high-speed small tools

MECH ENG herramientas pequeñas de alta velocidad f pl

MECH de acción rápida, de alta velocidad, de marcha rápida, ultrarrápido, ultraveloz

MECH ENG de alta velocidad

n pl (HSS small tools)

MECH ENG herramientas pequeñas de acero de alta velocidad f pl, herramientas pequeñas de acero de corte rápido f pl

MECH, METALL acero de corte rápido m

n (high-speed steel small tools)

MECH ENG herramientas pequeñas de acero de alta velocidad f pl, herramientas pequeñas de acero de corte rápido f pl

1 adj

MECH ENG elevado, máximo

2 n

GEOL área anticiclónica f

METEO alta f, área anticiclónica f

1) система

2) установка; устройство

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- 2D CAD system

SUBJECT AREA: Mechanical, pneumatic and hydraulic engineering, Metallurgy

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Edward Geisler Herbert was educated at Nottingham High School in 1876–87, and at University College, London, in 1887–90, graduating with a BSc in Physics in 1889 and remaining for a further year to take an engineering course. He began his career as a premium apprentice at the Nottingham works of Messrs James Hill \& Co, manufacturers of lace machinery. In 1892 he became a partner with Charles Richardson in the firm of Richardson \& Herbert, electrical engineers in Manchester, and when this partnership was dissolved in 1895 he carried on the business in his own name and began to produce machine tools. He remained as Managing Director of this firm, reconstituted in 1902 as a limited liability company styled Edward G.Herbert Ltd, until his retirement in 1928. He was joined by Charles Fletcher (1868–1930), who as joint Managing Director contributed greatly to the commercial success of the firm, which specialized in the manufacture of small machine tools and testing machinery.

Around 1900 Herbert had discovered that hacksaw machines cut very much quicker when only a few teeth are in operation, and in 1902 he patented a machine which utilized this concept by automatically changing the angle of incidence of the blade as cutting proceeded. These saws were commercially successful, but by 1912, when his original patents were approaching expiry, Herbert and Fletcher began to develop improved methods of applying the rapid-saw concept. From this work the well-known Rapidor and Manchester saws emerged soon after the First World War. A file-testing machine invented by Herbert before the war made an autographic record of the life and performance of the file and brought him into close contact with the file and tool steel manufacturers of Sheffield. A tool-steel testing machine, working like a lathe, was introduced when high-speed steel had just come into general use, and Herbert became a prominent member of the Cutting Tools Research Committee of the Institution of Mechanical Engineers in 1919, carrying out many investigations for that body and compiling four of its Reports published between 1927 and 1933. He was the first to conceive the idea of the "tool-work" thermocouple which allowed cutting tool temperatures to be accurately measured. For this advance he was awarded the Thomas Hawksley Gold Medal of the Institution in 1926.

His best-known invention was the Pendulum Hardness Tester, introduced in 1923. This used a spherical indentor, which was rolled over, rather than being pushed into, the surface being examined, by a small, heavy, inverted pendulum. The period of oscillation of this pendulum provided a sensitive measurement of the specimen's hardness. Following this work Herbert introduced his "Cloudburst" surface hardening process, in which hardened steel engineering components were bombarded by steel balls moving at random in all directions at very high velocities like gaseous molecules. This treatment superhardened the surface of the components, improved their resistance to abrasion, and revealed any surface defects. After bombardment the hardness of the superficially hardened layers increased slowly and spontaneously by a room-temperature ageing process. After his retirement in 1928 Herbert devoted himself to a detailed study of the influence of intense magnetic fields on the hardening of steels.

Herbert was a member of several learned societies, including the Manchester Association of Engineers, the Institute of Metals, the American Society of Mechanical Engineers and the Institution of Mechanical Engineers. He retained a seat on the Board of his company from his retirement until the end of his life.

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ASD / RTS

SUBJECT AREA: Electricity, Land transport, Railways and locomotives

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Davidson, son of an Aberdeen merchant, attended Marischal College, Aberdeen, between 1819 and 1822: his studies included mathematics, mechanics and chemistry. He subsequently joined his father's grocery business, which from time to time received enquiries for yeast: to meet these, Davidson began to manufacture yeast for sale and from that start built up a successful chemical manufacturing business with the emphasis on yeast and dyes. About 1837 he started to experiment first with electric batteries and then with motors. He invented a form of electromagnetic engine in which soft iron bars arranged on the periphery of a wooden cylinder, parallel to its axis, around which the cylinder could rotate, were attracted by fixed electromagnets. These were energized in turn by current controlled by a simple commutaring device. Electric current was produced by his batteries. His activities were brought to the attention of Michael Faraday and to the scientific world in general by a letter from Professor Forbes of King's College, Aberdeen. Davidson declined to patent his inventions, believing that all should be able freely to draw advantage from them, and in order to afford an opportunity for all interested parties to inspect them an exhibition was held at 36 Union Street, Aberdeen, in October 1840 to demonstrate his "apparatus actuated by electro-magnetic power". It included: a model locomotive carriage, large enough to carry two people, that ran on a railway; a turning lathe with tools for visitors to use; and a small printing machine. In the spring of 1842 he put on a similar exhibition in Edinburgh, this time including a sawmill. Davidson sought support from railway companies for further experiments and the construction of an electromagnetic locomotive; the Edinburgh exhibition successfully attracted the attention of the proprietors of the Edinburgh 585\& Glasgow Railway (E \& GR), whose line had been opened in February 1842. Davidson built a full-size locomotive incorporating his principle, apparently at the expense of the railway company. The locomotive weighed 7 tons: each of its two axles carried a cylinder upon which were fastened three iron bars, and four electromagnets were arranged in pairs on each side of the cylinders. The motors he used were reluctance motors, the power source being zinc-iron batteries. It was named Galvani and was demonstrated on the E \& GR that autumn, when it achieved a speed of 4 mph (6.4 km/h) while hauling a load of 6 tons over a distance of 1 1/2 miles (2.4 km); it was the first electric locomotive. Nevertheless, further support from the railway company was not forthcoming, although to some railway workers the locomotive seems to have appeared promising enough: they destroyed it in Luddite reaction. Davidson staged a further exhibition in London in 1843 without result and then, the cost of battery chemicals being high, ceased further experiments of this type. He survived long enough to see the electric railway become truly practicable in the 1880s.

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PJGR / GW