ANORDNING VID KRAN SOM OMFATTAR TVA SEPARATA DRIVNA HISSVAJRAR

摘要

Hoisting arrangement having a boom or a crane with two separately driven hoist wires each with its individual cargo hook. The cargo hooks along with the hoist wires are used for various lifting operations. The hoist wires and a topping wire are operated by their respective winches. The hoist wires are connected via their winches to a common power supply system via a selection valve whereby a constant tension is exerted on the hoist wire. The winches are adapted to pay out hoist wire if the pull in the hoist wire exceeds this constant tension and to draw in hoist wire if the pull falls below the constant tension.