Chain

Produced is a Aneinandereihung of movable, nested or associated with joints, limbs, which are often made ​​of metals such as steel (formerly iron, see also sponge iron ) - A chain (from Latin catena, Old High German ketina, Middle High German keten ) - in terms of number, flock will.

History of the chain

The history of the chain began in the Bronze Age as a piece of jewelry and for constraining ( in - chains - set ) of prisoners of war, who later became slaves or criminals for neck, ankles and wrists. Other uses found for hanging chains, for example, of boilers, as well and later anchor chains. The first ship or anchor chain from iron ( now Khorsabad in Iraq ) found from the period 1400-800 BC in Assyrian major Šarrukin.

Latest from this period were made ​​of iron chains fixed part of the Mediterranean. The comparatively small finds can be explained by the corrosion of the iron. From the history of art ( eg in the form of stone reliefs ) or from Greek mythology (eg the god of metalworking Hephaestus forges heavy chain for Prometheus ) are to present evidence.

First armor chains have been found dating from the 4th century BC, in Celtic graves. The practical chain armor has been taken over in the 3rd century BC by the Romans under the name Lorica Hamata. The peoples of the Orient, such as the Sassanids used in the sequence that protection.

In ancient times, many scholars also dealt with the chain as a technical element for transmitting power, like the Greek precision engineer Philon of Byzantium in his books Mechanike syntaxis. A pumping station with forged link chain was already in the 1st century BC Cr. built by the Roman architect and engineer Marcus Vitruvius Pollio.

The universal inventor, philosopher and artist Leonardo da Vinci, often outlined in his drawings articulated chains that are very similar to the current standard block and leaf chain.

The Englishman Ph. 1634 White received the first patent for an iron anchor chain. The philosopher and scientist Gottfried Wilhelm Leibniz developed in 1686, the " endless chain " which runs in a closed circuit, the output of ore in mining. In 1813 Th Brunten constructed a link chain with footbridge links.

Your comprehensive meaning today won the chain but it was only with the onset of the Industrial Revolution. The Frenchman André Galle invented in 1829 named after him Gallkette and the Swiss Hans Renold acquired in 1880 in England the patent for the steel link chain. Due to the industrial manufacturing chain was then available in large quantities and could be used in many different areas, eg as a caterpillar in tracked vehicles. In the industrial use of the chain from the middle of the 19th century was complemented by the wire rope.

Development in underground mining

In underground mining, the development of the chain ran over the wire back to the chain. Until the mid- 40s of last century the coal plow was drawn carbon shock side by means of a wire rope. With the development of Löbbe - planer in 1947, the round link chain broke the wire rope used to date in the plow operating underground from ( plow chain ). The plow chain is described in its geometrical structure and their technical requirements in DIN 22252. The size range is from Ø 26 mm to Ø 42 mm. Accordingly, the failure loads are between 850 - 2220 kN. By special materials (HO = Highly Optimised ), these values ​​were 960 - to be increased 2520 kN.

Besides the use of the plow chain in underground mining also a so-called conveyor chain is used. The conveyor chains are mounted with scratches. With the help of this conveyor, the coal produced is transported away. These chains are defined in the standards DIN 22252, and for the flat chains in DIN 22255. Over the past few years, the classic conveyor chain was developed in their geometric structure of the chain manufacturers and on. One of these results is called F -class chain and 60 mm in double medium chain conveyor is used in the range up to Ø. Objective of these developments is the increase in productivity of coal mining.

To build Hobel-/Fördererketten endlessly in these dimensions, it requires special connection locks. Here a distinction is flat locks according to DIN 22258-1 and DIN 22258-2 block locks after. The flat lock finds its use in the plow chain, where does the Block Castle predominantly in the conveyor chains for use. The flat lock can run horizontally as well as vertically through the sprocket. The block lock should not be run vertically through the sprocket.

Historical production technology

Basically, durable bronze or iron chains were finished only in forging technology since the beginning of its production until the late modern age. Attempts to produce chains in the casting technique, applied only partially successful, because they broke easily. In the late Middle Ages, as a special form (sub guild ) blacksmithing have specialized in the chain forge. The profession existed until the early 20th century, yet have survived to this day some chain forge showing off their art partly in museums. Still in the 70s of last century the production of chain links with Feuerschweißung was a part of the curriculum to the blacksmith.

While there is evidence that the history of iron probably first was from the Hethiterngeschrieben, with the discovery of anchor chains in major Šarrukin proved by the archaeo that before about 3000 years ago the Assyrians familiar with the forge welding of solid iron - a connection, the high loads holds.

The members of the first historical chains of copper, bronze or iron could only be bent together, riveted or intertwined; a technique that is used today for decorative reasons of blacksmiths.

Other application forms

• Chain bridges

Further use of the term

With time, the chain is also a symbol of small items which are connected together, such as a mountain range, a retail chain as well as an abstract concept for temporally and spatially successive things.

" A chain is only as strong as its weakest ( chains) element. "