US Patent 10266266 Payload delivery system with removable spool

An apparatus may include (i) a support structure, (ii) at least one shaft coupled to the support structure via at least one swing arm, wherein the swing arm allows upward movement, and restricts downward movement, of the at least one shaft from a resting position, (iii) a spool, wherein in the spool is shaped so as to rest on the at least one shaft when the at least one shaft is in the resting position, and wherein the spool is operable to unwind a tether coupled to a payload, and (iv) at least one fan coupled to the at least one shaft, wherein rotation of the spool when unwinding the tether also causes rotation of the at least one fan coupled to the at least one shaft, thereby controlling a descent rate of the payload.