Today in 1981, US Patent 4275097 A was issued, an invention of Frank L. Shriver, assigned to the Coors Container Company, for his “Protective Coating for Cans and Methods for Application of Coating Thereto.” Here’s the Abstract:

Apparatus and methods of applying a thin narrow width coating to can body members comprising a feed control means associated with a guideway means for causing rotating moving of the can body members across an elongated coating applicator roller member extending parallel to the path of movement of the can body members, the rotation of and spacing of the can body members and the rotation of the applicator roller member being controlled to apply the coating during substantially only one revolution of the can body member and less than one revolution of the roller member.