US Patent 10251498 Fitted sheet having expandable corner segments

A fitted sheet is disclosed which will fit either of two mattresses of different sizes without undue wrinkling or bunching of fabric. This fitted sheet has an elastic segment at each corner. Each elastic segment is attached to the top panel, one of the side panels and either the front panel or the rear panel of the fitted sheet. The elastic segments are substantially similar in size and shape and are stretchable in two directions. Each elastic segment also has a seam extending from the straight upper edge portion toward the free lower edge that defines a corner in the elastic segment when the elastic segment is in a relaxed condition. The corner is between the upper edge and the lower edge of the elastic segment.