TOWER CRANE Russian patent published in 2014 - IPC B66C13/00 

FIELD: transport.

SUBSTANCE: proposed crane comprises tower 1 fitted at the bed 2, rotary support 3, rotary head 4, boom 5, cargo carriage 6 with hook 7, counterweight support 8 with counterweight 9 and air screw 10 with controlled reversible drive. Air screw 11 with controlled reversible drive fitted at the end of counterweight support 8 is mounted at the end of boom 5. Drives 12, 13 of both screws are mutually interlocked and with rotary support drive mechanism by control system 14. Drives of said screws contrarotate while airflows produced thereby are inversely proportional to spacing between screw rotational axes and that of rotary support.

EFFECT: decreased stress at crane structures and mechanisms at boom turn.

2 dwg