five matching late 19th century antique american ornamental cast iron "screwless" spindle doorknob backplates or escutcheons featuring gothic style quatrefoils. the passage door backplates were fabricated by the chicago hardware co., chicago, il. the backplates were designed specifically to accommodate the niles "screwless spindle" doorknobs. the oversized collars or thimbles were designed for extended doorknob shanks. these backplates were often paired with "jet" black porcelain doorknobs. measure approximately 5 1/2 x 1 3/4 inches. priced for the lot.