A mechanical grab is described that has two telescopic members, with one attached to a single hoist line and the other having jaw elements mounted thereon. Linkage interconnects the one member with the jaw elements to automatically open and close the jaw elements as the two telescopic members move in relation to each other when the mechanical grab is lowered and raised from the ground. The mechanical grab has a provision for preventing the jaw elements from closing every other time the mechanical grab is lowered to the ground to prevent the jaws from closing on a just released load and for maintaining the jaws open until the mechanical grab is again lowered to the ground.

A crane is a lifting machine, generally equipped with a winder (also called a wire rope drum), wire ropes or chains and sheaves, that can be used both to lift and lower materials and to move them horizontally. It uses one or more simple machines to create mechanical advantage and thus move loads beyond the normal capability of a human. Cranes are commonly employed in the transport industry for the loading and unloading of freight, in the construction industry for the movement of materials and in the manufacturing industry for the assembling of heavy equipment.

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