Month in the Patent Office

Aircraft structures and in particular thick wing structures comprise ribs 2 of zigzag formation, Fig. 2, assembled in such manner as to form upper and lower reticulated frames which are spaced apart by posts 4 and are directly secured to the outer covering or skin 1 of the wing or other structure. Longitudinal booms 3 are also secured to the outer covering and to the ribs at the points of inter‐attachment thereof, Fig. 6. Ribs 2 are of channel section shaped at the bends to form flats 2a and to form recesses to allow passage of the booms 3. Adjacent ribs are attached to each other and to the booms at each junction by straps 5, Fig. 5, bent to the shape of the rib angle at 5a, and to that of the underside of the boom at 5b. Parts 5a of opposed straps are introduced between flats 2a of the ribs, the strap extending under the rib channel and then upwardly to connect with the boom, Fig. 6. Tubular posts 4 are secured to flats 5a, Fig. 5, of straps 5 by flanges 6, Fig. 2; the joints may be stiffened by additional gussets such as 7.