Joseph Day

Joseph Day may refer to:

See also

Joseph Day (inventor)

Joseph Day (1855 in London – 1946) is a little-known English engineer who developed the extremely widely used crankcase-compression two-stroke petrol engine, as used for small engines from lawnmowers to mopeds and small motorcycles. He trained as an engineer at the Crystal Palace School of Engineering at Crystal Palace in London, began work at Stothert & Pitt in Bath, and in 1889 designed the crankcase-compression two-stroke engine as it is widely known today (in contrast to the two-stroke engine designed by Dugald Clark), the Valve-less Two-Stroke Engine. In 1878 he started his own business, an iron foundry making cranes, mortar mills and compressors amongst other things.

Valveless two-stroke engine

He advertised a new design of "valveless air compressor" which he made on licence from the patentee, Edmund Edwards. By 1889, he was working on an engine design which would not infringe the patents that Otto had on the four-stroke, and that he eventually called the Valveless Two-Stroke Engine. In fact there were two flap valves in Joseph Day's original design, one in the inlet port, where you would probably find a reed valve on a modern two stroke, and one in the crown of the piston, because he did not come up with the idea of the transfer ports until a couple of years later. He made about 250 of these first two-port motors, fitting them to small generating sets, which won a prize at the International Electrical Exhibition in 1892.