Yost was the designer and inventor of the 1947 unloading auger, the catalyst for the development of Hesston Manufacturing in Hesston, Kansas. The device was used to unload grain from farm combines. The company's controlling stake was sold to Italian corporation Fiat Trattori in 1977. Fiat Trattori bought the rest of Hesston Manufacturing in 1987. In 1991, a year after being created, AGCO Corporation bought the rights to Hesston Manufacturing.