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Chain
A chain is a serial assembly of connected pieces, called links, typically made of metal, with an overall character similar to that of a rope in that it is flexible and curved in compression but linear, rigid, and load-bearing in tension. A chain may consist of two or more links. Chains can be classified by their design, which can be dictated by their use: * Those designed for lifting, such as when used with a hoist; for pulling; or for securing, such as with a bicycle lock, have links that are torus-shaped, which make the chain flexible in two dimensions (the fixed third dimension being a chain's length). Small chains serving as jewellery are a mostly decorative analogue of such types. * Those designed for transferring power in machines have links designed to mesh with the teeth of the sprockets of the machine, and are flexible in only one dimension. They are known as roller chains, though there are also non-roller chains such as block chains. Two distinct chains can be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chainsaw
A chainsaw (or chain saw) is a portable handheld power saw, power saw that cuts with a set of teeth attached to a rotating chain driven along a guide bar. Modern chainsaws are typically gasoline or electric and are used in activities such as tree felling, limbing, Log bucking, bucking, pruning, cutting firebreaks in wildland fire suppression, harvesting of Wood fuel#Firewood, firewood, for use in Chainsaw carving, chainsaw art and chainsaw mills, for cutting concrete, and cutting ice. Precursors to modern chainsaws were first used in surgery, with patents for wood chainsaws beginning in the late 19th century. A chainsaw comprises an engine, a drive mechanism, a guide bar, a cutting chain, a tensioning mechanism, and safety features. Various safety practices and working techniques are used with chainsaws. History In surgery A "flexible saw", consisting of a fine serrated link chain held between two wooden handles, was pioneered in the late 18th century (–1785) by two Scot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Roller Chain
Roller chain or bush roller chain is the type of chain drive most commonly used for transmission of mechanical power on many kinds of domestic, industrial and agricultural machinery, including conveyors, wire- and tube-drawing machines, printing presses, cars, motorcycles, and bicycles. It consists of a series of short cylindrical rollers held together by side links. It is driven by a toothed wheel called a sprocket. It is a simple, reliable, and efficientAs much as 98% efficient under ideal conditions, according to means of power transmission. Sketches by Leonardo da Vinci in the 16th century show a chain with a roller bearing. In 1800, James Fussell patented a roller chain on development of his balance lock and in 1880 Hans Renold patented a bush roller chain. Construction There are two types of links alternating in the bush roller chain. The first type is inner links, having two inner plates held together by two sleeves or bushings upon which rotate two rol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chain Stopper
A chain is a serial assembly of connected pieces, called links, typically made of metal, with an overall character similar to that of a rope in that it is flexible and curved in compression but linear, rigid, and load-bearing in tension. A chain may consist of two or more links. Chains can be classified by their design, which can be dictated by their use: * Those designed for lifting, such as when used with a hoist; for pulling; or for securing, such as with a bicycle lock, have links that are torus-shaped, which make the chain flexible in two dimensions (the fixed third dimension being a chain's length). Small chains serving as jewellery are a mostly decorative analogue of such types. * Those designed for transferring power in machines have links designed to mesh with the teeth of the sprockets of the machine, and are flexible in only one dimension. They are known as roller chains, though there are also non-roller chains such as block chains. Two distinct chains can be c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bicycle Chain
A bicycle chain is a roller chain that transfers power (physics), power from the Bicycle pedal, pedals to the Drive wheel, drive-Bicycle wheel, wheel of a bicycle, thus propelling it. Most bicycle chains are made from carbon steel, plain carbon or alloy steel, but some are nickel electroplating, nickel-plated to prevent rust, or simply for aesthetics. History Obsolete chain designs previously used on bicycles included the bar-link chain, block chain, the skip-link chain, and the Simpson lever chain. The first chains were of a simple, bushing-less design. These had inherent reliability problems and a bit more friction (and mechanical efficiency losses) than modern chains. With these limitations in mind, the Nevoigt brothers, of the German Diamant (German bicycle company), Diamant Bicycle Company, designed the roller chain in 1898, which uses bushings. More recently, the "bushingless roller chain" design has superseded the bushed chain. This design incorporates the bearing surfac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jewellery Chain
Jewellery chains, jewelry chains or body chains are metal chains that are used in jewellery to encircle parts of the body, namely the neck, wrists and ankles, and they also serve as points to hang decorative charms and pendants. Material Jewellery chains are typically made from precious metals, mainly gold and silver. Platinum, palladium and stainless steel, steel may also be used. These metals are used because they are not very reactive, keep both their intricate shape and their strength, and require only minimal maintenance to keep their shine. Small lever mechanisms called clasps serve as fastenings to enable the chain to be undone and redone. History The earliest chain necklaces have been found in ancient Babylonia among jewellery dating back to 2500 BC. The tomb of Puabi, Queen Puabi, who was buried in 2600 BC, included several gold chains that she wore in different ways. The old Greek, Roman and Egyptian civilisations followed later. An intricate 4th or 5th century Roman ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saw Chain
The saw chain, or cutting chain, is a key component of a chainsaw. It consists of steel links held together by rivets, and superficially resembles the bicycle-style roller chain, although it is closer in design to a leaf chain. Its key differences are sharp cutting teeth on the outside of the chain loop, and flat drive links on the inside, to retain the chain on the saw's bar and allow propulsion by the engine or motor. Saw chains (and chainsaws generally) are used for cutting wood. This may be for harvesting trees for pulp or timber, for tree surgery, or for processing firewood. Whether for hand-held chainsaws, Harvester (forestry), mechanical timber harvesters or chain mortisers, the saw chain has undergone dramatic development since its invention. Modern chains designed for high power, high-speed sawing applications will vastly outperform older designs, while allowing a far greater degree of safety and reliability in use. Principles of saw chain operation Saw chains operate b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Belly Chain
A belly chain or waist chain is the popular English term for the Indian jewelry called ''kamarbandh''. The belly chain is a type of body jewelry worn around the waist. Some belly chains attach to a navel piercing; these are also called "pierced belly chains". They are often made of silver or gold. Sometimes a thread is used around the waist instead of a chain. The chain may be delicate and thin, or heavy and thick. Belly chains are considered auspicious for women in Indian culture. History The use of waist chains can be traced back to 4000 years or more originating in the Indian Subcontinent. Historically, waist chains have been used in India, by men and women, as ornaments and as part of religious ceremonies, as accessories and to show affluence. Many ancient sculptures and paintings from locations in India, dating back to the Indus Valley civilization, indicate that waist chains were a very popular jewelry. Many deities in the Hinduism, such as Lord Krishna, wore waist chain ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chain Pumps
The chain pump is type of a water pump in which several circular discs are positioned on an endless chain. One part of the chain dips into the water, and the chain runs through a tube, slightly bigger than the diameter of the discs. As the chain is drawn up the tube, water becomes trapped between the discs and is lifted to and discharged at the top. Chain pumps were used for centuries in the ancient Middle East, Europe, and China. In the Near East and Europe The earliest evidence for this device is in a Babylonian text from about 700 B.C. They were commonly powered by humans or animals. The device then appeared in ancient Egypt from about 200 B.C., featuring a pair of gear-wheels. A version of the chain pump was used in ancient Greece and Rome, sometimes with pots, or scoops fixed to the chain, which, as they passed over the top pulley, tipped the water out; a 2nd-century example is preserved in London. Philo of Byzantium wrote of such a device in the 2nd century B.C.; the historia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chain Gun
A chain gun is a type of autocannon or machine gun that uses an external source of power to cycle the weapon's action via a continuous loop of chain, similar to that used on a motorcycle or bicycle, instead of diverting excess energy from the cartridges' propellant as in a typical automatic firearm. History In 1972, Hughes Helicopters began a company-funded research effort to design a single machine gun to fire the U.S. Army's M50 round. In April 1973, the program fired test rounds in more powerful WECOM linked ammunition, from a prototype A model. In January 1975, a model "C" was added, a linkless version for the proposed Advanced Attack Helicopter YAH-64. The helicopter was later adopted as the Hughes Model 77/AH-64A Apache, with the model C receiving the designation M230 chain gun as its standard armament. In 1976, Hughes Helicopters patented the chain gun, and it has since been further developed into several other systems of different calibers.Richardson & Peaco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sprocket
A sprocket, sprocket-wheel or chainwheel is a profiled wheel A wheel is a rotating component (typically circular in shape) that is intended to turn on an axle Bearing (mechanical), bearing. The wheel is one of the key components of the wheel and axle which is one of the Simple machine, six simple machin ... with teeth that mesh with a chain, rack and pinion, rack or other perforated or indented material. The name 'sprocket' applies generally to any wheel upon which radial projections engage a chain passing over it. It is distinguished from a gear in that sprockets are never meshed together directly, and differs from a pulley in that sprockets have teeth and pulleys are smooth except for timing pulleys used with toothed belts. Sprockets are used in bicycles, motorcycles, continuous track, tracked vehicles, and other machinery either to transmit rotary motion between two shafts where gears are unsuitable or to impart linear motion to a track, tape etc. Perhaps the most commo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Livery Collar
A livery collar or chain of office is a collar (jewelry), collar or heavy Link chain, chain, usually of gold, worn as insignia of office or a mark of fealty or other association in Europe from the Middle Ages onwards. One of the oldest and best-known livery collars is the #Collar of Esses, Collar of Esses, which has been in continuous use in England since the 14th century. History Origins Various forms of livery were used in the Middle Ages to denote attachment to a great person by friends, servants, and political supporters. The collar, usually of precious metal, was the grandest form of these, usually given by the person the livery denoted to his closest or most important associates, but should not, in the early period, be seen as separate from the wider phenomenon of livery badges, clothes and other forms. From the collar hung a heraldic badge, badge or device indicating the person the livery related to; the most important part of the ensemble for contemporaries. Equally gold ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bicycle Lock
A bicycle lock is a security device used to deter bicycle theft, either by simply locking one of the wheels or by fastening the bicycle to a fixed object, e.g., a bike rack. Locking devices vary in size and security, the most secure tending to be the largest, heaviest and least portable. Thus, like other security equipment, bicycle locks must balance the competing interests of security, portability, and cost. Some are made of particularly expensive materials chosen for their acceptable strength and low density. Types U-locks and D-locks A U-lock is a rigid metal ring in the shape of the letter U. The U part of the lock attaches to a crossbar section, and for this reason they are also called ''D-locks.'' To lock the bicycle, one locks it physically to some other object, such as a bike rack, parking meter or other pole installed securely in the solid ground. Merely locking the bike frame to the wheel is not recommended because, although it cannot be rolled away, the entire bi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
