Moment-limiting arrangement for cranes with articulated jibs, in particular those which are provided for mounting on trucks

摘要

This moment-limiting arrangement contains an appliance which is able to detect instant by instant the moment to which the crane is subjected as well as an appropriately adjusted control device which is able to compare the moment to which the crane is actually subjected with a reference limit value and, as soon as the actual moment reaches the said limit value, is able to trigger the opening of a drain valve which directs to the drain the fluid quantity discharged by the pump and fed by the distributors to the hydraulic winches which control the jibs of the crane. In addition, means are provided which, in the event of the maximum permissible moment value being reached, act on the said drain valve and on the distributors of the various winches so that then only the winch movements can be performed which as an overall action bring about a weakening in the moment to which the crane is actually subjected.