|
A wire is a single, usually cylindrical, flexible strand or rod of metal. Wires are used to bear mechanical loads or electricity and telecommunications signals. Wire is commonly formed by drawing the metal through a hole in a die or draw plate. Wire gauges come in various standard sizes, as expressed in terms of a gauge number. The term ''wire'' is also used more loosely to refer to a bundle of such strands, as in 'multistranded wire', which is more correctly termed a wire rope in mechanics, or a cable in electricity. Wire comes in solid core, stranded, or braided forms. Although usually circular in cross-section, wire can be made in square, hexagonal, flattened rectangular, or other cross-sections, either for decorative purposes, or for technical purposes such as high-efficiency voice coils in loudspeakers. Edge-wound coil springs, such as the Slinky toy, are made of special flattened wire. ==History== In antiquity, jewelry often contains, in the form of chains and applied decoration, large amounts of wire that is accurately made and which must have been produced by some efficient, if not technically advanced, means. In some cases, strips cut from metal sheet were made into wire by pulling them through perforations in stone beads. This causes the strips to fold round on themselves to form thin tubes. This strip drawing technique was in use in Egypt by the 2nd Dynasty. From the middle of the 2nd millennium BC most of the gold wires in jewellery are characterised by seam lines that follow a spiral path along the wire. Such twisted strips can be converted into solid round wires by rolling them between flat surfaces or the strip wire drawing method. The strip twist wire manufacturing method was superseded by drawing in the ancient Old World sometime between about the 8th and 10th centuries AD.〔Jack Ogden, ‘Classical Gold wire: Some Aspects of its Manufacture and Use’, ''Jewellery Studies'', 5, 1991, pp. 95–105.〕 There is some evidence for the use of drawing further East prior to this period.〔Jack Ogden, ‘Connections between Islam, Europe, and the Far East in the Medieval Period: The Evidence of the Jewelry Technology’. Eds P. Jett, J Douglas, B. McCarthy, J Winter. ''Scientific Research in the Field of Asian Art. Fiftieth-Anniversary Symposium Proceedings''. Archetype Publications, London in association with the Freer Gallery of Art, Smithsonian Institution, 2003.〕 Square and hexagonal wires were possibly made using a swaging technique. In this method a metal rod was struck between grooved metal blocks, or between a grooved punch and a grooved metal anvil. Swaging is of great antiquity, possibly dating to the beginning of the 2nd millennium BC in Egypt and in the Bronze and Iron Ages in Europe for torcs and fibulae. Twisted square section wires are a very common filigree decoration in early Etruscan jewellery. In about the middle of the 2nd millennium BC a new category of decorative tube was introduced which imitated a line of granules. True beaded wire, produced by mechanically distorting a round-section wire, appeared in the Eastern Mediterranean and Italy in the seventh century BC, perhaps disseminated by the Phoenicians. Beaded wire continued to be used in jewellery into modern times, although it largely fell out of favour in about the tenth century AD when two drawn round wires, twisted together to form what are termed 'ropes', provided a simpler-to-make alternative. A forerunner to beaded wire may be the notched strips and wires which first occur from around 2000 BC in Anatolia. Wire was drawn in England from the medieval period. The wire was used to make wool cards and pins, manufactured goods whose import was prohibited by Edward IV in 1463.〔H. R. Schubert, 'The wiredrawers of Bristol' ''Journal Iron & Steel Institute'' 159 (1948), 16-22.〕 The first wire mill in Great Britain was established at Tintern in about 1568 by the founders of the Company of Mineral and Battery Works, who had a monopoly on this.〔M. B. Donald, ''Elizabethan Monopolies: Company of Mineral and Battery Works'' (Olver & Boyd, Edinburgh 1961), 95-141.〕 Apart from their second wire mill at nearby Whitebrook,〔D. G. Tucker, 'The seventeenth century wireworks at Whitebrook, Monmouthshire' ''Bull. Hist. Metall. Gp'' 7(1) (1973), 28-35.〕 there were no other wire mills before the second half of the 17th century. Despite the existence of mills, the drawing of wire down to fine sizes continued to be done manually. Wire is usually drawn of cylindrical form; but it may be made of any desired section by varying the outline of the holes in the draw-plate through which it is passed in the process of manufacture. The draw-plate or die is a piece of hard cast-iron or hard steel, or for fine work it may be a diamond or a ruby. The object of utilising precious stones is to enable the dies to be used for a considerable period without losing their size, and so producing wire of incorrect diameter. Diamond dies must be rebored when they have lost their original diameter of hole, but metal dies are brought down to size again by hammering up the hole and then drifting it out to correct diameter with a punch. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Wire」の詳細全文を読む スポンサード リンク
|