Foldable bed frame having pivotally connected frame units

A foldable bed frame, comprising:

• a first frame unit and a second frame unit pivotally connected to each other at proximal sides thereof, wherein each frame unit comprises:
• an upper frame;
• a lower frame disposed below the upper frame when the foldable bed frame is unfolded;
• a plurality of vertical links comprising first and second vertical links disposed on left and right sides of the frame unit, and at or adjacent to the proximal side of the frame unit, wherein each of the first and second vertical links is pivotally connected to the upper and lower frames;
• and
• a plurality of limiting pieces disposed on the upper frame and the lower frame to limit rotation angles or directions of the vertical links;
• and
• a connecting assembly disposed between the first and second frame units and pivotally connected to the first frame unit and the second frame unit, the connecting assembly comprising a middle leg assembly and a plurality of connecting pieces,
• wherein the middle leg assembly comprises:
• a top lateral bar having first and second ends;
• first and second middle legs coupled to the first and second ends of the top lateral bar at a lower side of the top lateral bar, wherein each middle leg comprises an inner tube and an outer tube slidably coupled to each other;
• and
• first and second pivotal links coupled to the first and second ends of the top lateral bar and pivotally connected to the upper frames of the first and second frame units;
• and
• wherein each of the connecting pieces has one end pivotally connected to the first or second middle leg, and the other end pivotally connected to the lower frame of the first or second frame unit at a location where a corresponding vertical link is connected to the lower frame.