Month in the Patent Office: A Selection of the More Important Aircraft and Engine Specifications Published Recently

The wing spar described in the parent specification is modified by arranging the corrugated booms with their edge parts directed inwardly and forming them with Hat sides A6, B6 to scat the stiffeners C, D and bracing members I, J, which are arranged outside the booms and formed as channel‐section struts with outwardly directed flanges. The stiffeners C, D have Hanged pad pieces E1 fitted in their ends, extensions E3 being formed on the pad pieces for securing them to blocks G5, H5 fixed to bridge pieces G, H. The stiffeners and bracing members are secured to the booms by hollow rivets F. Rivets passed through distance tubes L strengthen the members C, D, and similar bracing may be placed across those booms that are in compression at points between their connections to the stiffeners C, D. The gauge of the metal may vary to suit the load on the girder; for example, one boom may be thicker than the other and the thickness or the spacing of the members C, D may be varied. The diagonal struts I, J may be fixed to the booms by separate connections instead of overlapping the members C, D.