner as "the greatest English architectural historian of the 19th century". Biography Early life and first years in Cambridge Willis was born in London on 27 February 1800. His father was Dr Robert Darling Willis, physician to King George III. He was a grandson of Francis Willis. His paternal uncle was Rear Admiral Richard Willis. His health was delicate, which prevented him from going to school, and he was privately tutored. He showed talent in music, and as a draughtsman, and when he was 19 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Christopher Polhem
Christopher Polhammar (18 December 1661 – 30 August 1751) better known as Christopher Polhem (), which he took after his ennoblement in 1716, was a Swedish scientist, inventor and industrialist. He made significant contributions to the economic and industrial development of Sweden, particularly mining. He was ennobled by King Charles XII of Sweden for his contributions to Swedish technological development. Christopher Polhem Svenskt biografiskt lexicon Biography Polhem (Polhammar) was born on the island of in the small village of , situated northeast of ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Johannes Hevelius
Johannes Hevelius Some sources refer to Hevelius as Polish: * * * * * * * Some sources refer to Hevelius as German: * * * * *of the Royal Society * (in German also known as ''Hevel''; pl, Jan Heweliusz; – 28 January 1687) was a councillor and mayor of Gdańsk (Danzig), in the Polish–Lithuanian Commonwealth. As an astronomer, he gained a reputation as "the founder of lunar topography", and described ten new constellations, seven of which are still used by astronomers. Etymology According to the Polish Academy of Sciences (1975) the origin of the name goes back to the surname Hawke, a historical alternative spelling for the English word hawk, which changed into ''Hawelke'' or ''Hawelecke''. In Poland he is known as ''Jan Heweliusz''. Other versions of the name include Hewel, Hevel, Hevelke or Hoefel, Höwelcke, Höfelcke. According to Feliks Bentkowski (1814), during his early years he also signed as Hoefelius. Along with the Latinized version of his name, Ludwig Gü ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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