FOUR-SECTION FULLY HYDRAULICALLY OPERATED CRANE BOOM HAVING THREE INDIVIDUALLY SUPPORTED SINGLE PISTON RAMS CONTAINED WITHIN FLY SECTION

摘要

A four-section fully hydraulically operated telescoping crane boom is constructed so that the three operating rams of the boom can be contained within the boom fly section and are independently supported and operated. Single piston rams are utilized throughout. The ram which interconnects the base section and the inner mid-section of the boom is reversed from the conventional arrangement with the rod end of this ram anchored to the base section and the cylinder end cantilevered forwardly from a rear pivotal connection with the inner mid-section of the boom and having a sliding support and guide means on its forward end engaging a core or box forming a part of the outer mid-section of the boom. As a result of the arrangement of the rams the vertical heights of the several boom sections can be made nearly equal and the amount of metal utilized in the boom is minimized while maintaining maximum rigidity.