US Patent 10208982 Airfoil blade and method of assembly

An airfoil blade assembly includes a first shell member having a body having a first lock seam formed at one end thereof and a free distal end opposite the first lock seam, and a second shell member having a body having and a second lock seam formed at one end thereof and an a free distal end opposite the second lock seam. The second shell member is inverted with respect to the first shell member. The free distal end of the first shell member is captured within the second lock seam of the second shell member and the free distal end of the second shell member is captured within the first lock seam of the first shell member to lock the blades to one another.