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Dovetail Joint
A dovetail joint or simply dovetail is a joinery technique most commonly used in woodworking joinery (carpentry), including furniture, cabinets, log buildings, and traditional timber framing. Noted for its resistance to being pulled apart (tensile strength), the dovetail joint is commonly used to join the sides of a drawer to the front. A series of 'pins' cut to extend from the end of one board interlock with a series of 'tails' cut into the end of another board. The pins and tails have a trapezoidal shape. Once glued, a wooden dovetail joint requires no mechanical fasteners. History The dovetail joint technique probably pre-dates written history. Some of the earliest known examples of the dovetail joint are in ancient Egyptian furniture entombed with mummies dating from First Dynasty, the tombs of Chinese emperors, and a stone pillar at the Vazhappally Maha Siva Temple in India. The dovetail design is an important method of distinguishing various periods of furniture. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Joinery
Joinery is a part of woodworking that involves joining pieces of wood, engineered lumber, or synthetic substitutes (such as laminate), to produce more complex items. Some woodworking joints employ mechanical fasteners, bindings, or adhesives, while others use only wood elements (such as dowels or plain mortise and tenon fittings). The characteristics of wooden joints - strength, flexibility, toughness, appearance, etc. - derive from the properties of the materials involved and the purpose of the joint. Therefore, different joinery techniques are used to meet differing requirements. For example, the joinery used to construct a house can be different from that used to make cabinetry or furniture, although some concepts overlap. While a form of carpentry elsewhere, in British English usage it is distinguished from it, which is considered to be a form of structural timber work. History Many traditional wood joinery techniques use the distinctive material properties of wood, often ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Woodworking Joints
Joinery is a part of woodworking that involves joining pieces of wood, engineered lumber, or synthetic substitutes (such as laminate), to produce more complex items. Some woodworking joints employ mechanical fasteners, bindings, or adhesives, while others use only wood elements (such as dowels or plain mortise and tenon fittings). The characteristics of wooden joints - strength, flexibility, toughness, appearance, etc. - derive from the properties of the materials involved and the purpose of the joint. Therefore, different joinery techniques are used to meet differing requirements. For example, the joinery used to construct a house can be different from that used to make cabinetry or furniture, although some concepts overlap. While a form of carpentry elsewhere, in British English usage it is distinguished from it, which is considered to be a form of structural timber work. History Many traditional wood joinery techniques use the distinctive material properties of wood, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ironbridge2
Ironbridge is a large village in the borough of Telford and Wrekin in Shropshire, England. Located on the bank of the River Severn, at the heart of the Ironbridge Gorge, it lies in the civil parish of The Gorge. Ironbridge developed beside, and takes its name from, The Iron Bridge, a cast iron bridge that was built in 1779. History The area around Ironbridge is described by those promoting it as a tourist destination as the "Birthplace of the Industrial Revolution". This description is based on the idea that Abraham Darby perfected the technique of smelting iron with coke, in Coalbrookdale, allowing much cheaper production of iron. However, the industrial revolution did not begin in any one place. Darby's iron smelting was but one small part of this generalised revolution and was soon superseded by the great iron-smelting areas. However, the bridge – being the first of its kind fabricated from cast iron, and one of the few which have survived to the present day&nbs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pistol Slide
The slide on the majority of fully/semi-automatic pistols is the upper part that reciprocates ("slides") with recoil during the gun's operating cycle. It serves as the bolt carrier group (BCG) and partly as the receiver, and generally houses the firing pin/ striker, the extractor and frequently also the barrel, and provides a mounting platform for iron and optical sights. Through the principles of short recoil or simple blowback operations, the slide is moved backwards with each shot by the energy of expanding gasses caused by the combusting propellant (often a nitrocellulose-based smokeless powder, very rarely black powder). Because the slide is spring-loaded, once at the rearmost position, the spring tension will push it back towards the front. Generally, this slide movement cycle serves three functions: the extractor will empty the chamber by pulling out the spent casing from the previous shot (which then gets removed out of the gun by the ejector), the slide inertia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Receiver (firearms)
In firearms terminology, the firearm frame or receiver is the part of a firearm which integrates other components by providing housing for internal action components such as the hammer, bolt or breechblock, firing pin and extractor, and has threaded interfaces for externally attaching ("receiving") components such as the barrel, stock, trigger mechanism and iron/ optical sights. The receiver is often made of forged, machined, or stamped steel or aluminium; in addition to these traditional materials, modern science and engineering have introduced polymers and sintered metal powders to receiver construction. Mounting A barrel can be fixed to the receiver using barrel and receiver action threads or similar methods. In US law For the purposes of United States law, the receiver or frame is legally the firearm, and as such it is the controlled part. The definition of which assembly is the legal receiver varies from firearm to firearm, under US law. Generally, the law req ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dovetail Rail
A dovetail rail or dovetail mount can refer to several types of sliding rail system found on firearms primarily for mounting telescopic sights. Colloquially, the term ''dovetail rail'' usually refer to any straight mounting bracket with an inverted trapezoid (dovetail) cross-section (though the hexagonal-profiled Weaver rail and Picatinny rail are also derivative dovetail designs) running parallel to the bore for mounting a scope or diopter sight to a rifle. These are sometimes also called "tip-off" mounts, and allow the user to easily take on or off the sight. ''Dovetail mount'' can also refer to a dovetail track running perpendicular to the bore (see "Other uses" below). Dovetail rails for rifles Dovetails come in several different types and sizes depending on manufacturer, but the most common are the 11 mm and inch (9.5 mm). Some other less known, but currently commercially available dovetail mounts, are 12, 13, 13.5, 14, 14.5, 16, 16.5, 17 and 19 mm, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iron Sights
Iron sights are a system of physical alignment markers (usually made of metallic material) used as a sighting device to assist the accurate aiming of ranged weapons (such as a firearm, airgun, crossbow or even compound bow), or less commonly as a primitive finder sight for optical telescopes. The earliest sighting device, it relies completely on the viewer's naked eye (mostly under ambient lighting), and is distinctly different to optical sights such as telescopic sights, reflector (reflex) sights, holographic sights and laser sights, which make use of optical manipulation and/or active illumination, as well as the newer optoelectronics, which use digital imaging and even incorporate augmented reality. Iron sights are typically composed of two components mounted perpendicularly above the weapon's bore axis: a rear sight nearer (or ''proximally'') to the shooter's eye, and a front sight farther forward (or ''distally'') near the muzzle. During aiming, the shooter alig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
3D Printing
3D printing or additive manufacturing is the construction of a three-dimensional object from a CAD model or a digital 3D model. It can be done in a variety of processes in which material is deposited, joined or solidified under computer control, with material being added together (such as plastics, liquids or powder grains being fused), typically layer by layer. In the 1980s, 3D printing techniques were considered suitable only for the production of functional or aesthetic prototypes, and a more appropriate term for it at the time was rapid prototyping. , the precision, repeatability, and material range of 3D printing have increased to the point that some 3D printing processes are considered viable as an industrial-production technology, whereby the term ''additive manufacturing'' can be used synonymously with ''3D printing''. One of the key advantages of 3D printing is the ability to produce very complex shapes or geometries that would be otherwise impossible to construct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fastnet Lighthouse
Fastnet Lighthouse is a 54m high lighthouse situated on the remote Fastnet Rock in the Atlantic Ocean. It is the most southerly point of Ireland and lies southwest of Cape Clear Island and from County Cork on the Irish mainland. The current lighthouse is the second to be built on the rock and is the tallest in Ireland. First lighthouse Construction of the first lighthouse began in 1853, and it first produced a light on 1 January 1854. The lighthouse replaced an early one built on Cape Clear Island in 1818, partly motivated by the loss of an American sailing packet, ''Stephen Whitney'', in thick fog during November 1847 on nearby West Calf Island causing the death of 92 of her 110 passengers and crew. The new lighthouse was constructed of cast iron with an inner lining of brick and was designed by George Halpin. Costing £17,390, the tower was tall with a high lantern structure on top, giving a total height of around . It had an oil-burning lamp of 38 kilocandelas; in contr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eddystone Lighthouse
The Eddystone Lighthouse is a lighthouse that is located on the dangerous Eddystone Rocks, south of Rame Head in Cornwall, England. The rocks are submerged below the surface of the sea and are composed of Precambrian gneiss. View at 1:50000 scale The current structure is the fourth to be built on the site. The first lighthouse (Winstanley's) was swept away in a powerful storm, killing its architect and five other men in the process. The second (Rudyard's) stood for fifty years before it burned down. The third (Smeaton's) is renowned because of its influence on lighthouse design and its importance in the development of concrete for building; its upper portions were re-erected in Plymouth as a monument. The first lighthouse, completed in 1699, was the world's first open ocean lighthouse, although the Cordouan Lighthouse off the western French coast preceded it as the first offshore lighthouse. The need for a light The Eddystone Rocks are an extensive reef approximately 12 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NASA Tech Briefs
The National Aeronautics and Space Administration is required by its charter to report to industry any new, commercially significant technologies developed in the course of their R&D. Since the early 1960s, this has been accomplished primarily through the publication of ''NASA Tech Briefs''. ''NASA Tech Briefs'' were first published about 1963 by the Technology Utilization Office at NASA HQ (Washington DC) as single page documents. Over the years, hundreds of such documents were published and disseminated covering many areas of science and industry. The material for these documents was collected by TU offices in each of the NASA field centers, as well as from all of their contractors. Most work done under NASA contract was presumed to be the property of NASA and was freely disseminated to industry and the public. Compilations of these became available in the 1970s. Since then, it has been a joint publishing venture of NASA and Tech Briefs Media Group, a unit of SAE International ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turbine
A turbine ( or ) (from the Greek , ''tyrbē'', or Latin ''turbo'', meaning vortex) is a rotary mechanical device that extracts energy from a fluid flow and converts it into useful work. The work produced by a turbine can be used for generating electrical power when combined with a generator.Munson, Bruce Roy, T. H. Okiishi, and Wade W. Huebsch. "Turbomachines." Fundamentals of Fluid Mechanics. 6th ed. Hoboken, NJ: J. Wiley & Sons, 2009. Print. A turbine is a turbomachine with at least one moving part called a rotor assembly, which is a shaft or drum with blades attached. Moving fluid acts on the blades so that they move and impart rotational energy to the rotor. Early turbine examples are windmills and waterwheels. Gas, steam, and water turbines have a casing around the blades that contains and controls the working fluid. Credit for invention of the steam turbine is given both to Anglo-Irish engineer Sir Charles Parsons (1854–1931) for invention of the reaction turbine, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
