US Patent No. 1,751,307, granted March 18, 1930 to Frederick B. Cumpston of Blooming Grove, Texas, assignor to Associated Factories Corporation, for a cotton-gin machine. It describes a ribless gin in which a central screw conveyor carries cotton past surrounding carding saws rotating in the same direction at progressively increasing speeds. The saws remove lint from the seed, and brushes doff the lint into flues. A slightly wider gap lets wadded cotton pass to a stripper. The text includes the description, thirteen claims and a sheet of drawings (Figs. 1 and 2). The machine can also relint cotton seed.

US Patent No. 1,751,306, granted March 18, 1930 to Frederick B. Cumpston of Blooming Grove, Texas, assignor to Associated Factories Corporation, for a ribless cotton gin. The design uses a series of gin saws on inclined shafts, each turning faster than the one below, with curved brushes that clean lint from the seed. Seed is thrown off by centrifugal force into a conveyor, and lint of different fiber lengths is withdrawn separately. The patent includes a drawing of two figures, a specification, and nine claims.