Today in 1941, US Patent 694584 A was issued, an invention of William G. Wagner, for his “Bottle Cap.” There’s no Abstract, but the description claims that the “object of the invention is to provide an improved bottle cap for use on conventionally shaped or conventionally formed bottle mouths wherein the cap is of such design that it may be readily applied to the bottles by means of conventional bottle capping machines, the cap being advantageous in that it forms and maintains a superior seal with the bottle mouth.”