 Then there is Clarence Karrer, the son of an X-ray equipment distributor claims to have built the first unit in 1924 in Milwaukee, but had his idea stolen and patented by one of his father's employees.In the meantime, the British company Pedoscope filed a British patent application in 1924, granted in 1926, and claimed to have been building these machines since 1920.The X-ray Shoe Fitter Corporation of Milwaukee and Pedoscope Company became the largest manufacturers of shoe-fitting fluoroscopes in the world.