Load handline grab mechanism - has jack coupled to grab via damper allowing relative movement on encountering obstruction

摘要

The mechanism has a load handling grab coupled to a drive with a limited amount of lift, e.g. a jack. Between the jack or other drive unit and the grab is a resilient damper, allowing relative movement between unit and grab in the event of the latter encountering a resistance. This relative movement is detected by a mechanism working in conjunction with a unit controlling the jack drive as a function of the movement concerned. The grab can be arranged to work in guides fixed to the damper. The jack can be in the form of a ram whose piston is solidly coupled to the guides and its cylinder to the lifting jack piston rod. The damper ram cylinder is connected to atmosphere via calibrated pipes.