This innovation addresses the problem of automatic engagement and disengagement of payloads from their transport vehicle when lifted by a crane or other material handling device. The prior state-of-the-art is in material handling devices that require personnel to activate the latch, or latches that are actuated by heavy, bulky actuator systems fixed to the transportation device. These require significant accommodations on the transport vehicle to mate to the latch.
A mechanism was developed that negates the need for ground personnel to be present during loading and unloading. The latch requires a minimum of accommodation on the transport device for an interface — only an appropriate hole. The latch locks the payload via a motion that is perpendicular to the loads applied during transport, thus securing the payload until activated. The device also includes provisions for rigid links that are released via explosive bolts, and provides an approach for personnel to release the latch as a backup. The latch can be used on all mechanical systems that are actuated by the action of lifting the payload; however, the latch does not preclude the use of actuators in the latching mechanism.
The latch is designed to operate in a dirty environment, and channels are provided so that material present on the mating interfaces will be moved to prevent jamming of the interface. The latch can be scaled up and down to accommodate different sized payloads. In addition, the carrier interface is designed as a series of panels that can be quickly reconfigured to accommodate different payloads.
As a payload is lifted by a lifting hook at the top of the payload, the hook initially slides on a center post, putting tension on the release lines, and releasing the latches. The release lines do not carry the weight of the payload; the lifting hook and lift pins carry the weight. Thus, a single set of latch locks can be applied to a range of payloads. The latch is released or engaged by the action of a latch plunger in response to either the release line or latch spring. Removing a payload is accomplished by reversing this sequence. As tension is applied to the release line, the latch plunger is pulled upward, retracting the latch locks and freeing the payload from the carrier interface.