| 摘要 |
A playard includes a frame structure movable between an open arrangement and a folded arrangement. The frame structure includes a plurality of pivot joints arranged in an upper set and a lower set, each pivot joint in the upper set being positioned over a corresponding pivot joint in the lower set, and a plurality of cross members connected at respective slants to the upper and lower sets of pivot joints. The playard further includes a plurality of top rails, each top rail being attached to adjacent pivot joints in the upper set. The frame structure lacks legs to support the upper set of pivot joints at an elevation above the lower set of pivot joints. The elevation decreases as the respective slants of the cross members change to move the frame structure from the folded arrangement to the open arrangement until the top rails are under tension.
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