The increased speed of operation

SUBJECT AREA: Mechanical, pneumatic and hydraulic engineering, Metallurgy

[br]

[br]

[br]

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.

[br]

ASD / RTS