US Patent 11566443 Folding backup key

A foldable card includes first and second sections, each defining a base and a layer of a blade of a key extending therefrom; and a hinge interface connecting the bases of the first and second sections, wherein the first section is configured to fold over the second section at the hinge interface so that a top surface of the first section is against a bottom surface of the second section and each of the layers of the blades align to form the blade of the key, and the first and second sections are configured to fold at the hinge interface into a storage position to form a collective flat surface.