Patent attributes
Described herein are apparatuses for passively releasing a payload of an unmanned aerial vehicle (UAV). An example apparatus may include, among other features, (i) a housing; (ii) a swing arm coupled to the housing, wherein the swing arm is operable to toggle between an open position and a closed position; (iii) a spring mechanism adapted to exert a force on the swing arm from the open position toward the closed position; (iv) a receiving system of a UAV adapted to receive the housing, wherein the receiving system causes the swing arm to be arranged in the open position; and (v) a spool operable to unwind and wind a tether coupled to the housing, wherein unwinding the tether causes a descent of the housing from the receiving system, and wherein winding the tether causes an ascent of the housing to the receiving system.