US Patent 10285506 Foldable bed frame having pivotally connected frame units

A foldable bed frame includes frame units pivotally connected to each other by one or more connecting assemblies. A frame unit includes upper and lower frames, legs or links connected to the upper and lower frames, and limiting pieces disposed on the upper and lower frames to limit rotation angles or directions of the legs or links. A connecting assembly includes middle leg(s) or middle bar(s), and connecting pieces. When folded, the bed frame is compact. When unfolded, the bed frame provides storage spaces underneath, and facilitates positioning and holding of bed shirts/sheets.