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.

A control device that controls an electric hoisting machine includes: a tension sensor that detects tension of a pulling member; a mode input unit that inputs a mode switch signal to switch between a winding mode and an unwinding mode; and a control unit that controls the operation of a electric motor. The control unit, when set in the unwinding mode, controls the electric motor in accordance with a detection signal from the tension sensor to cause the rotating body to be inversely rotated when the tension of the pulling member is not less than a predetermined threshold value, and to prevent the rotating body from being inversely rotated when the tension of the pulling member is lower than the predetermined threshold value.

A self-release mechanism. The self-release mechanism includes a counter-weight, wherein the counter-weight is located on a first end of the self-release mechanism; a shaft having a top portion and a bottom portion, wherein the top portion of the shaft is coupled to the counter-weight, wherein the shaft defines a perforation, wherein the perforation is adapted to receive a cord; and a hook including a hook bend, wherein the hook is located on a second end of the self-release mechanism, wherein the hook is coupled to the bottom portion of the shaft, wherein the self-release mechanism moves to a first position when a tension is exerted on the self-release mechanism due to gravity caused by coupling of the hook to a payload via the hook bend, wherein the self-release mechanism moves to a second position when the exerted tension is released.

A self-release mechanism. The self-release mechanism includes a counter-weight, wherein the counter-weight is located on a first end of the self-release mechanism; a shaft having a top portion and a bottom portion, wherein the top portion of the shaft is coupled to the counter-weight, wherein the shaft defines a perforation, wherein the perforation is adapted to receive a cord; and a hook including a hook bend, wherein the hook is located on a second end of the self-release mechanism, wherein the hook is coupled to the bottom portion of the shaft, wherein the self-release mechanism moves to a first position when a tension is exerted on the self-release mechanism due to gravity caused by coupling of the hook to a payload via the hook bend, wherein the self-release mechanism moves to a second position when the exerted tension is released.

A retaining mechanism for a clevis hook assembly with an axial device that provides a retaining mechanism for a load pin. The axial device is disposed inside a first opening behind the load pin. The axial device may provide a retention mechanism to obstruct the load pin when the load pin is inserted into the first opening of one of the pair of opposed members and extends across a space into the first opening in the other opposed member.

A hoist or hoisting device is configure to place a pallet on a roof without the need of a person on the roof. The hoist includes a deflector that moves between a first position and a second position and releases a strap from an open hook as the deflector moves from the first position. A release arm on the deflector contacts a portion of the strap to push the strap off the open hook after the pallet has contacted the roof. The hoist may then be raised and the strap be unthreaded and pulled upward through the pallet to leave the pallet installed on the roof.

A hoist or hoisting device is configure to place a pallet on a roof without the need of a person on the roof. The hoist includes a deflector that moves between a first position and a second position and releases a strap from an open hook as the deflector moves from the first position. A release arm on the deflector contacts a portion of the strap to push the strap off the open hook after the pallet has contacted the roof. The hoist may then be raised and the strap be unthreaded and pulled upward through the pallet to leave the pallet installed on the roof.

A lifting mechanism assembly comprising a lifting section, a compression section, and an attaching section.

A lifting mechanism assembly comprising a lifting section, a compression section, and an attaching section.

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.