System and method for automatic unstowing and stowing of a crane boom

摘要

A system and method are disclosed whereby a crane boom assembly of relatively long length and large load carrying capacity may be automatically stowed and carried on the superstructure of a crane assembly. With the boom assembly in the stowed position, the boom and superstructure combination may be carried on a single truck and trailer combination for highway transport. Power driven means are provided for unstowing and stowing the boom assembly with respect to the superstructure. To unstow the boom assembly, first power driven means are provided to translate the boom forwardly with respect to the superstructure. Foot pins located at the rear of the boom assembly are mountable in the main pivot means on the superstructure of the crane when the boom assembly is fully extended forwardly of the superstructure to an intermediate unstowed position. Second power means are provided for automatically raising and lowering the fully extended boom assembly from a substantially horizontal intermediate unstowed position to a fully unstowed or inclined working position. Latching means associated with the boom foot pins are engaged when the boom assembly is pivoted upward to the inclined working position, thus firmly locking the boom assembly to the superstructure. To stow the boom, the boom is returned from the working position to the intermediate unstowed position, the latch means are disengaged, and the boom foot pins are removed. The second power means also translates the boom rearwardly with respect to the superstructure to the initial fully stowed position.