Analytical and Multibody Modelling of a Quick-Release Hook Mechanism

Quick-Release Hooks (QRH) are particular accessories for connecting chains or metal ropes, that can be remotely unfastened under full-load conditions via application of an external force with limited magnitude. Despite their widespread use, and aside from a number of patents, the scientific literature related to QRH performance is rather limited. This paper reports about the modelling of a class of QRH, which relies on the use of a four-bar linkage mechanism operating in the proximity of a singularity configuration. Design graphs depicting the main functional parameters are reported. At last, a multibody model of the system is developed, which validates the analytical results while providing an insight of the frictional forces effect on the device modelling and performance.