Patent ID: 6991120

Claim:
A motorized device for manipulating extensible elements of a crane, the crane having a foldable mast comprising a lower mast element, including a top portion and a bottom portion articulated to a chassis of the crane; an upper mast element, including a top portion and a bottom portion articulated to the top portion of the lower mast element; and a distributing jib having a plurality of successive jib elements articulated to one another, wherein a first jib element is articulated to the top portion of the upper mast element, at least the first jib element is capable of being brought into a substantially vertical position in alignment with the foldable mast when raised so as to increase a height of the mast, and the plurality of jib elements form a rolling track for a jib carriage, the motorized device comprising: a hydraulic jack having a body and a stem; a lower rod assembly connected to the body, the lower rod assembly comprising a first rod articulated at a first point about an axis disposed on a first end of the body, articulated at an intermediate point about an axis on the bottom portion of the upper mast element, and articulated at a third point about an axis disposed on a second rod connected to the top portion of the lower mast element; an upper rod assembly connected to the stem, the upper rod assembly comprising a third rod articulated at a first end about an axis disposed on the top portion of the upper mast element, and articulated at a second end about an axis disposed on an end of a fourth rod and an end of the stem, wherein the fourth rod is articulated about an axis disposed on the first jib element; at least one rod connected to the bottom portion of the upper mast element and connected to the chassis of the crane; a locking system disposed at the bottom portion of the upper mast element for securing the hydraulic jack at a desired position; and a stop disposed at the top portion of the upper mast element to inhibit rotation of the third rod of the upper rod assembly.