Black American patentIn 1896, black American inventor, Willie H. Johnson, of Navasota, Texas, was issued a U.S. patent for "A Mechanism for Overcoming Dead Centers" which occur in machines when a shaft is driven by a crank (No. 554,223). The essential part of his invention consisted of a two-part or compound crank-rod of such construction that the members automatically locked together at the proper point in the stroke, so as to act as a single rod, and at other intervals of its travel would automatically unlocked, so that each member would act independently of the other. Either could act to carry the stroke past the top dead center of the other. Johnson secured a second patent in Oct 1898 for an improvement to his design (No. 612,345). |
