US Patent 10202191 Systems and methods for foldable arms

An unmanned aerial vehicle (UAV) comprises a central body, a plurality of arms that extend out from the central body, and a plurality of rotors. Each arm has one or more joints that segment the arm into a stem portion proximal to the central body and one or more branch portions distal to the central body. The one or more joints permit the one or more branch portions to move horizontally relative to the stem portion between an extended state and a compacted state. The one or more branch portions are arranged substantially parallel to a perimeter edge of the central body in the compacted state. Each rotor in the plurality is attached to the one or more branch portions.