The first practicable patent for an epicyclic gear by Tony Hadland

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Scott & Phillott’s British Patent No. 860 of 1878

Scott and Phillott’s seems to have been the first practicable patent for an epicyclic change-speed gear for cycles. These notes summarise key points from the patent. They were prepared by Tony Hadland in 1997 for Pryor Dodge when Pryor was working on the exhibition Bike: Cycles – A tour of bicycle design from 1825 to 2000, staged at London’s Design Museum from 30 October 1997 to 22 March 1998.

The Inventors

George Dennistoun Scott was an engineer from Derby, an industrial town in the English Midlands which is next door to Raleigh’s home town, Nottingham – not that Raleigh existed at this time. Scott’s middle name is also spelled Dennistown in the patent but that is probably just a typo.

George Henry Phillott was an architect from Cheltenham, an altogether more elegant and genteel Georgian spa town in Gloucestershire, in the west of England.

Basic Configuration

Scott & Phillott’s gear as illustrated in the patent is fitted into the hub of a front-driving cycle. It employs a variant of the simple epicyclic principle, whereby two equal-sized co-axial bevel gears take the place of the sun and annulus. Meshing with both were another pair of bevel gears, taking the place of planet pinions. These planet bevels were mounted on a cross-head, taking the place of a planet cage.

Because the sun and annulus equivalents were of equal size, the gear changes were very widely spaced – 100% increase or 50% decrease (doubled or halved).

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