JIB OF HOISTING MACHINES Russian patent published in 2019 - IPC B66C23/04 

FIELD: transportation.

SUBSTANCE: invention relates to hoisting equipment and can be used in hoisting machines. Boom comprises root and extending sections, boom lifting-lowering hydromechanism, pipelines, system of cargo lifting mechanisms. On the side of upper belts of each boom section tension ropes are fixed with tension hydraulic cylinders with possibility of prestressing in metal structures of sections and the whole boom. On portal of load-lifting machine, in lower zone of boom root section there installed is hydromechanical adjusting device of pre-stress variation in metal structure of boom depending on its inclination angle.

EFFECT: reduction of deformation of telescopic jibs is achieved at increase of its carrying capacity and rigidity.

1 cl, 4 dwg