A chain is a set of links or rings linked together, which serve to hold, stretch and transmit movement in machines. It is an object built using links, generally metal, that interlock with each other. They have been used since ancient times due to their strength combined with flexibility.
Its uses range from security to keep something fastened, for this you need a Padlock that joins both ends and to hold heavy objects.
Chains can be classified by their design, which can be dictated by their use:
Two different chains can be connected using a quick link,[1] carabiner, shackle or fork.
A chain can be joined to other elements. Load can be transferred from one chain to another object using a chain stopper.
History
The metal link chain has been in use since at least 225 BC. C.[2] The Romans never went to war without wearing protective chains for the prisoners and they had them made of iron, silver and even gold, to put them according to the class or rank of the prisoners or the defeated. Roman soldiers who had distinguished themselves in war received some chains as a reward from their captains with which they adorned themselves as a testimony of their good services or deeds.
Some ancient peoples, among them the Israelites, had a type of chains that Jeremiah "Jeremiah (prophet)" speaks of, at the top of which there was a type of ring "Argolla (punishment)") with a triangular shape, into which they made the prisoners or slaves put their heads, then tying their hands with the same chain, in the two corners of the base of the triangle or ring.
Among the Romans, when a man was taken prisoner, a chain was tied to his right arm and the other end of it was secured to the left arm of the soldier in charge of guarding him. On certain occasions, a chain was placed on the prisoner's right arm and another on his left, each of which was secured at the other end to the left arm of the two soldiers assigned to guard him.
When a judge wanted to secretly interrogate a prisoner guarded in this way, he would have the soldier untied and the judge himself would then have the end of the chain. This way of keeping a prisoner often made the precaution of locking him in a prison useless and he could live with his guard in a private house. It was not always simple soldiers who tied themselves up with the prisoners: several tribunes and centurions were sometimes seen assigned to carry out this painful task.
Quick links for industry
Introduction
A chain is a set of links or rings linked together, which serve to hold, stretch and transmit movement in machines. It is an object built using links, generally metal, that interlock with each other. They have been used since ancient times due to their strength combined with flexibility.
Its uses range from security to keep something fastened, for this you need a Padlock that joins both ends and to hold heavy objects.
Chains can be classified by their design, which can be dictated by their use:
Two different chains can be connected using a quick link,[1] carabiner, shackle or fork.
A chain can be joined to other elements. Load can be transferred from one chain to another object using a chain stopper.
History
The metal link chain has been in use since at least 225 BC. C.[2] The Romans never went to war without wearing protective chains for the prisoners and they had them made of iron, silver and even gold, to put them according to the class or rank of the prisoners or the defeated. Roman soldiers who had distinguished themselves in war received some chains as a reward from their captains with which they adorned themselves as a testimony of their good services or deeds.
Some ancient peoples, among them the Israelites, had a type of chains that Jeremiah "Jeremiah (prophet)" speaks of, at the top of which there was a type of ring "Argolla (punishment)") with a triangular shape, into which they made the prisoners or slaves put their heads, then tying their hands with the same chain, in the two corners of the base of the triangle or ring.
Among the Romans, when a man was taken prisoner, a chain was tied to his right arm and the other end of it was secured to the left arm of the soldier in charge of guarding him. On certain occasions, a chain was placed on the prisoner's right arm and another on his left, each of which was secured at the other end to the left arm of the two soldiers assigned to guard him.
When a judge wanted to secretly interrogate a prisoner guarded in this way, he would have the soldier untied and the judge himself would then have the end of the chain. This way of keeping a prisoner often made the precaution of locking him in a prison useless and he could live with his guard in a private house. It was not always simple soldiers who tied themselves up with the prisoners: several tribunes and centurions were sometimes seen assigned to carry out this painful task.
Flavius Josephus tells that it was customary among the Romans to break chains and not untie them when an accused was acquitted of his alleged crime. Tito ordered a security to be brought to break that of this same historian so that no one would doubt his innocence. The freedmen consecrated the chains they had worn during their slavery to the Lares gods. Horace mentions this use in his Satires.
Chains made of precious metals were part of the Roman ornaments and many of them were found in excavations that have been carried out at various times. Furthermore, Horace himself speaks about them in his Epistles.[3].
In the 19th century, Leonardo da Vinci made sketches of what appears to be the first steel chain. These chains were probably designed to transmit tensile force, not sheath force, because they consist only of plates and pins and have metal hardware. However, da Vinci's sketch shows a roller bearing.
It took some time for technology to catch up with the concept. Steel manufacturing and processing problems prevented the growth of chains until the 19th century, when new technologies made steel chains and bearings a reality. In the 19th century, a Frenchman named Gull obtained a patent for a similar bicycle chain. This chain, called a "Gull chain", is still used today in pendant applications.
When the cast chain was invented in the 19th century, things started moving pretty quickly. First came the molded detachable chain, composed of identical molded links. Then came the pivot chain, which has an independent pin. The cast detachable chain and pivot chain have been refined over the years and are still used in some special applications. They are being replaced - gradually - by high pitch steel conveyor chains.
At the end of the century, a new development - the bushing - revolutionized the steel chain. Chains with bushings had greater wear resistance than the Gaviota chain because the bushing acted as a bearing, protecting the pin. At this point, the network's story goes into superspeed. The chain with steel bushings was used in bicycles, in the rear-wheel drive of early automobiles, and, in 1903, as a propeller in the Wright brothers' airplane.
Development in underground mining
In underground mining, development moved from chain to wire rope. Until the mid-1940s, the coal plow was dragged by a wire rope in the coal face. With the development of the Löbbe planer in 1947, the round link chain replaced the wire rope previously used in underground planing operations (planing chain). The geometric structure and technical requirements of the brush chain are described in DIN 22252. The dimensions range from ⌀ 26 mm to ⌀ 42 mm. Consequently, the breaking forces are 850 to 220 kN. Special materials (HO=Highly Optimized) have increased these values to 960-2520 kN.
In addition to the use of the plow chain in underground mining, the so-called conveyor chain is also used. The conveyor chains are mounted with scrapers. This conveyor is used to transport the mined coal. These chains are defined in DIN 22252 and DIN 22255 for flat head chains. In recent years, chain manufacturers have continued to develop the geometric design of the classic conveyor chain. One of these results is known as class F chain and is used in the range up to ⌀ 60 mm on double center chain conveyors. The objective of these new developments is to increase coal extraction performance.
To build endless planer/conveyor chains of these dimensions, special connection locks are required. Here a distinction is made between flat locks according to DIN 22258-1 and block locks according to DIN 22258-2. Flat lock is used in planer chain, while block lock is mainly used in conveyor chains. The flat lock can pass both horizontally and vertically through the sprocket. The block lock can only pass vertically through the sprocket.
Symbolism
The symbolism of chains is varied and even opposite. With them, some grieve for their slavery and their misfortune, while others are proud of their prosapia and their power.
The Romans present us with proof of this antithesis: their emperors decorated with chains the soldiers who had distinguished themselves in war for their exploits and bravery, while at the same time they imposed them on the enemies they took prisoners as a sign of captivity and humiliation. Similar examples could be cited from other peoples and other times. The chains that have often been applied to the imprisoned, the captive, the slave, the insolvent debtor were frequently the distinctive character of kings, vassal lords, nobles and people constituted in dignity. Among the Gauls "Gauls (people)") was considered one of the main attributes of those who exercised power and among the English the chain represented the dignity of the lord-corridor of London, both during his duties and as a reminder of having performed them.
And in Spain, we can observe the opposite ideas symbolized in the chain. The weapons of one of the most powerful and flourishing kingdoms of ancient Christian Spain represent crossed gold chains in a field of gules or blood and in their center an emerald. They originate from the celebrated battle of Las Navas de Tolosa won against the Moors at the beginning of the century. In it, King Don Sancho of Navarra was the one who broke the chains of the palenque in which the Miramamolin became strong and then adopted that coat of arms for his monarchy. Other nobles, having distinguished themselves in this same feat of arms, also chose the same symbol to perpetuate their glory, such as the Mendozas, Peraltas, Estúñigas and others.
If on this occasion the chain was taken as a bell of honor, in other times in history it had to be used to punish rebellions or to prevent those that were feared in the future. It is known that once the resistance of the Catalans to recognizing Philip V as king was overcome, there was a certain order that knives could not be used but blunted and hanging from the tables or walls by means of a chain. Some private houses that the king had honored with his presence displayed chains on their main doors as if to imply that that place marked by the royal plant was closed to anyone else, no doubt alluding to the fact that in ancient palace etiquette, the doors and locks were called chain, from which comes the job of chain doorkeepers. These signs disappeared with the fall of the absolute regime, being judged incompatible with the one that was inaugurated.[4].
Figurative meaning
Some figurative meanings of chain are worth knowing:
Boats and bridges
In ships, chains are associated with anchors.
Royal Navy officer Samuel Brown (1776-1852) innovated on the HMS Penelope in 1806 by replacing the ships' cables with iron chains. The company he later founded supplied all the chains of the Royal Navy until 1916 and manufactured the chains of Isambard Kingdom Brunel's SS Great Eastern, of which the photographer Robert Howlett left evidence. This application of iron gave rise to a large amount of research and experiments in England on the strength and tensile of iron and on its various qualities. The soft iron used to make ship cables stretches under an effort of eighteen to twenty kilograms. Its soft, filamentous and above all homogeneous nature allows it to continue stretching uniformly for a fifth of its length before breaking.
Already in 1595, representations of a bridge with a deck suspended by chains, whose design is closer to a cable-stayed bridge, appear in the Machinae Novae (Venice, 1595) by Fausto Veranzio.[5] History records, however, that it was in the United States where the modern suspension bridge was born. A judge, James Finley&action=edit&redlink=1 "James Finley (engineer) (not yet drafted)") (1756-1828), had the idea of a suspension bridge with wrought iron chains (1801).
Brown registered a patent for the manufacture of chains in 1816 and patented wrought iron links for a suspension bridge in 1817. That same year, others built Dryburgh Abbey Bridge, Britain's first chain bridge (1817). Brown had already experimented with a chain suspension bridge, building a trial structure with a span in 1813, which met with the approval of John Rennie and Thomas Telford. Several unsuccessful attempts at Ponts des Invalides were made by Navier (1824) and then Vergès") (1829), until the notable achievements of Thomas Telford (Menai Suspension Bridge") in 1826).
The chains on the bridges were replaced by cables.
Speed variation
Chains are typically used at low speeds with heavy loads. Some common chain types and speeds are:.
There are chains designed for high speed operations, for example:.
In each of these high-speed operations, the chain must be carefully selected. It is important to consider not only strength and wear resistance, but also the type of lubrication required.
Find more "Quick links for industry" in the following countries:
[1] ↑ Un eslabón rápido, también llamado en inglés maillon o quick link, es un enlace de metal, similar a un mosquetón. Los eslabones rápidos tienen un manguito roscado que se ajusta sobre una rosca, a diferencia de la compuerta con bisagra de un mosquetón, lo que los hace más fuertes, pero más difíciles de usar.(«Ten years in the dark - Glossary». ) Al igual que los mosquetones, los eslabones rápidos están disponibles en una variedad de formas y grosores, y a menudo ofrecen una mayor versatilidad que los mosquetones, ya que sus diferentes formas y la falta de compuertas con bisagras permiten que se utilicen en situaciones de carga multidireccional.(«Maillon Rapides». Archivado desde el original el 21 de julio de 2011. Consultado el 27 de enero de 2011. ).: http://www.cavinguk.co.uk/book/index.php?chapter=15
[2] ↑ Ya en el año 225 a. C., se usaba una cadena para sacar un balde de agua de un pozo. Esta cadena de cangilones muy temprana estaba compuesta por anillos de metal conectados.Tsubakimoto Chain Co., ed. (1997). The Complete Guide to Chain. Kogyo Chosaki Publishing Co., Ltd. p. 240. ISBN 0-9658932-0-0. p. 211. Consultado el 17 de mayo de 2006.: http://chain-guide.com/breaks/brief-history-of-chain.html
[5] ↑ Helmut C. Schulitz, Werner Sobek y Karl J. Habermann, Construire en acier, PPUR presses polytechniques, 2003, online presentation.: https://books.google.be/books?id=C4ndiBwAZJgC
Flavius Josephus tells that it was customary among the Romans to break chains and not untie them when an accused was acquitted of his alleged crime. Tito ordered a security to be brought to break that of this same historian so that no one would doubt his innocence. The freedmen consecrated the chains they had worn during their slavery to the Lares gods. Horace mentions this use in his Satires.
Chains made of precious metals were part of the Roman ornaments and many of them were found in excavations that have been carried out at various times. Furthermore, Horace himself speaks about them in his Epistles.[3].
In the 19th century, Leonardo da Vinci made sketches of what appears to be the first steel chain. These chains were probably designed to transmit tensile force, not sheath force, because they consist only of plates and pins and have metal hardware. However, da Vinci's sketch shows a roller bearing.
It took some time for technology to catch up with the concept. Steel manufacturing and processing problems prevented the growth of chains until the 19th century, when new technologies made steel chains and bearings a reality. In the 19th century, a Frenchman named Gull obtained a patent for a similar bicycle chain. This chain, called a "Gull chain", is still used today in pendant applications.
When the cast chain was invented in the 19th century, things started moving pretty quickly. First came the molded detachable chain, composed of identical molded links. Then came the pivot chain, which has an independent pin. The cast detachable chain and pivot chain have been refined over the years and are still used in some special applications. They are being replaced - gradually - by high pitch steel conveyor chains.
At the end of the century, a new development - the bushing - revolutionized the steel chain. Chains with bushings had greater wear resistance than the Gaviota chain because the bushing acted as a bearing, protecting the pin. At this point, the network's story goes into superspeed. The chain with steel bushings was used in bicycles, in the rear-wheel drive of early automobiles, and, in 1903, as a propeller in the Wright brothers' airplane.
Development in underground mining
In underground mining, development moved from chain to wire rope. Until the mid-1940s, the coal plow was dragged by a wire rope in the coal face. With the development of the Löbbe planer in 1947, the round link chain replaced the wire rope previously used in underground planing operations (planing chain). The geometric structure and technical requirements of the brush chain are described in DIN 22252. The dimensions range from ⌀ 26 mm to ⌀ 42 mm. Consequently, the breaking forces are 850 to 220 kN. Special materials (HO=Highly Optimized) have increased these values to 960-2520 kN.
In addition to the use of the plow chain in underground mining, the so-called conveyor chain is also used. The conveyor chains are mounted with scrapers. This conveyor is used to transport the mined coal. These chains are defined in DIN 22252 and DIN 22255 for flat head chains. In recent years, chain manufacturers have continued to develop the geometric design of the classic conveyor chain. One of these results is known as class F chain and is used in the range up to ⌀ 60 mm on double center chain conveyors. The objective of these new developments is to increase coal extraction performance.
To build endless planer/conveyor chains of these dimensions, special connection locks are required. Here a distinction is made between flat locks according to DIN 22258-1 and block locks according to DIN 22258-2. Flat lock is used in planer chain, while block lock is mainly used in conveyor chains. The flat lock can pass both horizontally and vertically through the sprocket. The block lock can only pass vertically through the sprocket.
Symbolism
The symbolism of chains is varied and even opposite. With them, some grieve for their slavery and their misfortune, while others are proud of their prosapia and their power.
The Romans present us with proof of this antithesis: their emperors decorated with chains the soldiers who had distinguished themselves in war for their exploits and bravery, while at the same time they imposed them on the enemies they took prisoners as a sign of captivity and humiliation. Similar examples could be cited from other peoples and other times. The chains that have often been applied to the imprisoned, the captive, the slave, the insolvent debtor were frequently the distinctive character of kings, vassal lords, nobles and people constituted in dignity. Among the Gauls "Gauls (people)") was considered one of the main attributes of those who exercised power and among the English the chain represented the dignity of the lord-corridor of London, both during his duties and as a reminder of having performed them.
And in Spain, we can observe the opposite ideas symbolized in the chain. The weapons of one of the most powerful and flourishing kingdoms of ancient Christian Spain represent crossed gold chains in a field of gules or blood and in their center an emerald. They originate from the celebrated battle of Las Navas de Tolosa won against the Moors at the beginning of the century. In it, King Don Sancho of Navarra was the one who broke the chains of the palenque in which the Miramamolin became strong and then adopted that coat of arms for his monarchy. Other nobles, having distinguished themselves in this same feat of arms, also chose the same symbol to perpetuate their glory, such as the Mendozas, Peraltas, Estúñigas and others.
If on this occasion the chain was taken as a bell of honor, in other times in history it had to be used to punish rebellions or to prevent those that were feared in the future. It is known that once the resistance of the Catalans to recognizing Philip V as king was overcome, there was a certain order that knives could not be used but blunted and hanging from the tables or walls by means of a chain. Some private houses that the king had honored with his presence displayed chains on their main doors as if to imply that that place marked by the royal plant was closed to anyone else, no doubt alluding to the fact that in ancient palace etiquette, the doors and locks were called chain, from which comes the job of chain doorkeepers. These signs disappeared with the fall of the absolute regime, being judged incompatible with the one that was inaugurated.[4].
Figurative meaning
Some figurative meanings of chain are worth knowing:
Boats and bridges
In ships, chains are associated with anchors.
Royal Navy officer Samuel Brown (1776-1852) innovated on the HMS Penelope in 1806 by replacing the ships' cables with iron chains. The company he later founded supplied all the chains of the Royal Navy until 1916 and manufactured the chains of Isambard Kingdom Brunel's SS Great Eastern, of which the photographer Robert Howlett left evidence. This application of iron gave rise to a large amount of research and experiments in England on the strength and tensile of iron and on its various qualities. The soft iron used to make ship cables stretches under an effort of eighteen to twenty kilograms. Its soft, filamentous and above all homogeneous nature allows it to continue stretching uniformly for a fifth of its length before breaking.
Already in 1595, representations of a bridge with a deck suspended by chains, whose design is closer to a cable-stayed bridge, appear in the Machinae Novae (Venice, 1595) by Fausto Veranzio.[5] History records, however, that it was in the United States where the modern suspension bridge was born. A judge, James Finley&action=edit&redlink=1 "James Finley (engineer) (not yet drafted)") (1756-1828), had the idea of a suspension bridge with wrought iron chains (1801).
Brown registered a patent for the manufacture of chains in 1816 and patented wrought iron links for a suspension bridge in 1817. That same year, others built Dryburgh Abbey Bridge, Britain's first chain bridge (1817). Brown had already experimented with a chain suspension bridge, building a trial structure with a span in 1813, which met with the approval of John Rennie and Thomas Telford. Several unsuccessful attempts at Ponts des Invalides were made by Navier (1824) and then Vergès") (1829), until the notable achievements of Thomas Telford (Menai Suspension Bridge") in 1826).
The chains on the bridges were replaced by cables.
Speed variation
Chains are typically used at low speeds with heavy loads. Some common chain types and speeds are:.
There are chains designed for high speed operations, for example:.
In each of these high-speed operations, the chain must be carefully selected. It is important to consider not only strength and wear resistance, but also the type of lubrication required.
Find more "Quick links for industry" in the following countries:
[1] ↑ Un eslabón rápido, también llamado en inglés maillon o quick link, es un enlace de metal, similar a un mosquetón. Los eslabones rápidos tienen un manguito roscado que se ajusta sobre una rosca, a diferencia de la compuerta con bisagra de un mosquetón, lo que los hace más fuertes, pero más difíciles de usar.(«Ten years in the dark - Glossary». ) Al igual que los mosquetones, los eslabones rápidos están disponibles en una variedad de formas y grosores, y a menudo ofrecen una mayor versatilidad que los mosquetones, ya que sus diferentes formas y la falta de compuertas con bisagras permiten que se utilicen en situaciones de carga multidireccional.(«Maillon Rapides». Archivado desde el original el 21 de julio de 2011. Consultado el 27 de enero de 2011. ).: http://www.cavinguk.co.uk/book/index.php?chapter=15
[2] ↑ Ya en el año 225 a. C., se usaba una cadena para sacar un balde de agua de un pozo. Esta cadena de cangilones muy temprana estaba compuesta por anillos de metal conectados.Tsubakimoto Chain Co., ed. (1997). The Complete Guide to Chain. Kogyo Chosaki Publishing Co., Ltd. p. 240. ISBN 0-9658932-0-0. p. 211. Consultado el 17 de mayo de 2006.: http://chain-guide.com/breaks/brief-history-of-chain.html
[5] ↑ Helmut C. Schulitz, Werner Sobek y Karl J. Habermann, Construire en acier, PPUR presses polytechniques, 2003, online presentation.: https://books.google.be/books?id=C4ndiBwAZJgC