Original linen-backed patent lithograph for Ferdinand Porsche's invention of a universal joint for motor vehicles, one page, 12.5 x 10.25, January 5, 1933. The diagram features multiple views of the universal joint-block, designed to be stronger and more simply manufactured than existing versions. The top border reads: "385,778 Complete Specification." The lower border features the printed text: "Malby & Sons. Photo-Litho." The left border reads: "This Drawing is a reproduction of the Original on a reduced scale." Includes the printed British "Patent Specification" document, three pages on two sheets, which describes the shortcomings of the existing versions and the advantages of the Porsche design. The specification sheet bears a "U.S. Patent Office Library" ink stamp on the first page. In fine condition.
