| 摘要 |
An umbrella frame of the parallelogram type which includes a stick, a crown at one end of the stick, a main runner slidable on the stick, and an auxiliary runner slidable on the stick between the main runner and the crown. Stretcher members are hingedly connected to the main runner, while strut members are hinged to the auxiliary member and each to a mid point of each stretcher member. A dome rib is pivotally connected to each end of a stretcher member and extends inwardly from the end of the stretcher member a short distance where it is connected to a linkage member which in turn is hingedly connected to the strut member forming a quadrilateral parallelogram linkage with the dome rib.
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