|
Holman Brothers Ltd. was a mining equipment manufacturer founded in 1801 based in Camborne, Cornwall, UK. Holman was Camborne's, and indeed Cornwall's largest manufacturer of industrial equipment. Holman played a part in World War II making the Polish designed 20mm Polsten gun, similar to the Oerlikon but simpler to build and use. It also produced the Holman Projector for the Royal Navy. At its height Holmans was spread over three sites within Camborne, employing some three and half thousand men. Cornish mining is renowned worldwide. Alongside the mining industry there evolved an industry manufacturing specialised mining equipment. Holman’s founder, Nicholas Holman started a boiler works in 1801.〔Carter, Cornish Engineering, p. 6〕 The company expanded to develop subsidiary companies in centres of mining all over the world and at one stage approximately 80% of products were exported. == Rock drills == 1881-The brothers John Henry and James Miners Holman, had taken over running the business from their father John.〔Carter, Cornish Engineering, p. 16〕 They were offered the designs of a new rock drill by a James McCulloch. the brothers filed a joint patent with McCulloch, and began to manufacture the new drill.〔Carter, Cornish Engineering, p. 17〕 It became known as the "Cornish Rock Drill", and achieved great commercial success. 1882-The rock drill was at work at Dolcoath, Tincroft, East Pool, South Crofty, at Falmouth Docks and in mines in South Wales. The demand grew rapidly. 1896-More than 1,000 Cornish rock drills were in use on The South African Rand alone. By the turn of the 20th century the number had doubled. Most of these drills came from Holman in Camborne. 1910-The company took first and third prizes in a World Rock Drilling Contest, sponsored by the South African Chamber of Commerce. Later, the Holman Silver 303 Airleg was used all over the world for mine development. As well as the rock drills, the company also produced drill rigs and developed 'down the hole' drill primarily for quarrying. The company developed a hydraulic breaker, known as the Holbuster, but was ahead of its time and it was not a commercial success. Later developed by others, it is now a common sight. The first successful drills were the piston type, or "reciprocators." The drill steel piston and chuck moved together and reciprocated. In Leyner's hammer drill the steel was held loosely in a chuck attached to the cylinder itself, while the piston inside the cylinder reciprocated, striking blows on the blunt end of the drill steel. The hammer drill was lighter, speedier, and used less air than the reciprocating drill. Leyners earlier drills used a blast of air blown through a hollowed or channelled drill steel to keep the drill holes clear of rock chippings: these drills, however, raised too much dust. To overcome this Leyner introduced water along the drill together with the blast of air. This machine soon ousted the previous one, and was taken up by the Holman factory on a large scale. 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「Holman Brothers」の詳細全文を読む スポンサード リンク
|