Sharp, Stewart and Co: Early Milling Machines
In the mid-19th century a number of British firms produced machines for cutting keyways and slots for cotters, using rotating cutters. These were commonly called slot drilling machines. Sharp, Stewart & Co and Furnival and Co started making 'slot drilling' machines to Sharp and Furnival's patent of 1855. We would now call them vertical milling machines.
Sharp and Furnival's double-headed machine was described and illustrated in The Engineer 1856/09/05. p.488.
An accurate large scale model dated 1857 is on display at the Musée des Arts et Métiers in Paris, along with two sample workpieces produced on one of their early full-size machines. The material of the sample workpiece is wrought iron of indifferent quality. The samples were produced by end milling and slot drilling. The quality of finish from slot drilling is surprisingly impressive.
The London Science Museum also have a similar sample workpiece (not on display). Photo here. The Science Museum also have an apparently identical 1/4 scale model dating from 1857. Photo here. This model, or the one in Paris, may be the same as that exhibited at the 1861 meeting of the British Association in Manchester[1].
The machines had powered downfeed and longitudinal traverse, actuated by a ratchet mechanism.
See here for drawings of one of these machines.[2]
Sharp, Stewart & Co adapted one of these machines for a special purpose in their own works - milling cams for the Robinson and Oldfield patent feed motion for planing machines.[3]. See illustration.
See Also
Sources of Information
- ↑ Daily News (London) - Wednesday 4 September 1861
- ↑ [1] BnF Gallica website: Livre Des Machines-outils, leur importance, leur utilité, progrès apportés dans leur Fabrication by J. Chrétien, 1863: Drawings of Machine a fair les mortaises
- ↑ The Engineer 1895/02/22