Patent ID: 8813289

Claim:
A stringer structure having two opposing ends and a lengthwise portion having a first side and a second side and a top edge and a bottom edge, wherein said first side includes two parallel extended channels separated by a rounded region, wherein said channels are C-shaped, including rounded top and bottom edges leading to openings that are disposed at a location substantially opposite said second side, wherein said extended channels run the full length of said first side of said lengthwise portion, and wherein at least one of said channels includes a rounded edge at the bottom side of said lengthwise portion; wherein said second side includes first and second panels perpendicular to said second side of said lengthwise portion, wherein said first panel is substantially within the same plane as said bottom side of said lengthwise portion, wherein said second panel is at a level even with a portion of said rounded region of said first side of said lengthwise portion.