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The first American patent for a lenticular truss was issued to James Barnes in 1849 Fig. 6. It was an all-timber truss with curved chords that joined in rounded ends. As Barnes described it: ¡°I unite the two chords, the upper and lower, of an ordinary truss into one elliptical or oval curve.¡± U.S. Patent 26,230 1849. He claimed his truss could be built of iron, wood, or partially of each. The bridge deck was supported at midspan and all panels had counters.×îºóÒ»¾äÔõô·Òë°¡¡¢¡¢¡¢¡¢¡¢¡¢ÇóÖú Ö÷ÒªcountersÔõô·Òë°¡ |
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