US Patent No. 475,206, granted May 17, 1892 to Alfred M. Crooker of Boston, for a saw cotton gin that separates lint from seed, pods and immature bolls. The design uses an air current from suction fans to carry material up to the gin saws, with beater cylinders and a conveyor apron at the base. Breast-bars with guard flanges protect the saw teeth from refuse. The document has six sheets of patent drawings followed by the specification and thirteen claims.