Umbrella frame, has set of frame units each comprising main ribs and U-shaped branch ribs, where open ends of branch ribs are bent inward at specified angle such that sharp edges of branch ribs are aligned inward

摘要

The frame has a set of frame units, a shaft (1) and a slider (4). Each of the frame units comprises a set of main ribs (3) and branch ribs (5) that comprise a U-shaped cross section, where open ends of the branch ribs are bent inward at an angle of 90 degrees such that sharp edges of the branch ribs are aligned inward. The branch ribs have two ends that are rotatably supported at the main ribs and at the slider.