|
Mechanical Linkage
A mechanical linkage is an assembly of systems connected so as 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 design ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Variable Stroke Engine (Autocar Handbook, Ninth Edition)
Variable may refer to: Computer science * Variable (computer science), a symbolic name associated with a value and whose associated value may be changed Mathematics * Variable (mathematics), a symbol that represents a quantity in a mathematical expression, as used in many sciences * Propositional variable, taking the value true or false in mathematical logic * Random variable, a variable in statistics whose value depends on random events ** Categorical variable, taking one of a finite number of values in a statistical problem, such as the head or tail result of a tossed coin ** Independent and identically distributed random variables, statistically independent and having the same probability distribution * Fluent (mathematics), a time-varying quantity as coined by Isaac Newton in his early calculus * State variable, used to describe the mathematical "state" of a dynamical system * Slack variable, inserted to transform an inequality constraint in an optimization problem into a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Watt Steam Engine
The Watt steam engine design was an invention of James Watt that became synonymous with steam engines during the Industrial Revolution, and it was many years before significantly new designs began to replace the basic Watt design. The Newcomen atmospheric engine, first steam engines, introduced by Thomas Newcomen in 1712, were of the "atmospheric" design. At the end of the power stroke (engine), power stroke, the weight of the object being moved by the engine pulled the piston to the top of the cylinder as steam was introduced. Then the cylinder was cooled by a spray of water, which caused the steam to condense, forming a partial vacuum in the cylinder. Atmospheric pressure on the top of the piston pushed it down, lifting the work object. James Watt noticed that it required significant amounts of heat to warm the cylinder back up to the point where steam could enter the cylinder without immediately condensing. When the cylinder was warm enough that it became filled with steam th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
4 Bar Linkage Animated
4 (four) is a number, numeral and digit. It is the natural number following 3 and preceding 5. It is a square number, the smallest semiprime and composite number, and is considered unlucky in many East Asian cultures. Evolution of the Hindu-Arabic digit Brahmic numerals represented 1, 2, and 3 with as many lines. 4 was simplified by joining its four lines into a cross that looks like the modern plus sign. The Shunga would add a horizontal line on top of the digit, and the Kshatrapa and Pallava evolved the digit to a point where the speed of writing was a secondary concern. The Arabs' 4 still had the early concept of the cross, but for the sake of efficiency, was made in one stroke by connecting the "western" end to the "northern" end; the "eastern" end was finished off with a curve. The Europeans dropped the finishing curve and gradually made the digit less cursive, ending up with a digit very close to the original Brahmin cross. While the shape of the character ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Burmester's Theory
In kinematics, Burmester theory comprises geometric techniques for synthesis of linkages. It was introduced in the late 19th century by Ludwig Burmester (1840–1927). His approach was to compute the geometric constraints of the linkage directly from the inventor's desired movement for a floating link. From this point of view a four-bar linkage is a floating link that has two points constrained to lie on two circles. Burmester began with a set of locations, often called ''poses'', for the floating link, which are viewed as snapshots of the constrained movement of this floating link in the device that is to be designed. The design of a crank for the linkage now becomes finding a point in the moving floating link that when viewed in each of these specified positions has a trajectory that lies on a circle. The dimension of the crank is the distance from the point in the floating link, called the circling point, to the center of the circle it travels on, called the center point. Two ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ferdinand Freudenstein
Ferdinand Freudenstein (12 May 1926 – 30 March 2006) was an American physicist and engineer known as the "Father of Modern Kinematics." Freudenstein applied digital computation to the kinematic synthesis of mechanisms. In his Ph.D. dissertation, he developed what became known as the Freudenstein equation, which uses a simple algebraic method to synthesize planar four-bar function generators. Early life Ferdinand Freudenstein was born into a Jewish family, on May 12, 1926, in Frankfurt, Germany. He was the son of a successful merchant George Freudenstein and Charlotte Rosenberg. At the age of ten, Freudenstein — along with his parents and two sisters — fled Nazi Germany for refuge in the Netherlands. In the spring of 1937, Freudenstein moved to England after having spent six months in the city of Amsterdam. In England, he joined his brother and studied in London. During Hitler's blitzkrieg, Freudenstein temporarily moved to Cambridge, England, for safety, and then spent se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pafnuty Chebyshev
Pafnuty Lvovich Chebyshev ( rus, Пафну́тий Льво́вич Чебышёв, p=pɐfˈnutʲɪj ˈlʲvovʲɪtɕ tɕɪbɨˈʂof) ( – ) was a Russian mathematician and considered to be the founding father of Russian mathematics. Chebyshev is known for his fundamental contributions to the fields of probability, statistics, mechanics, and number theory. A number of important mathematical concepts are named after him, including the Chebyshev inequality (which can be used to prove the weak law of large numbers), the Bertrand–Chebyshev theorem, Chebyshev polynomials, Chebyshev linkage, and Chebyshev bias. Transcription The surname Chebyshev has been transliterated in several different ways, like Tchebichef, Tchebychev, Tchebycheff, Tschebyschev, Tschebyschef, Tschebyscheff, Čebyčev, Čebyšev, Chebysheff, Chebychov, Chebyshov (according to native Russian speakers, this one provides the closest pronunciation in English to the correct pronunciation in old Russian ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Descriptive Geometry
Descriptive geometry is the branch of geometry which allows the representation of three-dimensional objects in two dimensions by using a specific set of procedures. The resulting techniques are important for engineering, architecture, design and in art. The theoretical basis for descriptive geometry is provided by graphical projection, planar geometric projections. The earliest known publication on the technique was "Underweysung der Messung mit dem Zirckel und Richtscheyt" (''Observation of the measurement with the compass and spirit level''), published in Linien, Nuremberg: 1525, by Albrecht Dürer. Italian architect Guarino Guarini was also a pioneer of projective and descriptive geometry, as is clear from his ''Placita Philosophica'' (1665), ''Euclides Adauctus'' (1671) and ''Architettura Civile'' (1686—not published until 1737), anticipating the work of Gaspard Monge (1746–1818), who is usually credited with the invention of descriptive geometry. Gaspard Monge is usu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ludwig Burmester
Ludwig Ernst Hans Burmester (5 May 1840 – 20 April 1927) was a German Kinematics, kinematician and geometer. His doctoral thesis (from German language, German: ''About the elements of a theory of isophotes'') concerned lines on a surface defined by light direction. After a period as a teacher in Łódź he became professor of synthetic geometry at Dresden where his growing interest in kinematics culminated in his (''Textbook of Kinematics, First Volume, Planar Motion'') of 1888, developing the approach to the theory of linkage (mechanical), linkages introduced by Franz Reuleaux, whereby a planar mechanism was understood as a collection of Euclidean planes in relative motion with one Degrees of freedom (mechanics), degree of freedom. Burmester considered both the theory of planar kinematics and practically all actual mechanisms known in his time. In doing so, Burmester developed Burmester theory which applies projective geometry to the loci of points on planes moving in straigh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Franz Reuleaux
Franz Reuleaux (; ; 30 September 1829 – 20 August 1905) was a German mechanical engineer and a lecturer at ''Technische Hochschule Berlin'' (today Technische Universität Berlin), later appointed as the president of the academy. He was often called the father of kinematics. He was a leader in his profession, contributing to many important domains of science and knowledge. Today, he may be best remembered for the Reuleaux triangle, a curve of constant width that he helped develop as a useful mechanical form. Biography Early life Reuleaux was born in Eschweiler in Germany (at the time part of Prussia). His father and grandfather were both mechanical engineers. His technical training was at the Karlsruhe Polytechnic School. He then studied at universities in Berlin and Bonn. Middle years After a time spent in the family business he became a professor at the Swiss Federal Institute in Zürich. Eventually, in 1879 he became Rector at the Königs Technischen Hochschule Berlin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jacob E
Jacob, later known as Israel, is a Hebrew patriarch of the Abrahamic religions. He first appears in the Torah, where he is described in the Book of Genesis as a son of Isaac and Rebecca. Accordingly, alongside his older fraternal twin brother Esau, Jacob's paternal grandparents are Abraham and Sarah and his maternal grandfather is Bethuel, whose wife is not mentioned. He is said to have bought Esau's birthright and, with his mother's help, deceived his aging father to bless him instead of Esau. Then, following a severe drought in his homeland Canaan, Jacob and his descendants migrated to neighbouring Egypt through the efforts of his son Joseph, who had become a confidant of the pharaoh. After dying in Egypt at the age of 147, he is supposed to have been buried in the Cave of Machpelah in Hebron. Per the Hebrew Bible, Jacob's progeny were beget by four women: his wives (and maternal cousins) Leah and Rachel; and his concubines Bilhah and Zilpah. His sons were, in orde ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Discrete & Computational Geometry
'' Discrete & Computational Geometry'' is a peer-reviewed mathematics journal published quarterly by Springer. Founded in 1986 by Jacob E. Goodman and Richard M. Pollack, the journal publishes articles on discrete geometry and computational geometry. Abstracting and indexing The journal is indexed in: * ''Mathematical Reviews'' * '' Zentralblatt MATH'' * ''Science Citation Index'' * ''Current Contents ''Current Contents'' is a rapid alerting service database from Clarivate, formerly the Institute for Scientific Information and Thomson Reuters. It is published online and in several different printed subject sections. History ''Current Contents ...'' Notable articles Two articles published in ''Discrete & Computational Geometry'', one by Gil Kalai in 1992 with a proof of a subexponential upper bound on the diameter of a polytope and another by Samuel Ferguson in 2006 on the Kepler conjecture on optimal three-dimensional sphere packing, earned their authors the Fulk ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alfred Kempe
Sir Alfred Bray Kempe FRS (6 July 1849 – 21 April 1922) was a mathematician best known for his work on linkages and the four colour theorem. Biography Kempe was the son of the Rector of St James's Church, Piccadilly, the Rev. John Edward Kempe. Among his brothers were Sir John Arrow Kempe and Harry Robert Kempe. He was educated at St Paul's School, London and then studied at Trinity College, Cambridge, where Arthur Cayley was one of his teachers. He graduated BA (22nd wrangler) in 1872. Despite his interest in mathematics he became a barrister, specialising in the ecclesiastical law. He was knighted in 1913, the same year he became the Chancellor for the Diocese of London. He was also Chancellor of the dioceses of Newcastle, Southwell, St Albans, Peterborough, Chichester, and Chelmsford. He received the honorary degree DCL from the University of Durham and he was elected a Bencher of the Inner Temple in 1909. In 1876 he published his article ''On a General Met ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
