Rotary jack assembly for a crane

摘要

There is disclosed a rotary jack assembly which comprises a rotary frame assembly having first and second frames each having frame receiving members, a plurality of pairs of wheel frames are provided under the first frame receiving members at points above where a circular rail on which the wheel frames ride is placed, the frame assembly is vertically shiftable relative to the wheel frames by means of cylinders. A plurality of crane supporting arms are arranged on the frame assembly and spaced from the cylinders for vertically shifting the frame assembly. Cylinders are connected to the crane supporting arms to slide the crane supporting arms out of the frame assembly for supporting a crane thereon.