| 摘要 |
A two-tier umbrella has upper and lower series of radially extending ribs (16, 18) supporting upper and lower canopies (25, 26), respectively. The inner ends of the upper ribs are pivotally connected to the pole (11) and the inner ends of the lower ribs are pivotally connected to respective upper ribs at medial locations (17) while stretchers (21) are pivotally connected at respective opposite ends to a pole slider (23) and to the lower ribs at medial locations (22) thereof. The upper and lower ribs maintain upper, circular, and lower, annular canopies in dome-shape and spaced apart in imbricating condition with an annular wind escape aperture defined between the overlapping canopy portions. |
