original c. 1880's american ornamental cast iron triangular-shaped doorknob rosette or escutcheon manufactured by mallory, wheeler & co., new haven, conn. the unique and visually striking backplate features radiating curves emanating from various directions. the design was patented on november 9, 1875 by burton mallory of new haven, conn. for mallory wheeler. brushed metal finish treated with a clear coat sealant to prevent surface corrosion. the doorknob design is equally as striking.