US Patent 9855964 Stroller frame

A stroller frame includes a seat pan, an operating handle movably coupled to the seat pan, and two opposite foldable side frame units each including a front leg, a handle rod, a rear leg that has a top end pivotally connected to the handle rod, a bottom leg that has a lower end pivotally connected to the rear leg, and a sliding basket tube that is movably coupled to said seat pan and slidably connected to said rear leg. To unfold the stroller frame, said operating handle is pushed downward to drive said seat pan to pivot downward so that an angle between said front leg and said bottom leg of each of said side frame units increases until said stroller frame is converted from a folded state to an unfolded state.