Norman H. Gilman
American inventor and engineer.
At some point after WW1 Gilman became Chief Engineer of the Allison Engine Co of Indianapolis. His contributions included an improved type of big end bearing for V-type engines. See US Patent 1,581,083, filed 16 June 1923, patented 13 April 1926.[1]
1938, Sept. 20: US Patent 2,130,461 (filed 6 May 1929) described a method of making plain bearings. A relatively light steel shell was lined with a suitable bearing metal by heating the shell to above the melting point of the bearing metal, and pouring in the molten metal. The molten metal was confined to the area required by a thin cylinder, subsequently removed. Gilman's patent proposed 'plastic bronze' (lead bronze, 70% copper, 30% lead), but was not confined to that material. To prevent segregation of the copper and the bronze, the bearing was quenched soon after pouring but after allowing time for the steel and bronze to fuse.[2].