Abstract: A foldable tent frame includes a parallelepiped structure comprised of a rectangular front sub-frame having four front poles rotatably connected at four front corner members and a rectangular rear sub-frame having four rear poles rotatably connected at four rear corner members and four length-adjustable horizontal poles which are respectively rotatably connect between the front and rear corner members. Each front pole has two sections pivotally connected to a front joint member and each rear pole has two sections detachably connected a rear joint member. Four reinforcing bars respectively rotatably connected to the rear corner members extend diagonally to pivotally joint to a common central joint which includes two halves rotatably relative to each other. A brace pole, comprised of two sections detachably jointed by a joint member, is oriented upright and pivoted at two opposite ends thereof to every two horizontal poles.

Abstract: A collapsible closet frame includes two upright front posts and two upright rear posts connected together at both their upper ends and lower ends with two pairs of parallel horizontal bars by means of corner members in a pivotable manner so as to form a parallelepiped structure. At each of the upper and lower ends of the rear posts, a brace is mounted and extending toward a brace joint to pivot thereto.

Abstract: A playpen frame structure comprises a rectangular top rail frame supported by four upright primary legs. The top rail frame comprises four rails, each constituted by two bar members pivotally connected to a mid-joint which allows the bar members to be rotatable about pivots mounted on the mid-joint. A retaining member is provided on each of the mid-joint to form a releasable retaining engagement with the two bar members to maintain the bar members in the expanded condition. The retaining member comprises release button for breaking the retaining engagement. There is also provided a reinforcement structure on the lower ends of the primary legs to hold the legs in position and thus avoid accident collapses of the legs.